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-rw-r--r--libotr/libgpg-error-1.42/src/estream.c5414
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diff --git a/libotr/libgpg-error-1.42/src/estream.c b/libotr/libgpg-error-1.42/src/estream.c
new file mode 100644
index 0000000..f75e052
--- /dev/null
+++ b/libotr/libgpg-error-1.42/src/estream.c
@@ -0,0 +1,5414 @@
+/* estream.c - Extended Stream I/O Library
+ * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011,
+ *               2014, 2015, 2016, 2017 g10 Code GmbH
+ *
+ * This file is part of Libestream.
+ *
+ * Libestream is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * Libestream is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libestream; if not, see <https://www.gnu.org/licenses/>.
+ *
+ * ALTERNATIVELY, Libestream may be distributed under the terms of the
+ * following license, in which case the provisions of this license are
+ * required INSTEAD OF the GNU General Public License. If you wish to
+ * allow use of your version of this file only under the terms of the
+ * GNU General Public License, and not to allow others to use your
+ * version of this file under the terms of the following license,
+ * indicate your decision by deleting this paragraph and the license
+ * below.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef USE_ESTREAM_SUPPORT_H
+# include <estream-support.h>
+#endif
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#if defined(_WIN32) && !defined(HAVE_W32_SYSTEM)
+# define HAVE_W32_SYSTEM 1
+# if defined(__MINGW32CE__) && !defined (HAVE_W32CE_SYSTEM)
+#  define HAVE_W32CE_SYSTEM
+# endif
+#endif
+
+#ifdef HAVE_SYS_SELECT_H
+# include <sys/select.h>
+#endif
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#include <sys/types.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stddef.h>
+#ifdef HAVE_W32_SYSTEM
+# ifdef HAVE_WINSOCK2_H
+#  include <winsock2.h>
+# endif
+# include <windows.h>
+#else
+# ifdef HAVE_POLL_H
+#  include <poll.h>
+# endif
+#endif
+
+/* Enable tracing.  The value is the module name to be printed.  */
+/*#define ENABLE_TRACING "estream"*/
+
+#include "gpgrt-int.h"
+#include "estream-printf.h"
+#include "thread.h"
+#include "lock.h"
+
+
+#ifndef O_BINARY
+# define O_BINARY 0
+#endif
+#ifndef HAVE_DOSISH_SYSTEM
+# ifdef HAVE_W32_SYSTEM
+#  define HAVE_DOSISH_SYSTEM 1
+# endif
+#endif
+
+
+#ifdef HAVE_W32_SYSTEM
+# ifndef  S_IRGRP
+#  define S_IRGRP S_IRUSR
+# endif
+# ifndef  S_IROTH
+#  define S_IROTH S_IRUSR
+# endif
+# ifndef  S_IWGRP
+#  define S_IWGRP S_IWUSR
+# endif
+# ifndef  S_IWOTH
+#  define S_IWOTH S_IWUSR
+# endif
+# ifndef  S_IXGRP
+#  define S_IXGRP S_IXUSR
+# endif
+# ifndef  S_IXOTH
+#  define S_IXOTH S_IXUSR
+# endif
+#endif
+
+#if !defined (EWOULDBLOCK) && defined (HAVE_W32_SYSTEM)
+/* Compatibility with errno.h from mingw-2.0 */
+# define EWOULDBLOCK 140
+#endif
+
+#ifndef EAGAIN
+# define EAGAIN  EWOULDBLOCK
+#endif
+
+
+#ifdef HAVE_W32CE_SYSTEM
+# define _set_errno(a)  gpg_err_set_errno ((a))
+/* Setmode is missing in cegcc but available since CE 5.0.  */
+int _setmode (int handle, int mode);
+# define setmode(a,b)   _setmode ((a),(b))
+#else
+# define _set_errno(a)  do { errno = (a); } while (0)
+#endif
+
+#define IS_INVALID_FD(a)    ((a) == -1)
+
+/* Calculate array dimension.  */
+#ifndef DIM
+#define DIM(array) (sizeof (array) / sizeof (*array))
+#endif
+
+/* A helper macro used to convert to a hex string.  */
+#define tohex(n) ((n) < 10 ? ((n) + '0') : (((n) - 10) + 'A'))
+
+
+/* Generally used types.  */
+
+typedef void *(*func_realloc_t) (void *mem, size_t size);
+typedef void (*func_free_t) (void *mem);
+
+
+
+
+/*
+ * A linked list to hold active stream objects.
+ * Protected by ESTREAM_LIST_LOCK.
+ */
+struct estream_list_s
+{
+  struct estream_list_s *next;
+  estream_t stream;  /* Entry is not used if NULL.  */
+};
+typedef struct estream_list_s *estream_list_t;
+static estream_list_t estream_list;
+
+/*
+ * File descriptors registered for use as the standard file handles.
+ * Protected by ESTREAM_LIST_LOCK.
+ */
+static int custom_std_fds[3];
+static unsigned char custom_std_fds_valid[3];
+
+/*
+ * A lock object to protect ESTREAM LIST, CUSTOM_STD_FDS and
+ * CUSTOM_STD_FDS_VALID.  Used by lock_list() and unlock_list().
+ */
+GPGRT_LOCK_DEFINE (estream_list_lock);
+
+
+/*
+ * Error code replacements.
+ */
+#ifndef EOPNOTSUPP
+# define EOPNOTSUPP ENOSYS
+#endif
+
+
+/* Local prototypes.  */
+static void fname_set_internal (estream_t stream, const char *fname, int quote);
+
+
+
+
+/*
+ * Memory allocation wrappers used in this file.
+ */
+static void *
+mem_alloc (size_t n)
+{
+  return _gpgrt_malloc (n);
+}
+
+static void *
+mem_realloc (void *p, size_t n)
+{
+  return _gpgrt_realloc (p, n);
+}
+
+static void
+mem_free (void *p)
+{
+  if (p)
+    _gpgrt_free (p);
+}
+
+
+/*
+ * A Windows helper function to map a W32 API error code to a standard
+ * system error code.  That actually belong into sysutils but to allow
+ * standalone use of estream we keep it here.
+ */
+#ifdef HAVE_W32_SYSTEM
+static int
+map_w32_to_errno (DWORD w32_err)
+{
+  switch (w32_err)
+    {
+    case 0:
+      return 0;
+
+    case ERROR_FILE_NOT_FOUND:
+      return ENOENT;
+
+    case ERROR_PATH_NOT_FOUND:
+      return ENOENT;
+
+    case ERROR_ACCESS_DENIED:
+      return EPERM;  /* ReactOS uses EACCES ("Permission denied") and
+                      * is likely right because they used an
+                      * undocumented function to associate the error
+                      * codes.  However we have always used EPERM
+                      * ("Operation not permitted", e.g. function is
+                      * required to be called by root) and we better
+                      * stick to that to avoid surprising bugs. */
+
+    case ERROR_INVALID_HANDLE:
+      return EBADF;
+
+    case ERROR_INVALID_BLOCK:
+      return ENOMEM;
+
+    case ERROR_NOT_ENOUGH_MEMORY:
+      return ENOMEM;
+
+    case ERROR_NO_DATA:
+      return EPIPE;
+
+    case ERROR_ALREADY_EXISTS:
+      return EEXIST;
+
+      /* This mapping has been taken from reactOS.  */
+    case ERROR_TOO_MANY_OPEN_FILES: return EMFILE;
+    case ERROR_ARENA_TRASHED: return ENOMEM;
+    case ERROR_BAD_ENVIRONMENT: return E2BIG;
+    case ERROR_BAD_FORMAT: return ENOEXEC;
+    case ERROR_INVALID_DRIVE: return ENOENT;
+    case ERROR_CURRENT_DIRECTORY: return EACCES;
+    case ERROR_NOT_SAME_DEVICE: return EXDEV;
+    case ERROR_NO_MORE_FILES: return ENOENT;
+    case ERROR_WRITE_PROTECT: return EACCES;
+    case ERROR_BAD_UNIT: return EACCES;
+    case ERROR_NOT_READY: return EACCES;
+    case ERROR_BAD_COMMAND: return EACCES;
+    case ERROR_CRC: return EACCES;
+    case ERROR_BAD_LENGTH: return EACCES;
+    case ERROR_SEEK: return EACCES;
+    case ERROR_NOT_DOS_DISK: return EACCES;
+    case ERROR_SECTOR_NOT_FOUND: return EACCES;
+    case ERROR_OUT_OF_PAPER: return EACCES;
+    case ERROR_WRITE_FAULT: return EACCES;
+    case ERROR_READ_FAULT: return EACCES;
+    case ERROR_GEN_FAILURE: return EACCES;
+    case ERROR_SHARING_VIOLATION: return EACCES;
+    case ERROR_LOCK_VIOLATION: return EACCES;
+    case ERROR_WRONG_DISK: return EACCES;
+    case ERROR_SHARING_BUFFER_EXCEEDED: return EACCES;
+    case ERROR_BAD_NETPATH: return ENOENT;
+    case ERROR_NETWORK_ACCESS_DENIED: return EACCES;
+    case ERROR_BAD_NET_NAME: return ENOENT;
+    case ERROR_FILE_EXISTS: return EEXIST;
+    case ERROR_CANNOT_MAKE: return EACCES;
+    case ERROR_FAIL_I24: return EACCES;
+    case ERROR_NO_PROC_SLOTS: return EAGAIN;
+    case ERROR_DRIVE_LOCKED: return EACCES;
+    case ERROR_BROKEN_PIPE: return EPIPE;
+    case ERROR_DISK_FULL: return ENOSPC;
+    case ERROR_INVALID_TARGET_HANDLE: return EBADF;
+    case ERROR_WAIT_NO_CHILDREN: return ECHILD;
+    case ERROR_CHILD_NOT_COMPLETE: return ECHILD;
+    case ERROR_DIRECT_ACCESS_HANDLE: return EBADF;
+    case ERROR_SEEK_ON_DEVICE: return EACCES;
+    case ERROR_DIR_NOT_EMPTY: return ENOTEMPTY;
+    case ERROR_NOT_LOCKED: return EACCES;
+    case ERROR_BAD_PATHNAME: return ENOENT;
+    case ERROR_MAX_THRDS_REACHED: return EAGAIN;
+    case ERROR_LOCK_FAILED: return EACCES;
+    case ERROR_INVALID_STARTING_CODESEG: return ENOEXEC;
+    case ERROR_INVALID_STACKSEG: return ENOEXEC;
+    case ERROR_INVALID_MODULETYPE: return ENOEXEC;
+    case ERROR_INVALID_EXE_SIGNATURE: return ENOEXEC;
+    case ERROR_EXE_MARKED_INVALID: return ENOEXEC;
+    case ERROR_BAD_EXE_FORMAT: return ENOEXEC;
+    case ERROR_ITERATED_DATA_EXCEEDS_64k: return ENOEXEC;
+    case ERROR_INVALID_MINALLOCSIZE: return ENOEXEC;
+    case ERROR_DYNLINK_FROM_INVALID_RING: return ENOEXEC;
+    case ERROR_IOPL_NOT_ENABLED: return ENOEXEC;
+    case ERROR_INVALID_SEGDPL: return ENOEXEC;
+    case ERROR_AUTODATASEG_EXCEEDS_64k: return ENOEXEC;
+    case ERROR_RING2SEG_MUST_BE_MOVABLE: return ENOEXEC;
+    case ERROR_RELOC_CHAIN_XEEDS_SEGLIM: return ENOEXEC;
+    case ERROR_INFLOOP_IN_RELOC_CHAIN: return ENOEXEC;
+    case ERROR_FILENAME_EXCED_RANGE: return ENOENT;
+    case ERROR_NESTING_NOT_ALLOWED: return EAGAIN;
+    case ERROR_NOT_ENOUGH_QUOTA: return ENOMEM;
+
+    default:
+      return EIO;
+    }
+}
+
+/* Wrapper to be used by other modules to set ERRNO from the Windows
+ * error.  EC may be -1 to get the last error.  */
+void
+_gpgrt_w32_set_errno (int ec)
+{
+  if (ec == -1)
+    ec = GetLastError ();
+  _set_errno (map_w32_to_errno (ec));
+}
+
+
+#endif /*HAVE_W32_SYSTEM*/
+
+/*
+ * Replacement for a missing memrchr.
+ */
+#ifndef HAVE_MEMRCHR
+static void *
+memrchr (const void *buffer, int c, size_t n)
+{
+  const unsigned char *p = buffer;
+
+  for (p += n; n ; n--)
+    if (*--p == c)
+      return (void *)p;
+  return NULL;
+}
+#endif /*HAVE_MEMRCHR*/
+
+
+
+/*
+ * Wrappers to lock a stream or the list of streams.
+ */
+#if 0
+# define dbg_lock_0(f)        fprintf (stderr, "estream: " f);
+# define dbg_lock_1(f, a)     fprintf (stderr, "estream: " f, (a));
+# define dbg_lock_2(f, a, b)  fprintf (stderr, "estream: " f, (a), (b));
+#else
+# define dbg_lock_0(f)
+# define dbg_lock_1(f, a)
+# define dbg_lock_2(f, a, b)
+#endif
+
+static int
+init_stream_lock (estream_t _GPGRT__RESTRICT stream)
+{
+  int rc;
+
+  if (!stream->intern->samethread)
+    {
+      dbg_lock_1 ("enter init_stream_lock for %p\n", stream);
+      memset (&stream->intern->lock, 0 , sizeof stream->intern->lock);
+      rc = _gpgrt_lock_init (&stream->intern->lock);
+      dbg_lock_2 ("leave init_stream_lock for %p: rc=%d\n", stream, rc);
+    }
+  else
+    rc = 0;
+  return rc;
+}
+
+
+static void
+destroy_stream_lock (estream_t _GPGRT__RESTRICT stream)
+{
+  if (!stream->intern->samethread)
+    {
+      dbg_lock_1 ("enter destroy_stream_lock for %p\n", stream);
+      _gpgrt_lock_destroy (&stream->intern->lock);
+      dbg_lock_1 ("leave destroy_stream_lock for %p\n", stream);
+    }
+}
+
+
+static void
+lock_stream (estream_t _GPGRT__RESTRICT stream)
+{
+  if (!stream->intern->samethread)
+    {
+      dbg_lock_1 ("enter lock_stream for %p\n", stream);
+      _gpgrt_lock_lock (&stream->intern->lock);
+      dbg_lock_1 ("leave lock_stream for %p\n", stream);
+    }
+}
+
+
+static int
+trylock_stream (estream_t _GPGRT__RESTRICT stream)
+{
+  int rc;
+
+  if (!stream->intern->samethread)
+    {
+      dbg_lock_1 ("enter trylock_stream for %p\n", stream);
+      rc = _gpgrt_lock_trylock (&stream->intern->lock)? 0 : -1;
+      dbg_lock_2 ("leave trylock_stream for %p: rc=%d\n", stream, rc);
+    }
+  else
+    rc = 0;
+  return rc;
+}
+
+
+static void
+unlock_stream (estream_t _GPGRT__RESTRICT stream)
+{
+  if (!stream->intern->samethread)
+    {
+      dbg_lock_1 ("enter unlock_stream for %p\n", stream);
+      _gpgrt_lock_unlock (&stream->intern->lock);
+      dbg_lock_1 ("leave unlock_stream for %p\n", stream);
+    }
+}
+
+
+static void
+lock_list (void)
+{
+  dbg_lock_0 ("enter lock_list\n");
+  _gpgrt_lock_lock (&estream_list_lock);
+  dbg_lock_0 ("leave lock_list\n");
+}
+
+
+static void
+unlock_list (void)
+{
+  dbg_lock_0 ("enter unlock_list\n");
+  _gpgrt_lock_unlock (&estream_list_lock);
+  dbg_lock_0 ("leave unlock_list\n");
+}
+
+
+#undef dbg_lock_0
+#undef dbg_lock_1
+#undef dbg_lock_2
+
+
+
+/*
+ * Manipulation of the list of stream.
+ */
+
+/*
+ * Add STREAM to the list of registered stream objects.  If
+ * WITH_LOCKED_LIST is true it is assumed that the list of streams is
+ * already locked.  The implementation is straightforward: We first
+ * look for an unused entry in the list and use that; if none is
+ * available we put a new item at the head.  We drawback of the
+ * strategy never to shorten the list is that a one time allocation of
+ * many streams will lead to scanning unused entries later.  If that
+ * turns out to be a problem, we may either free some items from the
+ * list or append new entries at the end; or use a table.  Returns 0
+ * on success; on error or non-zero is returned and ERRNO set.
+ */
+static int
+do_list_add (estream_t stream, int with_locked_list)
+{
+  estream_list_t item;
+
+  if (!with_locked_list)
+    lock_list ();
+
+  for (item = estream_list; item && item->stream; item = item->next)
+    ;
+  if (!item)
+    {
+      item = mem_alloc (sizeof *item);
+      if (item)
+        {
+          item->next = estream_list;
+          estream_list = item;
+        }
+    }
+  if (item)
+    item->stream = stream;
+
+  if (!with_locked_list)
+    unlock_list ();
+
+  return item? 0 : -1;
+}
+
+/*
+ * Remove STREAM from the list of registered stream objects.
+ */
+static void
+do_list_remove (estream_t stream, int with_locked_list)
+{
+  estream_list_t item, item_prev = NULL;
+
+  if (!with_locked_list)
+    lock_list ();
+
+  for (item = estream_list; item; item = item->next)
+    if (item->stream == stream)
+      break;
+    else
+      item_prev = item;
+
+  if (item)
+    {
+      if (item_prev)
+        item_prev->next = item->next;
+      else
+        estream_list = item->next;
+      mem_free (item);
+    }
+
+  if (!with_locked_list)
+    unlock_list ();
+}
+
+
+
+/*
+ * The atexit handler for the entire gpgrt.
+ */
+static void
+do_deinit (void)
+{
+  /* Flush all streams. */
+  _gpgrt_fflush (NULL);
+
+  /* We should release the estream_list.  However there is one
+     problem: That list is also used to search for the standard
+     estream file descriptors.  If we would remove the entire list,
+     any use of es_foo in another atexit function may re-create the
+     list and the streams with possible undesirable effects.  Given
+     that we don't close the stream either, it should not matter that
+     we keep the list and let the OS clean it up at process end.  */
+
+  /* Reset the syscall clamp.  */
+  _gpgrt_set_syscall_clamp (NULL, NULL);
+}
+
+
+/*
+ * Initialization of the estream module.
+ */
+int
+_gpgrt_estream_init (void)
+{
+  static int initialized;
+
+  if (!initialized)
+    {
+      initialized = 1;
+      atexit (do_deinit);
+    }
+  return 0;
+}
+
+
+/*
+ * Implementation of memory based I/O.
