Commit 1ed65871 authored by David Benjamin's avatar David Benjamin Committed by Kurt Roeckx
Browse files

Resolve DTLS cookie and version before session resumption. 



Session resumption involves a version check, so version negotiation must
happen first. Currently, the DTLS implementation cannot do session
resumption in DTLS 1.0 because the ssl_version check always checks
against 1.2.

Switching the order also removes the need to fixup ssl_version in DTLS
version negotiation.

Signed-off-by: default avatarKurt Roeckx <kurt@roeckx.be>
Reviewed-by: default avatarViktor Dukhovni <viktor@openssl.org>

RT: #4392, MR: #2452
parent 71ccf961

ssl/statem/statem_srvr.c

+32 −33
Original line number Diff line number Diff line
@@ -1152,6 +1152,38 @@ MSG_PROCESS_RETURN tls_process_client_hello(SSL *s, PACKET *pkt) 
        extensions = *pkt;

    }



    if (SSL_IS_DTLS(s)) {

        /* Empty cookie was already handled above by returning early. */

        if (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) {

            if (s->ctx->app_verify_cookie_cb != NULL) {

                if (s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookie),

                                                 PACKET_remaining(&cookie)) == 0) {

                    al = SSL_AD_HANDSHAKE_FAILURE;

                    SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO,

                           SSL_R_COOKIE_MISMATCH);

                    goto f_err;

                    /* else cookie verification succeeded */

                }

            /* default verification */

            } else if (!PACKET_equal(&cookie, s->d1->cookie,

                                     s->d1->cookie_len)) {

                al = SSL_AD_HANDSHAKE_FAILURE;

                SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_COOKIE_MISMATCH);

                goto f_err;

            }

            s->d1->cookie_verified = 1;

        }

        if (s->method->version == DTLS_ANY_VERSION) {

            protverr = ssl_choose_server_version(s);

            if (protverr != 0) {

                SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, protverr);

                s->version = s->client_version;

                al = SSL_AD_PROTOCOL_VERSION;

                goto f_err;

            }

        }

    }



    s->hit = 0;



    /*
@@ -1198,39 +1230,6 @@ MSG_PROCESS_RETURN tls_process_client_hello(SSL *s, PACKET *pkt) 
        }

    }



    if (SSL_IS_DTLS(s)) {

        /* Empty cookie was already handled above by returning early. */

        if (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) {

            if (s->ctx->app_verify_cookie_cb != NULL) {

                if (s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookie),

                                                 PACKET_remaining(&cookie)) == 0) {

                    al = SSL_AD_HANDSHAKE_FAILURE;

                    SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO,

                           SSL_R_COOKIE_MISMATCH);

                    goto f_err;

                    /* else cookie verification succeeded */

                }

            /* default verification */

            } else if (!PACKET_equal(&cookie, s->d1->cookie,

                                     s->d1->cookie_len)) {

                al = SSL_AD_HANDSHAKE_FAILURE;

                SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, SSL_R_COOKIE_MISMATCH);

                goto f_err;

            }

            s->d1->cookie_verified = 1;

        }

        if (s->method->version == DTLS_ANY_VERSION) {

            protverr = ssl_choose_server_version(s);

            if (protverr != 0) {

                SSLerr(SSL_F_TLS_PROCESS_CLIENT_HELLO, protverr);

                s->version = s->client_version;

                al = SSL_AD_PROTOCOL_VERSION;

                goto f_err;

            }

            s->session->ssl_version = s->version;

        }

    }



    if (ssl_bytes_to_cipher_list(s, &cipher_suites, &(ciphers),

                                 is_v2_record, &al) == NULL) {

        goto f_err;