source: https://code.google.com/p/mod-spdy/issues/detail?id=64 diff -ru modules/ssl/mod_ssl.c modules/ssl/mod_ssl.c --- modules/ssl/mod_ssl.c 2012-12-11 10:55:03.000000000 +0100 +++ modules/ssl/mod_ssl.c 2013-04-18 19:20:51.000000000 +0200 @@ -272,6 +272,18 @@ AP_END_CMD }; +/* Implement 'modssl_run_npn_advertise_protos_hook'. */ +APR_IMPLEMENT_OPTIONAL_HOOK_RUN_ALL( + modssl, AP, int, npn_advertise_protos_hook, + (conn_rec *connection, apr_array_header_t *protos), + (connection, protos), OK, DECLINED); + +/* Implement 'modssl_run_npn_proto_negotiated_hook'. */ +APR_IMPLEMENT_OPTIONAL_HOOK_RUN_ALL( + modssl, AP, int, npn_proto_negotiated_hook, + (conn_rec *connection, const char *proto_name, apr_size_t proto_name_len), + (connection, proto_name, proto_name_len), OK, DECLINED); + /* * the various processing hooks */ diff -ru modules/ssl/mod_ssl.h modules/ssl/mod_ssl.h --- modules/ssl/mod_ssl.h 2011-09-23 15:38:09.000000000 +0200 +++ modules/ssl/mod_ssl.h 2013-04-18 19:20:51.000000000 +0200 @@ -63,5 +63,26 @@ APR_DECLARE_OPTIONAL_FN(int, ssl_engine_disable, (conn_rec *)); +/** The npn_advertise_protos optional hook allows other modules to add entries + * to the list of protocol names advertised by the server during the Next + * Protocol Negotiation (NPN) portion of the SSL handshake. The hook callee is + * given the connection and an APR array; it should push one or more char*'s + * pointing to null-terminated strings (such as "http/1.1" or "spdy/2") onto + * the array and return OK, or do nothing and return DECLINED. */ +APR_DECLARE_EXTERNAL_HOOK(modssl, AP, int, npn_advertise_protos_hook, + (conn_rec *connection, apr_array_header_t *protos)); + +/** The npn_proto_negotiated optional hook allows other modules to discover the + * name of the protocol that was chosen during the Next Protocol Negotiation + * (NPN) portion of the SSL handshake. Note that this may be the empty string + * (in which case modules should probably assume HTTP), or it may be a protocol + * that was never even advertised by the server. The hook callee is given the + * connection, a non-null-terminated string containing the protocol name, and + * the length of the string; it should do something appropriate (i.e. insert or + * remove filters) and return OK, or do nothing and return DECLINED. */ +APR_DECLARE_EXTERNAL_HOOK(modssl, AP, int, npn_proto_negotiated_hook, + (conn_rec *connection, const char *proto_name, + apr_size_t proto_name_len)); + #endif /* __MOD_SSL_H__ */ /** @} */ diff -ru modules/ssl/ssl_engine_init.c modules/ssl/ssl_engine_init.c --- modules/ssl/ssl_engine_init.c 2012-12-11 10:55:03.000000000 +0100 +++ modules/ssl/ssl_engine_init.c 2013-04-18 19:20:51.000000000 +0200 @@ -725,6 +725,11 @@ #endif SSL_CTX_set_info_callback(ctx, ssl_callback_Info); + +#ifdef HAVE_TLS_NPN + SSL_CTX_set_next_protos_advertised_cb( + ctx, ssl_callback_AdvertiseNextProtos, NULL); +#endif } static void ssl_init_ctx_verify(server_rec *s, diff -ru modules/ssl/ssl_engine_io.c modules/ssl/ssl_engine_io.c --- modules/ssl/ssl_engine_io.c 2012-09-21 17:10:12.000000000 +0200 +++ modules/ssl/ssl_engine_io.c 2013-04-18 19:20:51.000000000 +0200 @@ -297,6 +297,7 @@ apr_pool_t *pool; char buffer[AP_IOBUFSIZE]; ssl_filter_ctx_t *filter_ctx; + int npn_finished; /* 1 if NPN has finished, 0 otherwise */ } bio_filter_in_ctx_t; /* @@ -1385,6 +1386,27 @@ APR_BRIGADE_INSERT_TAIL(bb, bucket); } +#ifdef HAVE_TLS_NPN + /* By this point, Next Protocol Negotiation (NPN) should be completed (if + * our version of OpenSSL supports it). If we haven't already, find out + * which protocol was decided upon and inform other modules by calling + * npn_proto_negotiated_hook. */ + if (!inctx->npn_finished) { + const unsigned char *next_proto = NULL; + unsigned next_proto_len = 0; + + SSL_get0_next_proto_negotiated( + inctx->ssl, &next_proto, &next_proto_len); + ap_log_cerror(APLOG_MARK, APLOG_DEBUG, APR_SUCCESS, f->c, + "SSL NPN negotiated protocol: '%s'", + apr_pstrmemdup(f->c->pool, (const