Fix length checks in ssl3_get_client_hello().
Use s->s3->in_read_app_data differently to fix ssl3_read_internal().
Changes between 0.9.6c and 0.9.6d [XX xxx 2002]
+ *) Implement a countermeasure against a vulnerability recently found
+ in CBC ciphersuites in SSL 3.0/TLS 1.0: Send an empty fragment
+ before application data chunks to avoid the use of known IVs
+ with data potentially chosen by the attacker.
+ [Bodo Moeller]
+
+ *) Fix length checks in ssl3_get_client_hello().
+ [Bodo Moeller]
+
+ *) TLS/SSL library bugfix: use s->s3->in_read_app_data differently
+ to prevent ssl3_read_internal() from incorrectly assuming that
+ ssl3_read_bytes() found application data while handshake
+ processing was enabled when in fact s->s3->in_read_app_data was
+ merely automatically cleared during the initial handshake.
+ [Bodo Moeller; problem pointed out by Arne Ansper <arne@ats.cyber.ee>]
+
*) Fix object definitions for Private and Enterprise: they were not
recognized in their shortname (=lowercase) representation. Extend
obj_dat.pl to issue an error when using undefined keywords instead
OpenSSL STATUS Last modified at
- ______________ $Date: 2002/03/11 09:35:33 $
+ ______________ $Date: 2002/04/13 22:50:47 $
DEVELOPMENT STATE
NEEDS PATCH
- o An (optional) countermeasure against the predictable-IV CBC
- weakness in SSL/TLS should be added; see
- http://www.openssl.org/~bodo/tls-cbc.txt
-
o apps/ca.c: "Sign the certificate?" - "n" creates empty certificate file
o "OpenSSL STATUS" is never up-to-date.
* [including the GNU Public Licence.]
*/
/* ====================================================================
- * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved.
+ * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
{
unsigned char *p;
unsigned int extra;
+ size_t len;
if (s->s3->rbuf.buf == NULL)
{
extra=SSL3_RT_MAX_EXTRA;
else
extra=0;
- if ((p=OPENSSL_malloc(SSL3_RT_MAX_PACKET_SIZE+extra))
- == NULL)
+ len = SSL3_RT_MAX_PACKET_SIZE + extra;
+ if ((p=OPENSSL_malloc(len)) == NULL)
goto err;
- s->s3->rbuf.buf=p;
+ s->s3->rbuf.buf = p;
+ s->s3->rbuf.len = len;
}
if (s->s3->wbuf.buf == NULL)
{
- if ((p=OPENSSL_malloc(SSL3_RT_MAX_PACKET_SIZE))
- == NULL)
+ len = SSL3_RT_MAX_PACKET_SIZE;
+ len += SSL3_RT_HEADER_LENGTH + 256; /* extra space for empty fragment */
+ if ((p=OPENSSL_malloc(len)) == NULL)
goto err;
- s->s3->wbuf.buf=p;
+ s->s3->wbuf.buf = p;
+ s->s3->wbuf.len = len;
}
s->packet= &(s->s3->rbuf.buf[0]);
return(1);
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
+/* ====================================================================
+ * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
+ *
+ * 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, 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 acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED 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 OpenSSL PROJECT OR
+ * ITS 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.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
#include <stdio.h>
#include <openssl/evp.h>
const EVP_CIPHER *c;
const EVP_MD *hash;
int num;
+ int ret = 0;
SSL_COMP *comp;
if (s->s3->tmp.key_block_length != 0)
s->s3->tmp.key_block_length=num;
s->s3->tmp.key_block=p;
- return ssl3_generate_key_block(s,p,num);
+ ret = ssl3_generate_key_block(s,p,num);
+
+ /* enable vulnerability countermeasure for CBC ciphers with
+ * known-IV problem (http://www.openssl.org/~bodo/tls-cbc.txt) */
+ s->s3->need_empty_fragments = 1;
+#ifndef OPENSSL_NO_RC4
+ if ((s->session->cipher != NULL) && ((s->session->cipher->algorithms & SSL_ENC_MASK) == SSL_RC4))
+ s->s3->need_empty_fragments = 0;
+#endif
+ return ret;
+
err:
SSLerr(SSL_F_SSL3_SETUP_KEY_BLOCK,ERR_R_MALLOC_FAILURE);
return(0);
void ssl3_clear(SSL *s)
{
unsigned char *rp,*wp;
+ size_t rlen, wlen;
ssl3_cleanup_key_block(s);
if (s->s3->tmp.ca_names != NULL)
DH_free(s->s3->tmp.dh);
#endif
- rp=s->s3->rbuf.buf;
- wp=s->s3->wbuf.buf;
+ rp = s->s3->rbuf.buf;
+ wp = s->s3->wbuf.buf;
+ rlen = s->s3->rbuf.len;
+ wlen = s->s3->wbuf.len;
EVP_MD_CTX_cleanup(&s->s3->finish_dgst1);
EVP_MD_CTX_cleanup(&s->s3->finish_dgst2);
memset(s->s3,0,sizeof *s->s3);
- if (rp != NULL) s->s3->rbuf.buf=rp;
- if (wp != NULL) s->s3->wbuf.buf=wp;
+ s->s3->rbuf.buf = rp;
+ s->s3->wbuf.buf = wp;
+ s->s3->rbuf.len = rlen;
+ s->s3->wbuf.len = wlen;
ssl_free_wbio_buffer(s);
if (s->s3->renegotiate) ssl3_renegotiate_check(s);
s->s3->in_read_app_data=1;
ret=ssl3_read_bytes(s,SSL3_RT_APPLICATION_DATA,buf,len,peek);
- if ((ret == -1) && (s->s3->in_read_app_data == 0))
+ if ((ret == -1) && (s->s3->in_read_app_data == 2))
{
/* ssl3_read_bytes decided to call s->handshake_func, which
* called ssl3_read_bytes to read handshake data.
