Commit 68a16628 authored by Matt Caswell's avatar Matt Caswell
Browse files

Don't advance PACKET in ssl_check_for_safari 



The function ssl_check_for_safari fingerprints the incoming extensions
to see whether it is one of the broken versions of safari. However it was
failing to reset the PACKET back to the same position it started in, hence
causing some extensions to be skipped incorrectly.

Reviewed-by: default avatarEmilia Käsper <emilia@openssl.org>
parent 2d284623

ssl/t1_lib.c

+13 −10
Original line number Diff line number Diff line
@@ -1815,10 +1815,11 @@ static int tls1_alpn_handle_client_hello(SSL *s, PACKET *pkt, int *al) 
 * Sadly we cannot differentiate 10.6, 10.7 and 10.8.4 (which work), from

 * 10.8..10.8.3 (which don't work).

 */

static void ssl_check_for_safari(SSL *s, PACKET *pkt)

static void ssl_check_for_safari(SSL *s, const PACKET *pkt)

{

    unsigned int type, size;

    unsigned char *eblock1, *eblock2;

    PACKET tmppkt;



    static const unsigned char kSafariExtensionsBlock[] = {

        0x00, 0x0a,             /* elliptic_curves extension */
@@ -1846,10 +1847,12 @@ static void ssl_check_for_safari(SSL *s, PACKET *pkt) 
        0x02, 0x03,             /* SHA-1/ECDSA */

    };



    if (!PACKET_forward(pkt, 2)

            || !PACKET_get_net_2(pkt, &type)

            || !PACKET_get_net_2(pkt, &size)

            || !PACKET_forward(pkt, size))

    tmppkt = *pkt;



    if (!PACKET_forward(&tmppkt, 2)

            || !PACKET_get_net_2(&tmppkt, &type)

            || !PACKET_get_net_2(&tmppkt, &size)

            || !PACKET_forward(&tmppkt, size))

        return;



    if (type != TLSEXT_TYPE_server_name)
@@ -1859,9 +1862,9 @@ static void ssl_check_for_safari(SSL *s, PACKET *pkt) 
        const size_t len1 = sizeof(kSafariExtensionsBlock);

        const size_t len2 = sizeof(kSafariTLS12ExtensionsBlock);



        if (!PACKET_get_bytes(pkt, &eblock1, len1)

                || !PACKET_get_bytes(pkt, &eblock2, len2)

                || PACKET_remaining(pkt))

        if (!PACKET_get_bytes(&tmppkt, &eblock1, len1)

                || !PACKET_get_bytes(&tmppkt, &eblock2, len2)

                || PACKET_remaining(&tmppkt))

            return;

        if (memcmp(eblock1, kSafariExtensionsBlock, len1) != 0)

            return;
@@ -1870,8 +1873,8 @@ static void ssl_check_for_safari(SSL *s, PACKET *pkt) 
    } else {

        const size_t len = sizeof(kSafariExtensionsBlock);



        if (!PACKET_get_bytes(pkt, &eblock1, len)

                || PACKET_remaining(pkt))

        if (!PACKET_get_bytes(&tmppkt, &eblock1, len)

                || PACKET_remaining(&tmppkt))

            return;

        if (memcmp(eblock1, kSafariExtensionsBlock, len) != 0)

            return;