wbrawner/openssl
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions
openssl/ssl/s2_lib.c
Emilia Kasper 65c588c140 Fix reachable assert in SSLv2 servers. 
This assert is reachable for servers that support SSLv2 and export ciphers.
Therefore, such servers can be DoSed by sending a specially crafted
SSLv2 CLIENT-MASTER-KEY.

Also fix s2_srvr.c to error out early if the key lengths are malformed.
These lengths are sent unencrypted, so this does not introduce an oracle.

CVE-2015-0293

This issue was discovered by Sean Burford (Google) and Emilia Käsper of
the OpenSSL development team.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
2015-03-19 13:00:45 +00:00

488 lines
13 KiB
C
Raw Blame History

/* ssl/s2_lib.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* 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 copyright
* notice, this list of conditions and the following disclaimer.
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 OR CONTRIBUTORS 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.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include "ssl_locl.h"
#ifndef OPENSSL_NO_SSL2
# include <stdio.h>
# include <openssl/objects.h>
# include <openssl/evp.h>
# include <openssl/md5.h>
const char ssl2_version_str[] = "SSLv2" OPENSSL_VERSION_PTEXT;
# define SSL2_NUM_CIPHERS (sizeof(ssl2_ciphers)/sizeof(SSL_CIPHER))
/* list of available SSLv2 ciphers (sorted by id) */
OPENSSL_GLOBAL SSL_CIPHER ssl2_ciphers[] = {
/* NULL_WITH_MD5 v3 */
# if 0
{
1,
SSL2_TXT_NULL_WITH_MD5,
SSL2_CK_NULL_WITH_MD5,
SSL_kRSA | SSL_aRSA | SSL_eNULL | SSL_MD5 | SSL_SSLV2,
SSL_EXPORT | SSL_EXP40 | SSL_STRONG_NONE,
0,
0,
0,
SSL_ALL_CIPHERS,
SSL_ALL_STRENGTHS,
},
# endif
/* RC4_128_WITH_MD5 */
{
1,
SSL2_TXT_RC4_128_WITH_MD5,
SSL2_CK_RC4_128_WITH_MD5,
SSL_kRSA | SSL_aRSA | SSL_RC4 | SSL_MD5 | SSL_SSLV2,
SSL_NOT_EXP | SSL_MEDIUM,
0,
128,
128,
SSL_ALL_CIPHERS,
SSL_ALL_STRENGTHS,
},
/* RC4_128_EXPORT40_WITH_MD5 */
{
1,
SSL2_TXT_RC4_128_EXPORT40_WITH_MD5,
SSL2_CK_RC4_128_EXPORT40_WITH_MD5,
SSL_kRSA | SSL_aRSA | SSL_RC4 | SSL_MD5 | SSL_SSLV2,
SSL_EXPORT | SSL_EXP40,
SSL2_CF_5_BYTE_ENC,
40,
128,
SSL_ALL_CIPHERS,
SSL_ALL_STRENGTHS,
},
/* RC2_128_CBC_WITH_MD5 */
{
1,
SSL2_TXT_RC2_128_CBC_WITH_MD5,
SSL2_CK_RC2_128_CBC_WITH_MD5,
SSL_kRSA | SSL_aRSA | SSL_RC2 | SSL_MD5 | SSL_SSLV2,
SSL_NOT_EXP | SSL_MEDIUM,
0,
128,
128,
SSL_ALL_CIPHERS,
SSL_ALL_STRENGTHS,
},
/* RC2_128_CBC_EXPORT40_WITH_MD5 */
{
1,
SSL2_TXT_RC2_128_CBC_EXPORT40_WITH_MD5,
SSL2_CK_RC2_128_CBC_EXPORT40_WITH_MD5,
SSL_kRSA | SSL_aRSA | SSL_RC2 | SSL_MD5 | SSL_SSLV2,
SSL_EXPORT | SSL_EXP40,
SSL2_CF_5_BYTE_ENC,
40,
128,
SSL_ALL_CIPHERS,
SSL_ALL_STRENGTHS,
},
/* IDEA_128_CBC_WITH_MD5 */
# ifndef OPENSSL_NO_IDEA
{
1,
SSL2_TXT_IDEA_128_CBC_WITH_MD5,
SSL2_CK_IDEA_128_CBC_WITH_MD5,
SSL_kRSA | SSL_aRSA | SSL_IDEA | SSL_MD5 | SSL_SSLV2,
SSL_NOT_EXP | SSL_MEDIUM,
0,
128,
128,
SSL_ALL_CIPHERS,
SSL_ALL_STRENGTHS,
},
# endif
/* DES_64_CBC_WITH_MD5 */
{
1,
SSL2_TXT_DES_64_CBC_WITH_MD5,
SSL2_CK_DES_64_CBC_WITH_MD5,
SSL_kRSA | SSL_aRSA | SSL_DES | SSL_MD5 | SSL_SSLV2,