* However, ssl3_read_bytes actually found application data
- * and thinks that application data makes sense here (signalled
- * by resetting 'in_read_app_data', strangely); so disable
+ * and thinks that application data makes sense here; so disable
* handshake processing and try to read application data again. */
s->in_handshake++;
ret=ssl3_read_bytes(s,SSL3_RT_APPLICATION_DATA,buf,len,peek);
* [including the GNU Public Licence.]
*/
/* ====================================================================
- * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved.
+ * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
#include "ssl_locl.h"
static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
- unsigned int len);
+ unsigned int len, int create_empty_fragment);
static int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
unsigned int len);
static int ssl3_get_record(SSL *s);
{
/* avoid buffer overflow */
- int max_max = SSL3_RT_MAX_PACKET_SIZE - s->packet_length;
- if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
- max_max += SSL3_RT_MAX_EXTRA;
+ int max_max = s->s3->rbuf.len - s->packet_length;
if (max > max_max)
max = max_max;
}
extra=SSL3_RT_MAX_EXTRA;
else
extra=0;
+ if (extra != (s->s3->rbuf.len - SSL3_RT_MAX_PACKET_SIZE))
+ {
+ /* actually likely an application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
+ * set after ssl3_setup_buffers() was done */
+ SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
+ return -1;
+ }
again:
/* check if we have the header */
if ( (s->rstate != SSL_ST_READ_BODY) ||
(s->packet_length < SSL3_RT_HEADER_LENGTH))
{
- n=ssl3_read_n(s,SSL3_RT_HEADER_LENGTH,
- SSL3_RT_MAX_PACKET_SIZE,0);
+ n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
if (n <= 0) return(n); /* error or non-blocking */
s->rstate=SSL_ST_READ_BODY;
if (i == 0)
{
SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
- return(-1);
+ return -1;
}
}
else
nw=n;
- i=do_ssl3_write(s,type,&(buf[tot]),nw);
+ i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
if (i <= 0)
{
s->s3->wnum=tot;
- return(i);
+ return i;
}
if ((i == (int)n) ||
(type == SSL3_RT_APPLICATION_DATA &&
(s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
{
- return(tot+i);
+ /* next chunk of data should get another prepended empty fragment
+ * in ciphersuites with known-IV weakness: */
+ s->s3->empty_fragment_done = 0;
+
+ return tot+i;
}
n-=i;
}
static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
- unsigned int len)
+ unsigned int len, int create_empty_fragment)
{
unsigned char *p,*plen;
int i,mac_size,clear=0;
+ int prefix_len = 0;
SSL3_RECORD *wr;
SSL3_BUFFER *wb;
SSL_SESSION *sess;
- /* first check is there is a SSL3_RECORD still being written
+ /* first check if there is a SSL3_BUFFER still being written
* out. This will happen with non blocking IO */
if (s->s3->wbuf.left != 0)
return(ssl3_write_pending(s,type,buf,len));
/* if it went, fall through and send more stuff */
}
- if (len == 0) return(len);
+ if (len == 0 && !create_empty_fragment)
+ return 0;
wr= &(s->s3->wrec);
wb= &(s->s3->wbuf);
else
mac_size=EVP_MD_size(s->write_hash);
- p=wb->buf;
+ /* 'create_empty_fragment' is true only when this function calls itself */
+ if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
+ {
+ /* countermeasure against known-IV weakness in CBC ciphersuites
+ * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
+
+ if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
+ {
+ /* recursive function call with 'create_empty_fragment' set;
+ * this prepares and buffers the data for an empty fragment
+ * (these 'prefix_len' bytes are sent out later
+ * together with the actual payload) */
+ prefix_len = do_ssl3_write(s, type, buf, 0, 1);
+ if (prefix_len <= 0)
+ goto err;
+
+ if (s->s3->wbuf.len < prefix_len + SSL3_RT_MAX_PACKET_SIZE)
+ {
+ /* insufficient space */
+ SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ }
+
+ s->s3->empty_fragment_done = 1;
+ }
+
+ p = wb->buf + prefix_len;
/* write the header */
+
*(p++)=type&0xff;
wr->type=type;
*(p++)=(s->version>>8);
*(p++)=s->version&0xff;
- /* record where we are to write out packet length */
+ /* field where we are to write out packet length */
plen=p;
p+=2;
wr->type=type; /* not needed but helps for debugging */
wr->length+=SSL3_RT_HEADER_LENGTH;
- /* Now lets setup wb */
- wb->left=wr->length;
- wb->offset=0;
+ if (create_empty_fragment)
+ {
+ /* we are in a recursive call;
+ * just return the length, don't write out anything here
+ */
+ return wr->length;
