/*
* ssl.c v0.0.3
* Copyright (C) 2000 -- DaP <profeta@freemail.c3.hu>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#ifdef __APPLE__
#define __AVAILABILITYMACROS__
#define DEPRECATED_IN_MAC_OS_X_VERSION_10_7_AND_LATER
#endif
#include "inet.h" /* make it first to avoid macro redefinitions */
#include <openssl/ssl.h> /* SSL_() */
#include <openssl/err.h> /* ERR_() */
#include <openssl/x509v3.h>
#ifdef WIN32
#include <openssl/rand.h> /* RAND_seed() */
#endif
#include "config.h"
#include <time.h> /* asctime() */
#include <string.h> /* strncpy() */
#include "ssl.h" /* struct cert_info */
#include <glib.h>
#include <glib/gprintf.h>
#include <gio/gio.h>
#include "util.h"
/* If openssl was built without ec */
#ifndef SSL_OP_SINGLE_ECDH_USE
#define SSL_OP_SINGLE_ECDH_USE 0
#endif
#ifndef SSL_OP_NO_COMPRESSION
#define SSL_OP_NO_COMPRESSION 0
#endif
/* globals */
static struct chiper_info chiper_info; /* static buffer for _SSL_get_cipher_info() */
static char err_buf[256]; /* generic error buffer */
/* +++++ Internal functions +++++ */
static void
__SSL_fill_err_buf (char *funcname)
{
int err;
char buf[256];
err = ERR_get_error ();
ERR_error_string (err, buf);
g_snprintf (err_buf, sizeof (err_buf), "%s: %s (%d)\n", funcname, buf, err);
}
static void
__SSL_critical_error (char *funcname)
{
__SSL_fill_err_buf (funcname);
fprintf (stderr, "%s\n", err_buf);
exit (1);
}
/* +++++ SSL functions +++++ */
SSL_CTX *
_SSL_context_init (void (*info_cb_func))
{
SSL_CTX *ctx;
SSLeay_add_ssl_algorithms ();
SSL_load_error_strings ();
ctx = SSL_CTX_new (SSLv23_client_method ());
SSL_CTX_set_session_cache_mode (ctx, SSL_SESS_CACHE_BOTH);
SSL_CTX_set_timeout (ctx, 300);
SSL_CTX_set_options (ctx, SSL_OP_NO_SSLv2|SSL_OP_NO_SSLv3
|SSL_OP_NO_COMPRESSION
|SSL_OP_SINGLE_DH_USE|SSL_OP_SINGLE_ECDH_USE
|SSL_OP_NO_TICKET
|SSL_OP_CIPHER_SERVER_PREFERENCE);
#if OPENSSL_VERSION_NUMBER >= 0x00908000L && !defined (OPENSSL_NO_COMP) /* workaround for OpenSSL 0.9.8 */
sk_SSL_COMP_zero(SSL_COMP_get_compression_methods());
#endif
/* used in SSL_connect(), SSL_accept() */
SSL_CTX_set_info_callback (ctx, info_cb_func);
return(ctx);
}
static void
ASN1_TIME_snprintf (char *buf, int buf_len, ASN1_TIME * tm)
{
char *expires = NULL;
BIO *inMem = BIO_new (BIO_s_mem ());
ASN1_TIME_print (inMem, tm);
BIO_get_mem_data (inMem, &expires);
buf[0] = 0;
if (expires != NULL)
{
/* expires is not \0 terminated */
safe_strcpy (buf, expires, MIN(24, buf_len));
}
BIO_free (inMem);
}
static void
broke_oneline (char *oneline, char *parray[])
{
char *pt, *ppt;
int i;
i = 0;
ppt = pt = oneline + 1;
while ((pt = strchr (pt, '/')))
{
*pt = 0;
parray[i++] = ppt;
ppt = ++pt;
}
parray[i++] = ppt;
parray[i] = NULL;
}
/*
FIXME: Master-Key, Extensions, CA bits
(openssl x509 -text -in servcert.pem)
*/
int
_SSL_get_cert_info (struct cert_info *cert_info, SSL * ssl)
{
X509 *peer_cert;
EVP_PKEY *peer_pkey;
/* EVP_PKEY *ca_pkey; */
/* EVP_PKEY *tmp_pkey; */
char notBefore[64];
char notAfter[64];
int alg;
int sign_alg;
if (!(peer_cert = SSL_get_peer_certificate (ssl)))
return (1); /* FATAL? */
X509_NAME_oneline (X509_get_subject_name (peer_cert), cert_info->subject,
sizeof (cert_info->subject));
X509_NAME_oneline (X509_get_issuer_name (peer_cert), cert_info->issuer,
sizeof (cert_info->issuer));
broke_oneline (cert_info->subject, cert_info->subject_word);
broke_oneline (cert_info->issuer, cert_info->issuer_word);
alg = OBJ_obj2nid (peer_cert->cert_info->key->algor->algorithm);
sign_alg = OBJ_obj2nid (peer_cert->sig_alg->algorithm);
ASN1_TIME_snprintf (notBefore, sizeof (notBefore),