+ */
+
+/* Cookie for memory objects.  */
+typedef struct estream_cookie_mem
+{
+  unsigned int modeflags;	/* Open flags.  */
+  unsigned char *memory;	/* Allocated data buffer.  */
+  size_t memory_size;		/* Allocated size of MEMORY.  */
+  size_t memory_limit;          /* Caller supplied maximum allowed
+                                   allocation size or 0 for no limit.  */
+  size_t offset;		/* Current offset in MEMORY.  */
+  size_t data_len;		/* Used length of data in MEMORY.  */
+  size_t block_size;		/* Block size.  */
+  struct {
+    unsigned int grow: 1;	/* MEMORY is allowed to grow.  */
+  } flags;
+  func_realloc_t func_realloc;
+  func_free_t func_free;
+} *estream_cookie_mem_t;
+
+
+/*
+ * Create function for memory objects.  DATA is either NULL or a user
+ * supplied buffer with the initial conetnt of the memory buffer.  If
+ * DATA is NULL, DATA_N and DATA_LEN need to be 0 as well.  If DATA is
+ * not NULL, DATA_N gives the allocated size of DATA and DATA_LEN the
+ * used length in DATA.  If this function succeeds DATA is now owned
+ * by this function.  If GROW is false FUNC_REALLOC is not
+ * required.
+ */
+static int
+func_mem_create (void *_GPGRT__RESTRICT *_GPGRT__RESTRICT cookie,
+                 unsigned char *_GPGRT__RESTRICT data, size_t data_n,
+                 size_t data_len,
+                 size_t block_size, unsigned int grow,
+                 func_realloc_t func_realloc, func_free_t func_free,
+                 unsigned int modeflags,
+                 size_t memory_limit)
+{
+  estream_cookie_mem_t mem_cookie;
+  int err;
+
+  if (!data && (data_n || data_len))
+    {
+      _set_errno (EINVAL);
+      return -1;
+    }
+  if (grow && func_free && !func_realloc)
+    {
+      _set_errno (EINVAL);
+      return -1;
+    }
+
+  /* Round a memory limit up to the next block length.  */
+  if (memory_limit && block_size)
+    {
+      memory_limit += block_size - 1;
+      memory_limit /= block_size;
+      memory_limit *= block_size;
+    }
+
+  mem_cookie = mem_alloc (sizeof (*mem_cookie));
+  if (!mem_cookie)
+    err = -1;
+  else
+    {
+      mem_cookie->modeflags = modeflags;
+      mem_cookie->memory = data;
+      mem_cookie->memory_size = data_n;
+      mem_cookie->memory_limit = memory_limit;
+      mem_cookie->offset = 0;
+      mem_cookie->data_len = data_len;
+      mem_cookie->block_size = block_size;
+      mem_cookie->flags.grow = !!grow;
+      mem_cookie->func_realloc
+        = grow? (func_realloc ? func_realloc : mem_realloc) : NULL;
+      mem_cookie->func_free = func_free ? func_free : mem_free;
+      *cookie = mem_cookie;
+      err = 0;
+    }
+
+  return err;
+}
+
+
+/*
+ * Read function for memory objects.
+ */
+static gpgrt_ssize_t
+func_mem_read (void *cookie, void *buffer, size_t size)
+{
+  estream_cookie_mem_t mem_cookie = cookie;
+  gpgrt_ssize_t ret;
+
+  if (!size)  /* Just the pending data check.  */
+    return (mem_cookie->data_len - mem_cookie->offset)? 0 : -1;
+
+  if (size > mem_cookie->data_len - mem_cookie->offset)
+    size = mem_cookie->data_len - mem_cookie->offset;
+
+  if (size)
+    {
+      memcpy (buffer, mem_cookie->memory + mem_cookie->offset, size);
+      mem_cookie->offset += size;
+    }
+
+  ret = size;
+  return ret;
+}
+
+
+/*
+ * Write function for memory objects.
+ */
+static gpgrt_ssize_t
+func_mem_write (void *cookie, const void *buffer, size_t size)
+{
+  estream_cookie_mem_t mem_cookie = cookie;
+  gpgrt_ssize_t ret;
+  size_t nleft;
+
+  if (!size)
+    return 0;  /* A flush is a NOP for memory objects.  */
+
+  if (mem_cookie->modeflags & O_APPEND)
+    {
+      /* Append to data.  */
+      mem_cookie->offset = mem_cookie->data_len;
+    }
+
+  gpgrt_assert (mem_cookie->memory_size >= mem_cookie->offset);
+  nleft = mem_cookie->memory_size - mem_cookie->offset;
+
+  /* If we are not allowed to grow the buffer, limit the size to the
+     left space.  */
+  if (!mem_cookie->flags.grow && size > nleft)
+    size = nleft;
+
+  /* Enlarge the memory buffer if needed.  */
+  if (size > nleft)
+    {
+      unsigned char *newbuf;
+      size_t newsize;
+
+      if (!mem_cookie->memory_size)
+        newsize = size;  /* Not yet allocated.  */
+      else
+        newsize = mem_cookie->memory_size + (size - nleft);
+      if (newsize < mem_cookie->offset)
+        {
+          _set_errno (EINVAL);
+          return -1;
+        }
+
+      /* Round up to the next block length.  BLOCK_SIZE should always
+         be set; we check anyway.  */
+      if (mem_cookie->block_size)
+        {
+          newsize += mem_cookie->block_size - 1;
+          if (newsize < mem_cookie->offset)
+            {
+              _set_errno (EINVAL);
+              return -1;
+            }
+          newsize /= mem_cookie->block_size;
+          newsize *= mem_cookie->block_size;
+        }
+
+      /* Check for a total limit.  */
+      if (mem_cookie->memory_limit && newsize > mem_cookie->memory_limit)
+        {
+          _set_errno (ENOSPC);
+          return -1;
+        }
+
+      gpgrt_assert (mem_cookie->func_realloc);
+      newbuf = mem_cookie->func_realloc (mem_cookie->memory, newsize);
+      if (!newbuf)
+        return -1;
+
+      mem_cookie->memory = newbuf;
+      mem_cookie->memory_size = newsize;
+
+      gpgrt_assert (mem_cookie->memory_size >= mem_cookie->offset);
+      nleft = mem_cookie->memory_size - mem_cookie->offset;
+
+      gpgrt_assert (size <= nleft);
+    }
+
+  memcpy (mem_cookie->memory + mem_cookie->offset, buffer, size);
+  if (mem_cookie->offset + size > mem_cookie->data_len)
+    mem_cookie->data_len = mem_cookie->offset + size;
+  mem_cookie->offset += size;
+
+  ret = size;
+  return ret;
+}
+
+
+/*
+ * Seek function for memory objects.
+ */
+static int
+func_mem_seek (void *cookie, gpgrt_off_t *offset, int whence)
+{
+  estream_cookie_mem_t mem_cookie = cookie;
+  gpgrt_off_t pos_new;
+
+  switch (whence)
+    {
+    case SEEK_SET:
+      pos_new = *offset;
+      break;
+
+    case SEEK_CUR:
+      pos_new = mem_cookie->offset += *offset;
+      break;
+
+    case SEEK_END:
+      pos_new = mem_cookie->data_len += *offset;
+      break;
+
+    default:
+      _set_errno (EINVAL);
+      return -1;
+    }
+
+  if (pos_new > mem_cookie->memory_size)
+    {
+      size_t newsize;
+      void *newbuf;
+
+      if (!mem_cookie->flags.grow)
+	{
+	  _set_errno (ENOSPC);
+	  return -1;
+        }
+
+      newsize = pos_new + mem_cookie->block_size - 1;
+      if (newsize < pos_new)
+        {
+          _set_errno (EINVAL);
+          return -1;
+        }
+      newsize /= mem_cookie->block_size;
+      newsize *= mem_cookie->block_size;
+
+      if (mem_cookie->memory_limit && newsize > mem_cookie->memory_limit)
+        {
+          _set_errno (ENOSPC);
+          return -1;
+        }
+
+      gpgrt_assert (mem_cookie->func_realloc);
+      newbuf = mem_cookie->func_realloc (mem_cookie->memory, newsize);
+      if (!newbuf)
+        return -1;
+
+      mem_cookie->memory = newbuf;
+      mem_cookie->memory_size = newsize;
+    }
+
+  if (pos_new > mem_cookie->data_len)
+    {
+      /* Fill spare space with zeroes.  */
+      memset (mem_cookie->memory + mem_cookie->data_len,
+              0, pos_new - mem_cookie->data_len);
+      mem_cookie->data_len = pos_new;
+    }
+
+  mem_cookie->offset = pos_new;
+  *offset = pos_new;
+
+  return 0;
+}
+
+
+/*
+ * The IOCTL function for memory objects.
+ */
+static int
+func_mem_ioctl (void *cookie, int cmd, void *ptr, size_t *len)
+{
+  estream_cookie_mem_t mem_cookie = cookie;
+  int ret;
+
+  if (cmd == COOKIE_IOCTL_SNATCH_BUFFER)
+    {
+      /* Return the internal buffer of the stream to the caller and
+         invalidate it for the stream.  */
+      *(void**)ptr = mem_cookie->memory;
+      *len = mem_cookie->data_len;
+      mem_cookie->memory = NULL;
+      mem_cookie->memory_size = 0;
+      mem_cookie->offset = 0;
+      ret = 0;
+    }
+  else if (cmd == COOKIE_IOCTL_TRUNCATE)
+    {
+      gpgrt_off_t length = *(gpgrt_off_t *)ptr;
+
+      ret = func_mem_seek (cookie, &length, SEEK_SET);
+      if (ret != -1)
+        mem_cookie->data_len = mem_cookie->offset;
+    }
+  else
+    {
+      _set_errno (EINVAL);
+      ret = -1;
+    }
+
+  return ret;
+}
+
+
+/*
+ * The destroy function for memory objects.
+ */
+static int
+func_mem_destroy (void *cookie)
+{
+  estream_cookie_mem_t mem_cookie = cookie;
+
+  if (cookie)
+    {
+      mem_cookie->func_free (mem_cookie->memory);
+      mem_free (mem_cookie);
+    }
+  return 0;
+}
+
+/*
+ * Access object for the memory functions.
+ */
+static struct cookie_io_functions_s estream_functions_mem =
+  {
+    {
+      func_mem_read,
+      func_mem_write,
+      func_mem_seek,
+      func_mem_destroy,
+    },
+    func_mem_ioctl,
+  };
+
+
+
+/*
+ * Implementation of file descriptor based I/O.
+ */
+
+/* Cookie for fd objects.  */
+typedef struct estream_cookie_fd
+{
+  int fd;        /* The file descriptor we are using for actual output.  */
+  int no_close;  /* If set we won't close the file descriptor.  */
+  int nonblock;  /* Non-blocking mode is enabled.  */
+} *estream_cookie_fd_t;
+
+
+/*
+ * Create function for objects indentified by a libc file descriptor.
+ */
+static int
+func_fd_create (void **cookie, int fd, unsigned int modeflags, int no_close)
+{
+  estream_cookie_fd_t fd_cookie;
+  int err;
+
+  trace (("enter: fd=%d mf=%x nc=%d", fd, modeflags, no_close));
+
+  fd_cookie = mem_alloc (sizeof (*fd_cookie));
+  if (! fd_cookie)
+    err = -1;
+  else
+    {
+#ifdef HAVE_DOSISH_SYSTEM
+      /* Make sure it is in binary mode if requested.  */
+      if ( (modeflags & O_BINARY) )
+        setmode (fd, O_BINARY);
+#endif
+      fd_cookie->fd = fd;
+      fd_cookie->no_close = no_close;
+      fd_cookie->nonblock = !!(modeflags & O_NONBLOCK);
+      *cookie = fd_cookie;
+      err = 0;
+    }
+
+  trace_errno (err, ("leave: cookie=%p err=%d", *cookie, err));
+  return err;
+}
+
+
+/*
+ * Read function for fd objects.
+ */
+static gpgrt_ssize_t
+func_fd_read (void *cookie, void *buffer, size_t size)
+
+{
+  estream_cookie_fd_t file_cookie = cookie;
+  gpgrt_ssize_t bytes_read;
+
+  trace (("enter: cookie=%p buffer=%p size=%d", cookie, buffer, (int)size));
+
+  if (!size)
+    bytes_read = -1; /* We don't know whether anything is pending.  */
+  else if (IS_INVALID_FD (file_cookie->fd))
+    {
+      _gpgrt_yield ();
+      bytes_read = 0;
+    }
+  else
+    {
+      _gpgrt_pre_syscall ();
+      do
+        {
+          bytes_read = read (file_cookie->fd, buffer, size);
+        }
+      while (bytes_read == -1 && errno == EINTR);
+      _gpgrt_post_syscall ();
+    }
+
+  trace_errno (bytes_read == -1, ("leave: bytes_read=%d", (int)bytes_read));
+  return bytes_read;
+}
+
+
+/*
+ * Write function for fd objects.
+ */
+static gpgrt_ssize_t
+func_fd_write (void *cookie, const void *buffer, size_t size)
+{
+  estream_cookie_fd_t file_cookie = cookie;
+  gpgrt_ssize_t bytes_written;
+
+  trace (("enter: cookie=%p buffer=%p size=%d", cookie, buffer, (int)size));
+
+  if (IS_INVALID_FD (file_cookie->fd))
+    {
+      _gpgrt_yield ();
+      bytes_written = size; /* Yeah:  Success writing to the bit bucket.  */
+    }
+  else if (buffer)
+    {
+      _gpgrt_pre_syscall ();
+      do
+        {
+          bytes_written = write (file_cookie->fd, buffer, size);
+        }
+      while (bytes_written == -1 && errno == EINTR);
+      _gpgrt_post_syscall ();
+    }
+  else
+    bytes_written = size; /* Note that for a flush SIZE should be 0.  */
+
+  trace_errno (bytes_written == -1,
+               ("leave: bytes_written=%d", (int)bytes_written));
+  return bytes_written;
+}
+
+
+/*
+ * Seek function for fd objects.
+ */
+static int
+func_fd_seek (void *cookie, gpgrt_off_t *offset, int whence)
+{
+  estream_cookie_fd_t file_cookie = cookie;
+  gpgrt_off_t offset_new;
+  int err;
+
+  if (IS_INVALID_FD (file_cookie->fd))
+    {
+      _set_errno (ESPIPE);
+      err = -1;
+    }
+  else
+    {
+      _gpgrt_pre_syscall ();
+      offset_new = lseek (file_cookie->fd, *offset, whence);
+      _gpgrt_post_syscall ();
+      if (offset_new == -1)
+        err = -1;
+      else
+        {
+          *offset = offset_new;
+          err = 0;
+        }
+    }
+
+  return err;
+}
+
+
+/*
+ * The IOCTL function for fd objects.
+ */
+static int
+func_fd_ioctl (void *cookie, int cmd, void *ptr, size_t *len)
+{
+  estream_cookie_fd_t fd_cookie = cookie;
+  int ret;
+
+  if (cmd == COOKIE_IOCTL_NONBLOCK && !len)
+    {
+      fd_cookie->nonblock = !!ptr;
+      if (IS_INVALID_FD (fd_cookie->fd))
+        {
+          _set_errno (EINVAL);
+          ret = -1;
+        }
+      else
+        {
+#ifdef _WIN32
+          _set_errno (EOPNOTSUPP); /* FIXME: Implement for Windows.  */
+          ret = -1;
+#else
+          _set_errno (0);
+          ret = fcntl (fd_cookie->fd, F_GETFL, 0);
+          if (ret == -1 && errno)
+            ;
+          else if (fd_cookie->nonblock)
+            ret = fcntl (fd_cookie->fd, F_SETFL, (ret | O_NONBLOCK));
+          else
+            ret = fcntl (fd_cookie->fd, F_SETFL, (ret & ~O_NONBLOCK));
+#endif
+        }
+    }
+  else
+    {
+      _set_errno (EINVAL);
+      ret = -1;
+    }
+
+  return ret;
+}
+
+/*
+ * The destroy function for fd objects.
+ */
+static int
+func_fd_destroy (void *cookie)
+{
+  estream_cookie_fd_t fd_cookie = cookie;
+  int err;
+
+  trace (("enter: cookie=%p", cookie));
+
+  if (fd_cookie)
+    {
+      if (IS_INVALID_FD (fd_cookie->fd))
+        err = 0;
+      else
+        err = fd_cookie->no_close? 0 : close (fd_cookie->fd);
+      mem_free (fd_cookie);
+    }
+  else
+    err = 0;
+
+  trace_errno (err,("leave: err=%d", err));
+  return err;
+}
+
+
+/*
+ * Access object for the fd functions.
+ */
+static struct cookie_io_functions_s estream_functions_fd =
+  {
+    {
+      func_fd_read,
+      func_fd_write,
+      func_fd_seek,
+      func_fd_destroy,
+    },
+    func_fd_ioctl,
+  };
+
+
+
+
+/*
+ * Implementation of W32 handle based I/O.
+ */
+#ifdef HAVE_W32_SYSTEM
+
+/* Cookie for fd objects.  */
+typedef struct estream_cookie_w32
+{
+  HANDLE hd;     /* The handle we are using for actual output.  */
+  int no_close;  /* If set we won't close the handle.  */
+  int no_syscall_clamp; /* Do not use the syscall clamp. */
+} *estream_cookie_w32_t;
+
+
+/*
+ * Create function for w32 handle objects.
+ */
+static int
+func_w32_create (void **cookie, HANDLE hd,
+                 unsigned int modeflags, int no_close, int no_syscall_clamp)
+{
+  estream_cookie_w32_t w32_cookie;
+  int err;
+
+  trace (("enter: hd=%p mf=%x nc=%d nsc=%d",
+          hd, modeflags, no_close, no_syscall_clamp));
+  w32_cookie = mem_alloc (sizeof (*w32_cookie));
+  if (!w32_cookie)
+    err = -1;
+  else
+    {
+      /* CR/LF translations are not supported when using the bare W32
+         API.  If that is really required we need to implemented that
+         in the upper layer.  */
+      (void)modeflags;
+
+      w32_cookie->hd = hd;
+      w32_cookie->no_close = no_close;
+      w32_cookie->no_syscall_clamp = no_syscall_clamp;
+      *cookie = w32_cookie;
+      err = 0;
+    }
+
+  trace_errno (err, ("leave: cookie=%p err=%d", *cookie, err));
+  return err;
+}
+
+/*
+ * Read function for W32 handle objects.
+ *
+ * Note that this function may also be used by the reader thread of
+ * w32-stream.  In that case the NO_SYSCALL_CLAMP is set.
+ */
+static gpgrt_ssize_t
+func_w32_read (void *cookie, void *buffer, size_t size)
+{
+  estream_cookie_w32_t w32_cookie = cookie;
+  gpgrt_ssize_t bytes_read;
+
+  trace (("enter: cookie=%p buffer=%p size=%d", cookie, buffer, (int)size));
+
+  if (!size)
+    bytes_read = -1; /* We don't know whether anything is pending.  */
+  else if (w32_cookie->hd == INVALID_HANDLE_VALUE)
+    {
+      _gpgrt_yield ();
+      bytes_read = 0;
+    }
+  else
+    {
+      if (!w32_cookie->no_syscall_clamp)
+        _gpgrt_pre_syscall ();
+      do
+        {
+          DWORD nread, ec;
+
+          trace (("cookie=%p calling ReadFile", cookie));
+          if (!ReadFile (w32_cookie->hd, buffer, size, &nread, NULL))
+            {
+              ec = GetLastError ();
+              trace (("cookie=%p ReadFile failed: ec=%ld", cookie,ec));
+              if (ec == ERROR_BROKEN_PIPE)
+                bytes_read = 0; /* Like our pth_read we handle this as EOF.  */
+              else
+                {
+                  _set_errno (map_w32_to_errno (ec));
+                  bytes_read = -1;
+                }
+            }
+          else
+            bytes_read = (int)nread;
+        }
+      while (bytes_read == -1 && errno == EINTR);
+      if (!w32_cookie->no_syscall_clamp)
+        _gpgrt_post_syscall ();
+    }
+
+  trace_errno (bytes_read==-1,("leave: bytes_read=%d", (int)bytes_read));
+  return bytes_read;
+}
+
+
+/*
+ * Write function for W32 handle objects.
