Commit 967d943b authored by Paul Querna's avatar Paul Querna
Browse files

Add support for RFC 5077 TLS Session tickets. This adds two new directives: 

* SSLTicketKeyFile: To store the private information for the encryption of the ticket.
* SSLTicketKeyDefault To set the default, otherwise the first listed token is used.  This enables key rotation across servers.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1200040 13f79535-47bb-0310-9956-ffa450edef68
parent cd66061d

CHANGES

+3 −0
Original line number Diff line number Diff line 
                                                         -*- coding: utf-8 -*-

Changes with Apache 2.3.16



  *) mod_ssl: Add support for RFC 5077 TLS Session tickets.

     [Paul Querna]



  *) mod_usertrack: Use random value instead of remote IP address.

     [Stefan Fritsch]

modules/ssl/mod_ssl.c

+8 −0
Original line number Diff line number Diff line
@@ -79,6 +79,14 @@ static const command_rec ssl_config_cmds[] = { 
    SSL_CMD_SRV(FIPS, FLAG,

                "Enable FIPS-140 mode "

                "(`on', `off')")

#ifdef HAVE_TLSEXT_TICKETS

    SSL_CMD_SRV(TicketKeyFile, TAKE2,

                "Key file to use for encrypting and decrypting the client ticket (RFC 5077) "

                "(keyname '/path/to/file')")

    SSL_CMD_SRV(TicketKeyDefault, TAKE1,

                "Set the key name used by default for new sessions "

               "(keyname)")

#endif

    SSL_CMD_ALL(CipherSuite, TAKE1,

                "Colon-delimited list of permitted SSL Ciphers "

                "('XXX:...:XXX' - see manual)")

modules/ssl/ssl_engine_config.c

+67 −0
Original line number Diff line number Diff line
@@ -200,6 +200,12 @@ static SSLSrvConfigRec *ssl_config_server_new(apr_pool_t *p) 
    sc->fips                   = UNSET;

#endif



#ifdef HAVE_TLSEXT_TICKETS

    sc->default_ticket_name = NULL;

    sc->default_ticket = NULL;

    sc->tickets = apr_array_make(p, 4, sizeof(modssl_ticket_t*));

#endif



    modssl_ctx_init_proxy(sc, p);



    modssl_ctx_init_server(sc, p);
@@ -304,6 +310,11 @@ void *ssl_config_server_merge(apr_pool_t *p, void *basev, void *addv) 


    cfgMerge(mc, NULL);

    cfgMerge(enabled, SSL_ENABLED_UNSET);

#ifdef HAVE_TLSEXT_TICKETS

    cfgMergeString(default_ticket_name);

    apr_array_cat(mrg->tickets, base->tickets);

    apr_array_cat(mrg->tickets, add->tickets);

#endif

    cfgMergeBool(proxy_enabled);

    cfgMergeInt(session_cache_timeout);

    cfgMergeBool(cipher_server_pref);
@@ -584,6 +595,62 @@ const char *ssl_cmd_SSLEngine(cmd_parms *cmd, void *dcfg, const char *arg) 
    return "Argument must be On, Off, or Optional";

}



const char *ssl_cmd_SSLTicketKeyDefault(cmd_parms *cmd, void *dcfg, const char *name)

{

#ifdef HAVE_TLSEXT_TICKETS

    SSLSrvConfigRec *sc = mySrvConfig(cmd->server);



    sc->default_ticket_name = name;



    return NULL;

#else

    return "TLS Ticket keys are not supported.";

#endif

}



const char *ssl_cmd_SSLTicketKeyFile(cmd_parms *cmd, void *dcfg, const char *name, const char *path)

{

#ifdef HAVE_TLSEXT_TICKETS

    apr_status_t rv;

    apr_file_t *fp;

    apr_size_t len;

    char buf[TLSEXT_TICKET_KEYLEN];

    modssl_ticket_t* ticket = NULL;

    SSLSrvConfigRec *sc = mySrvConfig(cmd->server);



    rv = apr_file_open(&fp, path, APR_READ|APR_BINARY,

                       APR_OS_DEFAULT, cmd->temp_pool);



    if (rv != APR_SUCCESS) {

      return apr_psprintf(cmd->pool,

                          "Failed to open %s: (%d) %pm",

                          path, rv, &rv);

    }



    rv = apr_file_read_full(fp, &buf[0], TLSEXT_TICKET_KEYLEN, &len);



    if (rv != APR_SUCCESS) {

      return apr_psprintf(cmd->pool,

                          "Failed to read at least 48 bytes from %s: (%d) %pm",

                          path, rv, &rv);

    }



    ticket = apr_palloc(cmd->pool, sizeof(modssl_ticket_t));



    ticket->conf_name = name;



    memcpy(ticket->key_name, buf, 16);

    memcpy(ticket->hmac_secret, buf + 16, 16);

    memcpy(ticket->aes_key, buf + 32, 16);



    APR_ARRAY_PUSH(sc->tickets, modssl_ticket_t*) = ticket;



    return NULL;

#else

    return "TLS Ticket keys are not supported.";