X509_get_notBefore (peer_cert));
ASN1_TIME_snprintf (notAfter, sizeof (notAfter),
X509_get_notAfter (peer_cert));
peer_pkey = X509_get_pubkey (peer_cert);
safe_strcpy (cert_info->algorithm,
(alg == NID_undef) ? "Unknown" : OBJ_nid2ln (alg),
sizeof (cert_info->algorithm));
cert_info->algorithm_bits = EVP_PKEY_bits (peer_pkey);
safe_strcpy (cert_info->sign_algorithm,
(sign_alg == NID_undef) ? "Unknown" : OBJ_nid2ln (sign_alg),
sizeof (cert_info->sign_algorithm));
/* EVP_PKEY_bits(ca_pkey)); */
cert_info->sign_algorithm_bits = 0;
safe_strcpy (cert_info->notbefore, notBefore, sizeof (cert_info->notbefore));
safe_strcpy (cert_info->notafter, notAfter, sizeof (cert_info->notafter));
EVP_PKEY_free (peer_pkey);
/* SSL_SESSION_print_fp(stdout, SSL_get_session(ssl)); */
/*
if (ssl->session->sess_cert->peer_rsa_tmp) {
tmp_pkey = EVP_PKEY_new();
EVP_PKEY_assign_RSA(tmp_pkey, ssl->session->sess_cert->peer_rsa_tmp);
cert_info->rsa_tmp_bits = EVP_PKEY_bits (tmp_pkey);
EVP_PKEY_free(tmp_pkey);
} else
fprintf(stderr, "REMOTE SIDE DOESN'T PROVIDES ->peer_rsa_tmp\n");
*/
cert_info->rsa_tmp_bits = 0;
X509_free (peer_cert);
return (0);
}
struct chiper_info *
_SSL_get_cipher_info (SSL * ssl)
{
const SSL_CIPHER *c;
c = SSL_get_current_cipher (ssl);
safe_strcpy (chiper_info.version, SSL_CIPHER_get_version (c),
sizeof (chiper_info.version));
safe_strcpy (chiper_info.chiper, SSL_CIPHER_get_name (c),
sizeof (chiper_info.chiper));
SSL_CIPHER_get_bits (c, &chiper_info.chiper_bits);
return (&chiper_info);
}
int
_SSL_send (SSL * ssl, char *buf, int len)
{
int num;
num = SSL_write (ssl, buf, len);
switch (SSL_get_error (ssl, num))
{
case SSL_ERROR_SSL: /* setup errno! */
/* ??? */
__SSL_fill_err_buf ("SSL_write");
fprintf (stderr, "%s\n", err_buf);
break;
case SSL_ERROR_SYSCALL:
/* ??? */
perror ("SSL_write/write");
break;
case SSL_ERROR_ZERO_RETURN:
/* fprintf(stderr, "SSL closed on write\n"); */
break;
}
return (num);
}
int
_SSL_recv (SSL * ssl, char *buf, int len)
{
int num;
num = SSL_read (ssl, buf, len);
switch (SSL_get_error (ssl, num))
{
case SSL_ERROR_SSL:
/* ??? */
__SSL_fill_err_buf ("SSL_read");
fprintf (stderr, "%s\n", err_buf);
break;
case SSL_ERROR_SYSCALL:
/* ??? */
if (!would_block ())
perror ("SSL_read/read");
break;
case SSL_ERROR_ZERO_RETURN:
/* fprintf(stdeerr, "SSL closed on read\n"); */
break;
}
return (num);
}
SSL *
_SSL_socket (SSL_CTX *ctx, int sd)
{
SSL *ssl;
if (!(ssl = SSL_new (ctx)))
/* FATAL */
__SSL_critical_error ("SSL_new");
SSL_set_fd (ssl, sd);
if (ctx->method == SSLv23_client_method())
SSL_set_connect_state (ssl);
else
SSL_set_accept_state(ssl);
return (ssl);
}
char *
_SSL_set_verify (SSL_CTX *ctx, void *verify_callback, char *cacert)
{
if (!SSL_CTX_set_default_verify_paths (ctx))
{
__SSL_fill_err_buf ("SSL_CTX_set_default_verify_paths");
return (err_buf);
}
/*
if (cacert)
{
if (!SSL_CTX_load_verify_locations (ctx, cacert, NULL))
{
__SSL_fill_err_buf ("SSL_CTX_load_verify_locations");
return (err_buf);
}
}
*/
SSL_CTX_set_verify (ctx, SSL_VERIFY_PEER, verify_callback);
return (NULL);
}
void
_SSL_close (SSL * ssl)
{
SSL_set_shutdown (ssl, SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN);
SSL_free (ssl);
ERR_remove_state (0); /* free state buffer */
}
/* Hostname validation code based on OpenBSD's libtls. */
static int
_SSL_match_hostname (const char *cert_hostname, const char *hostname)
{
const char *cert_domain, *domain, *next_dot;
if (g_ascii_strcasecmp (cert_hostname, hostname) == 0)
return 0;
/* Wildcard match? */
if (cert_hostname[0] == '*')
{
/*
* Valid wildcards:
* - "*.domain.tld"
* - "*.sub.domain.tld"
* - etc.