+ *
+ * Note that this function may also be used by the writer thread of
+ * w32-stream.  In that case the NO_SYSCALL_CLAMP is set.
+ */
+static gpgrt_ssize_t
+func_w32_write (void *cookie, const void *buffer, size_t size)
+{
+  estream_cookie_w32_t w32_cookie = cookie;
+  gpgrt_ssize_t bytes_written;
+
+  trace (("enter: cookie=%p buffer=%p size=%d", cookie, buffer, (int)size));
+
+  if (w32_cookie->hd == INVALID_HANDLE_VALUE)
+    {
+      _gpgrt_yield ();
+      bytes_written = size; /* Yeah:  Success writing to the bit bucket.  */
+    }
+  else if (buffer)
+    {
+      if (!w32_cookie->no_syscall_clamp)
+        _gpgrt_pre_syscall ();
+      do
+        {
+          DWORD nwritten;
+
+          trace (("cookie=%p calling WriteFile", cookie));
+	  if (!WriteFile (w32_cookie->hd, buffer, size, &nwritten, NULL))
+	    {
+              DWORD ec = GetLastError ();
+              trace (("cookie=%p WriteFile failed: ec=%ld", cookie, ec));
+	      _set_errno (map_w32_to_errno (ec));
+	      bytes_written = -1;
+	    }
+	  else
+	    bytes_written = (int)nwritten;
+        }
+      while (bytes_written == -1 && errno == EINTR);
+      if (!w32_cookie->no_syscall_clamp)
+        _gpgrt_post_syscall ();
+    }
+  else
+    bytes_written = size; /* Note that for a flush SIZE should be 0.  */
+
+  trace_errno (bytes_written==-1,
+               ("leave: bytes_written=%d", (int)bytes_written));
+  return bytes_written;
+}
+
+
+/*
+ * Seek function for W32 handle objects.
+ */
+static int
+func_w32_seek (void *cookie, gpgrt_off_t *offset, int whence)
+{
+  estream_cookie_w32_t w32_cookie = cookie;
+  DWORD method;
+  LARGE_INTEGER distance, newoff;
+
+  if (w32_cookie->hd == INVALID_HANDLE_VALUE)
+    {
+      _set_errno (ESPIPE);
+      return -1;
+    }
+
+  if (whence == SEEK_SET)
+    {
+      method = FILE_BEGIN;
+      distance.QuadPart = (unsigned long long)(*offset);
+    }
+  else if (whence == SEEK_CUR)
+    {
+      method = FILE_CURRENT;
+      distance.QuadPart = (long long)(*offset);
+    }
+  else if (whence == SEEK_END)
+    {
+      method = FILE_END;
+      distance.QuadPart = (long long)(*offset);
+    }
+  else
+    {
+      _set_errno (EINVAL);
+      return -1;
+    }
+#ifdef HAVE_W32CE_SYSTEM
+# warning need to use SetFilePointer
+#else
+  if (!w32_cookie->no_syscall_clamp)
+    _gpgrt_pre_syscall ();
+  if (!SetFilePointerEx (w32_cookie->hd, distance, &newoff, method))
+    {
+      _set_errno (map_w32_to_errno (GetLastError ()));
+      _gpgrt_post_syscall ();
+      return -1;
+    }
+  if (!w32_cookie->no_syscall_clamp)
+    _gpgrt_post_syscall ();
+#endif
+  /* Note that gpgrt_off_t is always 64 bit.  */
+  *offset = (gpgrt_off_t)newoff.QuadPart;
+  return 0;
+}
+
+
+/*
+ * Destroy function for W32 handle objects.
+ */
+static int
+func_w32_destroy (void *cookie)
+{
+  estream_cookie_w32_t w32_cookie = cookie;
+  int err;
+
+  trace (("enter: cookie=%p", cookie));
+
+  if (w32_cookie)
+    {
+      if (w32_cookie->hd == INVALID_HANDLE_VALUE)
+        err = 0;
+      else if (w32_cookie->no_close)
+        err = 0;
+      else
+        {
+          trace (("cookie=%p closing handle %p", cookie, w32_cookie->hd));
+          if (!CloseHandle (w32_cookie->hd))
+            {
+              DWORD ec = GetLastError ();
+              trace (("cookie=%p CloseHandle failed: ec=%ld", cookie,ec));
+	      _set_errno (map_w32_to_errno (ec));
+              err = -1;
+            }
+          else
+            err = 0;
+        }
+      mem_free (w32_cookie);
+    }
+  else
+    err = 0;
+
+  trace_errno (err, ("leave: err=%d", err));
+  return err;
+}
+
+
+/*
+ * Access object for the W32 handle based objects.
+ */
+static struct cookie_io_functions_s estream_functions_w32 =
+  {
+    {
+      func_w32_read,
+      func_w32_write,
+      func_w32_seek,
+      func_w32_destroy,
+    },
+    NULL,
+  };
+#endif /*HAVE_W32_SYSTEM*/
+
+
+
+
+/*
+ * Implementation of stdio based I/O.
+ */
+
+/* Cookie for fp objects.  */
+typedef struct estream_cookie_fp
+{
+  FILE *fp;      /* The file pointer we are using for actual output.  */
+  int no_close;  /* If set we won't close the file pointer.  */
+} *estream_cookie_fp_t;
+
+
+/*
+ * Create function for stdio based objects.
+ */
+static int
+func_fp_create (void **cookie, FILE *fp,
+                unsigned int modeflags, int no_close)
+{
+  estream_cookie_fp_t fp_cookie;
+  int err;
+
+  fp_cookie = mem_alloc (sizeof *fp_cookie);
+  if (!fp_cookie)
+    err = -1;
+  else
+    {
+#ifdef HAVE_DOSISH_SYSTEM
+      /* Make sure it is in binary mode if requested.  */
+      if ( (modeflags & O_BINARY) )
+        setmode (fileno (fp), O_BINARY);
+#else
+      (void)modeflags;
+#endif
+      fp_cookie->fp = fp;
+      fp_cookie->no_close = no_close;
+      *cookie = fp_cookie;
+      err = 0;
+    }
+
+  return err;
+}
+
+
+/*
+ * Read function for stdio based objects.
+ */
+static gpgrt_ssize_t
+func_fp_read (void *cookie, void *buffer, size_t size)
+
+{
+  estream_cookie_fp_t file_cookie = cookie;
+  gpgrt_ssize_t bytes_read;
+
+  if (!size)
+    return -1; /* We don't know whether anything is pending.  */
+
+  if (file_cookie->fp)
+    {
+      _gpgrt_pre_syscall ();
+      bytes_read = fread (buffer, 1, size, file_cookie->fp);
+      _gpgrt_post_syscall ();
+    }
+  else
+    bytes_read = 0;
+  if (!bytes_read && ferror (file_cookie->fp))
+    return -1;
+  return bytes_read;
+}
+
+
+/*
+ * Write function for stdio bases objects.
+ */
+static gpgrt_ssize_t
+func_fp_write (void *cookie, const void *buffer, size_t size)
+{
+  estream_cookie_fp_t file_cookie = cookie;
+  size_t bytes_written;
+
+  if (file_cookie->fp)
+    {
+      _gpgrt_pre_syscall ();
+      if (buffer)
+        {
+#ifdef HAVE_W32_SYSTEM
+          /* Using an fwrite to stdout connected to the console fails
+             with the error "Not enough space" for an fwrite size of
+             >= 52KB (tested on Windows XP SP2).  To solve this we
+             always chunk the writes up into smaller blocks.  */
+          bytes_written = 0;
+          while (bytes_written < size)
+            {
+              size_t cnt = size - bytes_written;
+
+              if (cnt > 32*1024)
+                cnt = 32*1024;
+              if (fwrite ((const char*)buffer + bytes_written,
+                          cnt, 1, file_cookie->fp) != 1)
+                break; /* Write error.  */
+              bytes_written += cnt;
+            }
+#else
+          bytes_written = fwrite (buffer, 1, size, file_cookie->fp);
+#endif
+        }
+      else /* Only flush requested.  */
+        bytes_written = size;
+
+      fflush (file_cookie->fp);
+      _gpgrt_post_syscall ();
+    }
+  else
+    bytes_written = size; /* Successfully written to the bit bucket.  */
+
+  if (bytes_written != size)
+    return -1;
+  return bytes_written;
+}
+
+
+/*
+ * Seek function for stdio based objects.
+ */
+static int
+func_fp_seek (void *cookie, gpgrt_off_t *offset, int whence)
+{
+  estream_cookie_fp_t file_cookie = cookie;
+  long int offset_new;
+
+  if (!file_cookie->fp)
+    {
+      _set_errno (ESPIPE);
+      return -1;
+    }
+
+  _gpgrt_pre_syscall ();
+  if ( fseek (file_cookie->fp, (long int)*offset, whence) )
+    {
+      /* fprintf (stderr, "\nfseek failed: errno=%d (%s)\n", */
+      /*          errno,strerror (errno)); */
+      _gpgrt_post_syscall ();
+      return -1;
+    }
+
+  offset_new = ftell (file_cookie->fp);
+  _gpgrt_post_syscall ();
+  if (offset_new == -1)
+    {
+      /* fprintf (stderr, "\nftell failed: errno=%d (%s)\n",  */
+      /*          errno,strerror (errno)); */
+      return -1;
+    }
+  *offset = offset_new;
+  return 0;
+}
+
+
+/*
+ * Destroy function for stdio based objects.
+ */
+static int
+func_fp_destroy (void *cookie)
+{
+  estream_cookie_fp_t fp_cookie = cookie;
+  int err;
+
+  if (fp_cookie)
+    {
+      if (fp_cookie->fp)
+        {
+          _gpgrt_pre_syscall ();
+          fflush (fp_cookie->fp);
+          _gpgrt_post_syscall ();
+          err = fp_cookie->no_close? 0 : fclose (fp_cookie->fp);
+        }
+      else
+        err = 0;
+      mem_free (fp_cookie);
+    }
+  else
+    err = 0;
+
+  return err;
+}
+
+
+/*
+ * Access object for stdio based objects.
+ */
+static struct cookie_io_functions_s estream_functions_fp =
+  {
+    {
+      func_fp_read,
+      func_fp_write,
+      func_fp_seek,
+      func_fp_destroy,
+    },
+    NULL,
+  };
+
+
+
+
+/*
+ * Implementation of file name based I/O.
+ *
+ * Note that only a create function is required because the other
+ * operations ares handled by file descriptor based I/O.
+ */
+
+#ifdef HAVE_W32_SYSTEM
+static int
+any8bitchar (const char *string)
+{
+  if (string)
+    for ( ; *string; string++)
+      if ((*string & 0x80))
+        return 1;
+  return 0;
+}
+#endif /*HAVE_W32_SYSTEM*/
+
+/* Create function for objects identified by a file name.  */
+static int
+func_file_create (void **cookie, int *filedes,
+                  const char *path, unsigned int modeflags, unsigned int cmode)
+{
+  estream_cookie_fd_t file_cookie;
+  int err;
+  int fd;
+
+  err = 0;
+
+  file_cookie = mem_alloc (sizeof (*file_cookie));
+  if (! file_cookie)
+    {
+      err = -1;
+      goto out;
+    }
+
+#ifdef HAVE_W32_SYSTEM
+  if (any8bitchar (path))
+    {
+      wchar_t *wpath;
+
+      wpath = _gpgrt_utf8_to_wchar (path);
+      if (!wpath)
+        fd = -1;
+      else
+        {
+          fd = _wopen (wpath, modeflags, cmode);
+          _gpgrt_free_wchar (wpath);
+        }
+    }
+  else  /* Avoid unnecessary conversion.  */
+    fd = open (path, modeflags, cmode);
+#else
+  fd = open (path, modeflags, cmode);
+#endif
+  if (fd == -1)
+    {
+      err = -1;
+      goto out;
+    }
+#ifdef HAVE_DOSISH_SYSTEM
+  /* Make sure it is in binary mode if requested.  */
+  if ( (modeflags & O_BINARY) )
+    setmode (fd, O_BINARY);
+#endif
+
+  file_cookie->fd = fd;
+  file_cookie->no_close = 0;
+  *cookie = file_cookie;
+  *filedes = fd;
+
+ out:
+
+  if (err)
+    mem_free (file_cookie);
+
+  return err;
+}
+
+
+
+/* Flags used by parse_mode and friends.  */
+#define X_SAMETHREAD	(1 << 0)
+#define X_SYSOPEN	(1 << 1)
+#define X_POLLABLE	(1 << 2)
+
+/* Parse the mode flags of fopen et al.  In addition to the POSIX
+ * defined mode flags keyword parameters are supported.  These are
+ * key/value pairs delimited by comma and optional white spaces.
+ * Keywords and values may not contain a comma or white space; unknown
+ * keywords are skipped. Supported keywords are:
+ *
+ * mode=<string>
+ *
+ *    Creates a file and gives the new file read and write permissions
+ *    for the user and read permission for the group.  The format of
+ *    the string is the same as shown by the -l option of the ls(1)
+ *    command.  However the first letter must be a dash and it is
+ *    allowed to leave out trailing dashes.  If this keyword parameter
+ *    is not given the default mode for creating files is "-rw-rw-r--"
+ *    (664).  Note that the system still applies the current umask to
+ *    the mode when creating a file.  Example:
+ *
+ *       "wb,mode=-rw-r--"
+ *
+ * samethread
+ *
+ *    Assumes that the object is only used by the creating thread and
+ *    disables any internal locking.  This keyword is also found on
+ *    IBM systems.
+ *
+ * nonblock
+ *
+ *    The object is opened in non-blocking mode.  This is the same as
+ *    calling gpgrt_set_nonblock on the file.
+ *
+ * sysopen
+ *
+ *    The object is opened in sysmode.  On POSIX this is a NOP but
+ *    under Windows the direct W32 API functions (HANDLE) are used
+ *    instead of their libc counterparts (fd).
+ *    FIXME: The functionality is not yet implemented.
+ *
+ * pollable
+ *
+ *    The object is opened in a way suitable for use with es_poll.  On
+ *    POSIX this is a NOP but under Windows we create up to two
+ *    threads, one for reading and one for writing, do any I/O there,
+ *    and synchronize with them in order to support es_poll.
+ *
+ * Note: R_CMODE is optional because is only required by functions
+ * which are able to creat a file.
+ */
+static int
+parse_mode (const char *modestr,
+            unsigned int *modeflags,
+            unsigned int *r_xmode,
+            unsigned int *r_cmode)
+{
+  unsigned int omode, oflags, cmode;
+  int got_cmode = 0;
+
+  *r_xmode = 0;
+
+  switch (*modestr)
+    {
+    case 'r':
+      omode = O_RDONLY;
+      oflags = 0;
+      break;
+    case 'w':
+      omode = O_WRONLY;
+      oflags = O_TRUNC | O_CREAT;
+      break;
+    case 'a':
+      omode = O_WRONLY;
+      oflags = O_APPEND | O_CREAT;
+      break;
+    default:
+      _set_errno (EINVAL);
+      return -1;
+    }
+  for (modestr++; *modestr; modestr++)
+    {
+      switch (*modestr)
+        {
+        case '+':
+          omode = O_RDWR;
+          break;
+        case 'b':
+          oflags |= O_BINARY;
+          break;
+        case 'x':
+          oflags |= O_EXCL;
+          break;
+        case ',':
+          goto keyvalue;
+        default: /* Ignore unknown flags.  */
+          break;
+        }
+    }
+
+ keyvalue:
+  /* Parse key/value pairs (similar to fopen on mainframes).  */
+  for (cmode=0; *modestr == ','; modestr += strcspn (modestr, ","))
+    {
+      modestr++;
+      modestr += strspn (modestr, " \t");
+      if (!strncmp (modestr, "mode=", 5))
+        {
+          static struct {
+            char letter;
+            unsigned int value;
+          } table[] = { { '-', 0 },
+                        { 'r', S_IRUSR }, { 'w', S_IWUSR }, { 'x', S_IXUSR },
+                        { 'r', S_IRGRP }, { 'w', S_IWGRP }, { 'x', S_IXGRP },
+                        { 'r', S_IROTH }, { 'w', S_IWOTH }, { 'x', S_IXOTH }};
+          int idx;
+
+          got_cmode = 1;
+          modestr += 5;
+          /* For now we only support a string as used by ls(1) and no
+             octal numbers.  The first character must be a dash.  */
+          for (idx=0; idx < 10 && *modestr; idx++, modestr++)
+            {
+              if (*modestr == table[idx].letter)
+                cmode |= table[idx].value;
+              else if (*modestr != '-')
+                break;
+            }
+          if (*modestr && !strchr (" \t,", *modestr))
+            {
+              _set_errno (EINVAL);
+              return -1;
+            }
+        }
+      else if (!strncmp (modestr, "samethread", 10))
+        {
+          modestr += 10;
+          if (*modestr && !strchr (" \t,", *modestr))
+            {
+              _set_errno (EINVAL);
+              return -1;
+            }
+          *r_xmode |= X_SAMETHREAD;
+        }
+      else if (!strncmp (modestr, "nonblock", 8))
+        {
+          modestr += 8;
+          if (*modestr && !strchr (" \t,", *modestr))
+            {
+              _set_errno (EINVAL);
+              return -1;
+            }
+          oflags |= O_NONBLOCK;
+#if HAVE_W32_SYSTEM
+          /* Currently, nonblock implies pollable on Windows.  */
+          *r_xmode |= X_POLLABLE;
+#endif
+        }
+      else if (!strncmp (modestr, "sysopen", 7))
+        {
+          modestr += 7;
+          if (*modestr && !strchr (" \t,", *modestr))
+            {
+              _set_errno (EINVAL);
+              return -1;
+            }
+          *r_xmode |= X_SYSOPEN;
+        }
+      else if (!strncmp (modestr, "pollable", 8))
+        {
+          modestr += 8;
+          if (*modestr && !strchr (" \t,", *modestr))
+            {
+              _set_errno (EINVAL);
+              return -1;
+            }
+          *r_xmode |= X_POLLABLE;
+        }
+    }
+  if (!got_cmode)
+    cmode = (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH);
+
+  *modeflags = (omode | oflags);
+  if (r_cmode)
+    *r_cmode = cmode;
+  return 0;
+}
+
+
+
+/*
+ * Low level stream functionality.
