From bc9058d041e32f75337a4dc8b8e1d10f7553871a Mon Sep 17 00:00:00 2001 From: "Dr. Stephen Henson" Date: Mon, 9 Nov 2009 18:45:42 +0000 Subject: [PATCH] First cut of renegotiation extension. (port to 1.0.0-stable) --- CHANGES | 10 ++ ssl/Makefile | 4 +- ssl/s3_both.c | 34 ++++++ ssl/ssl.h | 8 ++ ssl/ssl3.h | 6 ++ ssl/ssl_err.c | 7 ++ ssl/t1_reneg.c | 274 +++++++++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 341 insertions(+), 2 deletions(-) create mode 100644 ssl/t1_reneg.c diff --git a/CHANGES b/CHANGES index 4159bd4ec7..50edd8f9bb 100644 --- a/CHANGES +++ b/CHANGES @@ -831,6 +831,16 @@ Changes between 0.9.8k and 0.9.8l [xx XXX xxxx] + *) Implement + https://svn.resiprocate.org/rep/ietf-drafts/ekr/draft-rescorla-tls-renegotiate.txt. Re-enable + renegotiation but require the extension as needed. Unfortunately, + SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION turns out to be a + bad idea. It has been replaced by + SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION which can be set with + SSL_CTX_set_options(). This is really not recommended unless you + know what you are doing. + [Eric Rescorla and Ben Laurie] + *) Fixes to stateless session resumption handling. Use initial_ctx when issuing and attempting to decrypt tickets in case it has changed during servername handling. Use a non-zero length session ID when attempting diff --git a/ssl/Makefile b/ssl/Makefile index a97627c56d..2b8ee269f2 100644 --- a/ssl/Makefile +++ b/ssl/Makefile @@ -30,7 +30,7 @@ LIBSRC= \ ssl_lib.c ssl_err2.c ssl_cert.c ssl_sess.c \ ssl_ciph.c ssl_stat.c ssl_rsa.c \ ssl_asn1.c ssl_txt.c ssl_algs.c \ - bio_ssl.c ssl_err.c kssl.c + bio_ssl.c ssl_err.c kssl.c t1_reneg.c LIBOBJ= \ s2_meth.o s2_srvr.o s2_clnt.o s2_lib.o s2_enc.o s2_pkt.o \ s3_meth.o s3_srvr.o s3_clnt.o s3_lib.o s3_enc.o s3_pkt.o s3_both.o \ @@ -41,7 +41,7 @@ LIBOBJ= \ ssl_lib.o ssl_err2.o ssl_cert.o ssl_sess.o \ ssl_ciph.o ssl_stat.o ssl_rsa.o \ ssl_asn1.o ssl_txt.o ssl_algs.o \ - bio_ssl.o ssl_err.o kssl.o + bio_ssl.o ssl_err.o kssl.o t1_reneg.o SRC= $(LIBSRC) diff --git a/ssl/s3_both.c b/ssl/s3_both.c index d757c4dd58..16d92610e9 100644 --- a/ssl/s3_both.c +++ b/ssl/s3_both.c @@ -166,6 +166,23 @@ int ssl3_send_finished(SSL *s, int a, int b, const char *sender, int slen) p+=i; l=i; + /* Copy the finished so we can use it for + renegotiation checks */ + if(s->type == SSL_ST_CONNECT) + { + OPENSSL_assert(i <= EVP_MAX_MD_SIZE); + memcpy(s->s3->previous_client_finished, + s->s3->tmp.finish_md, i); + s->s3->previous_client_finished_len=i; + } + else + { + OPENSSL_assert(i <= EVP_MAX_MD_SIZE); + memcpy(s->s3->previous_server_finished, + s->s3->tmp.finish_md, i); + s->s3->previous_server_finished_len=i; + } + #ifdef OPENSSL_SYS_WIN16 /* MSVC 1.5 does not clear the top bytes of the word unless * I do this. @@ -230,6 +247,23 @@ int ssl3_get_finished(SSL *s, int a, int b) goto f_err; } + /* Copy the finished so we can use it for + renegotiation checks */ + if(s->type == SSL_ST_ACCEPT) + { + OPENSSL_assert(i <= EVP_MAX_MD_SIZE); + memcpy(s->s3->previous_client_finished, + s->s3->tmp.peer_finish_md, i); + s->s3->previous_client_finished_len=i; + } + else + { + OPENSSL_assert(i <= EVP_MAX_MD_SIZE); + memcpy(s->s3->previous_server_finished, + s->s3->tmp.peer_finish_md, i); + s->s3->previous_server_finished_len=i; + } + return(1); f_err: ssl3_send_alert(s,SSL3_AL_FATAL,al); diff --git a/ssl/ssl.h b/ssl/ssl.h index 8e901b913c..c4a5fc9d41 100644 --- a/ssl/ssl.h +++ b/ssl/ssl.h @@ -524,6 +524,7 @@ typedef struct ssl_session_st #define SSL_OP_SSLEAY_080_CLIENT_DH_BUG 0x00000080L #define SSL_OP_TLS_D5_BUG 0x00000100L #define SSL_OP_TLS_BLOCK_PADDING_BUG 0x00000200L +#define SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION 0x00000400L /* Disable SSL 3.0/TLS 1.0 CBC vulnerability workaround that was added * in OpenSSL 0.9.6d. Usually (depending on the application protocol) @@ -1904,9 +1905,11 @@ void ERR_load_SSL_strings(void); #define SSL_F_SSL3_SETUP_WRITE_BUFFER 291 #define SSL_F_SSL3_WRITE_BYTES 158 #define SSL_F_SSL3_WRITE_PENDING 159 +#define SSL_F_SSL_ADD_CLIENTHELLO_RENEGOTIATE_EXT 298 #define SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT 277 #define SSL_F_SSL_ADD_DIR_CERT_SUBJECTS_TO_STACK 215 #define SSL_F_SSL_ADD_FILE_CERT_SUBJECTS_TO_STACK 216 +#define SSL_F_SSL_ADD_SERVERHELLO_RENEGOTIATE_EXT 299 #define SSL_F_SSL_ADD_SERVERHELLO_TLSEXT 278 #define SSL_F_SSL_BAD_METHOD 160 #define SSL_F_SSL_BYTES_TO_CIPHER_LIST 161 @@ -1950,6 +1953,8 @@ void ERR_load_SSL_strings(void); #define SSL_F_SSL_INIT_WBIO_BUFFER 184 #define SSL_F_SSL_LOAD_CLIENT_CA_FILE 185 #define SSL_F_SSL_NEW 186 +#define SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT 300 +#define SSL_F_SSL_PARSE_SERVERHELLO_RENEGOTIATE_EXT 301 #define SSL_F_SSL_PEEK 270 #define SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT 281 #define SSL_F_SSL_PREPARE_SERVERHELLO_TLSEXT 282 @@ -2164,6 +2169,9 @@ void ERR_load_SSL_strings(void); #define SSL_R_RECORD_LENGTH_MISMATCH 213 #define SSL_R_RECORD_TOO_LARGE 214 #define SSL_R_RECORD_TOO_SMALL 298 +#define SSL_R_RENEGOTIATE_EXT_TOO_LONG 335 +#define SSL_R_RENEGOTIATION_ENCODING_ERR 336 +#define SSL_R_RENEGOTIATION_MISMATCH 337 #define SSL_R_REQUIRED_CIPHER_MISSING 215 #define SSL_R_REUSE_CERT_LENGTH_NOT_ZERO 216 #define SSL_R_REUSE_CERT_TYPE_NOT_ZERO 217 diff --git a/ssl/ssl3.h b/ssl/ssl3.h index a4a6ce28c3..5f0eee6dbb 100644 --- a/ssl/ssl3.h +++ b/ssl/ssl3.h @@ -503,6 +503,12 @@ typedef struct ssl3_state_st int cert_request; } tmp; + /* Connection binding to prevent renegotiation attacks */ + unsigned char previous_client_finished[EVP_MAX_MD_SIZE]; + unsigned char previous_client_finished_len; + unsigned char previous_server_finished[EVP_MAX_MD_SIZE]; + unsigned char previous_server_finished_len; + int send_connection_binding; /* TODOEKR */ } SSL3_STATE; diff --git a/ssl/ssl_err.c b/ssl/ssl_err.c index f29e61692c..f20c0548ab 100644 --- a/ssl/ssl_err.c +++ b/ssl/ssl_err.c @@ -177,9 +177,11 @@ static ERR_STRING_DATA