char*)next_proto, + next_proto_len)); + modssl_run_npn_proto_negotiated_hook( + f->c, (const char*)next_proto, next_proto_len); + inctx->npn_finished = 1; + } +#endif + return APR_SUCCESS; } @@ -1866,6 +1888,7 @@ inctx->block = APR_BLOCK_READ; inctx->pool = c->pool; inctx->filter_ctx = filter_ctx; + inctx->npn_finished = 0; } /* The request_rec pointer is passed in here only to ensure that the diff -ru modules/ssl/ssl_engine_kernel.c modules/ssl/ssl_engine_kernel.c --- modules/ssl/ssl_engine_kernel.c 2012-12-11 10:55:03.000000000 +0100 +++ modules/ssl/ssl_engine_kernel.c 2013-04-18 19:20:51.000000000 +0200 @@ -2186,3 +2186,84 @@ } #endif /* OPENSSL_NO_SRP */ + +#ifdef HAVE_TLS_NPN +/* + * This callback function is executed when SSL needs to decide what protocols + * to advertise during Next Protocol Negotiation (NPN). It must produce a + * string in wire format -- a sequence of length-prefixed strings -- indicating + * the advertised protocols. Refer to SSL_CTX_set_next_protos_advertised_cb + * in OpenSSL for reference. + */ +int ssl_callback_AdvertiseNextProtos(SSL *ssl, const unsigned char **data_out, + unsigned int *size_out, void *arg) +{ + conn_rec *c = (conn_rec*)SSL_get_app_data(ssl); + apr_array_header_t *protos; + int num_protos; + unsigned int size; + int i; + unsigned char *data; + unsigned char *start; + + *data_out = NULL; + *size_out = 0; + + /* If the connection object is not available, then there's nothing for us + * to do. */ + if (c == NULL) { + return SSL_TLSEXT_ERR_OK; + } + + /* Invoke our npn_advertise_protos hook, giving other modules a chance to + * add alternate protocol names to advertise. */ + protos = apr_array_make(c->pool, 0, sizeof(char*)); + modssl_run_npn_advertise_protos_hook(c, protos); + num_protos = protos->nelts; + + /* We now have a list of null-terminated strings; we need to concatenate + * them together into a single string, where each protocol name is prefixed + * by its length. First, calculate how long that string will be. */ + size = 0; + for (i = 0; i < num_protos; ++i) { + const char *string = APR_ARRAY_IDX(protos, i, const char*); + unsigned int length = strlen(string); + /* If the protocol name is too long (the length must fit in one byte), + * then log an error and skip it. */ + if (length > 255) { + ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, + "SSL NPN protocol name too long (length=%u): %s", + length, string); + continue; + } + /* Leave room for the length prefix (one byte) plus the protocol name + * itself. */ + size += 1 + length; + } + + /* If there is nothing to advertise (either because no modules added + * anything to the protos array, or because all strings added to the array + * were skipped), then we're done. */ + if (size == 0) { + return SSL_TLSEXT_ERR_OK; + } + + /* Now we can build the string. Copy each protocol name string into the + * larger string, prefixed by its length. */ + data = apr_palloc(c->pool, size * sizeof(unsigned char)); + start = data; + for (i = 0; i < num_protos; ++i) { + const char *string = APR_ARRAY_IDX(protos, i, const char*); + apr_size_t length = strlen(string); + *start = (unsigned char)length; + ++start; + memcpy(start, string, length * sizeof(unsigned char)); + start += length; + } + + /* Success. */ + *data_out = data; + *size_out = size; + return SSL_TLSEXT_ERR_OK; +} +#endif diff -ru modules/ssl/ssl_private.h modules/ssl/ssl_private.h --- modules/ssl/ssl_private.h 2012-12-11 10:55:03.000000000 +0100 +++ modules/ssl/ssl_private.h 2013-04-18 19:20:51.000000000 +0200 @@ -149,6 +149,11 @@ #define OPENSSL_NO_EC #endif +#if OPENSSL_VERSION_NUMBER >= 0x10001000L && !defined(OPENSSL_NO_NEXTPROTONEG) \ + && !defined(OPENSSL_NO_TLSEXT) +#define HAVE_TLS_NPN +#endif + #ifndef PEM_F_DEF_CALLBACK #ifdef PEM_F_PEM_DEF_CALLBACK /** In OpenSSL 0.9.8 PEM_F_DEF_CALLBACK was renamed */ @@ -614,6 +619,7 @@ unsigned char aes_key[16]; } modssl_ticket_key_t; #endif +int ssl_callback_AdvertiseNextProtos(SSL *ssl, const unsigned char **data, unsigned int *len, void *arg); typedef struct SSLSrvConfigRec SSLSrvConfigRec;