+ */
+
+static int
+fill_stream (estream_t stream)
+{
+  size_t bytes_read = 0;
+  int err;
+
+  if (!stream->intern->func_read)
+    {
+      _set_errno (EOPNOTSUPP);
+      err = -1;
+    }
+  else if (!stream->buffer_size)
+    err = 0;
+  else
+    {
+      gpgrt_cookie_read_function_t func_read = stream->intern->func_read;
+      gpgrt_ssize_t ret;
+
+      ret = (*func_read) (stream->intern->cookie,
+			  stream->buffer, stream->buffer_size);
+      if (ret == -1)
+	{
+	  bytes_read = 0;
+	  err = -1;
+#if EWOULDBLOCK != EAGAIN
+          if (errno == EWOULDBLOCK)
+            _set_errno (EAGAIN);
+#endif
+	}
+      else
+	{
+	  bytes_read = ret;
+	  err = 0;
+	}
+    }
+
+  if (err)
+    {
+      if (errno != EAGAIN)
+        {
+          if (errno == EPIPE)
+            stream->intern->indicators.hup = 1;
+          stream->intern->indicators.err = 1;
+        }
+    }
+  else if (!bytes_read)
+    stream->intern->indicators.eof = 1;
+
+  stream->intern->offset += stream->data_len;
+  stream->data_len = bytes_read;
+  stream->data_offset = 0;
+
+  return err;
+}
+
+static int
+flush_stream (estream_t stream)
+{
+  gpgrt_cookie_write_function_t func_write = stream->intern->func_write;
+  int err;
+
+  gpgrt_assert (stream->flags.writing);
+
+  if (stream->data_offset)
+    {
+      size_t bytes_written;
+      size_t data_flushed;
+      gpgrt_ssize_t ret;
+
+      if (! func_write)
+	{
+          _set_errno (EOPNOTSUPP);
+          err = -1;
+	  goto out;
+	}
+
+      /* Note: to prevent an endless loop caused by user-provided
+	 write-functions that pretend to have written more bytes than
+	 they were asked to write, we have to check for
+	 "(stream->data_offset - data_flushed) > 0" instead of
+	 "stream->data_offset - data_flushed".  */
+
+      data_flushed = 0;
+      err = 0;
+
+      while ((((gpgrt_ssize_t) (stream->data_offset - data_flushed)) > 0)
+             && !err)
+	{
+	  ret = (*func_write) (stream->intern->cookie,
+			       stream->buffer + data_flushed,
+			       stream->data_offset - data_flushed);
+	  if (ret == -1)
+	    {
+	      bytes_written = 0;
+	      err = -1;
+#if EWOULDBLOCK != EAGAIN
+              if (errno == EWOULDBLOCK)
+                _set_errno (EAGAIN);
+#endif
+	    }
+	  else
+	    bytes_written = ret;
+
+	  data_flushed += bytes_written;
+	  if (err)
+	    break;
+	}
+
+      stream->data_flushed += data_flushed;
+      if (stream->data_offset == data_flushed)
+	{
+	  stream->intern->offset += stream->data_offset;
+	  stream->data_offset = 0;
+	  stream->data_flushed = 0;
+	}
+    }
+  else
+    err = 0;
+
+  /* Always propagate flush event in case gpgrt_fflush was called
+   * explictly to do flush buffers in caller's cookie functions.  */
+  (*func_write) (stream->intern->cookie, NULL, 0);
+
+ out:
+
+  if (err && errno != EAGAIN)
+    {
+      if (errno == EPIPE)
+        stream->intern->indicators.hup = 1;
+      stream->intern->indicators.err = 1;
+    }
+
+  return err;
+}
+
+
+/*
+ * Discard buffered data for STREAM.
+ */
+static void
+es_empty (estream_t stream)
+{
+  gpgrt_assert (!stream->flags.writing);
+  stream->data_len = 0;
+  stream->data_offset = 0;
+  stream->unread_data_len = 0;
+}
+
+
+/*
+ * Initialize STREAM.
+ */
+static void
+init_stream_obj (estream_t stream,
+                 void *cookie, es_syshd_t *syshd,
+                 gpgrt_stream_backend_kind_t kind,
+                 struct cookie_io_functions_s functions,
+                 unsigned int modeflags, unsigned int xmode)
+{
+  stream->intern->kind = kind;
+  stream->intern->cookie = cookie;
+  stream->intern->opaque = NULL;
+  stream->intern->offset = 0;
+  stream->intern->func_read = functions.public.func_read;
+  stream->intern->func_write = functions.public.func_write;
+  stream->intern->func_seek = functions.public.func_seek;
+  stream->intern->func_ioctl = functions.func_ioctl;
+  stream->intern->func_close = functions.public.func_close;
+  stream->intern->strategy = _IOFBF;
+  stream->intern->syshd = *syshd;
+  stream->intern->print_ntotal = 0;
+  stream->intern->indicators.err = 0;
+  stream->intern->indicators.eof = 0;
+  stream->intern->indicators.hup = 0;
+  stream->intern->is_stdstream = 0;
+  stream->intern->stdstream_fd = 0;
+  stream->intern->deallocate_buffer = 0;
+  stream->intern->printable_fname = NULL;
+  stream->intern->printable_fname_inuse = 0;
+  stream->intern->samethread = !! (xmode & X_SAMETHREAD);
+  stream->intern->onclose = NULL;
+
+  stream->data_len = 0;
+  stream->data_offset = 0;
+  stream->data_flushed = 0;
+  stream->unread_data_len = 0;
+  /* Depending on the modeflags we set whether we start in writing or
+     reading mode.  This is required in case we are working on a
+     stream which is not seeekable (like stdout).  Without this
+     pre-initialization we would do a seek at the first write call and
+     as this will fail no output will be delivered. */
+  if ((modeflags & O_WRONLY) || (modeflags & O_RDWR) )
+    stream->flags.writing = 1;
+  else
+    stream->flags.writing = 0;
+}
+
+
+/*
+ * Deinitialize the STREAM object.  This does _not_ free the memory,
+ * destroys the lock, or closes the underlying descriptor.
+ */
+static int
+deinit_stream_obj (estream_t stream)
+{
+  gpgrt_cookie_close_function_t func_close;
+  int err, tmp_err;
+
+  trace (("enter: stream %p", stream));
+  func_close = stream->intern->func_close;
+
+  err = 0;
+  if (stream->flags.writing)
+    {
+      tmp_err = flush_stream (stream);
+      if (!err)
+        err = tmp_err;
+    }
+  if (func_close)
+    {
+      trace (("stream %p calling func_close", stream));
+      tmp_err = func_close (stream->intern->cookie);
+      if (!err)
+        err = tmp_err;
+    }
+
+  mem_free (stream->intern->printable_fname);
+  stream->intern->printable_fname = NULL;
+  stream->intern->printable_fname_inuse = 0;
+  while (stream->intern->onclose)
+    {
+      notify_list_t tmp = stream->intern->onclose->next;
+      mem_free (stream->intern->onclose);
+      stream->intern->onclose = tmp;
+    }
+
+  trace_errno (err, ("leave: stream %p err=%d", stream, err));
+  return err;
+}
+
+
+/*
+ * Create a new stream and initialize it.  On success the new stream
+ * handle is tsored at R_STREAM.  On failure NULL is stored at
+ * R_STREAM.
+ */
+static int
+create_stream (estream_t *r_stream, void *cookie, es_syshd_t *syshd,
+               gpgrt_stream_backend_kind_t kind,
+               struct cookie_io_functions_s functions, unsigned int modeflags,
+               unsigned int xmode, int with_locked_list)
+{
+  estream_internal_t stream_internal_new;
+  estream_t stream_new;
+  int err;
+#if HAVE_W32_SYSTEM
+  void *old_cookie = NULL;
+#endif
+
+  stream_new = NULL;
+  stream_internal_new = NULL;
+
+#if HAVE_W32_SYSTEM
+  if ((xmode & X_POLLABLE) && kind != BACKEND_W32)
+    {
+      /* We require the W32 backend, because only that allows us to
+       * write directly using the native W32 API and to disable the
+       * system clamp.  Note that func_w32_create has already been
+       * called with the flag to disable the system call clamp.  */
+      _set_errno (EINVAL);
+      err = -1;
+      goto out;
+    }
+#endif /*HAVE_W32_SYSTEM*/
+
+  stream_new = mem_alloc (sizeof (*stream_new));
+  if (! stream_new)
+    {
+      err = -1;
+      goto out;
+    }
+
+  stream_internal_new = mem_alloc (sizeof (*stream_internal_new));
+  if (! stream_internal_new)
+    {
+      err = -1;
+      goto out;
+    }
+
+  stream_new->buffer = stream_internal_new->buffer;
+  stream_new->buffer_size = sizeof (stream_internal_new->buffer);
+  stream_new->unread_buffer = stream_internal_new->unread_buffer;
+  stream_new->unread_buffer_size = sizeof (stream_internal_new->unread_buffer);
+  stream_new->intern = stream_internal_new;
+
+#if HAVE_W32_SYSTEM
+  if ((xmode & X_POLLABLE))
+    {
+      void *new_cookie;
+
+      err = _gpgrt_w32_pollable_create (&new_cookie, modeflags,
+                                        functions, cookie);
+      if (err)
+        goto out;
+
+      modeflags &= ~O_NONBLOCK;
+      old_cookie = cookie;
+      cookie = new_cookie;
+      kind = BACKEND_W32_POLLABLE;
+      functions = _gpgrt_functions_w32_pollable;
+    }
+#endif /*HAVE_W32_SYSTEM*/
+
+  init_stream_obj (stream_new, cookie, syshd, kind, functions, modeflags,
+                   xmode);
+  init_stream_lock (stream_new);
+
+  err = do_list_add (stream_new, with_locked_list);
+  if (err)
+    goto out;
+
+  *r_stream = stream_new;
+
+ out:
+
+  if (err)
+    {
+      trace_errno (err, ("leave: err=%d", err));
+      if (stream_new)
+	{
+	  deinit_stream_obj (stream_new);
+          destroy_stream_lock (stream_new);
+	  mem_free (stream_new->intern);
+	  mem_free (stream_new);
+	}
+    }
+#if HAVE_W32_SYSTEM
+  else if (old_cookie)
+    trace (("leave: success stream=%p cookie=%p,%p",
+            *r_stream, old_cookie, cookie));
+#endif
+  else
+    trace (("leave: success stream=%p cookie=%p", *r_stream, cookie));
+
+  return err;
+}
+
+
+/*
+ * Deinitialize a stream object and destroy it.  With CANCEL_MODE set
+ * try to cancel as much as possible (see _gpgrt_fcancel).
+ */
+static int
+do_close (estream_t stream, int cancel_mode, int with_locked_list)
+{
+  int err;
+
+  trace (("stream %p %s", stream, with_locked_list? "(with locked list)":""));
+
+  if (stream)
+    {
+      do_list_remove (stream, with_locked_list);
+      if (cancel_mode)
+        {
+          stream->flags.writing = 0;
+          es_empty (stream);
+        }
+      while (stream->intern->onclose)
+        {
+          notify_list_t tmp = stream->intern->onclose->next;
+
+          if (stream->intern->onclose->fnc)
+            stream->intern->onclose->fnc (stream,
+                                          stream->intern->onclose->fnc_value);
+          mem_free (stream->intern->onclose);
+          stream->intern->onclose = tmp;
+        }
+      err = deinit_stream_obj (stream);
+      destroy_stream_lock (stream);
+      if (stream->intern->deallocate_buffer)
+        mem_free (stream->buffer);
+      mem_free (stream->intern);
+      mem_free (stream);
+    }
+  else
+    err = 0;
+
+  trace_errno (err, ("stream %p err=%d", stream, err));
+  return err;
+}
+
+
+/*
+ * The onclose worker function which is called with a locked
+ * stream.
+ */
+static int
+do_onclose (estream_t stream, int mode,
+            void (*fnc) (estream_t, void*), void *fnc_value)
+{
+  notify_list_t item;
+
+  if (!mode)
+    {
+      for (item = stream->intern->onclose; item; item = item->next)
+        if (item->fnc && item->fnc == fnc && item->fnc_value == fnc_value)
+          item->fnc = NULL; /* Disable this notification.  */
+    }
+  else
+    {
+      item = mem_alloc (sizeof *item);
+      if (!item)
+        return -1;
+      item->fnc = fnc;
+      item->fnc_value = fnc_value;
+      item->next = stream->intern->onclose;
+      stream->intern->onclose = item;
+    }
+  return 0;
+}
+
+
+/*
+ * Try to read BYTES_TO_READ bytes from STREAM into BUFFER in
+ * unbuffered-mode, storing the amount of bytes read at BYTES_READ.
+ */
+static int
+do_read_nbf (estream_t _GPGRT__RESTRICT stream,
+	     unsigned char *_GPGRT__RESTRICT buffer,
+	     size_t bytes_to_read, size_t *_GPGRT__RESTRICT bytes_read)
+{
+  gpgrt_cookie_read_function_t func_read = stream->intern->func_read;
+  size_t data_read;
+  gpgrt_ssize_t ret;
+  int err;
+
+  data_read = 0;
+  err = 0;
+
+  while (bytes_to_read - data_read)
+    {
+      ret = (*func_read) (stream->intern->cookie,
+			  buffer + data_read, bytes_to_read - data_read);
+      if (ret == -1)
+	{
+	  err = -1;
+#if EWOULDBLOCK != EAGAIN
+          if (errno == EWOULDBLOCK)
+            _set_errno (EAGAIN);
+#endif
+	  break;
+	}
+      else if (ret)
+	data_read += ret;
+      else
+	break;
+    }
+
+  stream->intern->offset += data_read;
+  *bytes_read = data_read;
+
+  return err;
+}
+
+
+/*
+ * Helper for check_pending.
+ */
+static int
+check_pending_nbf (estream_t _GPGRT__RESTRICT stream)
+{
+  gpgrt_cookie_read_function_t func_read = stream->intern->func_read;
+  char buffer[1];
+
+  if (!(*func_read) (stream->intern->cookie, buffer, 0))
+    return 1; /* Pending bytes.  */
+  return 0; /* No pending bytes or error.  */
+}
+
+
+/*
+ * Try to read BYTES_TO_READ bytes from STREAM into BUFFER in
+ * fully-buffered-mode, storing the amount of bytes read at
+ * BYTES_READ.
+ */
+static int
+do_read_fbf (estream_t _GPGRT__RESTRICT stream,
+	     unsigned char *_GPGRT__RESTRICT buffer,
+	     size_t bytes_to_read, size_t *_GPGRT__RESTRICT bytes_read)
+{
+  size_t data_available;
+  size_t data_to_read;
+  size_t data_read;
+  int err;
+
+  data_read = 0;
+  err = 0;
+
+  while ((bytes_to_read - data_read) && (! err))
+    {
+      if (stream->data_offset == stream->data_len)
+	{
+	  /* Nothing more to read in current container, try to
+	     fill container with new data.  */
+	  err = fill_stream (stream);
+	  if (! err)
+	    if (! stream->data_len)
+	      /* Filling did not result in any data read.  */
+	      break;
+	}
+
+      if (! err)
+	{
+	  /* Filling resulted in some new data.  */
+
+	  data_to_read = bytes_to_read - data_read;
+	  data_available = stream->data_len - stream->data_offset;
+	  if (data_to_read > data_available)
+	    data_to_read = data_available;
+
+	  memcpy (buffer + data_read,
+		  stream->buffer + stream->data_offset, data_to_read);
+	  stream->data_offset += data_to_read;
+	  data_read += data_to_read;
+	}
+    }
+
+  *bytes_read = data_read;
+
+  return err;
+}
+
+
+/*
+ * Helper for check_pending.
+ */
+static int
+check_pending_fbf (estream_t _GPGRT__RESTRICT stream)
+{
+  gpgrt_cookie_read_function_t func_read = stream->intern->func_read;
+  char buffer[1];
+
+  if (stream->data_offset == stream->data_len)
+    {
+      /* Nothing more to read in current container, check whether it
+         would be possible to fill the container with new data.  */
+      if (!(*func_read) (stream->intern->cookie, buffer, 0))
+        return 1; /* Pending bytes.  */
+    }
+  else
+    return 1;
+  return 0;
+}
+
+
+/*
+ * Try to read BYTES_TO_READ bytes from STREAM into BUFFER in
+ * line-buffered-mode, storing the amount of bytes read at BYTES_READ.
+ */
+static int
+do_read_lbf (estream_t _GPGRT__RESTRICT stream,
+	     unsigned char *_GPGRT__RESTRICT buffer,
+	     size_t bytes_to_read, size_t *_GPGRT__RESTRICT bytes_read)
+{
+  int err;
+
+  err = do_read_fbf (stream, buffer, bytes_to_read, bytes_read);
+
+  return err;
+}
+
+
+/*
+ * Try to read BYTES_TO_READ bytes from STREAM into BUFFER, storing
+ * the amount of bytes read at BYTES_READ.
+ */
+static int
+es_readn (estream_t _GPGRT__RESTRICT stream,
+	  void *_GPGRT__RESTRICT buffer_arg,
+	  size_t bytes_to_read, size_t *_GPGRT__RESTRICT bytes_read)
+{
+  unsigned char *buffer = (unsigned char *)buffer_arg;
+  size_t data_read_unread, data_read;
+  int err;
+
+  data_read_unread = 0;
+  data_read = 0;
+  err = 0;
+
+  if (stream->flags.writing)
+    {
+      /* Switching to reading mode -> flush output.  */
+      err = flush_stream (stream);
+      if (err)
+	goto out;
+      stream->flags.writing = 0;
+    }
+
+  /* Read unread data first.  */
+  while ((bytes_to_read - data_read_unread) && stream->unread_data_len)
+    {
+      buffer[data_read_unread]
+	= stream->unread_buffer[stream->unread_data_len - 1];
+      stream->unread_data_len--;
+      data_read_unread++;
+    }
+
+  switch (stream->intern->strategy)
+    {
+    case _IONBF:
+      err = do_read_nbf (stream,
+			 buffer + data_read_unread,
+			 bytes_to_read - data_read_unread, &data_read);
+      break;
+    case _IOLBF:
+      err = do_read_lbf (stream,
+			 buffer + data_read_unread,
+			 bytes_to_read - data_read_unread, &data_read);
+      break;
+    case _IOFBF:
+      err = do_read_fbf (stream,
+			 buffer + data_read_unread,
+			 bytes_to_read - data_read_unread, &data_read);
+      break;
+    }
+
+ out:
+
+  if (bytes_read)
+    *bytes_read = data_read_unread + data_read;
+
+  return err;
+}
+
+
+/*
+ * Return true if at least one byte is pending for read.  This is a
+ * best effort check and it it possible that bytes are still pending
+ * even if false is returned.  If the stream is in writing mode it is
+ * switched to read mode.
+ */
+static int
+check_pending (estream_t _GPGRT__RESTRICT stream)
+{
+  if (stream->flags.writing)
+    {
+      /* Switching to reading mode -> flush output.  */
+      if (flush_stream (stream))
+	return 0; /* Better return 0 on error.  */
+      stream->flags.writing = 0;
+    }
+
+  /* Check unread data first.  */
+  if (stream->unread_data_len)
+    return 1;
+
+  switch (stream->intern->strategy)
+    {
+    case _IONBF:
+      return check_pending_nbf (stream);
+    case _IOLBF:
+    case _IOFBF:
+      return check_pending_fbf (stream);
+    }
+
+  return 0;
+}
+
+
+/*
+ * Try to unread DATA_N bytes from DATA into STREAM, storing the
+ * amount of bytes successfully unread at BYTES_UNREAD.
