1 files changed, 366 insertions, 0 deletions
diff --git a/libotr/libgcrypt-1.8.7/cipher/cipher-ccm.c b/libotr/libgcrypt-1.8.7/cipher/cipher-ccm.c
new file mode 100644
index 0000000..d7f14d8
--- /dev/null
+++ b/libotr/libgcrypt-1.8.7/cipher/cipher-ccm.c
@@ -0,0 +1,366 @@
+/* cipher-ccm.c - CTR mode with CBC-MAC mode implementation
+ * Copyright (C) 2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Libgcrypt 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.
+ *
+ * Libgcrypt 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 this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "g10lib.h"
+#include "cipher.h"
+#include "bufhelp.h"
+#include "./cipher-internal.h"
+
+
+#define set_burn(burn, nburn) do { \
+  unsigned int __nburn = (nburn); \
+  (burn) = (burn) > __nburn ? (burn) : __nburn; } while (0)
+
+
+static unsigned int
+do_cbc_mac (gcry_cipher_hd_t c, const unsigned char *inbuf, size_t inlen,
+            int do_padding)
+{
+  const unsigned int blocksize = 16;
+  gcry_cipher_encrypt_t enc_fn = c->spec->encrypt;
+  unsigned char tmp[blocksize];
+  unsigned int burn = 0;
+  unsigned int unused = c->u_mode.ccm.mac_unused;
+  size_t nblocks;
+
+  if (inlen == 0 && (unused == 0 || !do_padding))
+    return 0;
+
+  do
+    {
+      if (inlen + unused < blocksize || unused > 0)
+        {
+          for (; inlen && unused < blocksize; inlen--)
+            c->u_mode.ccm.macbuf[unused++] = *inbuf++;
+        }
+      if (!inlen)
+        {
+          if (!do_padding)
+            break;
+
+          while (unused < blocksize)
+            c->u_mode.ccm.macbuf[unused++] = 0;
+        }
+
+      if (unused > 0)
+        {
+          /* Process one block from macbuf.  */
+          buf_xor(c->u_iv.iv, c->u_iv.iv, c->u_mode.ccm.macbuf, blocksize);
+          set_burn (burn, enc_fn ( &c->context.c, c->u_iv.iv, c->u_iv.iv ));
+
+          unused = 0;
+        }
+
+      if (c->bulk.cbc_enc)
+        {
+          nblocks = inlen / blocksize;
+          c->bulk.cbc_enc (&c->context.c, c->u_iv.iv, tmp, inbuf, nblocks, 1);
+          inbuf += nblocks * blocksize;
+          inlen -= nblocks * blocksize;
+
+          wipememory (tmp, sizeof(tmp));
+        }
+      else
+        {
+          while (inlen >= blocksize)
+            {
+              buf_xor(c->u_iv.iv, c->u_iv.iv, inbuf, blocksize);
+
+              set_burn (burn, enc_fn ( &c->context.c, c->u_iv.iv, c->u_iv.iv ));
+
+              inlen -= blocksize;
+              inbuf += blocksize;
+            }
+        }
+    }
+  while (inlen > 0);
+
+  c->u_mode.ccm.mac_unused = unused;
+
+  if (burn)
+    burn += 4 * sizeof(void *);
+
+  return burn;
+}
+
+
+gcry_err_code_t
+_gcry_cipher_ccm_set_nonce (gcry_cipher_hd_t c, const unsigned char *nonce,
+                            size_t noncelen)
+{
+  unsigned int marks_key;
+  size_t L = 15 - noncelen;
+  size_t L_;
+
+  L_ = L - 1;
+
+  if (!nonce)
+    return GPG_ERR_INV_ARG;
+  /* Length field must be 2, 3, ..., or 8. */
+  if (L < 2 || L > 8)
+    return GPG_ERR_INV_LENGTH;
+
+  /* Reset state */
+  marks_key = c->marks.key;
+  memset (&c->u_mode, 0, sizeof(c->u_mode));
+  memset (&c->marks, 0, sizeof(c->marks));
+  memset (&c->u_iv, 0, sizeof(c->u_iv));
