Implement known-IV countermeasure. Fix length checks in ssl3_get_client_hello(). Use s->s3->in_read_app_data differently to fix ssl3_read_internal().
diff --git a/ssl/s3_both.c b/ssl/s3_both.c index 89b54b7..58a24cd 100644 --- a/ssl/s3_both.c +++ b/ssl/s3_both.c
@@ -56,7 +56,7 @@ * [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 @@ -592,6 +592,7 @@ { unsigned char *p; unsigned int extra; + size_t len; if (s->s3->rbuf.buf == NULL) { @@ -599,18 +600,21 @@ 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);
diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c index 6d9f986..6dfef5c 100644 --- a/ssl/s3_enc.c +++ b/ssl/s3_enc.c
@@ -55,6 +55,59 @@ * 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> @@ -296,6 +349,7 @@ const EVP_CIPHER *c; const EVP_MD *hash; int num; + int ret = 0; SSL_COMP *comp; if (s->s3->tmp.key_block_length != 0) @@ -322,8 +376,18 @@ 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);
diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c index 4ccc70b..6869924 100644 --- a/ssl/s3_lib.c +++ b/ssl/s3_lib.c
@@ -994,6 +994,7 @@ 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) @@ -1009,15 +1010,19 @@ 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); @@ -1609,13 +1614,12 @@ 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);
diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c index 616698f..5e60e18 100644 --- a/ssl/s3_pkt.c +++ b/ssl/s3_pkt.c
@@ -56,7 +56,7 @@ * [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 @@ -117,7 +117,7 @@ #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); @@ -162,9 +162,7 @@ { /* 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; } @@ -247,14 +245,20 @@ 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; @@ -509,7 +513,7 @@ if (i == 0) { SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE); - return(-1); + return -1; } } @@ -521,18 +525,22 @@ 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; @@ -541,15 +549,16 @@ } 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)); @@ -563,7 +572,8 @@ /* 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); @@ -579,16 +589,44 @@ 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; @@ -639,19 +677,28 @@ 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 */ @@ -1124,7 +1171,7 @@ ) )) { - s->s3->in_read_app_data=0; + s->s3->in_read_app_data=2; return(-1); } else @@ -1210,7 +1257,7 @@ 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;
diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c index d6247a6..99b6a86 100644 --- a/ssl/s3_srvr.c +++ b/ssl/s3_srvr.c
@@ -727,7 +727,7 @@ 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; @@ -784,6 +784,13 @@ /* 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++) { @@ -831,7 +838,7 @@ /* 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 */
diff --git a/ssl/ssl3.h b/ssl/ssl3.h index 0528588..8fd6951 100644 --- a/ssl/ssl3.h +++ b/ssl/ssl3.h
@@ -55,6 +55,59 @@ * 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 @@ -218,10 +271,11 @@ 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 @@ -251,6 +305,10 @@ 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 */
diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c index 8b7844c..b80525f 100644 --- a/ssl/t1_enc.c +++ b/ssl/t1_enc.c
@@ -55,6 +55,59 @@ * 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> @@ -430,6 +483,14 @@ { 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);