+ */
+static void
+es_unreadn (estream_t _GPGRT__RESTRICT stream,
+	    const unsigned char *_GPGRT__RESTRICT data, size_t data_n,
+	    size_t *_GPGRT__RESTRICT bytes_unread)
+{
+  size_t space_left;
+
+  space_left = stream->unread_buffer_size - stream->unread_data_len;
+
+  if (data_n > space_left)
+    data_n = space_left;
+
+  if (! data_n)
+    goto out;
+
+  memcpy (stream->unread_buffer + stream->unread_data_len, data, data_n);
+  stream->unread_data_len += data_n;
+  stream->intern->indicators.eof = 0;
+
+ out:
+
+  if (bytes_unread)
+    *bytes_unread = data_n;
+}
+
+
+/*
+ * Seek in STREAM.
+ */
+static int
+es_seek (estream_t _GPGRT__RESTRICT stream, gpgrt_off_t offset, int whence,
+	 gpgrt_off_t *_GPGRT__RESTRICT offset_new)
+{
+  gpgrt_cookie_seek_function_t func_seek = stream->intern->func_seek;
+  int err, ret;
+  gpgrt_off_t off;
+
+  if (! func_seek)
+    {
+      _set_errno (EOPNOTSUPP);
+      err = -1;
+      goto out;
+    }
+
+  if (stream->flags.writing)
+    {
+      /* Flush data first in order to prevent flushing it to the wrong
+	 offset.  */
+      err = flush_stream (stream);
+      if (err)
+	goto out;
+      stream->flags.writing = 0;
+    }
+
+  off = offset;
+  if (whence == SEEK_CUR)
+    {
+      off = off - stream->data_len + stream->data_offset;
+      off -= stream->unread_data_len;
+    }
+
+  ret = (*func_seek) (stream->intern->cookie, &off, whence);
+  if (ret == -1)
+    {
+      err = -1;
+#if EWOULDBLOCK != EAGAIN
+      if (errno == EWOULDBLOCK)
+        _set_errno (EAGAIN);
+#endif
+      goto out;
+    }
+
+  err = 0;
+  es_empty (stream);
+
+  if (offset_new)
+    *offset_new = off;
+
+  stream->intern->indicators.eof = 0;
+  stream->intern->offset = off;
+
+ out:
+
+  if (err)
+    {
+      if (errno == EPIPE)
+        stream->intern->indicators.hup = 1;
+      stream->intern->indicators.err = 1;
+    }
+
+  return err;
+}
+
+
+/*
+ * Write BYTES_TO_WRITE bytes from BUFFER into STREAM in
+ * unbuffered-mode, storing the amount of bytes written at
+ * BYTES_WRITTEN.
+ */
+static int
+es_write_nbf (estream_t _GPGRT__RESTRICT stream,
+	      const unsigned char *_GPGRT__RESTRICT buffer,
+	      size_t bytes_to_write, size_t *_GPGRT__RESTRICT bytes_written)
+{
+  gpgrt_cookie_write_function_t func_write = stream->intern->func_write;
+  size_t data_written;
+  gpgrt_ssize_t ret;
+  int err;
+
+  if (bytes_to_write && (! func_write))
+    {
+      _set_errno (EOPNOTSUPP);
+      err = -1;
+      goto out;
+    }
+
+  data_written = 0;
+  err = 0;
+
+  while (bytes_to_write - data_written)
+    {
+      ret = (*func_write) (stream->intern->cookie,
+			   buffer + data_written,
+			   bytes_to_write - data_written);
+      if (ret == -1)
+	{
+	  err = -1;
+#if EWOULDBLOCK != EAGAIN
+          if (errno == EWOULDBLOCK)
+            _set_errno (EAGAIN);
+#endif
+	  break;
+	}
+      else
+	data_written += ret;
+    }
+
+  stream->intern->offset += data_written;
+  *bytes_written = data_written;
+
+ out:
+
+  return err;
+}
+
+
+/*
+ * Write BYTES_TO_WRITE bytes from BUFFER into STREAM in
+ * fully-buffered-mode, storing the amount of bytes written at
+ * BYTES_WRITTEN.
+ */
+static int
+es_write_fbf (estream_t _GPGRT__RESTRICT stream,
+	      const unsigned char *_GPGRT__RESTRICT buffer,
+	      size_t bytes_to_write, size_t *_GPGRT__RESTRICT bytes_written)
+{
+  size_t space_available;
+  size_t data_to_write;
+  size_t data_written;
+  int err;
+
+  data_written = 0;
+  err = 0;
+
+  while ((bytes_to_write - data_written) && (! err))
+    {
+      if (stream->data_offset == stream->buffer_size)
+	/* Container full, flush buffer.  */
+	err = flush_stream (stream);
+
+      if (! err)
+	{
+	  /* Flushing resulted in empty container.  */
+
+	  data_to_write = bytes_to_write - data_written;
+	  space_available = stream->buffer_size - stream->data_offset;
+	  if (data_to_write > space_available)
+	    data_to_write = space_available;
+
+	  memcpy (stream->buffer + stream->data_offset,
+		  buffer + data_written, data_to_write);
+	  stream->data_offset += data_to_write;
+	  data_written += data_to_write;
+	}
+    }
+
+  *bytes_written = data_written;
+
+  return err;
+}
+
+
+/* Write BYTES_TO_WRITE bytes from BUFFER into STREAM in
+   line-buffered-mode, storing the amount of bytes written in
+   *BYTES_WRITTEN.  */
+static int
+es_write_lbf (estream_t _GPGRT__RESTRICT stream,
+	      const unsigned char *_GPGRT__RESTRICT buffer,
+	      size_t bytes_to_write, size_t *_GPGRT__RESTRICT bytes_written)
+{
+  size_t data_flushed = 0;
+  size_t data_buffered = 0;
+  unsigned char *nlp;
+  int err = 0;
+
+  nlp = memrchr (buffer, '\n', bytes_to_write);
+  if (nlp)
+    {
+      /* Found a newline, directly write up to (including) this
+	 character.  */
+      err = flush_stream (stream);
+      if (!err)
+	err = es_write_nbf (stream, buffer, nlp - buffer + 1, &data_flushed);
+    }
+
+  if (!err)
+    {
+      /* Write remaining data fully buffered.  */
+      err = es_write_fbf (stream, buffer + data_flushed,
+			  bytes_to_write - data_flushed, &data_buffered);
+    }
+
+  *bytes_written = data_flushed + data_buffered;
+  return err;
+}
+
+
+/* Write BYTES_TO_WRITE bytes from BUFFER into STREAM in, storing the
+   amount of bytes written in BYTES_WRITTEN.  */
+static int
+es_writen (estream_t _GPGRT__RESTRICT stream,
+	   const void *_GPGRT__RESTRICT buffer,
+	   size_t bytes_to_write, size_t *_GPGRT__RESTRICT bytes_written)
+{
+  size_t data_written;
+  int err;
+
+  data_written = 0;
+  err = 0;
+
+  if (!stream->flags.writing)
+    {
+      /* Switching to writing mode -> discard input data and seek to
+	 position at which reading has stopped.  We can do this only
+	 if a seek function has been registered. */
+      if (stream->intern->func_seek)
+        {
+          err = es_seek (stream, 0, SEEK_CUR, NULL);
+          if (err)
+            {
+              if (errno == ESPIPE)
+                err = 0;
+              else
+                goto out;
+            }
+          stream->flags.writing = 1;
+        }
+    }
+
+  switch (stream->intern->strategy)
+    {
+    case _IONBF:
+      err = es_write_nbf (stream, buffer, bytes_to_write, &data_written);
+      break;
+
+    case _IOLBF:
+      err = es_write_lbf (stream, buffer, bytes_to_write, &data_written);
+      break;
+
+    case _IOFBF:
+      err = es_write_fbf (stream, buffer, bytes_to_write, &data_written);
+      break;
+    }
+
+ out:
+
+  if (bytes_written)
+    *bytes_written = data_written;
+
+  return err;
+}
+
+
+static int
+peek_stream (estream_t _GPGRT__RESTRICT stream,
+             unsigned char **_GPGRT__RESTRICT data,
+             size_t *_GPGRT__RESTRICT data_len)
+{
+  int err;
+
+  if (stream->flags.writing)
+    {
+      /* Switching to reading mode -> flush output.  */
+      err = flush_stream (stream);
+      if (err)
+	goto out;
+      stream->flags.writing = 0;
+    }
+
+  if (stream->data_offset == stream->data_len)
+    {
+      /* Refill container.  */
+      err = fill_stream (stream);
+      if (err)
+	goto out;
+    }
+
+  if (data)
+    *data = stream->buffer + stream->data_offset;
+  if (data_len)
+    *data_len = stream->data_len - stream->data_offset;
+  err = 0;
+
+ out:
+
+  return err;
+}
+
+
+/* Skip SIZE bytes of input data contained in buffer.  */
+static int
+skip_stream (estream_t stream, size_t size)
+{
+  int err;
+
+  if (stream->data_offset + size > stream->data_len)
+    {
+      _set_errno (EINVAL);
+      err = -1;
+    }
+  else
+    {
+      stream->data_offset += size;
+      err = 0;
+    }
+
+  return err;
+}
+
+
+static int
+doreadline (estream_t _GPGRT__RESTRICT stream, size_t max_length,
+            char *_GPGRT__RESTRICT *_GPGRT__RESTRICT line,
+            size_t *_GPGRT__RESTRICT line_length)
+{
+  size_t line_size;
+  estream_t line_stream;
+  char *line_new;
+  void *line_stream_cookie;
+  char *newline;
+  unsigned char *data;
+  size_t data_len;
+  int err;
+  es_syshd_t syshd;
+
+  line_new = NULL;
+  line_stream = NULL;
+  line_stream_cookie = NULL;
+
+  err = func_mem_create (&line_stream_cookie, NULL, 0, 0,
+                         BUFFER_BLOCK_SIZE, 1,
+                         mem_realloc, mem_free,
+                         O_RDWR,
+                         0);
+  if (err)
+    goto out;
+
+  memset (&syshd, 0, sizeof syshd);
+  err = create_stream (&line_stream, line_stream_cookie,
+                       &syshd, BACKEND_MEM,
+                       estream_functions_mem, O_RDWR, 1, 0);
+  if (err)
+    goto out;
+
+  {
+    size_t space_left = max_length;
+
+    line_size = 0;
+    for (;;)
+      {
+        if (max_length && (space_left == 1))
+          break;
+
+        err = peek_stream (stream, &data, &data_len);
+        if (err || (! data_len))
+          break;
+
+        if (data_len > (space_left - 1))
+          data_len = space_left - 1;
+
+        newline = memchr (data, '\n', data_len);
+        if (newline)
+          {
+            data_len = (newline - (char *) data) + 1;
+            err = _gpgrt_write (line_stream, data, data_len, NULL);
+            if (! err)
+              {
+                /* Not needed: space_left -= data_len */
+                line_size += data_len;
+                skip_stream (stream, data_len);
+                break; /* endless loop */
+              }
+          }
+        else
+          {
+            err = _gpgrt_write (line_stream, data, data_len, NULL);
+            if (! err)
+              {
+                space_left -= data_len;
+                line_size += data_len;
+                skip_stream (stream, data_len);
+              }
+          }
+        if (err)
+          break;
+      }
+  }
+  if (err)
+    goto out;
+
+  /* Complete line has been written to line_stream.  */
+
+  if ((max_length > 1) && (! line_size))
+    {
+      stream->intern->indicators.eof = 1;
+      goto out;
+    }
+
+  err = es_seek (line_stream, 0, SEEK_SET, NULL);
+  if (err)
+    goto out;
+
+  if (! *line)
+    {
+      line_new = mem_alloc (line_size + 1);
+      if (! line_new)
+	{
+	  err = -1;
+	  goto out;
+	}
+    }
+  else
+    line_new = *line;
+
+  err = _gpgrt_read (line_stream, line_new, line_size, NULL);
+  if (err)
+    goto out;
+
+  line_new[line_size] = '\0';
+
+  if (! *line)
+    *line = line_new;
+  if (line_length)
+    *line_length = line_size;
+
+ out:
+
+  if (line_stream)
+    do_close (line_stream, 0, 0);
+  else if (line_stream_cookie)
+    func_mem_destroy (line_stream_cookie);
+
+  if (err)
+    {
+      if (! *line)
+	mem_free (line_new);
+      stream->intern->indicators.err = 1;
+    }
+
+  return err;
+}
+
+
+/* Output function used by estream_format.  */
+static int
+print_writer (void *outfncarg, const char *buf, size_t buflen)
+{
+  estream_t stream = outfncarg;
+  size_t nwritten;
+  int rc;
+
+  nwritten = 0;
+  rc = es_writen (stream, buf, buflen, &nwritten);
+  stream->intern->print_ntotal += nwritten;
+  return rc;
+}
+
+
+/* The core of our printf function.  This is called in locked state. */
+static int
+do_print_stream (estream_t _GPGRT__RESTRICT stream,
+                 gpgrt_string_filter_t sf, void *sfvalue,
+                 const char *_GPGRT__RESTRICT format, va_list ap)
+{
+  int rc;
+
+  stream->intern->print_ntotal = 0;
+  rc = _gpgrt_estream_format (print_writer, stream, sf, sfvalue, format, ap);
+  if (rc)
+    return -1;
+  return (int)stream->intern->print_ntotal;
+}
+
+
+static int
+es_set_buffering (estream_t _GPGRT__RESTRICT stream,
+		  char *_GPGRT__RESTRICT buffer, int mode, size_t size)
+{
+  int err;
+
+  /* Flush or empty buffer depending on mode.  */
+  if (stream->flags.writing)
+    {
+      err = flush_stream (stream);
+      if (err)
+	goto out;
+    }
+  else
+    es_empty (stream);
+
+  stream->intern->indicators.eof = 0;
+
+  /* Free old buffer in case that was allocated by this function.  */
+  if (stream->intern->deallocate_buffer)
+    {
+      stream->intern->deallocate_buffer = 0;
+      mem_free (stream->buffer);
+      stream->buffer = NULL;
+    }
+
+  if (mode == _IONBF)
+    stream->buffer_size = 0;
+  else
+    {
+      void *buffer_new;
+
+      if (buffer)
+	buffer_new = buffer;
+      else
+	{
+          if (!size)
+            size = BUFSIZ;
+	  buffer_new = mem_alloc (size);
+	  if (! buffer_new)
+	    {
+	      err = -1;
+	      goto out;
+	    }
+	}
+
+      stream->buffer = buffer_new;
+      stream->buffer_size = size;
+      if (! buffer)
+	stream->intern->deallocate_buffer = 1;
+    }
+  stream->intern->strategy = mode;
+  err = 0;
+
+ out:
+
+  return err;
+}
+
+
+static gpgrt_off_t
+es_offset_calculate (estream_t stream)
+{
+  gpgrt_off_t offset;
+
+  offset = stream->intern->offset + stream->data_offset;
+  if (offset < stream->unread_data_len)
+    /* Offset undefined.  */
+    offset = 0;
+  else
+    offset -= stream->unread_data_len;
+
+  return offset;
+}
+
+
+static void
+es_opaque_ctrl (estream_t _GPGRT__RESTRICT stream,
+                void *_GPGRT__RESTRICT opaque_new,
+		void **_GPGRT__RESTRICT opaque_old)
+{
+  if (opaque_old)
+    *opaque_old = stream->intern->opaque;
+  if (opaque_new)
+    stream->intern->opaque = opaque_new;
+}
+
+
+/* API.  */
+
+estream_t
+_gpgrt_fopen (const char *_GPGRT__RESTRICT path,
+              const char *_GPGRT__RESTRICT mode)
+{
+  unsigned int modeflags, cmode, xmode;
+  int create_called;
+  estream_t stream;
+  void *cookie;
+  int err;
+  int fd;
+  es_syshd_t syshd;
+
+  stream = NULL;
+  cookie = NULL;
+  create_called = 0;
+
+  err = parse_mode (mode, &modeflags, &xmode, &cmode);
+  if (err)
+    goto out;
+
+  err = func_file_create (&cookie, &fd, path, modeflags, cmode);
+  if (err)
+    goto out;
+
+  syshd.type = ES_SYSHD_FD;
+  syshd.u.fd = fd;
+  create_called = 1;
+  err = create_stream (&stream, cookie, &syshd, BACKEND_FD,
+                       estream_functions_fd, modeflags, xmode, 0);
+  if (err)
+    goto out;
+
+  if (stream && path)
+    fname_set_internal (stream, path, 1);
+
+ out:
+
+  if (err && create_called)
+    (*estream_functions_fd.public.func_close) (cookie);
+
+  return stream;
+}
+
+
+
+/* Create a new estream object in memory.  If DATA is not NULL this
+   buffer will be used as the memory buffer; thus after this functions
+   returns with the success the the memory at DATA belongs to the new
+   estream.  The allocated length of DATA is given by DATA_LEN and its
+   used length by DATA_N.  Usually this is malloced buffer; if a
+   static buffer is provided, the caller must pass false for GROW and
+   provide a dummy function for FUNC_FREE.  FUNC_FREE and FUNC_REALLOC
+   allow the caller to provide custom functions for realloc and free
+   to be used by the new estream object.  Note that the realloc
+   function is also used for initial allocation.  If DATA is NULL a
+   buffer is internally allocated; either using internal function or
+   those provide by the caller.  It is an error to provide a realloc
+   function but no free function.  Providing only a free function is
+   allowed as long as GROW is false.  */
+estream_t
+_gpgrt_mopen (void *_GPGRT__RESTRICT data, size_t data_n, size_t data_len,
+              unsigned int grow,
+              func_realloc_t func_realloc, func_free_t func_free,
+              const char *_GPGRT__RESTRICT mode)
+{
+  int create_called = 0;
+  estream_t stream = NULL;
+  void *cookie = NULL;
+  unsigned int modeflags, xmode;
+  int err;
+  es_syshd_t syshd;
+
+  err = parse_mode (mode, &modeflags, &xmode, NULL);
+  if (err)
+    goto out;
+
+  err = func_mem_create (&cookie, data, data_n, data_len,
+                         BUFFER_BLOCK_SIZE, grow,
+                         func_realloc, func_free, modeflags, 0);
+  if (err)
+    goto out;
+
+  memset (&syshd, 0, sizeof syshd);
+  create_called = 1;
+  err = create_stream (&stream, cookie, &syshd, BACKEND_MEM,
+                       estream_functions_mem, modeflags, xmode, 0);
+
+ out:
+
+  if (err && create_called)
+    (*estream_functions_mem.public.func_close) (cookie);
+
+  return stream;
+}
+
+
+
+estream_t
+_gpgrt_fopenmem (size_t memlimit, const char *_GPGRT__RESTRICT mode)
+{
+  unsigned int modeflags, xmode;
+  estream_t stream = NULL;
+  void *cookie = NULL;
+  es_syshd_t syshd;
+
+  /* Memory streams are always read/write.  We use MODE only to get
+     the append flag.  */
+  if (parse_mode (mode, &modeflags, &xmode, NULL))
+    return NULL;
+  modeflags |= O_RDWR;
+
+  if (func_mem_create (&cookie, NULL, 0, 0,
+                       BUFFER_BLOCK_SIZE, 1,
+                       mem_realloc, mem_free, modeflags,
+                       memlimit))
+    return NULL;
+
+  memset (&syshd, 0, sizeof syshd);
+  if (create_stream (&stream, cookie, &syshd, BACKEND_MEM,
+                     estream_functions_mem, modeflags, xmode, 0))
+    (*estream_functions_mem.public.func_close) (cookie);