+  memset (&c->u_ctr, 0, sizeof(c->u_ctr));
+  memset (c->lastiv, 0, sizeof(c->lastiv));
+  c->unused = 0;
+  c->marks.key = marks_key;
+
+  /* Setup CTR */
+  c->u_ctr.ctr[0] = L_;
+  memcpy (&c->u_ctr.ctr[1], nonce, noncelen);
+  memset (&c->u_ctr.ctr[1 + noncelen], 0, L);
+
+  /* Setup IV */
+  c->u_iv.iv[0] = L_;
+  memcpy (&c->u_iv.iv[1], nonce, noncelen);
+  /* Add (8 * M_ + 64 * flags) to iv[0] and set iv[noncelen + 1 ... 15] later
+     in set_aad.  */
+  memset (&c->u_iv.iv[1 + noncelen], 0, L);
+
+  c->u_mode.ccm.nonce = 1;
+
+  return GPG_ERR_NO_ERROR;
+}
+
+
+gcry_err_code_t
+_gcry_cipher_ccm_set_lengths (gcry_cipher_hd_t c, u64 encryptlen, u64 aadlen,
+                              u64 taglen)
+{
+  unsigned int burn = 0;
+  unsigned char b0[16];
+  size_t noncelen = 15 - (c->u_iv.iv[0] + 1);
+  u64 M = taglen;
+  u64 M_;
+  int i;
+
+  M_ = (M - 2) / 2;
+
+  /* Authentication field must be 4, 6, 8, 10, 12, 14 or 16. */
+  if ((M_ * 2 + 2) != M || M < 4 || M > 16)
+    return GPG_ERR_INV_LENGTH;
+  if (!c->u_mode.ccm.nonce || c->marks.tag)
+    return GPG_ERR_INV_STATE;
+  if (c->u_mode.ccm.lengths)
+    return GPG_ERR_INV_STATE;
+
+  c->u_mode.ccm.authlen = taglen;
+  c->u_mode.ccm.encryptlen = encryptlen;
+  c->u_mode.ccm.aadlen = aadlen;
+
+  /* Complete IV setup.  */
+  c->u_iv.iv[0] += (aadlen > 0) * 64 + M_ * 8;
+  for (i = 16 - 1; i >= 1 + noncelen; i--)
+    {
+      c->u_iv.iv[i] = encryptlen & 0xff;
+      encryptlen >>= 8;
+    }
+
+  memcpy (b0, c->u_iv.iv, 16);
+  memset (c->u_iv.iv, 0, 16);
+
+  set_burn (burn, do_cbc_mac (c, b0, 16, 0));
+
+  if (aadlen == 0)
+    {
+      /* Do nothing.  */
+    }
+  else if (aadlen > 0 && aadlen <= (unsigned int)0xfeff)
+    {
+      b0[0] = (aadlen >> 8) & 0xff;
+      b0[1] = aadlen & 0xff;
+      set_burn (burn, do_cbc_mac (c, b0, 2, 0));
+    }
+  else if (aadlen > 0xfeff && aadlen <= (unsigned int)0xffffffff)
+    {
+      b0[0] = 0xff;
+      b0[1] = 0xfe;
+      buf_put_be32(&b0[2], aadlen);
+      set_burn (burn, do_cbc_mac (c, b0, 6, 0));
+    }
+  else if (aadlen > (unsigned int)0xffffffff)
+    {
+      b0[0] = 0xff;
+      b0[1] = 0xff;
+      buf_put_be64(&b0[2], aadlen);
+      set_burn (burn, do_cbc_mac (c, b0, 10, 0));
+    }
+
+  /* Generate S_0 and increase counter.  */
+  set_burn (burn, c->spec->encrypt ( &c->context.c, c->u_mode.ccm.s0,
+                                     c->u_ctr.ctr ));
+  c->u_ctr.ctr[15]++;
+
+  if (burn)
+    _gcry_burn_stack (burn + sizeof(void *) * 5);
+
+  c->u_mode.ccm.lengths = 1;
+
+  return GPG_ERR_NO_ERROR;
+}
+
+
+gcry_err_code_t
+_gcry_cipher_ccm_authenticate (gcry_cipher_hd_t c, const unsigned char *abuf,
+                               size_t abuflen)
+{
+  unsigned int burn;
+
+  if (abuflen > 0 && !abuf)
+    return GPG_ERR_INV_ARG;
+  if (!c->u_mode.ccm.nonce || !c->u_mode.ccm.lengths || c->marks.tag)
+    return GPG_ERR_INV_STATE;
+  if (abuflen > c->u_mode.ccm.aadlen)
+    return GPG_ERR_INV_LENGTH;
+
+  c->u_mode.ccm.aadlen -= abuflen;
+  burn = do_cbc_mac (c, abuf, abuflen, c->u_mode.ccm.aadlen == 0);
+
+  if (burn)
+    _gcry_burn_stack (burn + sizeof(void *) * 5);
+
+  return GPG_ERR_NO_ERROR;
+}
+
+
+gcry_err_code_t