#endif

}



const char *ssl_cmd_SSLFIPS(cmd_parms *cmd, void *dcfg, int flag)

{

#ifdef HAVE_FIPS

modules/ssl/ssl_engine_init.c

+37 −0
Original line number Diff line number Diff line
@@ -1143,6 +1143,43 @@ static void ssl_init_server_certs(server_rec *s, 
#endif

        ssl_die();

    }



#ifdef HAVE_TLSEXT_TICKETS

    if (mctx->sc->tickets->nelts > 0) { 



        if (mctx->sc->default_ticket_name != NULL) {

            int i;

            modssl_ticket_t* ticket = NULL;

            mctx->sc->default_ticket = NULL;



            for (i = 0; i < mctx->sc->tickets->nelts; i++) {

                ticket = APR_ARRAY_IDX(mctx->sc->tickets, i, modssl_ticket_t*);

                if (strcmp(ticket->conf_name, mctx->sc->default_ticket_name) == 0) {

                    mctx->sc->default_ticket = ticket;

                }

            }



            if (mctx->sc->default_ticket == NULL) {

                ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s,

                            "Misconfigured TLS Tickets.  Couldn't find key named '%s'",

                            mctx->sc->default_ticket_name);

                ssl_die();

            }

        }

        else {

            mctx->sc->default_ticket = APR_ARRAY_IDX(mctx->sc->tickets, 0, modssl_ticket_t*);

        }



        if (!SSL_CTX_set_tlsext_ticket_key_cb(mctx->ssl_ctx, ssl_callback_tlsext_tickets)) {

            ap_log_error(APLOG_MARK, APLOG_EMERG, 0, s,

                        "Unable to initialize TLS session ticket extension "

                        "(incompatible OpenSSL version?)");

            ssl_log_ssl_error(SSLLOG_MARK, APLOG_EMERG, s);

            ssl_die();

        }

    }

#endif



}



static void ssl_init_proxy_certs(server_rec *s,

modules/ssl/ssl_engine_kernel.c

+91 −0
Original line number Diff line number Diff line
@@ -2067,3 +2067,94 @@ static int ssl_find_vhost(void *servername, conn_rec *c, server_rec *s) 
    return 0;

}

#endif



#ifdef HAVE_TLSEXT_TICKETS



#ifndef tlsext_tick_md

#ifdef OPENSSL_NO_SHA256

#define tlsext_tick_md	EVP_sha1

#else

#define tlsext_tick_md	EVP_sha256

#endif

#endif



int ssl_callback_tlsext_tickets(SSL *ssl,

                                char *keyname,

                                char *iv,

                                EVP_CIPHER_CTX *cipher_ctx,

                                HMAC_CTX *hctx,

                                int mode)

{

    conn_rec *conn      = (conn_rec *)SSL_get_app_data(ssl);

    server_rec *s       = mySrvFromConn(conn);

    SSLSrvConfigRec *sc = mySrvConfig(s);



    if (mode == 1) {

        modssl_ticket_t* ticket = sc->default_ticket;



        /* Setting up the stuff for encrypting:

         *  - keyname contains at least 16 bytes we can write to.

         *  - iv contains at least EVP_MAX_IV_LENGTH (16) bytes we can write to.

         *  - hctx is already allocated, we just need to set the

         *    secret key via HMAC_Init_ex.

         *  - cipher_ctx is also allocated, and we need to configure

         *    the cipher and private key.

         */



        if (ticket == NULL) {

            /* this should not happen, we always set the default

             * ticket.

             */

            return -1;

        }



        memcpy(keyname, ticket->key_name, 16);



        RAND_pseudo_bytes(iv, EVP_MAX_IV_LENGTH);



        memcpy(iv, iv, EVP_MAX_IV_LENGTH);



        EVP_EncryptInit_ex(cipher_ctx, EVP_aes_128_cbc(), NULL,

                           ticket->aes_key, iv);



        HMAC_Init_ex(hctx, ticket->hmac_secret, 16, tlsext_tick_md(), NULL);



        return 0;

    }

    else if (mode == 0) {

        /* Setup contextes for decryption, based on the keyname input */

        int i;

        modssl_ticket_t* ticket = NULL;



        for (i = 0; i < sc->tickets->nelts; i++) {

            modssl_ticket_t* itticket = APR_ARRAY_IDX(sc->tickets, i, modssl_ticket_t*);

            if (memcmp(keyname, itticket->key_name, 16) == 0) {

                ticket = itticket;

                break;

            }

        }



        if (ticket == NULL) {

            /* Ticket key not found, but no error */

            return 0;

        }



        EVP_DecryptInit_ex(cipher_ctx, EVP_aes_128_cbc(), NULL, ticket->aes_key, iv);



        HMAC_Init_ex(hctx, ticket->hmac_secret, 16, tlsext_tick_md(), NULL);



        if (ticket != sc->default_ticket) {

            /* Ticket key found, we did our stuff, but didn't use the default,

             * re-issue a ticket with the default ticket */

            return 2;

        }

        else {

            return 1;

        }

    }



    /* TODO: log invalid use */

    return -1;

}



#endif