+
+  return stream;
+}
+
+
+/* This is the same as es_fopenmem but intializes the memory with a
+   copy of (DATA,DATALEN).  The stream is initially set to the
+   beginning.  If MEMLIMIT is not 0 but shorter than DATALEN it
+   DATALEN will be used as the value for MEMLIMIT.  */
+estream_t
+_gpgrt_fopenmem_init (size_t memlimit, const char *_GPGRT__RESTRICT mode,
+                      const void *data, size_t datalen)
+{
+  estream_t stream;
+
+  if (memlimit && memlimit < datalen)
+    memlimit = datalen;
+
+  stream = _gpgrt_fopenmem (memlimit, mode);
+  if (stream && data && datalen)
+    {
+      if (es_writen (stream, data, datalen, NULL))
+        {
+          int saveerrno = errno;
+          _gpgrt_fclose (stream);
+          stream = NULL;
+          _set_errno (saveerrno);
+        }
+      else
+        {
+          es_seek (stream, 0L, SEEK_SET, NULL);
+          stream->intern->indicators.eof = 0;
+          stream->intern->indicators.err = 0;
+        }
+    }
+  return stream;
+}
+
+
+
+estream_t
+_gpgrt_fopencookie (void *_GPGRT__RESTRICT cookie,
+                    const char *_GPGRT__RESTRICT mode,
+                    gpgrt_cookie_io_functions_t functions)
+{
+  unsigned int modeflags, xmode;
+  estream_t stream;
+  int err;
+  es_syshd_t syshd;
+  struct cookie_io_functions_s io_functions = { functions, NULL };
+
+  stream = NULL;
+  modeflags = 0;
+
+  err = parse_mode (mode, &modeflags, &xmode, NULL);
+  if (err)
+    goto out;
+
+  memset (&syshd, 0, sizeof syshd);
+  err = create_stream (&stream, cookie, &syshd, BACKEND_USER, io_functions,
+                       modeflags, xmode, 0);
+  if (err)
+    goto out;
+
+ out:
+  return stream;
+}
+
+
+
+static estream_t
+do_fdopen (int filedes, const char *mode, int no_close, int with_locked_list)
+{
+  int create_called = 0;
+  estream_t stream = NULL;
+  void *cookie = NULL;
+  unsigned int modeflags, xmode;
+  int err;
+  es_syshd_t syshd;
+
+  err = parse_mode (mode, &modeflags, &xmode, NULL);
+  if (err)
+    goto out;
+  if ((xmode & X_SYSOPEN))
+    {
+      /* Not allowed for fdopen.  */
+      _set_errno (EINVAL);
+      err = -1;
+      goto out;
+    }
+
+  err = func_fd_create (&cookie, filedes, modeflags, no_close);
+  if (err)
+    goto out;
+
+  syshd.type = ES_SYSHD_FD;
+  syshd.u.fd = filedes;
+  create_called = 1;
+  err = create_stream (&stream, cookie, &syshd,
+                       BACKEND_FD, estream_functions_fd,
+                       modeflags, xmode, with_locked_list);
+
+  if (!err && stream)
+    {
+      if ((modeflags & O_NONBLOCK))
+        err = stream->intern->func_ioctl (cookie, COOKIE_IOCTL_NONBLOCK,
+                                          "", NULL);
+    }
+
+ out:
+  if (err && create_called)
+    (*estream_functions_fd.public.func_close) (cookie);
+
+  return stream;
+}
+
+estream_t
+_gpgrt_fdopen (int filedes, const char *mode)
+{
+  return do_fdopen (filedes, mode, 0, 0);
+}
+
+/* A variant of es_fdopen which does not close FILEDES at the end.  */
+estream_t
+_gpgrt_fdopen_nc (int filedes, const char *mode)
+{
+  return do_fdopen (filedes, mode, 1, 0);
+}
+
+
+
+static estream_t
+do_fpopen (FILE *fp, const char *mode, int no_close, int with_locked_list)
+{
+  unsigned int modeflags, cmode, xmode;
+  int create_called = 0;
+  estream_t stream = NULL;
+  void *cookie = NULL;
+  int err;
+  es_syshd_t syshd;
+
+  err = parse_mode (mode, &modeflags, &xmode, &cmode);
+  if (err)
+    goto out;
+  if ((xmode & X_SYSOPEN))
+    {
+      /* Not allowed for fpopen.  */
+      _set_errno (EINVAL);
+      err = -1;
+      goto out;
+    }
+
+  if (fp)
+    fflush (fp);
+  err = func_fp_create (&cookie, fp, modeflags, no_close);
+  if (err)
+    goto out;
+
+  syshd.type = ES_SYSHD_FD;
+  syshd.u.fd = fp? fileno (fp): -1;
+  create_called = 1;
+  err = create_stream (&stream, cookie, &syshd,
+                       BACKEND_FP, estream_functions_fp,
+                       modeflags, xmode, with_locked_list);
+
+ out:
+  if (err && create_called)
+    (*estream_functions_fp.public.func_close) (cookie);
+
+  return stream;
+}
+
+
+/* Create an estream from the stdio stream FP.  This mechanism is
+   useful in case the stdio streams have special properties and may
+   not be mixed with fd based functions.  This is for example the case
+   under Windows where the 3 standard streams are associated with the
+   console whereas a duped and fd-opened stream of one of this stream
+   won't be associated with the console.  As this messes things up it
+   is easier to keep on using the standard I/O stream as a backend for
+   estream. */
+estream_t
+_gpgrt_fpopen (FILE *fp, const char *mode)
+{
+  return do_fpopen (fp, mode, 0, 0);
+}
+
+
+/* Same as es_fpopen but does not close  FP at the end.  */
+estream_t
+_gpgrt_fpopen_nc (FILE *fp, const char *mode)
+{
+  return do_fpopen (fp, mode, 1, 0);
+}
+
+
+
+#ifdef HAVE_W32_SYSTEM
+estream_t
+do_w32open (HANDLE hd, const char *mode,
+            int no_close, int with_locked_list)
+{
+  unsigned int modeflags, cmode, xmode;
+  int create_called = 0;
+  estream_t stream = NULL;
+  void *cookie = NULL;
+  int err;
+  es_syshd_t syshd;
+
+  /* For obvious reasons we ignore sysmode here.  */
+  err = parse_mode (mode, &modeflags, &xmode, &cmode);
+  if (err)
+    goto leave;
+
+  /* If we are pollable we create the function cookie with syscall
+   * clamp disabled.  This is because functions are called from
+   * separatre reader and writer threads in w32-stream.  */
+  err = func_w32_create (&cookie, hd, modeflags,
+                         no_close, !!(xmode & X_POLLABLE));
+  if (err)
+    goto leave;
+
+  syshd.type = ES_SYSHD_HANDLE;
+  syshd.u.handle = hd;
+  create_called = 1;
+  err = create_stream (&stream, cookie, &syshd,
+                       BACKEND_W32, estream_functions_w32,
+                       modeflags, xmode, with_locked_list);
+
+ leave:
+  if (err && create_called)
+    (*estream_functions_w32.public.func_close) (cookie);
+
+  return stream;
+}
+#endif /*HAVE_W32_SYSTEM*/
+
+static estream_t
+do_sysopen (es_syshd_t *syshd, const char *mode, int no_close)
+{
+  estream_t stream;
+
+  switch (syshd->type)
+    {
+    case ES_SYSHD_FD:
+    case ES_SYSHD_SOCK:
+      stream = do_fdopen (syshd->u.fd, mode, no_close, 0);
+      break;
+
+#ifdef HAVE_W32_SYSTEM
+    case ES_SYSHD_HANDLE:
+      stream = do_w32open (syshd->u.handle, mode, no_close, 0);
+      break;
+#endif
+
+    /* FIXME: Support RVIDs under Wince?  */
+
+    default:
+      _set_errno (EINVAL);
+      stream = NULL;
+    }
+  return stream;
+}
+
+/* On POSIX systems this function is an alias for es_fdopen.  Under
+   Windows it uses the bare W32 API and thus a HANDLE instead of a
+   file descriptor.  */
+estream_t
+_gpgrt_sysopen (es_syshd_t *syshd, const char *mode)
+{
+  return do_sysopen (syshd, mode, 0);
+}
+
+/* Same as es_sysopen but the handle/fd will not be closed by
+   es_fclose.  */
+estream_t
+_gpgrt_sysopen_nc (es_syshd_t *syshd, const char *mode)
+{
+  return do_sysopen (syshd, mode, 1);
+}
+
+
+
+/* Set custom standard descriptors to be used for stdin, stdout and
+   stderr.  This function needs to be called before any of the
+   standard streams are accessed.  This internal version uses a double
+   dash inside its name. */
+void
+_gpgrt__set_std_fd (int no, int fd)
+{
+  /* fprintf (stderr, "es_set_std_fd(%d, %d)\n", no, fd); */
+  lock_list ();
+  if (no >= 0 && no < 3 && !custom_std_fds_valid[no])
+    {
+      custom_std_fds[no] = fd;
+      custom_std_fds_valid[no] = 1;
+    }
+  unlock_list ();
+}
+
+
+/* Return the stream used for stdin, stdout or stderr.
+   This internal version uses a double dash inside its name. */
+estream_t
+_gpgrt__get_std_stream (int fd)
+{
+  estream_list_t list_obj;
+  estream_t stream = NULL;
+
+  fd %= 3; /* We only allow 0, 1 or 2 but we don't want to return an error. */
+
+  lock_list ();
+
+  for (list_obj = estream_list; list_obj; list_obj = list_obj->next)
+    if (list_obj->stream && list_obj->stream->intern->is_stdstream
+        && list_obj->stream->intern->stdstream_fd == fd)
+      {
+	stream = list_obj->stream;
+	break;
+      }
+  if (!stream)
+    {
+      /* Standard stream not yet created.  We first try to create them
+         from registered file descriptors.  */
+      if (!fd && custom_std_fds_valid[0])
+        stream = do_fdopen (custom_std_fds[0], "r", 1, 1);
+      else if (fd == 1 && custom_std_fds_valid[1])
+        stream = do_fdopen (custom_std_fds[1], "a", 1, 1);
+      else if (custom_std_fds_valid[2])
+        stream = do_fdopen (custom_std_fds[2], "a", 1, 1);
+
+      if (!stream)
+        {
+          /* Second try is to use the standard C streams.  */
+          if (!fd)
+            stream = do_fpopen (stdin, "r", 1, 1);
+          else if (fd == 1)
+            stream = do_fpopen (stdout, "a", 1, 1);
+          else
+            stream = do_fpopen (stderr, "a", 1, 1);
+        }
+
+      if (!stream)
+        {
+          /* Last try: Create a bit bucket.  */
+          stream = do_fpopen (NULL, fd? "a":"r", 0, 1);
+          if (!stream)
+            {
+              fprintf (stderr, "fatal: error creating a dummy estream"
+                       " for %d: %s\n", fd, strerror (errno));
+              _gpgrt_abort();
+            }
+        }
+
+      stream->intern->is_stdstream = 1;
+      stream->intern->stdstream_fd = fd;
+      if (fd == 2)
+        es_set_buffering (stream, NULL, _IOLBF, 0);
+      fname_set_internal (stream,
+                          fd == 0? "[stdin]" :
+                          fd == 1? "[stdout]" : "[stderr]", 0);
+    }
+
+  unlock_list ();
+  return stream;
+}
+
+/* Note: A "samethread" keyword given in "mode" is ignored and the
+ * value used by STREAM is used instead.  Note that this function is
+ * the reasons why some of the init and deinit code is split up into
+ * several functions.  */
+estream_t
+_gpgrt_freopen (const char *_GPGRT__RESTRICT path,
+                const char *_GPGRT__RESTRICT mode,
+                estream_t _GPGRT__RESTRICT stream)
+{
+  int err;
+
+  if (path)
+    {
+      unsigned int modeflags, cmode, xmode, dummy;
+      int create_called;
+      void *cookie;
+      int fd;
+      es_syshd_t syshd;
+
+      cookie = NULL;
+      create_called = 0;
+
+      xmode = stream->intern->samethread ? X_SAMETHREAD : 0;
+
+      lock_stream (stream);
+
+      deinit_stream_obj (stream);
+
+      err = parse_mode (mode, &modeflags, &dummy, &cmode);
+      if (err)
+	goto leave;
+      (void)dummy;
+
+      err = func_file_create (&cookie, &fd, path, modeflags, cmode);
+      if (err)
+	goto leave;
+
+      syshd.type = ES_SYSHD_FD;
+      syshd.u.fd = fd;
+      create_called = 1;
+      init_stream_obj (stream, cookie, &syshd, BACKEND_FD,
+                       estream_functions_fd, modeflags, xmode);
+
+    leave:
+
+      if (err)
+	{
+	  if (create_called)
+	    func_fd_destroy (cookie);
+
+	  do_close (stream, 0, 0);
+	  stream = NULL;
+	}
+      else
+        {
+          if (path)
+            fname_set_internal (stream, path, 1);
+          unlock_stream (stream);
+        }
+    }
+  else
+    {
+      /* FIXME?  We don't support re-opening at the moment.  */
+      _set_errno (EINVAL);
+      deinit_stream_obj (stream);
+      do_close (stream, 0, 0);
+      stream = NULL;
+    }
+
+  return stream;
+}
+
+
+int
+_gpgrt_fclose (estream_t stream)
+{
+  int err;
+
+  err = do_close (stream, 0, 0);
+
+  return err;
+}
+
+
+/* gpgrt_fcancel does the same as gpgrt_fclose but tries to avoid
+ * flushing out any data still held in internal buffers.  It may or
+ * may not remove a new file created for that stream by the open
+ * function.  */
+int
+_gpgrt_fcancel (estream_t stream)
+{
+  int err;
+
+  err = do_close (stream, 1, 0);
+
+  return err;
+}
+
+
+/* This is a special version of es_fclose which can be used with
+   es_fopenmem to return the memory buffer.  This is feature is useful
+   to write to a memory buffer using estream.  Note that the function
+   does not close the stream if the stream does not support snatching
+   the buffer.  On error NULL is stored at R_BUFFER.  Note that if no
+   write operation has happened, NULL may also be stored at BUFFER on
+   success.  The caller needs to release the returned memory using
+   gpgrt_free.  */
+int
+_gpgrt_fclose_snatch (estream_t stream, void **r_buffer, size_t *r_buflen)
+{
+  int err;
+
+  /* Note: There is no need to lock the stream in a close call.  The
+     object will be destroyed after the close and thus any other
+     contender for the lock would work on a closed stream.  */
+
+  if (r_buffer)
+    {
+      cookie_ioctl_function_t func_ioctl = stream->intern->func_ioctl;
+      size_t buflen;
+
+      *r_buffer = NULL;
+
+      if (!func_ioctl)
+        {
+          _set_errno (EOPNOTSUPP);
+          err = -1;
+          goto leave;
+        }
+
+      if (stream->flags.writing)
+        {
+          err = flush_stream (stream);
+          if (err)
+            goto leave;
+          stream->flags.writing = 0;
+        }
+
+      err = func_ioctl (stream->intern->cookie, COOKIE_IOCTL_SNATCH_BUFFER,
+                        r_buffer, &buflen);
+      if (err)
+        goto leave;
+      if (r_buflen)
+        *r_buflen = buflen;
+    }
+
+  err = do_close (stream, 0, 0);
+
+ leave:
+  if (err && r_buffer)
+    {
+      mem_free (*r_buffer);
+      *r_buffer = NULL;
+    }
+  return err;
+}
+
+
+/* Register or unregister a close notification function for STREAM.
+   FNC is the function to call and FNC_VALUE the value passed as
+   second argument.  To register the notification the value for MODE
+   must be 1.  If mode is 0 the function tries to remove or disable an
+   already registered notification; for this to work the value of FNC
+   and FNC_VALUE must be the same as with the registration and
+   FNC_VALUE must be a unique value.  No error will be returned if
+   MODE is 0.
+
+   FIXME: I think the next comment is not anymore correct:
+   Unregister should only be used in the error case because it may not
+   be able to remove memory internally allocated for the onclose
+   handler.
+
+   FIXME: Unregister is not thread safe.
+
+   The notification will be called right before the stream is
+   closed. If gpgrt_fcancel is used, the cancellation of internal
+   buffers is done before the notifications.  The notification handler
+   may not call any estream function for STREAM, neither direct nor
+   indirectly. */
+int
+_gpgrt_onclose (estream_t stream, int mode,
+                void (*fnc) (estream_t, void*), void *fnc_value)
+{
+  int err;
+
+  lock_stream (stream);
+  err = do_onclose (stream, mode, fnc, fnc_value);
+  unlock_stream (stream);
+
+  return err;
+}
+
+
+int
+_gpgrt_fileno_unlocked (estream_t stream)
+{
+  es_syshd_t syshd;
+
+  if (_gpgrt_syshd_unlocked (stream, &syshd))
+    return -1;
+  switch (syshd.type)
+    {
+    case ES_SYSHD_FD:   return syshd.u.fd;
+    case ES_SYSHD_SOCK: return syshd.u.sock;
+    default:
+      _set_errno (EINVAL);
+      return -1;
+    }
+}
+
+
+/* Return the handle of a stream which has been opened by es_sysopen.
+   The caller needs to pass a structure which will be filled with the
+   sys handle.  Return 0 on success or true on error and sets errno.
+   This is the unlocked version.  */
+int
+_gpgrt_syshd_unlocked (estream_t stream, es_syshd_t *syshd)
+{
+  if (!stream || !syshd || stream->intern->syshd.type == ES_SYSHD_NONE)
+    {
+      if (syshd)
+        syshd->type = ES_SYSHD_NONE;
+      _set_errno (EINVAL);
+      return -1;
+    }
+
+  *syshd = stream->intern->syshd;
+  return 0;
+}
+
+
+void
+_gpgrt_flockfile (estream_t stream)
+{
+  lock_stream (stream);
+}
+
+
+int
+_gpgrt_ftrylockfile (estream_t stream)
+{
+  return trylock_stream (stream);
+}
+
+
+void
+_gpgrt_funlockfile (estream_t stream)
+{
+  unlock_stream (stream);
+}
+
+
+int
+_gpgrt_fileno (estream_t stream)
+{
+  int ret;
+
+  lock_stream (stream);
+  ret = _gpgrt_fileno_unlocked (stream);
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+/* Return the handle of a stream which has been opened by es_sysopen.
+   The caller needs to pass a structure which will be filled with the
+   sys handle.  Return 0 on success or true on error and sets errno.
+   This is the unlocked version.  */
+int
+_gpgrt_syshd (estream_t stream, es_syshd_t *syshd)
+{
+  int ret;
+
+  lock_stream (stream);
+  ret = _gpgrt_syshd_unlocked (stream, syshd);
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+int
+_gpgrt__pending_unlocked (estream_t stream)
+{
+  return check_pending (stream);
+}
+
+
+/* Return true if there is at least one byte pending for read on
+   STREAM.  This does only work if the backend supports checking for
+   pending bytes and is thus mostly useful with cookie based backends.