+_gcry_cipher_ccm_tag (gcry_cipher_hd_t c, unsigned char *outbuf,
+		      size_t outbuflen, int check)
+{
+  unsigned int burn;
+
+  if (!outbuf || outbuflen == 0)
+    return GPG_ERR_INV_ARG;
+  /* Tag length must be same as initial authlen.  */
+  if (c->u_mode.ccm.authlen != outbuflen)
+    return GPG_ERR_INV_LENGTH;
+  if (!c->u_mode.ccm.nonce || !c->u_mode.ccm.lengths || c->u_mode.ccm.aadlen > 0)
+    return GPG_ERR_INV_STATE;
+  /* Initial encrypt length must match with length of actual data processed.  */
+  if (c->u_mode.ccm.encryptlen > 0)
+    return GPG_ERR_UNFINISHED;
+
+  if (!c->marks.tag)
+    {
+      burn = do_cbc_mac (c, NULL, 0, 1); /* Perform final padding.  */
+
+      /* Add S_0 */
+      buf_xor (c->u_iv.iv, c->u_iv.iv, c->u_mode.ccm.s0, 16);
+
+      wipememory (c->u_ctr.ctr, 16);
+      wipememory (c->u_mode.ccm.s0, 16);
+      wipememory (c->u_mode.ccm.macbuf, 16);
+
+      if (burn)
+        _gcry_burn_stack (burn + sizeof(void *) * 5);
+
+      c->marks.tag = 1;
+    }
+
+  if (!check)
+    {
+      memcpy (outbuf, c->u_iv.iv, outbuflen);
+      return GPG_ERR_NO_ERROR;
+    }
+  else
+    {
+      return buf_eq_const(outbuf, c->u_iv.iv, outbuflen) ?
+             GPG_ERR_NO_ERROR : GPG_ERR_CHECKSUM;
+    }
+}
+
+
+gcry_err_code_t
+_gcry_cipher_ccm_get_tag (gcry_cipher_hd_t c, unsigned char *outtag,
+			  size_t taglen)
+{
+  return _gcry_cipher_ccm_tag (c, outtag, taglen, 0);
+}
+
+
+gcry_err_code_t
+_gcry_cipher_ccm_check_tag (gcry_cipher_hd_t c, const unsigned char *intag,
+			    size_t taglen)
+{
+  return _gcry_cipher_ccm_tag (c, (unsigned char *)intag, taglen, 1);
+}
+
+
+gcry_err_code_t
+_gcry_cipher_ccm_encrypt (gcry_cipher_hd_t c, unsigned char *outbuf,
+                          size_t outbuflen, const unsigned char *inbuf,
+                          size_t inbuflen)
+{
+  unsigned int burn;
+
+  if (outbuflen < inbuflen)
+    return GPG_ERR_BUFFER_TOO_SHORT;
+  if (!c->u_mode.ccm.nonce || c->marks.tag || !c->u_mode.ccm.lengths ||
+      c->u_mode.ccm.aadlen > 0)
+    return GPG_ERR_INV_STATE;
+  if (inbuflen > c->u_mode.ccm.encryptlen)
+    return GPG_ERR_INV_LENGTH;
+
+  c->u_mode.ccm.encryptlen -= inbuflen;
+  burn = do_cbc_mac (c, inbuf, inbuflen, 0);
+  if (burn)
+    _gcry_burn_stack (burn + sizeof(void *) * 5);
+
+  return _gcry_cipher_ctr_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
+}
+
+
+gcry_err_code_t
+_gcry_cipher_ccm_decrypt (gcry_cipher_hd_t c, unsigned char *outbuf,
+                          size_t outbuflen, const unsigned char *inbuf,
+                          size_t inbuflen)
+{
+  gcry_err_code_t err;
+  unsigned int burn;
+
+  if (outbuflen < inbuflen)
+    return GPG_ERR_BUFFER_TOO_SHORT;
+  if (!c->u_mode.ccm.nonce || c->marks.tag || !c->u_mode.ccm.lengths ||
+      c->u_mode.ccm.aadlen > 0)
+    return GPG_ERR_INV_STATE;
+  if (inbuflen > c->u_mode.ccm.encryptlen)
+    return GPG_ERR_INV_LENGTH;
+
+  err = _gcry_cipher_ctr_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
+  if (err)
+    return err;
+
+  c->u_mode.ccm.encryptlen -= inbuflen;
+  burn = do_cbc_mac (c, outbuf, inbuflen, 0);
+  if (burn)
+    _gcry_burn_stack (burn + sizeof(void *) * 5);
+
+  return err;
+}