X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fstatem%2Fextensions.c;h=dc992010ec46f632a46e8d88bdee654157a6c006;hp=a50756a071ea6d61d4a676c96452b01149d9978b;hb=b2f7e8c0fe2f4e8d3d14fa30805211daa5456ffa;hpb=68db4ddab7d35f5a3df1beee9a95fe093682340b diff --git a/ssl/statem/extensions.c b/ssl/statem/extensions.c index a50756a071..dc992010ec 100644 --- a/ssl/statem/extensions.c +++ b/ssl/statem/extensions.c @@ -7,225 +7,252 @@ * https://www.openssl.org/source/license.html */ -#include #include "../ssl_locl.h" #include "statem_locl.h" -typedef struct { - /* The ID for the extension */ +static int final_renegotiate(SSL *s, unsigned int context, int sent, + int *al); +static int init_server_name(SSL *s, unsigned int context); +static int final_server_name(SSL *s, unsigned int context, int sent, + int *al); +#ifndef OPENSSL_NO_EC +static int final_ec_pt_formats(SSL *s, unsigned int context, int sent, + int *al); +#endif +static int init_session_ticket(SSL *s, unsigned int context); +#ifndef OPENSSL_NO_OCSP +static int init_status_request(SSL *s, unsigned int context); +#endif +#ifndef OPENSSL_NO_NEXTPROTONEG +static int init_npn(SSL *s, unsigned int context); +#endif +static int init_alpn(SSL *s, unsigned int context); +static int final_alpn(SSL *s, unsigned int context, int sent, int *al); +static int init_sig_algs(SSL *s, unsigned int context); +#ifndef OPENSSL_NO_SRP +static int init_srp(SSL *s, unsigned int context); +#endif +static int init_etm(SSL *s, unsigned int context); +static int init_ems(SSL *s, unsigned int context); +static int final_ems(SSL *s, unsigned int context, int sent, int *al); +static int init_psk_kex_modes(SSL *s, unsigned int context); +#ifndef OPENSSL_NO_SRTP +static int init_srtp(SSL *s, unsigned int context); +#endif +static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al); + +/* Structure to define a built-in extension */ +typedef struct extensions_definition_st { + /* The defined type for the extension */ unsigned int type; /* - * Initialise extension before parsing. Always called even if extension not - * present + * The context that this extension applies to, e.g. what messages and + * protocol versions */ - int (*init_ext)(SSL *s, unsigned int context); - /* Parse extension received by server from client */ - int (*parse_client_ext)(SSL *s, PACKET *pkt, int *al); - /* Parse extension received by client from server */ - int (*parse_server_ext)(SSL *s, PACKET *pkt, int *al); - /* Construct extension sent by server */ - int (*construct_server_ext)(SSL *s, WPACKET *pkt, int *al); - /* Construct extension sent by client */ - int (*construct_client_ext)(SSL *s, WPACKET *pkt, int *al); + unsigned int context; /* - * Finalise extension after parsing. Always called even if extension not - * present + * Initialise extension before parsing. Always called for relevant contexts + * even if extension not present */ - int (*finalise_ext)(SSL *s, unsigned int context); - unsigned int context; + int (*init)(SSL *s, unsigned int context); + /* Parse extension sent from client to server */ + int (*parse_ctos)(SSL *s, PACKET *pkt, X509 *x, size_t chainidx, int *al); + /* Parse extension send from server to client */ + int (*parse_stoc)(SSL *s, PACKET *pkt, X509 *x, size_t chainidx, int *al); + /* Construct extension sent from server to client */ + int (*construct_stoc)(SSL *s, WPACKET *pkt, X509 *x, size_t chainidx, + int *al); + /* Construct extension sent from client to server */ + int (*construct_ctos)(SSL *s, WPACKET *pkt, X509 *x, size_t chainidx, + int *al); + /* + * Finalise extension after parsing. Always called where an extensions was + * initialised even if the extension was not present. |sent| is set to 1 if + * the extension was seen, or 0 otherwise. + */ + int (*final)(SSL *s, unsigned int context, int sent, int *al); } EXTENSION_DEFINITION; /* - * TODO(TLS1.3): Temporarily modified the definitions below to put all TLS1.3 - * extensions in the ServerHello for now. That needs to be put back to correct - * setting once encrypted extensions is working properly. + * Definitions of all built-in extensions. NOTE: Changes in the number or order + * of these extensions should be mirrored with equivalent changes to the + * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h. + * Each extension has an initialiser, a client and + * server side parser and a finaliser. The initialiser is called (if the + * extension is relevant to the given context) even if we did not see the + * extension in the message that we received. The parser functions are only + * called if we see the extension in the message. The finalisers are always + * called if the initialiser was called. + * There are also server and client side constructor functions which are always + * called during message construction if the extension is relevant for the + * given context. + * The initialisation, parsing, finalisation and construction functions are + * always called