* Reject "*.tld".
* No attempt to prevent the use of eg. "*.co.uk".
*/
cert_domain = &cert_hostname[1];
/* Disallow "*" */
if (cert_domain[0] == '\0')
return -1;
/* Disallow "*foo" */
if (cert_domain[0] != '.')
return -1;
/* Disallow "*.." */
if (cert_domain[1] == '.')
return -1;
next_dot = strchr (&cert_domain[1], '.');
/* Disallow "*.bar" */
if (next_dot == NULL)
return -1;
/* Disallow "*.bar.." */
if (next_dot[1] == '.')
return -1;
domain = strchr (hostname, '.');
/* No wildcard match against a hostname with no domain part. */
if (domain == NULL || strlen(domain) == 1)
return -1;
if (g_ascii_strcasecmp (cert_domain, domain) == 0)
return 0;
}
return -1;
}
static int
_SSL_check_subject_altname (X509 *cert, const char *host)
{
STACK_OF(GENERAL_NAME) *altname_stack = NULL;
GInetAddress *addr;
GSocketFamily family;
int type = GEN_DNS;
int count, i;
int rv = -1;
altname_stack = X509_get_ext_d2i (cert, NID_subject_alt_name, NULL, NULL);
if (altname_stack == NULL)
return -1;
addr = g_inet_address_new_from_string (host);
if (addr != NULL)
{
family = g_inet_address_get_family (addr);
if (family == G_SOCKET_FAMILY_IPV4 || family == G_SOCKET_FAMILY_IPV6)
type = GEN_IPADD;
}
count = sk_GENERAL_NAME_num(altname_stack);
for (i = 0; i < count; i++)
{
GENERAL_NAME *altname;
altname = sk_GENERAL_NAME_value (altname_stack, i);
if (altname->type != type)
continue;
if (type == GEN_DNS)
{
unsigned char *data;
int format;
format = ASN1_STRING_type (altname->d.dNSName);
if (format == V_ASN1_IA5STRING)
{
data = ASN1_STRING_data (altname->d.dNSName);
if (ASN1_STRING_length (altname->d.dNSName) != (int)strlen(data))
{
g_warning("NUL byte in subjectAltName, probably a malicious certificate.\n");
rv = -2;
break;
}
if (_SSL_match_hostname (data, host) == 0)
{
rv = 0;
break;
}
}
else
g_warning ("unhandled subjectAltName dNSName encoding (%d)\n", format);
}
else if (type == GEN_IPADD)
{
unsigned char *data;
const guint8 *addr_bytes;
int datalen, addr_len;
datalen = ASN1_STRING_length (altname->d.iPAddress);
data = ASN1_STRING_data (altname->d.iPAddress);
addr_bytes = g_inet_address_to_bytes (addr);
addr_len = (int)g_inet_address_get_native_size (addr);
if (datalen == addr_len && memcmp (data, addr_bytes, addr_len) == 0)
{
rv = 0;
break;
}
}
}
if (addr != NULL)
g_object_unref (addr);
sk_GENERAL_NAME_pop_free (altname_stack, GENERAL_NAME_free);
return rv;
}
static int
_SSL_check_common_name (X509 *cert, const char *host)
{
X509_NAME *name;
char *common_name = NULL;
int common_name_len;
int rv = -1;
GInetAddress *addr;
name = X509_get_subject_name (cert);
if (name == NULL)
return -1;
common_name_len = X509_NAME_get_text_by_NID (name, NID_commonName, NULL, 0);
if (common_name_len < 0)
return -1;
common_name = g_malloc0 (common_name_len + 1);
X509_NAME_get_text_by_NID (name, NID_commonName, common_name, common_name_len + 1);
/* NUL bytes in CN? */
if (common_name_len != (int)strlen(common_name))
{
g_warning ("NUL byte in Common Name field, probably a malicious certificate.\n");
rv = -2;
goto out;
}
if ((addr = g_inet_address_new_from_string (host)) != NULL)
{
/*
* We don't want to attempt wildcard matching against IP
* addresses, so perform a simple comparison here.
*/
if (g_strcmp0 (common_name, host) == 0)
rv = 0;
else
rv = -1;
g_object_unref (addr);
}
else if (_SSL_match_hostname (common_name, host) == 0)
rv = 0;
out:
g_free(common_name);
return rv;
}
int
_SSL_check_hostname (X509 *cert, const char *host)
{
int rv;
rv = _SSL_check_subject_altname (cert, host);
if (rv == 0 || rv == -2)
return rv;
return _SSL_check_common_name (cert, host);
}