SSL_NOT_EXP | SSL_LOW,
0,
56,
56,
SSL_ALL_CIPHERS,
SSL_ALL_STRENGTHS,
},
/* DES_192_EDE3_CBC_WITH_MD5 */
{
1,
SSL2_TXT_DES_192_EDE3_CBC_WITH_MD5,
SSL2_CK_DES_192_EDE3_CBC_WITH_MD5,
SSL_kRSA | SSL_aRSA | SSL_3DES | SSL_MD5 | SSL_SSLV2,
SSL_NOT_EXP | SSL_HIGH,
0,
168,
168,
SSL_ALL_CIPHERS,
SSL_ALL_STRENGTHS,
},
/* RC4_64_WITH_MD5 */
# if 0
{
1,
SSL2_TXT_RC4_64_WITH_MD5,
SSL2_CK_RC4_64_WITH_MD5,
SSL_kRSA | SSL_aRSA | SSL_RC4 | SSL_MD5 | SSL_SSLV2,
SSL_NOT_EXP | SSL_LOW,
SSL2_CF_8_BYTE_ENC,
64,
64,
SSL_ALL_CIPHERS,
SSL_ALL_STRENGTHS,
},
# endif
/* NULL SSLeay (testing) */
# if 0
{
0,
SSL2_TXT_NULL,
SSL2_CK_NULL,
0,
SSL_STRONG_NONE,
0,
0,
0,
SSL_ALL_CIPHERS,
SSL_ALL_STRENGTHS,
},
# endif
/* end of list :-) */
};
long ssl2_default_timeout(void)
{
return (300);
}
IMPLEMENT_ssl2_meth_func(sslv2_base_method,
ssl_undefined_function,
ssl_undefined_function, ssl_bad_method)
int ssl2_num_ciphers(void)
{
return (SSL2_NUM_CIPHERS);
}
SSL_CIPHER *ssl2_get_cipher(unsigned int u)
{
if (u < SSL2_NUM_CIPHERS)
return (&(ssl2_ciphers[SSL2_NUM_CIPHERS - 1 - u]));
else
return (NULL);
}
int ssl2_pending(const SSL *s)
{
return SSL_in_init(s) ? 0 : s->s2->ract_data_length;
}
int ssl2_new(SSL *s)
{
SSL2_STATE *s2;
if ((s2 = OPENSSL_malloc(sizeof *s2)) == NULL)
goto err;
memset(s2, 0, sizeof *s2);
# if SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER + 3 > SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER + 2
# error "assertion failed"
# endif
if ((s2->rbuf =
OPENSSL_malloc(SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER + 2)) == NULL)
goto err;
/*
* wbuf needs one byte more because when using two-byte headers, we leave
* the first byte unused in do_ssl_write (s2_pkt.c)
*/
if ((s2->wbuf =
OPENSSL_malloc(SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER + 3)) == NULL)
goto err;
s->s2 = s2;
ssl2_clear(s);
return (1);
err:
if (s2 != NULL) {
if (s2->wbuf != NULL)
OPENSSL_free(s2->wbuf);
if (s2->rbuf != NULL)
OPENSSL_free(s2->rbuf);
OPENSSL_free(s2);
}
return (0);
}
void ssl2_free(SSL *s)
{
SSL2_STATE *s2;
if (s == NULL)
return;
s2 = s->s2;
if (s2->rbuf != NULL)
OPENSSL_free(s2->rbuf);
if (s2->wbuf != NULL)
OPENSSL_free(s2->wbuf);
OPENSSL_cleanse(s2, sizeof *s2);
OPENSSL_free(s2);
s->s2 = NULL;
}
void ssl2_clear(SSL *s)
{
SSL2_STATE *s2;
unsigned char *rbuf, *wbuf;
s2 = s->s2;
rbuf = s2->rbuf;
wbuf = s2->wbuf;
memset(s2, 0, sizeof *s2);
s2->rbuf = rbuf;
s2->wbuf = wbuf;
s2->clear_text = 1;
s->packet = s2->rbuf;
s->version = SSL2_VERSION;
s->packet_length = 0;
}
long ssl2_ctrl(SSL *s, int cmd, long larg, void *parg)
{
int ret = 0;
switch (cmd) {
case SSL_CTRL_GET_SESSION_REUSED:
ret = s->hit;
break;
case SSL_CTRL_CHECK_PROTO_VERSION:
return ssl3_ctrl(s, SSL_CTRL_CHECK_PROTO_VERSION, larg, parg);
default:
break;
}
return (ret);
}
long ssl2_callback_ctrl(SSL *s, int cmd, void (*fp) (void))
{
return (0);
}
long ssl2_ctx_ctrl(SSL_CTX *ctx, int cmd, long larg, void *parg)
{
return (0);
}
long ssl2_ctx_callback_ctrl(SSL_CTX *ctx, int cmd, void (*fp) (void))
{
return (0);
}
/*