in the order defined in this list. Some extensions may depend + * on others having been processed first, so the order of this list is + * significant. + * The extension context is defined by a series of flags which specify which + * messages the extension is relevant to. These flags also specify whether the + * extension is relevant to a particular protocol or protocol version. + * + * TODO(TLS1.3): Make sure we have a test to check the consistency of these */ +#define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL } static const EXTENSION_DEFINITION ext_defs[] = { { TLSEXT_TYPE_renegotiate, - NULL, - tls_parse_client_renegotiate, - tls_parse_server_renegotiate, - tls_construct_server_renegotiate, - tls_construct_client_renegotiate, - NULL, EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_SSL3_ALLOWED - | EXT_TLS1_2_AND_BELOW_ONLY + | EXT_TLS1_2_AND_BELOW_ONLY, + NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate, + tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate, + final_renegotiate }, { TLSEXT_TYPE_server_name, - NULL, - tls_parse_client_server_name, - tls_parse_server_server_name, - tls_construct_server_server_name, - tls_construct_client_server_name, - NULL, EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO - | EXT_TLS1_3_ENCRYPTED_EXTENSIONS + | EXT_TLS1_3_ENCRYPTED_EXTENSIONS, + init_server_name, + tls_parse_ctos_server_name, tls_parse_stoc_server_name, + tls_construct_stoc_server_name, tls_construct_ctos_server_name, + final_server_name }, #ifndef OPENSSL_NO_SRP { TLSEXT_TYPE_srp, - NULL, - tls_parse_client_srp, - NULL, - NULL, - tls_construct_client_srp, - NULL, - EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY + EXT_CLIENT_HELLO | EXT_TLS1_2_AND_BELOW_ONLY, + init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL }, +#else + INVALID_EXTENSION, #endif #ifndef OPENSSL_NO_EC { TLSEXT_TYPE_ec_point_formats, - NULL, - tls_parse_client_ec_pt_formats, - tls_parse_server_ec_pt_formats, - tls_construct_server_ec_pt_formats, - tls_construct_client_ec_pt_formats, - NULL, - EXT_CLIENT_HELLO | EXT_TLS1_2_AND_BELOW_ONLY + EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY, + NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats, + tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats, + final_ec_pt_formats }, { TLSEXT_TYPE_supported_groups, - NULL, - tls_parse_client_supported_groups, - NULL, + EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS, + NULL, tls_parse_ctos_supported_groups, NULL, NULL /* TODO(TLS1.3): Need to add this */, - tls_construct_client_supported_groups, - NULL, - EXT_CLIENT_HELLO | EXT_TLS1_3_ENCRYPTED_EXTENSIONS + tls_construct_ctos_supported_groups, NULL }, +#else + INVALID_EXTENSION, + INVALID_EXTENSION, #endif { TLSEXT_TYPE_session_ticket, - NULL, - tls_parse_client_session_ticket, - tls_parse_server_session_ticket, - tls_construct_server_session_ticket, - tls_construct_client_session_ticket, - NULL, - EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY + EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY, + init_session_ticket, tls_parse_ctos_session_ticket, + tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket, + tls_construct_ctos_session_ticket, NULL }, { TLSEXT_TYPE_signature_algorithms, - NULL, - tls_parse_client_sig_algs, - NULL, - NULL, - tls_construct_client_sig_algs, - NULL, - EXT_CLIENT_HELLO + EXT_CLIENT_HELLO, + init_sig_algs, tls_parse_ctos_sig_algs, NULL, NULL, + tls_construct_ctos_sig_algs, final_sig_algs }, #ifndef OPENSSL_NO_OCSP { TLSEXT_TYPE_status_request, - NULL, - tls_parse_client_status_request, - tls_parse_server_status_request, - tls_construct_server_status_request, - tls_construct_client_status_request, - NULL, EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO - | EXT_TLS1_3_CERTIFICATE + | EXT_TLS1_3_CERTIFICATE, + init_status_request, tls_parse_ctos_status_request, + tls_parse_stoc_status_request, tls_construct_stoc_status_request, + tls_construct_ctos_status_request, NULL }, +#else + INVALID_EXTENSION, #endif #ifndef OPENSSL_NO_NEXTPROTONEG { TLSEXT_TYPE_next_proto_neg, - NULL, - tls_parse_client_npn, - tls_parse_server_npn, - tls_construct_server_next_proto_neg, - tls_construct_client_npn, - NULL, - EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY + EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY, + init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn, + tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL }, +#else + INVALID_EXTENSION, #endif { + /* + * Must appear in this list after server_name so that finalisation + * happens after server_name callbacks + */ TLSEXT_TYPE_application_layer_protocol_negotiation, - NULL, - tls_parse_client_alpn, - tls_parse_server_alpn, - tls_construct_server_alpn, - tls_construct_client_alpn, - NULL, EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO - | EXT_TLS1_3_ENCRYPTED_EXTENSIONS + | EXT_TLS1_3_ENCRYPTED_EXTENSIONS, + init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn, + tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn }, #ifndef OPENSSL_NO_SRTP { TLSEXT_TYPE_use_srtp, - NULL, - tls_parse_client_use_srtp, - tls_parse_server_use_srtp, - tls_construct_server_use_srtp, - tls_construct_client_use_srtp, - NULL, EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO - | EXT_TLS1_3_ENCRYPTED_EXTENSIONS | EXT_DTLS_ONLY + | EXT_TLS1_3_ENCRYPTED_EXTENSIONS | EXT_DTLS_ONLY, + init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp, + tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL }, +#else + INVALID_EXTENSION, #endif { TLSEXT_TYPE_encrypt_then_mac, - NULL, - tls_parse_client_etm, - tls_parse_server_etm, - tls_construct_server_etm, - tls_construct_client_etm, - NULL, - EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY + EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY, + init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm, + tls_construct_stoc_etm, tls_construct_ctos_etm, NULL }, #ifndef OPENSSL_NO_CT { TLSEXT_TYPE_signed_certificate_timestamp, + EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO + | EXT_TLS1_3_CERTIFICATE, NULL, /* * No server side support for this, but can be provided by a custom * extension. This is an exception to the rule that custom extensions * cannot override built in ones. */ - NULL, - tls_parse_server_sct, - NULL, - tls_construct_client_sct, - NULL, - EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO - | EXT_TLS1_3_CERTIFICATE + NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL }, +#else + INVALID_EXTENSION, #endif { TLSEXT_TYPE_extended_master_secret, - NULL, - tls_parse_client_ems, - tls_parse_server_ems, - tls_construct_server_ems, - tls_construct_client_ems, - NULL, - EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY + EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY, + init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems, + tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems }, { TLSEXT_TYPE_supported_versions, + EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY, NULL, /* Processed inline as part of version selection */ - NULL, - NULL, - NULL, - tls_construct_client_supported_versions, - NULL, - EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY + NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL + }, + { + /* Must be before key_share */ + TLSEXT_TYPE_psk_kex_modes, + EXT_CLIENT_HELLO | EXT_TLS_IMPLEMENTATION_ONLY | EXT_TLS1_3_ONLY, + init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL, + tls_construct_ctos_psk_kex_modes, NULL }, { + /* + * Must be in this list after supported_groups. We need that to have + * been parsed before we do this one. + */ TLSEXT_TYPE_key_share, - NULL, - tls_parse_client_key_share, - tls_parse_server_key_share, - tls_construct_server_key_share, - tls_construct_client_key_share, - NULL, EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_ONLY - | EXT_TLS1_3_ONLY + | EXT_TLS1_3_ONLY, + NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share, + tls_construct_stoc_key_share, tls_construct_ctos_key_share, NULL }, { /* @@ -233,177 +260,167 @@ static const EXTENSION_DEFINITION ext_defs[] = { * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set */ TLSEXT_TYPE_cryptopro_bug, - NULL, - NULL, - NULL, - tls_construct_server_cryptopro_bug, - NULL, - NULL, - EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY + EXT_TLS1_2_SERVER_HELLO | EXT_TLS1_2_AND_BELOW_ONLY, + NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL }, { /* Last in the list because it must be added as the last extension */ TLSEXT_TYPE_padding, + EXT_CLIENT_HELLO, NULL, /* We send this, but don't read it */ - NULL, - NULL, - NULL, - tls_construct_client_padding, - NULL, - EXT_CLIENT_HELLO + NULL, NULL, NULL, tls_construct_ctos_padding, NULL } }; -/* - * Comparison function used in a call to qsort (see tls_collect_extensions() - * below.) - * The two arguments |p1| and |p2| are expected to be pointers to RAW_EXTENSIONs - * - * Returns: - * 1 if the type for p1 is greater than p2 - * 0 if the type for p1 and p2 are the same - * -1 if the type for p1 is less than p2 - */ -static int compare_extensions(const void *p1, const void *p2) -{ - const RAW_EXTENSION *e1 = (const RAW_EXTENSION *)p1; - const RAW_EXTENSION *e2 = (const RAW_EXTENSION *)p2; - - if (e1->type < e2->type) - return -1; - else if (e1->type > e2->type) - return 1; - - return 0; -} - /* * Verify whether we are allowed to use the extension |type| in the current * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to - * indicate the extension is not allowed. + * indicate the extension is not allowed. If returning 1 then |*found| is set to + * 1 if we found a definition for the extension, and |*idx| is set to its index */ -static int verify_extension(SSL *s, unsigned int context, unsigned int type) +static int verify_extension(SSL *s, unsigned int context, unsigned int type, + custom_ext_methods *meths, RAW_EXTENSION *rawexlist, + RAW_EXTENSION **found) { size_t i; + size_t builtin_num = OSSL_NELEM(ext_defs); + const EXTENSION_DEFINITION *thisext; - for (i = 0; i < OSSL_NELEM(ext_defs); i++) { - if (type == ext_defs[i].type) { + for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) { + if (type == thisext->type) { /* Check we're allowed to use this extension in this context */ - if ((context & ext_defs[i].context) == 0) + if ((context & thisext->context) == 0) return 0; if (SSL_IS_DTLS(s)) { - if ((ext_defs[i].context & EXT_TLS_ONLY) != 0) + if ((thisext->context & EXT_TLS_ONLY) != 0) return 0; - } else if ((ext_defs[i].context & EXT_DTLS_ONLY) != 0) { + } else if ((thisext->context & EXT_DTLS_ONLY) != 0) { return 0; } + *found = &rawexlist[i]; return 1; } } + if ((context & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) == 0) { + /* + * Custom extensions only apply to <=TLS1.2. This extension is unknown + * in this context - we allow it + */ + *found = NULL; + return 1; + } + + /* Check the custom extensions */ + if (meths != NULL) { + for (i = builtin_num; i < builtin_num + meths->meths_count; i++) { + if (meths->meths[i - builtin_num].ext_type == type) { + *found = &rawexlist[i]; + return 1; + } + } + } + /* Unknown extension. We allow it */ + *found = NULL; return 1; } /* - * Finds an extension definition for the give extension |type|. - * Returns 1 if found and stores the definition in |*def|, or returns 0 - * otherwise. + * Check whether the context defined for an extension |extctx| means whether + * the extension is relevant for the current context |thisctx| or not. Returns + * 1 if the extension is relevant for this context, and 0 otherwise */ -static int find_extension_definition(SSL *s, unsigned int type, - const EXTENSION_DEFINITION **def) +static int extension_is_relevant(SSL *s, unsigned int extctx, + unsigned int thisctx) { - size_t i; - - for (i = 0; i < OSSL_NELEM(ext_defs); i++) { - if (type == ext_defs[i].type) { - *def = &ext_defs[i]; - return 1; - } - } + if ((SSL_IS_DTLS(s) + && (extctx & EXT_TLS_IMPLEMENTATION_ONLY) != 0) + || (s->version == SSL3_VERSION + && (extctx & EXT_SSL3_ALLOWED) == 0) + || (SSL_IS_TLS13(s) + && (extctx & EXT_TLS1_2_AND_BELOW_ONLY) != 0) + || (!SSL_IS_TLS13(s) && (extctx & EXT_TLS1_3_ONLY) != 0)) + return 0; - /* Unknown extension */ - return 0; + return 1; } /* * Gather a list of all the extensions from the data in |packet]. |context| - * tells us which message this extension is for. Ttls_parse_server_ec_pt_formatshe raw extension data is - * stored in |*res| with the number of found extensions in |*numfound|. In the - * event of an error the alert type to use is stored in |*ad|. We don't actually - * process the content of the extensions yet, except to check their types. + * tells us which message this extension is for. The raw extension data is + * stored in |*res| on success. In the event of an error the alert type to use + * is stored in |*al|. We don't actually process the content of the extensions + * yet, except to check their types. This function also runs the initialiser + * functions for all known extensions (whether we have collected them or not). + * If successful the caller is responsible for freeing the contents of |*res|. * * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be * more than one extension of the same type in a ClientHello or ServerHello. * This function returns 1 if all extensions are unique and we have parsed their * types, and 0 if the extensions contain duplicates, could not be successfully - * parsed, or an internal error occurred. + * found, or an internal error occurred. We only check duplicates for + * extensions that we know about. We ignore others. */ - int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context, - RAW_EXTENSION **res, size_t *numfound, int *ad) + RAW_EXTENSION **res, int *al) { PACKET extensions = *packet; - size_t num_extensions = 0, i = 0; + size_t i = 0; + custom_ext_methods *exts = NULL; RAW_EXTENSION *raw_extensions = NULL; + const EXTENSION_DEFINITION *thisexd; + + *res = NULL; + + /* + * Initialise server side custom extensions. Client side is done during + * construction of extensions for the ClientHello. + */ + if ((context & EXT_CLIENT_HELLO) != 0) { + exts = &s->cert->srv_ext; + custom_ext_init(&s->cert->srv_ext); + } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) { + exts = &s->cert->cli_ext; + } + + raw_extensions = OPENSSL_zalloc((OSSL_NELEM(ext_defs) + + (exts != NULL ? exts->meths_count : 0)) + * sizeof(*raw_extensions)); + if (raw_extensions == NULL) { + *al = SSL_AD_INTERNAL_ERROR; + SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE); + return 0; + } - /* First pass: count the extensions. */ while (PACKET_remaining(&extensions) > 0) { unsigned int type; PACKET extension; + RAW_EXTENSION *thisex; if (!PACKET_get_net_2(&extensions, &type) || !PACKET_get_length_prefixed_2(&extensions, &extension)) { SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION); - *ad = SSL_AD_DECODE_ERROR; + *al = SSL_AD_DECODE_ERROR; goto err; } - /* Verify this extension is allowed */ - if (!verify_extension(s, context, type)) { + /* + * Verify this extension is allowed. We only check duplicates for + * extensions that we recognise. + */ + if (!verify_extension(s, context, type, exts, raw_extensions, &thisex) + || (thisex != NULL && thisex->present == 1)) { SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_BAD_EXTENSION); - *ad = SSL_AD_ILLEGAL_PARAMETER; - goto err; - } - num_extensions++; - } - - if (num_extensions > 0) { - raw_extensions = OPENSSL_zalloc(sizeof(*raw_extensions) - * num_extensions); - if (raw_extensions == NULL) { - *ad = SSL_AD_INTERNAL_ERROR; - SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_MALLOC_FAILURE); + *al = SSL_AD_ILLEGAL_PARAMETER; goto err; } - - /* Second pass: collect the extensions. */ - for (i = 0; i < num_extensions; i++) { - if (!PACKET_get_net_2(packet, &raw_extensions[i].type) || - !PACKET_get_length_prefixed_2(packet, - &raw_extensions[i].data)) { - /* This should not happen. */ - *ad = SSL_AD_INTERNAL_ERROR; - SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, ERR_R_INTERNAL_ERROR); - goto err; - } - } - - if (PACKET_remaining(packet) != 0) { - *ad = SSL_AD_DECODE_ERROR; - SSLerr(SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_LENGTH_MISMATCH); - goto err; - } - /* Sort the extensions and make sure there are no duplicates. */ - qsort(raw_extensions, num_extensions, sizeof(*raw_extensions), - compare_extensions); - for (i = 1; i < num_extensions; i++) { - if (raw_extensions[i - 1].type == raw_extensions[i].type) { - *ad = SSL_AD_DECODE_ERROR; - goto err; - } + if (thisex != NULL) { + thisex->data = extension; + thisex->present = 1; + thisex->type = type; } } @@ -411,16 +428,16 @@ int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context, * Initialise all known extensions relevant to this context, whether we have * found them or not */ - for (i = 0; i < OSSL_NELEM(ext_defs); i++) { - if(ext_defs[i].init_ext != NULL && (ext_defs[i].context & context) != 0 - && !ext_defs[i].init_ext(s, context)) { - *ad = SSL_AD_INTERNAL_ERROR; + for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); i++, thisexd++) { + if(thisexd->init != NULL && (thisexd->context & context) != 0 + && extension_is_relevant(s, thisexd->context, context) + && !thisexd->init(s, context)) { + *al = SSL_AD_INTERNAL_ERROR; goto err; } } *res = raw_extensions; - *numfound = num_extensions; return 1; err: @@ -429,119 +446,139 @@ int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context, } /* - * Parse all remaining extensions that have not yet been parsed. Also calls the - * finalisation for all extensions at the end. Returns 1 for success or 0 for - * failure. On failure, |*al| is populated with a suitable alert code. + * Runs the parser for a given extension with index |idx|. |exts| contains the + * list of all parsed extensions previously collected by + * tls_collect_extensions(). The parser is only run if it is applicable for the + * given |context| and the parser has not already been run. If this is for a + * Certificate message, then we also provide the parser with the relevant + * Certificate |x| and its position in the |chainidx| with 0 being the first + * Certificate. Returns 1 on success or 0 on failure. In the event of a failure + * |*al| is populated with a suitable alert code. If an extension is not present + * this counted as success. */ -int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, - size_t numexts, int *al) +int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context, + RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al) { - size_t loop; + RAW_EXTENSION *currext = &exts[idx]; + int (*parser)(SSL *s, PACKET *pkt, X509 *x, size_t chainidx, int *al) = NULL; - for (loop = 0; loop < numexts; loop++) { - RAW_EXTENSION *currext = &exts[loop]; - const EXTENSION_DEFINITION *extdef = NULL; - int (*parser)(SSL *s, PACKET *pkt, int *al) = NULL; + /* Skip if the extension is not present */ + if (!currext->present) + return 1; - if (s->tlsext_debug_cb) - s->tlsext_debug_cb(s, !s->server, currext->type, - PACKET_data(&currext->data), - PACKET_remaining(&currext->data), - s->tlsext_debug_arg); + if (s->ext.debug_cb) + s->ext.debug_cb(s, !s->server, currext->type, + PACKET_data(&currext->data), + PACKET_remaining(&currext->data), + s->ext.debug_arg); - /* Skip if we've already parsed this extension */ - if (currext->parsed) - continue; + /* Skip if we've already parsed this extension */ + if (currext->parsed) + return 1; - currext->parsed = 1; - - parser = NULL; - if (find_extension_definition(s, currext->type, &extdef)) { - parser = s->server ? extdef->parse_client_ext - : extdef->parse_server_ext; - - /* Check if extension is defined for our protocol. If not, skip */ - if ((SSL_IS_DTLS(s) - && (extdef->context & EXT_TLS_IMPLEMENTATION_ONLY) != 0) - || (s->version == SSL3_VERSION - && (extdef->context & EXT_SSL3_ALLOWED) == 0) - || (SSL_IS_TLS13(s) - && (extdef->context & EXT_TLS1_2_AND_BELOW_ONLY) != 0) - || (!SSL_IS_TLS13(s) - && (extdef->context & EXT_TLS1_3_ONLY) != 0)) - continue; - } + currext->parsed = 1; - if (parser == NULL) { - /* - * Could be a custom extension. We only allow this if it is a non - * resumed session on the server side. - * - * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions. - * We're going to need a new mechanism for TLS1.3 to specify which - * messages to add the custom extensions to. - */ - if ((!s->hit || !s->server) - && (context - & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0 - && custom_ext_parse(s, s->server, currext->type, - PACKET_data(&currext->data), - PACKET_remaining(&currext->data), - al) <= 0) - return 0; + if (idx < OSSL_NELEM(ext_defs)) { + /* We are handling a built-in extension */ + const EXTENSION_DEFINITION *extdef = &ext_defs[idx]; - continue; - } + /* Check if extension is defined for our protocol. If not, skip */ + if (!extension_is_relevant(s, extdef->context, context)) + return 1; - if (!parser(s, &currext->data, al)) - return 0; + parser = s->server ? extdef->parse_ctos : extdef->parse_stoc; + + if (parser != NULL) + return parser(s, &currext->data, x, chainidx, al); + + /* + * If the parser is NULL we fall through to the custom extension + * processing + */ } /* - * Finalise all known extensions relevant to this context, whether we have - * found them or not + * This is a custom extension. We only allow this if it is a non + * resumed session on the server side. + *chain + * TODO(TLS1.3): We only allow old style <=TLS1.2 custom extensions. + * We're going to need a new mechanism for TLS1.3 to specify which + * messages to add the custom extensions to. */ - for (loop = 0; loop < OSSL_NELEM(ext_defs); loop++) { - if(ext_defs[loop].finalise_ext != NULL - && (ext_defs[loop].context & context) != 0 - && !ext_defs[loop].finalise_ext(s, context)) { - *al = SSL_AD_INTERNAL_ERROR; - return 0; - } - } + if ((!s->hit || !s->server) + && (context + & (EXT_CLIENT_HELLO | EXT_TLS1_2_SERVER_HELLO)) != 0 + && custom_ext_parse(s, s->server, currext->type, + PACKET_data(&currext->data), + PACKET_remaining(&currext->data), + al) <= 0) + return 0; return 1; } /* - * Find a specific extension by |type| in the list |exts| containing |numexts| - * extensions, and the parse it immediately. Returns 1 on success, or 0 on - * failure. If a failure has occurred then |*al| will also be set to the alert - * to be sent. + * Parse all remaining extensions that have not yet been parsed. Also calls the + * finalisation for all extensions at the end, whether we collected them or not. + * Returns 1 for success or 0 for failure. If we are working on a Certificate + * message then we also pass the Certificate |x| and its position in the + * |chainidx|, with 0 being the first certificate. On failure, |*al| is + * populated with a suitable alert code. */ -int tls_parse_extension(SSL *s, int type, int context, RAW_EXTENSION *exts, - size_t numexts, int *al) +int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x, + size_t chainidx, int *al) { - RAW_EXTENSION *ext = tls_get_extension_by_type(exts, numexts, type); + size_t i, numexts = OSSL_NELEM(ext_defs); + const EXTENSION_DEFINITION *thisexd; - if (ext == NULL) - return 1; + /* Calculate the number of extensions in the extensions list */ + if ((context & EXT_CLIENT_HELLO) != 0) { + numexts += s->cert->srv_ext.meths_count; + } else if ((context & EXT_TLS1_2_SERVER_HELLO) != 0) { + numexts += s->cert->cli_ext.meths_count; + } + + /* Parse each extension in turn */ + for (i = 0; i < numexts; i++) { + if (!tls_parse_extension(s, i, context, exts, x, chainidx, al)) + return 0; + } + + /* + * Finalise all known extensions relevant to this context, whether we have + * found them or not + */ + for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) { + if(thisexd->final != NULL + && (thisexd->context & context) != 0 + && !thisexd->final(s, context, exts[i].present, al)) + return 0; + } - return tls_parse_all_extensions(s, context, ext, 1, al); + return 1; } +/* + * Construct all the extensions relevant to the current |context| and write + * them to |pkt|. If this is an extension for a Certificate in a Certificate + * message, then |x| will be set to the Certificate we are handling, and + * |chainidx| will indicate the position in the chainidx we are processing (with + * 0 being the first in the chain). Returns 1 on success or 0 on failure. If a + * failure occurs then |al| is populated with a suitable alert code. On a + * failure construction stops at the first extension to fail to construct. + */ int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context, - int *al) + X509 *x, size_t chainidx, int *al) { - size_t loop; - int addcustom = 0; - int min_version, max_version = 0, reason; + size_t i; + int addcustom = 0, min_version, max_version = 0, reason, tmpal; + const EXTENSION_DEFINITION *thisexd; /* - * Normally if something goes wrong during construction its an internal + * Normally if something goes wrong during construction it's an internal * error. We can always override this later. */ - *al = SSL_AD_INTERNAL_ERROR; + tmpal = SSL_AD_INTERNAL_ERROR; if (!WPACKET_start_sub_packet_u16(pkt) /* @@ -553,14 +590,14 @@ int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context, && !WPACKET_set_flags(pkt, WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) { SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR); - return 0; + goto err; } if ((context & EXT_CLIENT_HELLO) != 0) { reason = ssl_get_client_min_max_version(s, &min_version, &max_version); if (reason != 0) { SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, reason); - return 0; + goto err; } } @@ -572,7 +609,7 @@ int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context, /* * We already initialised the custom extensions during ClientHello * parsing. - * + * * TODO(TLS1.3): We're going to need a new custom extension mechanism * for TLS1.3, so that custom extensions can specify which of the * multiple message they wish to add themselves to. @@ -580,47 +617,339 @@ int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context, addcustom = 1; } - if (addcustom && !custom_ext_add(s, s->server, pkt, al)) { + if (addcustom && !custom_ext_add(s, s->server, pkt, &tmpal)) { SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR); - return 0; + goto err; } - for (loop = 0; loop < OSSL_NELEM(ext_defs); loop++) { - int (*construct)(SSL *s, WPACKET *pkt, int *al); + for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) { + int (*construct)(SSL *s, WPACKET *pkt, X509 *x, size_t chainidx, + int *al); /* Skip if not relevant for our context */ - if ((ext_defs[loop].context & context) == 0) + if ((thisexd->context & context) == 0) continue; - construct = s->server ? ext_defs[loop].construct_server_ext - : ext_defs[loop].construct_client_ext; + construct = s->server ? thisexd->construct_stoc + : thisexd->construct_ctos; /* Check if this extension is defined for our protocol. If not, skip */ if ((SSL_IS_DTLS(s) - && (ext_defs[loop].context & EXT_TLS_IMPLEMENTATION_ONLY) + && (thisexd->context & EXT_TLS_IMPLEMENTATION_ONLY) != 0) || (s->version == SSL3_VERSION - && (ext_defs[loop].context & EXT_SSL3_ALLOWED) == 0) + && (thisexd->context & EXT_SSL3_ALLOWED) == 0) || (SSL_IS_TLS13(s) - && (ext_defs[loop].context & EXT_TLS1_2_AND_BELOW_ONLY) + && (thisexd->context & EXT_TLS1_2_AND_BELOW_ONLY) != 0) || (!SSL_IS_TLS13(s) - && (ext_defs[loop].context & EXT_TLS1_3_ONLY) != 0 + && (thisexd->context & EXT_TLS1_3_ONLY) != 0 && (context & EXT_CLIENT_HELLO) == 0) - || ((ext_defs[loop].context & EXT_TLS1_3_ONLY) != 0 + || ((thisexd->context & EXT_TLS1_3_ONLY) != 0 && (context & EXT_CLIENT_HELLO) != 0 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION)) || construct == NULL) continue; - if (!construct(s, pkt, al)) - return 0; + if (!construct(s, pkt, x, chainidx, &tmpal)) + goto err; } if (!WPACKET_close(pkt)) { SSLerr(SSL_F_TLS_CONSTRUCT_EXTENSIONS, ERR_R_INTERNAL_ERROR); + goto err; + } + + return 1; + + err: + *al = tmpal; + return 0; +} + +/* + * Built in extension finalisation and initialisation functions. All initialise + * or finalise the associated extension type for the given |context|. For + * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0 + * otherwise. These functions return 1 on success or 0 on failure. In the event + * of a failure then |*al| is populated with a suitable error code. + */ + +static int final_renegotiate(SSL *s, unsigned int context, int sent, + int *al) +{ + if (!s->server) { + /* + * Check if we can connect to a server that doesn't support safe + * renegotiation + */ + if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT) + && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION) + && !sent) { + *al = SSL_AD_HANDSHAKE_FAILURE; + SSLerr(SSL_F_FINAL_RENEGOTIATE, + SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED); + return 0; + } + + return 1; + } + + /* Need RI if renegotiating */ + if (s->renegotiate + && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION) + && !sent) { + *al = SSL_AD_HANDSHAKE_FAILURE; + SSLerr(SSL_F_FINAL_RENEGOTIATE, + SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED); + return 0; + } + + + return 1; +} + +static int init_server_name(SSL *s, unsigned int context) +{ + if (s->server) + s->servername_done = 0; + + return 1; +} + +static int final_server_name(SSL *s, unsigned int context, int sent, + int *al) +{ + int ret = SSL_TLSEXT_ERR_NOACK; + int altmp = SSL_AD_UNRECOGNIZED_NAME; + + if (s->ctx != NULL && s->ctx->ext.servername_cb != 0) + ret = s->ctx->ext.servername_cb(s, &altmp, + s->ctx->ext.servername_arg); + else if (s->initial_ctx != NULL + && s->initial_ctx->ext.servername_cb != 0) + ret = s->initial_ctx->ext.servername_cb(s, &altmp, + s->initial_ctx->ext.servername_arg); + + switch (ret) { + case SSL_TLSEXT_ERR_ALERT_FATAL: + *al = altmp; return 0; + + case SSL_TLSEXT_ERR_ALERT_WARNING: + *al = altmp; + return 1; + + case SSL_TLSEXT_ERR_NOACK: + s->servername_done = 0; + return 1; + + default: + return 1; + } +} + +#ifndef OPENSSL_NO_EC +static int final_ec_pt_formats(SSL *s, unsigned int context, int sent, + int *al) +{ + unsigned long alg_k, alg_a; + + if (s->server) + return 1; + + alg_k = s->s3->tmp.new_cipher->algorithm_mkey; + alg_a = s->s3->tmp.new_cipher->algorithm_auth; + + /* + * If we are client and using an elliptic curve cryptography cipher + * suite, then if server returns an EC point formats lists extension it + * must contain uncompressed. + */ + if (s->ext.ecpointformats != NULL + && s->ext.ecpointformats_len > 0 + && s->session->ext.ecpointformats != NULL + && s->session->ext.ecpointformats_len > 0 + && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) { + /* we are using an ECC cipher */ + size_t i; + unsigned char *list = s->session->ext.ecpointformats; + + for (i = 0; i < s->session->ext.ecpointformats_len; i++) { + if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed) + break; + } + if (i == s->session->ext.ecpointformats_len) { + SSLerr(SSL_F_FINAL_EC_PT_FORMATS, + SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST); + return 0; + } + } + + return 1; +} +#endif + +static int init_session_ticket(SSL *s, unsigned int context) +{ + if (!s->server) + s->ext.ticket_expected = 0; + + return 1; +} + +#ifndef OPENSSL_NO_OCSP +static int init_status_request(SSL *s, unsigned int context) +{ + if (s->server) { + s->ext.status_type = TLSEXT_STATUSTYPE_nothing; + } else { + /* + * Ensure we get sensible values passed to tlsext_status_cb in the event + * that we don't receive a status message + */ + OPENSSL_free(s->ext.ocsp.resp); + s->ext.ocsp.resp = NULL; + s->ext.ocsp.resp_len = 0; } return 1; } +#endif + +#ifndef OPENSSL_NO_NEXTPROTONEG +static int init_npn(SSL *s, unsigned int context) +{ + s->s3->npn_seen = 0; + + return 1; +} +#endif + +static int init_alpn(SSL *s, unsigned int context) +{ + OPENSSL_free(s->s3->alpn_selected); + s->s3->alpn_selected = NULL; + if (s->server) { + s->s3->alpn_selected_len = 0; + OPENSSL_free(s->s3->alpn_proposed); + s->s3->alpn_proposed = NULL; + s->s3->alpn_proposed_len = 0; + } + return 1; +} + +static int final_alpn(SSL *s, unsigned int context, int sent, int *al) +{ + const unsigned char *selected = NULL; + unsigned char selected_len = 0; + + if (!s->server) + return 1; + + if (s->ctx->ext.alpn_select_cb != NULL && s->s3->alpn_proposed != NULL) { + int r = s->ctx->ext.alpn_select_cb(s, &selected, &selected_len, + s->s3->alpn_proposed, + (unsigned int)s->s3->alpn_proposed_len, + s->ctx->ext.alpn_select_cb_arg); + + if (r == SSL_TLSEXT_ERR_OK) { + OPENSSL_free(s->s3->alpn_selected); + s->s3->alpn_selected = OPENSSL_memdup(selected, selected_len); + if (s->s3->alpn_selected == NULL) { + *al = SSL_AD_INTERNAL_ERROR; + return 0; + } + s->s3->alpn_selected_len = selected_len; +#ifndef OPENSSL_NO_NEXTPROTONEG + /* ALPN takes precedence over NPN. */ + s->s3->npn_seen = 0; +#endif + } else { + *al = SSL_AD_NO_APPLICATION_PROTOCOL; + return 0; + } + } + + return 1; +} + +static int init_sig_algs(SSL *s, unsigned int context) +{ + /* Clear any signature algorithms extension received */ + OPENSSL_free(s->s3->tmp.peer_sigalgs); + s->s3->tmp.peer_sigalgs = NULL; + + return 1; +} + +#ifndef OPENSSL_NO_SRP +static int init_srp(SSL *s, unsigned int context) +{ + OPENSSL_free(s->srp_ctx.login); + s->srp_ctx.login = NULL; + + return 1; +} +#endif + +static int init_etm(SSL *s, unsigned int context) +{ + s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC; + + return 1; +} + +static int init_ems(SSL *s, unsigned int context) +{ + if (!s->server) + s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS; + + return 1; +} + +static int final_ems(SSL *s, unsigned int context, int sent, int *al) +{ + if (!s->server && s->hit) { + /* + * Check extended master secret extension is consistent with + * original session. + */ + if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) != + !(s->session->flags & SSL_SESS_FLAG_EXTMS)) { + *al = SSL_AD_HANDSHAKE_FAILURE; + SSLerr(SSL_F_FINAL_EMS, SSL_R_INCONSISTENT_EXTMS); + return 0; + } + } + + return 1; +} + +#ifndef OPENSSL_NO_SRTP +static int init_srtp(SSL *s, unsigned int context) +{ + if (s->server) + s->srtp_profile = NULL; + + return 1; +} +#endif + +static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al) +{ + if (!sent && SSL_IS_TLS13(s)) { + *al = TLS13_AD_MISSING_EXTENSION; + SSLerr(SSL_F_FINAL_SIG_ALGS, SSL_R_MISSING_SIGALGS_EXTENSION); + return 0; + } + + return 1; +} + +static int init_psk_kex_modes(SSL *s, unsigned int context) +{ + s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE; + + return 1; +}