+
+   Note that if this function is used with cookie based functions, the
+   read cookie may be called with 0 for the SIZE argument.  If bytes
+   are pending the function is expected to return -1 in this case and
+   thus deviates from the standard behavior of read(2).   */
+int
+_gpgrt__pending (estream_t stream)
+{
+  int ret;
+
+  lock_stream (stream);
+  ret = _gpgrt__pending_unlocked (stream);
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+int
+_gpgrt_feof_unlocked (estream_t stream)
+{
+  return stream->intern->indicators.eof;
+}
+
+
+int
+_gpgrt_feof (estream_t stream)
+{
+  int ret;
+
+  lock_stream (stream);
+  ret = _gpgrt_feof_unlocked (stream);
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+int
+_gpgrt_ferror_unlocked (estream_t stream)
+{
+  return stream->intern->indicators.err;
+}
+
+
+int
+_gpgrt_ferror (estream_t stream)
+{
+  int ret;
+
+  lock_stream (stream);
+  ret = _gpgrt_ferror_unlocked (stream);
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+void
+_gpgrt_clearerr_unlocked (estream_t stream)
+{
+  stream->intern->indicators.eof = 0;
+  stream->intern->indicators.err = 0;
+  /* We do not reset the HUP indicator because there is no way to
+     get out of this state.  */
+}
+
+
+void
+_gpgrt_clearerr (estream_t stream)
+{
+  lock_stream (stream);
+  _gpgrt_clearerr_unlocked (stream);
+  unlock_stream (stream);
+}
+
+
+static int
+do_fflush (estream_t stream)
+{
+  int err;
+
+  if (stream->flags.writing)
+    err = flush_stream (stream);
+  else
+    {
+      es_empty (stream);
+      err = 0;
+    }
+
+  return err;
+}
+
+
+int
+_gpgrt_fflush (estream_t stream)
+{
+  int err;
+
+  if (stream)
+    {
+      lock_stream (stream);
+      err = do_fflush (stream);
+      unlock_stream (stream);
+    }
+  else
+    {
+      estream_list_t item;
+
+      err = 0;
+      lock_list ();
+      for (item = estream_list; item; item = item->next)
+        if (item->stream)
+          {
+            lock_stream (item->stream);
+            err |= do_fflush (item->stream);
+            unlock_stream (item->stream);
+          }
+      unlock_list ();
+    }
+  return err ? EOF : 0;
+}
+
+
+int
+_gpgrt_fseek (estream_t stream, long int offset, int whence)
+{
+  int err;
+
+  lock_stream (stream);
+  err = es_seek (stream, offset, whence, NULL);
+  unlock_stream (stream);
+
+  return err;
+}
+
+
+int
+_gpgrt_fseeko (estream_t stream, gpgrt_off_t offset, int whence)
+{
+  int err;
+
+  lock_stream (stream);
+  err = es_seek (stream, offset, whence, NULL);
+  unlock_stream (stream);
+
+  return err;
+}
+
+
+long int
+_gpgrt_ftell (estream_t stream)
+{
+  long int ret;
+
+  lock_stream (stream);
+  ret = es_offset_calculate (stream);
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+gpgrt_off_t
+_gpgrt_ftello (estream_t stream)
+{
+  gpgrt_off_t ret = -1;
+
+  lock_stream (stream);
+  ret = es_offset_calculate (stream);
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+void
+_gpgrt_rewind (estream_t stream)
+{
+  lock_stream (stream);
+  es_seek (stream, 0L, SEEK_SET, NULL);
+  /* Note that es_seek already cleared the EOF flag.  */
+  stream->intern->indicators.err = 0;
+  unlock_stream (stream);
+}
+
+
+int
+_gpgrt_ftruncate (estream_t stream, gpgrt_off_t length)
+{
+  cookie_ioctl_function_t func_ioctl;
+  int ret;
+
+  lock_stream (stream);
+  func_ioctl = stream->intern->func_ioctl;
+  if (!func_ioctl)
+    {
+      _set_errno (EOPNOTSUPP);
+      ret = -1;
+    }
+  else
+    {
+      ret = func_ioctl (stream->intern->cookie, COOKIE_IOCTL_TRUNCATE,
+                        &length, NULL);
+    }
+  unlock_stream (stream);
+  return ret;
+}
+
+
+int
+_gpgrt__getc_underflow (estream_t stream)
+{
+  int err;
+  unsigned char c;
+  size_t bytes_read;
+
+  err = es_readn (stream, &c, 1, &bytes_read);
+
+  return (err || (! bytes_read)) ? EOF : c;
+}
+
+
+int
+_gpgrt__putc_overflow (int c, estream_t stream)
+{
+  unsigned char d = c;
+  int err;
+
+  err = es_writen (stream, &d, 1, NULL);
+
+  return err ? EOF : c;
+}
+
+
+int
+_gpgrt_fgetc (estream_t stream)
+{
+  int ret;
+
+  lock_stream (stream);
+  ret = _gpgrt_getc_unlocked (stream);
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+int
+_gpgrt_fputc (int c, estream_t stream)
+{
+  int ret;
+
+  lock_stream (stream);
+  ret = _gpgrt_putc_unlocked (c, stream);
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+int
+_gpgrt_ungetc (int c, estream_t stream)
+{
+  unsigned char data = (unsigned char) c;
+  size_t data_unread;
+
+  lock_stream (stream);
+  es_unreadn (stream, &data, 1, &data_unread);
+  unlock_stream (stream);
+
+  return data_unread ? c : EOF;
+}
+
+
+int
+_gpgrt_read (estream_t _GPGRT__RESTRICT stream,
+             void *_GPGRT__RESTRICT buffer, size_t bytes_to_read,
+             size_t *_GPGRT__RESTRICT bytes_read)
+{
+  int err;
+
+  if (bytes_to_read)
+    {
+      lock_stream (stream);
+      err = es_readn (stream, buffer, bytes_to_read, bytes_read);
+      unlock_stream (stream);
+    }
+  else
+    err = 0;
+
+  return err;
+}
+
+
+int
+_gpgrt_write (estream_t _GPGRT__RESTRICT stream,
+              const void *_GPGRT__RESTRICT buffer, size_t bytes_to_write,
+              size_t *_GPGRT__RESTRICT bytes_written)
+{
+  int err;
+
+  if (bytes_to_write)
+    {
+      lock_stream (stream);
+      err = es_writen (stream, buffer, bytes_to_write, bytes_written);
+      unlock_stream (stream);
+    }
+  else
+    err = 0;
+
+  return err;
+}
+
+
+size_t
+_gpgrt_fread (void *_GPGRT__RESTRICT ptr, size_t size, size_t nitems,
+              estream_t _GPGRT__RESTRICT stream)
+{
+  size_t ret, bytes;
+
+  if (size && nitems)
+    {
+      lock_stream (stream);
+      es_readn (stream, ptr, size * nitems, &bytes);
+      unlock_stream (stream);
+
+      ret = bytes / size;
+    }
+  else
+    ret = 0;
+
+  return ret;
+}
+
+
+size_t
+_gpgrt_fwrite (const void *_GPGRT__RESTRICT ptr, size_t size, size_t nitems,
+               estream_t _GPGRT__RESTRICT stream)
+{
+  size_t ret, bytes;
+
+  if (size && nitems)
+    {
+      lock_stream (stream);
+      es_writen (stream, ptr, size * nitems, &bytes);
+      unlock_stream (stream);
+
+      ret = bytes / size;
+    }
+  else
+    ret = 0;
+
+  return ret;
+}
+
+
+char *
+_gpgrt_fgets (char *_GPGRT__RESTRICT buffer, int length,
+              estream_t _GPGRT__RESTRICT stream)
+{
+  unsigned char *s = (unsigned char*)buffer;
+  int c;
+
+  if (!length)
+    return NULL;
+
+  c = EOF;
+  lock_stream (stream);
+  while (length > 1 && (c = _gpgrt_getc_unlocked (stream)) != EOF && c != '\n')
+    {
+      *s++ = c;
+      length--;
+    }
+  unlock_stream (stream);
+
+  if (c == EOF && s == (unsigned char*)buffer)
+    return NULL; /* Nothing read.  */
+
+  if (c != EOF && length > 1)
+    *s++ = c;
+
+  *s = 0;
+  return buffer;
+}
+
+
+int
+_gpgrt_fputs_unlocked (const char *_GPGRT__RESTRICT s,
+                       estream_t _GPGRT__RESTRICT stream)
+{
+  size_t length;
+  int err;
+
+  length = strlen (s);
+  err = es_writen (stream, s, length, NULL);
+  return err ? EOF : 0;
+}
+
+int
+_gpgrt_fputs (const char *_GPGRT__RESTRICT s, estream_t _GPGRT__RESTRICT stream)
+{
+  size_t length;
+  int err;
+
+  length = strlen (s);
+  lock_stream (stream);
+  err = es_writen (stream, s, length, NULL);
+  unlock_stream (stream);
+
+  return err ? EOF : 0;
+}
+
+
+gpgrt_ssize_t
+_gpgrt_getline (char *_GPGRT__RESTRICT *_GPGRT__RESTRICT lineptr,
+                size_t *_GPGRT__RESTRICT n, estream_t _GPGRT__RESTRICT stream)
+{
+  char *line = NULL;
+  size_t line_n = 0;
+  int err;
+
+  lock_stream (stream);
+  err = doreadline (stream, 0, &line, &line_n);
+  unlock_stream (stream);
+  if (err)
+    goto out;
+
+  if (*n)
+    {
+      /* Caller wants us to use his buffer.  */
+
+      if (*n < (line_n + 1))
+	{
+	  /* Provided buffer is too small -> resize.  */
+
+	  void *p;
+
+	  p = mem_realloc (*lineptr, line_n + 1);
+	  if (! p)
+	    err = -1;
+	  else
+	    {
+	      if (*lineptr != p)
+		*lineptr = p;
+	    }
+	}
+
+      if (! err)
+	{
+	  memcpy (*lineptr, line, line_n + 1);
+	  if (*n != line_n)
+	    *n = line_n;
+	}
+      mem_free (line);
+    }
+  else
+    {
+      /* Caller wants new buffers.  */
+      *lineptr = line;
+      *n = line_n;
+    }
+
+ out:
+
+  return err ? err : (gpgrt_ssize_t)line_n;
+}
+
+
+
+/* Same as fgets() but if the provided buffer is too short a larger
+   one will be allocated.  This is similar to getline. A line is
+   considered a byte stream ending in a LF.
+
+   If MAX_LENGTH is not NULL, it shall point to a value with the
+   maximum allowed allocation.
+
+   Returns the length of the line. EOF is indicated by a line of
+   length zero. A truncated line is indicated my setting the value at
+   MAX_LENGTH to 0.  If the returned value is less then 0 not enough
+   memory was available or another error occurred; ERRNO is then set
+   accordingly.
+
+   If a line has been truncated, the file pointer is moved forward to
+   the end of the line so that the next read starts with the next
+   line.  Note that MAX_LENGTH must be re-initialized in this case.
+
+   The caller initially needs to provide the address of a variable,
+   initialized to NULL, at ADDR_OF_BUFFER and don't change this value
+   anymore with the following invocations.  LENGTH_OF_BUFFER should be
+   the address of a variable, initialized to 0, which is also
+   maintained by this function.  Thus, both paramaters should be
+   considered the state of this function.
+
+   Note: The returned buffer is allocated with enough extra space to
+   allow the caller to append a CR,LF,Nul.  The buffer should be
+   released using gpgrt_free.
+ */
+gpgrt_ssize_t
+_gpgrt_read_line (estream_t stream,
+                  char **addr_of_buffer, size_t *length_of_buffer,
+                  size_t *max_length)
+{
+  int c;
+  char  *buffer = *addr_of_buffer;
+  size_t length = *length_of_buffer;
+  size_t nbytes = 0;
+  size_t maxlen = max_length? *max_length : 0;
+  char *p;
+
+  if (!buffer)
+    {
+      /* No buffer given - allocate a new one. */
+      length = 256;
+      buffer = mem_alloc (length);
+      *addr_of_buffer = buffer;
+      if (!buffer)
+        {
+          *length_of_buffer = 0;
+          if (max_length)
+            *max_length = 0;
+          return -1;
+        }
+      *length_of_buffer = length;
+    }
+
+  if (length < 4)
+    {
+      /* This should never happen. If it does, the function has been
+         called with wrong arguments. */
+      _set_errno (EINVAL);
+      return -1;
+    }
+  length -= 3; /* Reserve 3 bytes for CR,LF,EOL. */
+
+  lock_stream (stream);
+  p = buffer;
+  while  ((c = _gpgrt_getc_unlocked (stream)) != EOF)
+    {
+      if (nbytes == length)
+        {
+          /* Enlarge the buffer. */
+          if (maxlen && length > maxlen)
+            {
+              /* We are beyond our limit: Skip the rest of the line. */
+              while (c != '\n' && (c=_gpgrt_getc_unlocked (stream)) != EOF)
+                ;
+              *p++ = '\n'; /* Always append a LF (we reserved some space). */
+              nbytes++;
+              if (max_length)
+                *max_length = 0; /* Indicate truncation. */
+              break; /* the while loop. */
+            }
+          length += 3; /* Adjust for the reserved bytes. */
+          length += length < 1024? 256 : 1024;
+          *addr_of_buffer = mem_realloc (buffer, length);
+          if (!*addr_of_buffer)
+            {
+              int save_errno = errno;
+              mem_free (buffer);
+              *length_of_buffer = 0;
+              if (max_length)
+                *max_length = 0;
+              unlock_stream (stream);
+              _set_errno (save_errno);
+              return -1;
+            }
+          buffer = *addr_of_buffer;
+          *length_of_buffer = length;
+          length -= 3;
+          p = buffer + nbytes;
+	}
+      *p++ = c;
+      nbytes++;
+      if (c == '\n')
+        break;
+    }
+  *p = 0; /* Make sure the line is a string. */
+  unlock_stream (stream);
+
+  return nbytes;
+}
+
+/* Wrapper around free() to match the memory allocation system used by
+   estream.  Should be used for all buffers returned to the caller by
+   libestream.  If a custom allocation handler has been set with
+   gpgrt_set_alloc_func that register function may be used
+   instead.  This function has been moved to init.c.  */
+/* void */
+/* _gpgrt_free (void *a) */
+/* { */
+/*   mem_free (a); */
+/* } */
+
+
+int
+_gpgrt_vfprintf_unlocked (estream_t _GPGRT__RESTRICT stream,
+                          gpgrt_string_filter_t sf, void *sfvalue,
+                          const char *_GPGRT__RESTRICT format,
+                          va_list ap)
+{
+  return do_print_stream (stream, sf, sfvalue, format, ap);
+}
+
+
+int
+_gpgrt_vfprintf (estream_t _GPGRT__RESTRICT stream,
+                 gpgrt_string_filter_t sf, void *sfvalue,
+                 const char *_GPGRT__RESTRICT format,
+                 va_list ap)
+{
+  int ret;
+
+  lock_stream (stream);
+  ret = do_print_stream (stream, sf, sfvalue, format, ap);
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+int
+_gpgrt_fprintf_unlocked (estream_t _GPGRT__RESTRICT stream,
+                         const char *_GPGRT__RESTRICT format, ...)
+{
+  int ret;
+
+  va_list ap;
+  va_start (ap, format);
+  ret = do_print_stream (stream, NULL, NULL, format, ap);
+  va_end (ap);
+
+  return ret;
+}
+
+
+int
+_gpgrt_fprintf (estream_t _GPGRT__RESTRICT stream,
+                const char *_GPGRT__RESTRICT format, ...)
+{
+  int ret;
+
+  va_list ap;
+  va_start (ap, format);
+  lock_stream (stream);
+  ret = do_print_stream (stream, NULL, NULL, format, ap);
+  unlock_stream (stream);
+  va_end (ap);
+
+  return ret;
+}
+
+
+static int
+tmpfd (void)
+{
+#ifdef HAVE_W32_SYSTEM
+  int attempts, n;
+#ifdef HAVE_W32CE_SYSTEM
+  wchar_t buffer[MAX_PATH+9+12+1];
+# define mystrlen(a) wcslen (a)
+  wchar_t *name, *p;
+#else
+  char buffer[MAX_PATH+9+12+1];
+# define mystrlen(a) strlen (a)
+  char *name, *p;
+#endif
+  HANDLE file;
+  int pid = GetCurrentProcessId ();
+  unsigned int value;
+  int i;
+
+  n = GetTempPath (MAX_PATH+1, buffer);
+  if (!n || n > MAX_PATH || mystrlen (buffer) > MAX_PATH)
+    {
+      _set_errno (ENOENT);
+      return -1;
+    }
+  p = buffer + mystrlen (buffer);
+#ifdef HAVE_W32CE_SYSTEM
+  wcscpy (p, L"_estream");
+#else
+  strcpy (p, "_estream");
+#endif
+  p += 8;
+  /* We try to create the directory but don't care about an error as
+     it may already exist and the CreateFile would throw an error
+     anyway.  */
+  CreateDirectory (buffer, NULL);
+  *p++ = '\\';
+  name = p;
+  for (attempts=0; attempts < 10; attempts++)
+    {
+      p = name;
+      value = (GetTickCount () ^ ((pid<<16) & 0xffff0000));
+      for (i=0; i < 8; i++)
+        {
+          *p++ = tohex (((value >> 28) & 0x0f));
+          value <<= 4;
+        }
+#ifdef HAVE_W32CE_SYSTEM
+      wcscpy (p, L".tmp");
+#else
+      strcpy (p, ".tmp");
+#endif
+      file = CreateFile (buffer,
+                         GENERIC_READ | GENERIC_WRITE,
+                         0,
+                         NULL,
+                         CREATE_NEW,
+                         FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE,
+                         NULL);
+      if (file != INVALID_HANDLE_VALUE)
+        {
+#ifdef HAVE_W32CE_SYSTEM
+          int fd = (int)file;
+#else
+          int fd = _open_osfhandle ((intptr_t)file, 0);
+          if (fd == -1)
+            {
+              CloseHandle (file);
+              return -1;
+            }
+#endif
+          return fd;
+        }
+      Sleep (1); /* One ms as this is the granularity of GetTickCount.  */
+    }
+  _set_errno (ENOENT);
+  return -1;
+#else /*!HAVE_W32_SYSTEM*/
+  FILE *fp;
+  int fp_fd;
+  int fd;
+
+  fp = NULL;
+  fd = -1;
+
+  fp = tmpfile ();
+  if (! fp)
+    goto out;
+
+  fp_fd = fileno (fp);
+  fd = dup (fp_fd);
+
+ out:
+
+  if (fp)
+    fclose (fp);
+
+  return fd;
+#endif /*!HAVE_W32_SYSTEM*/
+}
+
+estream_t
+_gpgrt_tmpfile (void)
+{
+  unsigned int modeflags;
+  int create_called = 0;
+  estream_t stream = NULL;
+  void *cookie = NULL;
+  int err;
+  int fd;
+  es_syshd_t syshd;
+
+  modeflags = O_RDWR | O_TRUNC | O_CREAT;
+
+  fd = tmpfd ();
+  if (fd == -1)
+    {
+      err = -1;
+      goto out;
+    }
+
+  err = func_fd_create (&cookie, fd, modeflags, 0);
+  if (err)
+    goto out;
+
+  syshd.type = ES_SYSHD_FD;
+  syshd.u.fd = fd;
+  create_called = 1;
+  err = create_stream (&stream, cookie, &syshd,
+                       BACKEND_FD, estream_functions_fd,
+                       modeflags, 0, 0);
+
+ out:
+  if (err)
+    {
+      if (create_called)
+	func_fd_destroy (cookie);
+      else if (fd != -1)
+	close (fd);
+      stream = NULL;
+    }
+
+  return stream;
+}
+
+
+int
+_gpgrt_setvbuf (estream_t _GPGRT__RESTRICT stream,
+                char *_GPGRT__RESTRICT buf, int type, size_t size)
+{
+  int err;
+
+  if ((type == _IOFBF || type == _IOLBF || type == _IONBF)
+      && (!buf || size || type == _IONBF))
+    {
+      lock_stream (stream);
+      err = es_set_buffering (stream, buf, type, size);
+      unlock_stream (stream);
+    }
+  else
+    {
+      _set_errno (EINVAL);
+      err = -1;
+    }
+
+  return err;
+}
+
+
+/* Put a stream into binary mode.  This is only needed for the
+   standard streams if they are to be used in a binary way.  On Unix
+   systems it is never needed but MSDOS based systems require such a
+   call.  It needs to be called before any I/O is done on STREAM.  */
+void
+_gpgrt_set_binary (estream_t stream)
+{
+  lock_stream (stream);
+  if (!(stream->intern->modeflags & O_BINARY))
+    {
+      stream->intern->modeflags |= O_BINARY;
+#ifdef HAVE_DOSISH_SYSTEM
+      if (stream->intern->func_read == func_fd_read)
+        {
+          estream_cookie_fd_t fd_cookie = stream->intern->cookie;
+
+          if (!IS_INVALID_FD (fd_cookie->fd))
+            setmode (fd_cookie->fd, O_BINARY);
+        }
+      else if (stream->intern->func_read == func_fp_read)
+        {
+          estream_cookie_fp_t fp_cookie = stream->intern->cookie;
+
+          if (fp_cookie->fp)
+            setmode (fileno (fp_cookie->fp), O_BINARY);
+        }
+#endif
+    }
+  unlock_stream (stream);
+}
+
+
+/* Set non-blocking mode for STREAM.  Use true for ONOFF to enable and
+   false to disable non-blocking mode.  Returns 0 on success or -1 on
+   error and sets ERRNO.  Note that not all backends support
+   non-blocking mode.