* This function needs to check if the ciphers required are actually
* available
*/
SSL_CIPHER *ssl2_get_cipher_by_char(const unsigned char *p)
{
SSL_CIPHER c, *cp;
unsigned long id;
id = 0x02000000L | ((unsigned long)p[0] << 16L) |
((unsigned long)p[1] << 8L) | (unsigned long)p[2];
c.id = id;
cp = (SSL_CIPHER *)OBJ_bsearch((char *)&c,
(char *)ssl2_ciphers,
SSL2_NUM_CIPHERS, sizeof(SSL_CIPHER),
FP_ICC ssl_cipher_id_cmp);
if ((cp == NULL) || (cp->valid == 0))
return NULL;
else
return cp;
}
int ssl2_put_cipher_by_char(const SSL_CIPHER *c, unsigned char *p)
{
long l;
if (p != NULL) {
l = c->id;
if ((l & 0xff000000) != 0x02000000 && l != SSL3_CK_FALLBACK_SCSV)
return (0);
p[0] = ((unsigned char)(l >> 16L)) & 0xFF;
p[1] = ((unsigned char)(l >> 8L)) & 0xFF;
p[2] = ((unsigned char)(l)) & 0xFF;
}
return (3);
}
int ssl2_generate_key_material(SSL *s)
{
unsigned int i;
EVP_MD_CTX ctx;
unsigned char *km;
unsigned char c = '0';
const EVP_MD *md5;
md5 = EVP_md5();
# ifdef CHARSET_EBCDIC
c = os_toascii['0']; /* Must be an ASCII '0', not EBCDIC '0', see
* SSLv2 docu */
# endif
EVP_MD_CTX_init(&ctx);
km = s->s2->key_material;
if (s->session->master_key_length < 0 ||
s->session->master_key_length > (int)sizeof(s->session->master_key)) {
SSLerr(SSL_F_SSL2_GENERATE_KEY_MATERIAL, ERR_R_INTERNAL_ERROR);
return 0;
}
for (i = 0; i < s->s2->key_material_length; i += EVP_MD_size(md5)) {
if (((km - s->s2->key_material) + EVP_MD_size(md5)) >
(int)sizeof(s->s2->key_material)) {
/*
* EVP_DigestFinal_ex() below would write beyond buffer
*/
SSLerr(SSL_F_SSL2_GENERATE_KEY_MATERIAL, ERR_R_INTERNAL_ERROR);
return 0;
}
EVP_DigestInit_ex(&ctx, md5, NULL);
OPENSSL_assert(s->session->master_key_length >= 0
&& s->session->master_key_length
<= (int)sizeof(s->session->master_key));
EVP_DigestUpdate(&ctx, s->session->master_key,
s->session->master_key_length);
EVP_DigestUpdate(&ctx, &c, 1);
c++;
EVP_DigestUpdate(&ctx, s->s2->challenge, s->s2->challenge_length);
EVP_DigestUpdate(&ctx, s->s2->conn_id, s->s2->conn_id_length);
EVP_DigestFinal_ex(&ctx, km, NULL);
km += EVP_MD_size(md5);
}
EVP_MD_CTX_cleanup(&ctx);
return 1;
}
void ssl2_return_error(SSL *s, int err)
{
if (!s->error) {
s->error = 3;
s->error_code = err;
ssl2_write_error(s);
}
}
void ssl2_write_error(SSL *s)
{
unsigned char buf[3];
int i, error;
buf[0] = SSL2_MT_ERROR;
buf[1] = (s->error_code >> 8) & 0xff;
buf[2] = (s->error_code) & 0xff;
/* state=s->rwstate;*/
error = s->error; /* number of bytes left to write */
s->error = 0;
OPENSSL_assert(error >= 0 && error <= (int)sizeof(buf));
i = ssl2_write(s, &(buf[3 - error]), error);
/* if (i == error) s->rwstate=state; */
if (i < 0)
s->error = error;
else {
s->error = error - i;
if (s->error == 0)
if (s->msg_callback) {
/* ERROR */
s->msg_callback(1, s->version, 0, buf, 3, s,
s->msg_callback_arg);
}
}
}
int ssl2_shutdown(SSL *s)
{
s->shutdown = (SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN);
return (1);
}
#else /* !OPENSSL_NO_SSL2 */
# if PEDANTIC
static void *dummy = &dummy;
# endif
#endif
Reference in a new issue View git blame Copy permalink