SSL_str_functs[]= {ERR_FUNC(SSL_F_SSL3_SETUP_WRITE_BUFFER), "SSL3_SETUP_WRITE_BUFFER"}, {ERR_FUNC(SSL_F_SSL3_WRITE_BYTES), "SSL3_WRITE_BYTES"}, {ERR_FUNC(SSL_F_SSL3_WRITE_PENDING), "SSL3_WRITE_PENDING"}, +{ERR_FUNC(SSL_F_SSL_ADD_CLIENTHELLO_RENEGOTIATE_EXT), "SSL_ADD_CLIENTHELLO_RENEGOTIATE_EXT"}, {ERR_FUNC(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT), "SSL_ADD_CLIENTHELLO_TLSEXT"}, {ERR_FUNC(SSL_F_SSL_ADD_DIR_CERT_SUBJECTS_TO_STACK), "SSL_add_dir_cert_subjects_to_stack"}, {ERR_FUNC(SSL_F_SSL_ADD_FILE_CERT_SUBJECTS_TO_STACK), "SSL_add_file_cert_subjects_to_stack"}, +{ERR_FUNC(SSL_F_SSL_ADD_SERVERHELLO_RENEGOTIATE_EXT), "SSL_ADD_SERVERHELLO_RENEGOTIATE_EXT"}, {ERR_FUNC(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT), "SSL_ADD_SERVERHELLO_TLSEXT"}, {ERR_FUNC(SSL_F_SSL_BAD_METHOD), "SSL_BAD_METHOD"}, {ERR_FUNC(SSL_F_SSL_BYTES_TO_CIPHER_LIST), "SSL_BYTES_TO_CIPHER_LIST"}, @@ -223,6 +225,8 @@ static ERR_STRING_DATA SSL_str_functs[]= {ERR_FUNC(SSL_F_SSL_INIT_WBIO_BUFFER), "SSL_INIT_WBIO_BUFFER"}, {ERR_FUNC(SSL_F_SSL_LOAD_CLIENT_CA_FILE), "SSL_load_client_CA_file"}, {ERR_FUNC(SSL_F_SSL_NEW), "SSL_new"}, +{ERR_FUNC(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT), "SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT"}, +{ERR_FUNC(SSL_F_SSL_PARSE_SERVERHELLO_RENEGOTIATE_EXT), "SSL_PARSE_SERVERHELLO_RENEGOTIATE_EXT"}, {ERR_FUNC(SSL_F_SSL_PEEK), "SSL_peek"}, {ERR_FUNC(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT), "SSL_PREPARE_CLIENTHELLO_TLSEXT"}, {ERR_FUNC(SSL_F_SSL_PREPARE_SERVERHELLO_TLSEXT), "SSL_PREPARE_SERVERHELLO_TLSEXT"}, @@ -440,6 +444,9 @@ static ERR_STRING_DATA SSL_str_reasons[]= {ERR_REASON(SSL_R_RECORD_LENGTH_MISMATCH),"record length mismatch"}, {ERR_REASON(SSL_R_RECORD_TOO_LARGE) ,"record too large"}, {ERR_REASON(SSL_R_RECORD_TOO_SMALL) ,"record too small"}, +{ERR_REASON(SSL_R_RENEGOTIATE_EXT_TOO_LONG),"renegotiate ext too long"}, +{ERR_REASON(SSL_R_RENEGOTIATION_ENCODING_ERR),"renegotiation encoding err"}, +{ERR_REASON(SSL_R_RENEGOTIATION_MISMATCH),"renegotiation mismatch"}, {ERR_REASON(SSL_R_REQUIRED_CIPHER_MISSING),"required cipher missing"}, {ERR_REASON(SSL_R_REUSE_CERT_LENGTH_NOT_ZERO),"reuse cert length not zero"}, {ERR_REASON(SSL_R_REUSE_CERT_TYPE_NOT_ZERO),"reuse cert type not zero"}, diff --git a/ssl/t1_reneg.c b/ssl/t1_reneg.c new file mode 100644 index 0000000000..5222094f28 --- /dev/null +++ b/ssl/t1_reneg.c @@ -0,0 +1,274 @@ +/* ssl/t1_reneg.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.] + */ +/* ==================================================================== + * Copyright (c) 1998-2009 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 +#include +#include "ssl_locl.h" + +/* Add the client's renegotiation binding */ +int ssl_add_clienthello_renegotiate_ext(SSL *s, unsigned char *p, int *len, + int maxlen) + { + if(p) + { + if((s->s3->previous_client_finished_len+1) > maxlen) + { + SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATE_EXT_TOO_LONG); + return 0; + } + + /* Length byte */ + *p = s->s3->previous_client_finished_len; + p++; + + memcpy(p, s->s3->previous_client_finished, + s->s3->previous_client_finished_len); + } + + *len=s->s3->previous_client_finished_len + 1; + + return 1; + } + +/* Parse the client's renegotiation binding and abort if it's not + right */ +int ssl_parse_clienthello_renegotiate_ext(SSL *s, unsigned char *d, int len, + int *al) + { + int ilen; + + /* Parse the length byte */ + if(len < 1) + { + SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATION_ENCODING_ERR); + *al=SSL_AD_ILLEGAL_PARAMETER; + return 0; + } + ilen = *d; + d++; + + /* Consistency check */ + if((ilen+1) != len) + { + SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATION_ENCODING_ERR); + *al=SSL_AD_ILLEGAL_PARAMETER; + return 0; + } + + /* Check that the extension matches */ + if(ilen != s->s3->previous_client_finished_len) + { + SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATION_MISMATCH); + *al=SSL_AD_ILLEGAL_PARAMETER; + return 0; + } + + if(memcmp(d, s->s3->previous_client_finished, + s->s3->previous_client_finished_len)) + { + SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATION_MISMATCH); + *al=SSL_AD_ILLEGAL_PARAMETER; + return 0; + } + + s->s3->send_connection_binding=1; + + return 1; + } + +/* Add the server's renegotiation binding */ +int ssl_add_serverhello_renegotiate_ext(SSL *s, unsigned char *p, int *len, + int maxlen) + { + if(p) + { + if((s->s3->previous_client_finished_len + + s->s3->previous_server_finished_len + 1) > maxlen) + { + SSLerr(SSL_F_SSL_ADD_SERVERHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATE_EXT_TOO_LONG); + return 0; + } + + /* Length byte */ + *p = s->s3->previous_client_finished_len + s->s3->previous_server_finished_len; + p++; + + memcpy(p, s->s3->previous_client_finished, + s->s3->previous_client_finished_len); + p += s->s3->previous_client_finished_len; + + memcpy(p, s->s3->previous_server_finished, + s->s3->previous_server_finished_len); + } + + *len=s->s3->previous_client_finished_len + + s->s3->previous_server_finished_len + 1; + + return 1; + } + +/* Parse the server's renegotiation binding and abort if it's not + right */ +int ssl_parse_serverhello_renegotiate_ext(SSL *s, unsigned char *d, int len, + int *al) + { + int expected_len=s->s3->previous_client_finished_len + + s->s3->previous_server_finished_len; + int ilen; + + /* Check for logic errors */ + OPENSSL_assert(!expected_len || s->s3->previous_client_finished_len); + OPENSSL_assert(!expected_len || s->s3->previous_server_finished_len); + + /* Parse the length byte */ + if(len < 1) + { + SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATION_ENCODING_ERR); + *al=SSL_AD_ILLEGAL_PARAMETER; + return 0; + } + ilen = *d; + d++; + + /* Consistency check */ + if(ilen+1 != len) + { + SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATION_ENCODING_ERR); + *al=SSL_AD_ILLEGAL_PARAMETER; + return 0; + } + + /* Check that the extension matches */ + if(ilen != expected_len) + { + SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATION_MISMATCH); + *al=SSL_AD_ILLEGAL_PARAMETER; + return 0; + } + + if(memcmp(d, s->s3->previous_client_finished, + s->s3->previous_client_finished_len)) + { + SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATION_MISMATCH); + *al=SSL_AD_ILLEGAL_PARAMETER; + return 0; + } + d += s->s3->previous_client_finished_len; + + if(memcmp(d, s->s3->previous_server_finished, + s->s3->previous_server_finished_len)) + { + SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_RENEGOTIATE_EXT,SSL_R_RENEGOTIATION_MISMATCH); + *al=SSL_AD_ILLEGAL_PARAMETER; + return 0; + } + + return 1; + } -- 2.25.1