+
+   In non-blocking mode a system call will not block but return an
+   error and set errno to EAGAIN.  The estream API always uses EAGAIN
+   and not EWOULDBLOCK.  If a buffered function like es_fgetc() or
+   es_fgets() returns an error and both, feof() and ferror() return
+   false the caller may assume that the error condition was EAGAIN.
+
+   Switching back from non-blocking to blocking may raise problems
+   with buffering, thus care should be taken.  Although read+write
+   sockets are supported in theory, switching from write to read may
+   result into problems because estream may first flush the write
+   buffers and there is no way to handle that non-blocking (EAGAIN)
+   case.  Explicit flushing should thus be done before before
+   switching to read.  */
+int
+_gpgrt_set_nonblock (estream_t stream, int onoff)
+{
+  cookie_ioctl_function_t func_ioctl;
+  int ret;
+
+  lock_stream (stream);
+  func_ioctl = stream->intern->func_ioctl;
+  if (!func_ioctl)
+    {
+      _set_errno (EOPNOTSUPP);
+      ret = -1;
+    }
+  else
+    {
+      unsigned int save_flags = stream->intern->modeflags;
+
+      if (onoff)
+        stream->intern->modeflags |= O_NONBLOCK;
+      else
+        stream->intern->modeflags &= ~O_NONBLOCK;
+
+      ret = func_ioctl (stream->intern->cookie, COOKIE_IOCTL_NONBLOCK,
+                        onoff?"":NULL, NULL);
+      if (ret)
+        stream->intern->modeflags = save_flags;
+    }
+  unlock_stream (stream);
+  return ret;
+}
+
+
+/* Return true if STREAM is in non-blocking mode.  */
+int
+_gpgrt_get_nonblock (estream_t stream)
+{
+  int ret;
+
+  lock_stream (stream);
+  ret = !!(stream->intern->modeflags & O_NONBLOCK);
+  unlock_stream (stream);
+  return ret;
+}
+
+
+/* A version of poll(2) working on estream handles.  Note that not all
+   estream types work with this function.  In contrast to the standard
+   poll function the gpgrt_poll_t object uses a set of bit flags
+   instead of the EVENTS and REVENTS members.  An item with the IGNORE
+   flag set is entirely ignored.  The TIMEOUT values is given in
+   milliseconds, a value of -1 waits indefinitely, and a value of 0
+   returns immediately.
+
+   A positive return value gives the number of fds with new
+   information.  A return value of 0 indicates a timeout and -1
+   indicates an error in which case ERRNO is set.  */
+int
+_gpgrt_poll (gpgrt_poll_t *fds, unsigned int nfds, int timeout)
+{
+  gpgrt_poll_t *item;
+  int count = 0;
+  int idx;
+#ifndef HAVE_W32_SYSTEM
+# ifdef HAVE_POLL_H
+  struct pollfd *poll_fds = NULL;
+  nfds_t poll_nfds;
+# else
+  fd_set readfds, writefds, exceptfds;
+  int any_readfd, any_writefd, any_exceptfd;
+  int max_fd;
+#endif
+  int fd, ret, any;
+#endif /*HAVE_W32_SYSTEM*/
+
+  trace (("enter: nfds=%u timeout=%d", nfds, timeout));
+
+  if (!fds)
+    {
+      _set_errno (EINVAL);
+      count = -1;
+      goto leave;
+    }
+
+  /* Clear all response fields (even for ignored items).  */
+  for (item = fds, idx = 0; idx < nfds; item++, idx++)
+    {
+      item->got_read = 0;
+      item->got_write = 0;
+      item->got_oob = 0;
+      item->got_rdhup = 0;
+      item->got_err = 0;
+      item->got_hup = 0;
+      item->got_nval = 0;
+    }
+
+  /* Check for pending reads.  */
+  for (item = fds, idx = 0; idx < nfds; item++, idx++)
+    {
+      if (item->ignore)
+        continue;
+      if (!item->want_read)
+        continue;
+      if (_gpgrt__pending (item->stream))
+        {
+          item->got_read = 1;
+          count++;
+        }
+    }
+
+  /* Check for space in the write buffers.  */
+  for (item = fds, idx = 0; idx < nfds; item++, idx++)
+    {
+      if (item->ignore)
+        continue;
+      if (!item->want_write)
+        continue;
+      /* FIXME */
+    }
+
+  if (count)
+    goto leave;
+
+  /* Now do the real select.  */
+#ifdef HAVE_W32_SYSTEM
+
+  _gpgrt_pre_syscall ();
+  count = _gpgrt_w32_poll (fds, nfds, timeout);
+  _gpgrt_post_syscall ();
+
+#else /*!HAVE_W32_SYSTEM*/
+# ifdef HAVE_POLL_H
+  poll_fds = xtrymalloc (sizeof (*poll_fds)*nfds);
+  if (!poll_fds)
+    {
+      count = -1;
+      goto leave;
+    }
+  poll_nfds = 0;
+  for (item = fds, idx = 0; idx < nfds; item++, idx++)
+    {
+      if (item->ignore)
+        continue;
+      fd = _gpgrt_fileno (item->stream);
+      if (fd == -1)
+        continue;  /* Stream does not support polling.  */
+
+      if (item->want_read || item->want_write || item->want_oob)
+        {
+          poll_fds[poll_nfds].fd = fd;
+          poll_fds[poll_nfds].events = ((item->want_read ? POLLIN : 0)
+                                        |(item->want_write ? POLLOUT : 0)
+                                        |(item->want_oob ? POLLPRI : 0));
+          poll_fds[poll_nfds].revents = 0;
+          poll_nfds++;
+        }
+    }
+
+  _gpgrt_pre_syscall ();
+  do
+    ret = poll (poll_fds, poll_nfds, timeout);
+  while (ret == -1 && (errno == EINTR || errno == EAGAIN));
+  _gpgrt_post_syscall ();
+# else /* !HAVE_POLL_H */
+  any_readfd = any_writefd = any_exceptfd = 0;
+  max_fd = 0;
+  for (item = fds, idx = 0; idx < nfds; item++, idx++)
+    {
+      if (item->ignore)
+        continue;
+      fd = _gpgrt_fileno (item->stream);
+      if (fd == -1)
+        continue;  /* Stream does not support polling.  */
+
+      if (item->want_read)
+        {
+          if (!any_readfd)
+            {
+              FD_ZERO (&readfds);
+              any_readfd = 1;
+            }
+          FD_SET (fd, &readfds);
+          if (fd > max_fd)
+            max_fd = fd;
+        }
+      if (item->want_write)
+        {
+          if (!any_writefd)
+            {
+              FD_ZERO (&writefds);
+              any_writefd = 1;
+            }
+          FD_SET (fd, &writefds);
+          if (fd > max_fd)
+            max_fd = fd;
+        }
+      if (item->want_oob)
+        {
+          if (!any_exceptfd)
+            {
+              FD_ZERO (&exceptfds);
+              any_exceptfd = 1;
+            }
+          FD_SET (fd, &exceptfds);
+          if (fd > max_fd)
+            max_fd = fd;
+        }
+    }
+
+  _gpgrt_pre_syscall ();
+  do
+    {
+      struct timeval timeout_val;
+
+      timeout_val.tv_sec = timeout / 1000;
+      timeout_val.tv_usec = (timeout % 1000) * 1000;
+      ret = select (max_fd+1,
+                    any_readfd?   &readfds   : NULL,
+                    any_writefd?  &writefds  : NULL,
+                    any_exceptfd? &exceptfds : NULL,
+                    timeout == -1 ? NULL : &timeout_val);
+    }
+  while (ret == -1 && errno == EINTR);
+  _gpgrt_post_syscall ();
+# endif
+
+  if (ret == -1)
+    {
+# ifdef HAVE_POLL_H
+      trace_errno (1, ("poll failed: "));
+# else
+      trace_errno (1, ("select failed: "));
+# endif
+      count = -1;
+      goto leave;
+    }
+  if (!ret)
+    {
+      /* Timeout.  Note that in this case we can't return got_err for
+       * an invalid stream.  */
+      count = 0;
+      goto leave;
+    }
+
+# ifdef HAVE_POLL_H
+  poll_nfds = 0;
+  for (item = fds, idx = 0; idx < nfds; item++, idx++)
+    {
+      if (item->ignore)
+        continue;
+      fd = _gpgrt_fileno (item->stream);
+      if (fd == -1)
+        {
+          item->got_err = 1;  /* Stream does not support polling.  */
+          count++;
+          continue;
+        }
+
+      any = 0;
+      if (item->stream->intern->indicators.hup)
+        {
+          item->got_hup = 1;
+          any = 1;
+        }
+      if (item->want_read && (poll_fds[poll_nfds].revents & (POLLIN|POLLHUP)))
+        {
+          item->got_read = 1;
+          any = 1;
+        }
+      if (item->want_write && (poll_fds[poll_nfds].revents & POLLOUT))
+        {
+          item->got_write = 1;
+          any = 1;
+        }
+      if (item->want_oob && (poll_fds[poll_nfds].revents & ~(POLLIN|POLLOUT)))
+        {
+          item->got_oob = 1;
+          any = 1;
+        }
+
+      if (item->want_read || item->want_write || item->want_oob)
+        poll_nfds++;
+      if (any)
+        count++;
+    }
+# else
+  for (item = fds, idx = 0; idx < nfds; item++, idx++)
+    {
+      if (item->ignore)
+        continue;
+      fd = _gpgrt_fileno (item->stream);
+      if (fd == -1)
+        {
+          item->got_err = 1;  /* Stream does not support polling.  */
+          count++;
+          continue;
+        }
+
+      any = 0;
+      if (item->stream->intern->indicators.hup)
+        {
+          item->got_hup = 1;
+          any = 1;
+        }
+      if (item->want_read && FD_ISSET (fd, &readfds))
+        {
+          item->got_read = 1;
+          any = 1;
+        }
+      if (item->want_write && FD_ISSET (fd, &writefds))
+        {
+          item->got_write = 1;
+          any = 1;
+        }
+      if (item->want_oob && FD_ISSET (fd, &exceptfds))
+        {
+          item->got_oob = 1;
+          any = 1;
+        }
+
+      if (any)
+        count++;
+    }
+# endif
+#endif /*!HAVE_W32_SYSTEM*/
+
+ leave:
+#ifndef HAVE_W32_SYSTEM
+# ifdef HAVE_POLL_H
+  xfree (poll_fds);
+# endif
+#endif
+#ifdef ENABLE_TRACING
+  trace (("leave: count=%d", count));
+  if (count > 0)
+    {
+      for (item = fds, idx = 0; idx < nfds; item++, idx++)
+        {
+          trace (("     %3d  %c%c%c%c%c  %c%c%c%c%c%c%c",
+                  idx,
+                  fds[idx].want_read?  'r':'-',
+                  fds[idx].want_write? 'w':'-',
+                  fds[idx].want_oob?   'o':'-',
+                  fds[idx].want_rdhup? 'h':'-',
+                  fds[idx].ignore?     'i':'-',
+                  fds[idx].got_read?   'r':'-',
+                  fds[idx].got_write?  'w':'-',
+                  fds[idx].got_oob?    'o':'-',
+                  fds[idx].got_rdhup?  'h':'-',
+                  fds[idx].got_hup?    'H':'-',
+                  fds[idx].got_err?    'e':'-',
+                  fds[idx].got_nval?   'n':'-'
+                  ));
+        }
+    }
+#endif /*ENABLE_TRACING*/
+  return count;
+}
+
+
+void
+_gpgrt_opaque_set (estream_t stream, void *opaque)
+{
+  lock_stream (stream);
+  es_opaque_ctrl (stream, opaque, NULL);
+  unlock_stream (stream);
+}
+
+
+void *
+_gpgrt_opaque_get (estream_t stream)
+{
+  void *opaque;
+
+  lock_stream (stream);
+  es_opaque_ctrl (stream, NULL, &opaque);
+  unlock_stream (stream);
+
+  return opaque;
+}
+
+
+static void
+fname_set_internal (estream_t stream, const char *fname, int quote)
+{
+  if (stream->intern->printable_fname
+      && !stream->intern->printable_fname_inuse)
+    {
+      mem_free (stream->intern->printable_fname);
+      stream->intern->printable_fname = NULL;
+    }
+  if (stream->intern->printable_fname)
+    return; /* Can't change because it is in use.  */
+
+  if (*fname != '[')
+    quote = 0;
+  else
+    quote = !!quote;
+
+  stream->intern->printable_fname = mem_alloc (strlen (fname) + quote + 1);
+  if (quote)
+    stream->intern->printable_fname[0] = '\\';
+  strcpy (stream->intern->printable_fname+quote, fname);
+}
+
+
+/* Set the filename attribute of STREAM.  There is no error return.
+   as long as STREAM is valid.  This function is called internally by
+   functions which open a filename.  */
+void
+_gpgrt_fname_set (estream_t stream, const char *fname)
+{
+  if (fname)
+    {
+      lock_stream (stream);
+      fname_set_internal (stream, fname, 1);
+      unlock_stream (stream);
+    }
+}
+
+
+/* Return the filename attribute of STREAM.  In case no filename has
+   been set, "[?]" will be returned.  The returned file name is valid
+   as long as STREAM is valid.  */
+const char *
+_gpgrt_fname_get (estream_t stream)
+{
+  const char *fname;
+
+  lock_stream (stream);
+  fname = stream->intern->printable_fname;
+  if (fname)
+    stream->intern->printable_fname_inuse = 1;
+  unlock_stream (stream);
+  if (!fname)
+    fname = "[?]";
+  return fname;
+}
+
+
+
+/* Print a BUFFER to STREAM while replacing all control characters and
+   the characters in DELIMITERS by standard C escape sequences.
+   Returns 0 on success or -1 on error.  If BYTES_WRITTEN is not NULL
+   the number of bytes actually written are stored at this
+   address.  */
+int
+_gpgrt_write_sanitized (estream_t _GPGRT__RESTRICT stream,
+                        const void * _GPGRT__RESTRICT buffer, size_t length,
+                        const char * delimiters,
+                        size_t * _GPGRT__RESTRICT bytes_written)
+{
+  const unsigned char *p = buffer;
+  size_t count = 0;
+  int ret;
+
+  lock_stream (stream);
+  for (; length; length--, p++, count++)
+    {
+      if (*p < 0x20
+          || *p == 0x7f
+          || (delimiters
+              && (strchr (delimiters, *p) || *p == '\\')))
+        {
+          _gpgrt_putc_unlocked ('\\', stream);
+          count++;
+          if (*p == '\n')
+            {
+              _gpgrt_putc_unlocked ('n', stream);
+              count++;
+            }
+          else if (*p == '\r')
+            {
+              _gpgrt_putc_unlocked ('r', stream);
+              count++;
+            }
+          else if (*p == '\f')
+            {
+              _gpgrt_putc_unlocked ('f', stream);
+              count++;
+            }
+          else if (*p == '\v')
+            {
+              _gpgrt_putc_unlocked ('v', stream);
+              count++;
+            }
+          else if (*p == '\b')
+            {
+              _gpgrt_putc_unlocked ('b', stream);
+              count++;
+            }
+          else if (!*p)
+            {
+              _gpgrt_putc_unlocked('0', stream);
+              count++;
+            }
+          else
+            {
+              _gpgrt_fprintf_unlocked (stream, "x%02x", *p);
+              count += 3;
+            }
+	}
+      else
+        {
+          _gpgrt_putc_unlocked (*p, stream);
+          count++;
+        }
+    }
+
+  if (bytes_written)
+    *bytes_written = count;
+  ret =  _gpgrt_ferror_unlocked (stream)? -1 : 0;
+  unlock_stream (stream);
+
+  return ret;
+}
+
+
+/* Write LENGTH bytes of BUFFER to STREAM as a hex encoded string.
+   RESERVED must be 0.  Returns 0 on success or -1 on error.  If
+   BYTES_WRITTEN is not NULL the number of bytes actually written are
+   stored at this address.  */
+int
+_gpgrt_write_hexstring (estream_t _GPGRT__RESTRICT stream,
+                        const void *_GPGRT__RESTRICT buffer, size_t length,
+                        int reserved, size_t *_GPGRT__RESTRICT bytes_written )
+{
+  int ret;
+  const unsigned char *s;
+  size_t count = 0;
+
+  (void)reserved;
+
+#define tohex(n) ((n) < 10 ? ((n) + '0') : (((n) - 10) + 'A'))
+
+  if (!length)
+    return 0;
+
+  lock_stream (stream);
+
+  for (s = buffer; length; s++, length--)
+    {
+      _gpgrt_putc_unlocked ( tohex ((*s>>4)&15), stream);
+      _gpgrt_putc_unlocked ( tohex (*s&15), stream);
+      count += 2;
+    }
+
+  if (bytes_written)
+    *bytes_written = count;
+  ret = _gpgrt_ferror_unlocked (stream)? -1 : 0;
+
+  unlock_stream (stream);
+
+  return ret;
+
+#undef tohex
+}