From d64b6c980c8101e2d96c982c0b211ac3f94a3aaa Mon Sep 17 00:00:00 2001 From: Matt Caswell Date: Wed, 15 Oct 2014 01:03:32 +0100 Subject: [PATCH] Fix for SRTP Memory Leak CVE-2014-3513 This issue was reported to OpenSSL on 26th September 2014, based on an original issue and patch developed by the LibreSSL project. Further analysis of the issue was performed by the OpenSSL team. The fix was developed by the OpenSSL team. Reviewed-by: Tim Hudson --- ssl/d1_srtp.c | 93 +++++++++++++++++---------------------------------- ssl/t1_lib.c | 9 ++--- 2 files changed, 36 insertions(+), 66 deletions(-) diff --git a/ssl/d1_srtp.c b/ssl/d1_srtp.c index 928935bd8..ac1bef00a 100644 --- a/ssl/d1_srtp.c +++ b/ssl/d1_srtp.c @@ -167,25 +167,6 @@ static int find_profile_by_name(char *profile_name, return 1; } -static int find_profile_by_num(unsigned profile_num, - SRTP_PROTECTION_PROFILE **pptr) - { - SRTP_PROTECTION_PROFILE *p; - - p=srtp_known_profiles; - while(p->name) - { - if(p->id == profile_num) - { - *pptr=p; - return 0; - } - p++; - } - - return 1; - } - static int ssl_ctx_make_profiles(const char *profiles_string,STACK_OF(SRTP_PROTECTION_PROFILE) **out) { STACK_OF(SRTP_PROTECTION_PROFILE) *profiles; @@ -208,11 +189,19 @@ static int ssl_ctx_make_profiles(const char *profiles_string,STACK_OF(SRTP_PROTE if(!find_profile_by_name(ptr,&p, col ? col-ptr : (int)strlen(ptr))) { + if (sk_SRTP_PROTECTION_PROFILE_find(profiles,p) >= 0) + { + SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST); + sk_SRTP_PROTECTION_PROFILE_free(profiles); + return 1; + } + sk_SRTP_PROTECTION_PROFILE_push(profiles,p); } else { SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE); + sk_SRTP_PROTECTION_PROFILE_free(profiles); return 1; } @@ -304,13 +293,12 @@ int ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len, int max int ssl_parse_clienthello_use_srtp_ext(SSL *s, unsigned char *d, int len,int *al) { - SRTP_PROTECTION_PROFILE *cprof,*sprof; - STACK_OF(SRTP_PROTECTION_PROFILE) *clnt=0,*srvr; + SRTP_PROTECTION_PROFILE *sprof; + STACK_OF(SRTP_PROTECTION_PROFILE) *srvr; int ct; int mki_len; - int i,j; - int id; - int ret; + int i, srtp_pref; + unsigned int id; /* Length value + the MKI length */ if(len < 3) @@ -340,22 +328,32 @@ int ssl_parse_clienthello_use_srtp_ext(SSL *s, unsigned char *d, int len,int *al return 1; } + srvr=SSL_get_srtp_profiles(s); + s->srtp_profile = NULL; + /* Search all profiles for a match initially */ + srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr); - clnt=sk_SRTP_PROTECTION_PROFILE_new_null(); - while(ct) { n2s(d,id); ct-=2; len-=2; - if(!find_profile_by_num(id,&cprof)) + /* + * Only look for match in profiles of higher preference than + * current match. + * If no profiles have been have been configured then this + * does nothing. + */ + for (i = 0; i < srtp_pref; i++) { - sk_SRTP_PROTECTION_PROFILE_push(clnt,cprof); - } - else - { - ; /* Ignore */ + sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i); + if (sprof->id == id) + { + s->srtp_profile = sprof; + srtp_pref = i; + break; + } } } @@ -370,36 +368,7 @@ int ssl_parse_clienthello_use_srtp_ext(SSL *s, unsigned char *d, int len,int *al return 1; } - srvr=SSL_get_srtp_profiles(s); - - /* Pick our most preferred profile. If no profiles have been - configured then the outer loop doesn't run - (sk_SRTP_PROTECTION_PROFILE_num() = -1) - and so we just return without doing anything */ - for(i=0;iid==sprof->id) - { - s->srtp_profile=sprof; - *al=0; - ret=0; - goto done; - } - } - } - - ret=0; - -done: - if(clnt) sk_SRTP_PROTECTION_PROFILE_free(clnt); - - return ret; + return 0; } int ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len, int maxlen) diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c index 5fed446ae..c747b3092 100644 --- a/ssl/t1_lib.c +++ b/ssl/t1_lib.c @@ -1474,7 +1474,7 @@ unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned c ret += s->alpn_client_proto_list_len; } - if(SSL_get_srtp_profiles(s)) + if(SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)) { int el; @@ -1648,7 +1648,7 @@ unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf, unsigned c } #endif - if(s->srtp_profile) + if(SSL_IS_DTLS(s) && s->srtp_profile) { int el; @@ -2417,7 +2417,8 @@ static int ssl_scan_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char } /* session ticket processed earlier */ - else if (type == TLSEXT_TYPE_use_srtp) + else if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s) + && type == TLSEXT_TYPE_use_srtp) { if(ssl_parse_clienthello_use_srtp_ext(s, data, size, al)) @@ -2750,7 +2751,7 @@ static int ssl_scan_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char } } #endif - else if (type == TLSEXT_TYPE_use_srtp) + else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_use_srtp) { if(ssl_parse_serverhello_use_srtp_ext(s, data, size, al))