Commit 4040a7fd authored by Viktor Dukhovni's avatar Viktor Dukhovni Committed by Matt Caswell
Browse files

Better SSLv2 cipher-suite enforcement 



Based on patch by: Nimrod Aviram <nimrod.aviram@gmail.com>

CVE-2015-3197

Reviewed-by: default avatarTim Hudson <tjh@openssl.org>
Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
parent 8bc643ef

ssl/s2_srvr.c

+13 −2
Original line number Diff line number Diff line
@@ -402,7 +402,7 @@ static int get_client_master_key(SSL *s) 
        }



        cp = ssl2_get_cipher_by_char(p);

        if (cp == NULL) {

        if (cp == NULL || sk_SSL_CIPHER_find(s->session->ciphers, cp) < 0) {

            ssl2_return_error(s, SSL2_PE_NO_CIPHER);

            SSLerr(SSL_F_GET_CLIENT_MASTER_KEY, SSL_R_NO_CIPHER_MATCH);

            return (-1);
@@ -692,8 +692,12 @@ static int get_client_hello(SSL *s) 
            prio = cs;

            allow = cl;

        }



        /* Generate list of SSLv2 ciphers shared between client and server */

        for (z = 0; z < sk_SSL_CIPHER_num(prio); z++) {

            if (sk_SSL_CIPHER_find(allow, sk_SSL_CIPHER_value(prio, z)) < 0) {

            const SSL_CIPHER *cp = sk_SSL_CIPHER_value(prio, z);

            if ((cp->algorithm_ssl & SSL_SSLV2) == 0 ||

                sk_SSL_CIPHER_find(allow, cp) < 0) {

                (void)sk_SSL_CIPHER_delete(prio, z);

                z--;

            }
@@ -702,6 +706,13 @@ static int get_client_hello(SSL *s) 
            sk_SSL_CIPHER_free(s->session->ciphers);

            s->session->ciphers = prio;

        }



        /* Make sure we have at least one cipher in common */

        if (sk_SSL_CIPHER_num(s->session->ciphers) == 0) {

            ssl2_return_error(s, SSL2_PE_NO_CIPHER);

            SSLerr(SSL_F_GET_CLIENT_HELLO, SSL_R_NO_CIPHER_MATCH);

            return -1;

        }

        /*

         * s->session->ciphers should now have a list of ciphers that are on

         * both the client and server. This list is ordered by the order the