+ }
+ /* now let's set up wb */
+ wb->left = prefix_len + wr->length;
+ wb->offset = 0;
+
+ /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
s->s3->wpend_tot=len;
s->s3->wpend_buf=buf;
s->s3->wpend_type=type;
s->s3->wpend_ret=len;
/* we now just need to write the buffer */
- return(ssl3_write_pending(s,type,buf,len));
+ return ssl3_write_pending(s,type,buf,len);
err:
- return(-1);
+ return -1;
}
/* if s->s3->wbuf.left != 0, we need to call this */
)
))
{
- s->s3->in_read_app_data=0;
+ s->s3->in_read_app_data=2;
return(-1);
}
else
void (*cb)(const SSL *ssl,int type,int val)=NULL;
s->s3->alert_dispatch=0;
- i=do_ssl3_write(s,SSL3_RT_ALERT,&s->s3->send_alert[0],2);
+ i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
if (i <= 0)
{
s->s3->alert_dispatch=1;
SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_NO_CIPHERS_SPECIFIED);
goto f_err;
}
- if ((i+p) > (d+n))
+ if ((p+i) >= (d+n))
{
/* not enough data */
al=SSL_AD_DECODE_ERROR;
/* compression */
i= *(p++);
+ if ((p+i) > (d+n))
+ {
+ /* not enough data */
+ al=SSL_AD_DECODE_ERROR;
+ SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_LENGTH_MISMATCH);
+ goto f_err;
+ }
q=p;
for (j=0; j<i; j++)
{
/* TLS does not mind if there is extra stuff */
if (s->version == SSL3_VERSION)
{
- if (p > (d+n))
+ if (p < (d+n))
{
/* wrong number of bytes,
* there could be more to follow */
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
+/* ====================================================================
+ * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
+ *
+ * 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, 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 acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED 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 OpenSSL PROJECT OR
+ * ITS 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.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
#ifndef HEADER_SSL3_H
#define HEADER_SSL3_H
typedef struct ssl3_buffer_st
{
- unsigned char *buf; /* SSL3_RT_MAX_PACKET_SIZE bytes (more if
- * SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER is set) */
- int offset; /* where to 'copy from' */
- int left; /* how many bytes left */
+ unsigned char *buf; /* at least SSL3_RT_MAX_PACKET_SIZE bytes,
+ * see ssl3_setup_buffers() */
+ size_t len; /* buffer size */
+ int offset; /* where to 'copy from' */
+ int left; /* how many bytes left */
} SSL3_BUFFER;
#define SSL3_CT_RSA_SIGN 1
unsigned char server_random[SSL3_RANDOM_SIZE];
unsigned char client_random[SSL3_RANDOM_SIZE];
+ /* flags for countermeasure against known-IV weakness */
+ int need_empty_fragments;
+ int empty_fragment_done;
+
SSL3_BUFFER rbuf; /* read IO goes into here */
SSL3_BUFFER wbuf; /* write IO goes into here */
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
+/* ====================================================================
+ * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
+ *
+ * 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, 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 acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ * endorse or promote products derived from this software without
+ * prior written permission. For written permission, please contact
+ * openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ * nor may "OpenSSL" appear in their names without prior written
+ * permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ * acknowledgment:
+ * "This product includes software developed by the OpenSSL Project
+ * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED 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 OpenSSL PROJECT OR
+ * ITS 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.
+ * ====================================================================
+ *
+ * This product includes cryptographic software written by Eric Young
+ * (eay@cryptsoft.com). This product includes software written by Tim
+ * Hudson (tjh@cryptsoft.com).
+ *
+ */
#include <stdio.h>
#include <openssl/comp.h>
{ int z; for (z=0; z<num; z++) printf("%02X%c",p1[z],((z+1)%16)?' ':'\n'); }
#endif
+ /* enable vulnerability countermeasure for CBC ciphers with
+ * known-IV problem (http://www.openssl.org/~bodo/tls-cbc.txt) */
+ s->s3->need_empty_fragments = 1;
+#ifndef NO_RC4
+ if ((s->session->cipher != NULL) && ((s->session->cipher->algorithms & SSL_ENC_MASK) == SSL_RC4))
+ s->s3->need_empty_fragments = 0;
+#endif
+
return(1);
err:
SSLerr(SSL_F_TLS1_SETUP_KEY_BLOCK,ERR_R_MALLOC_FAILURE);