X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fstatem%2Fextensions.c;h=99326b2b55f58710259fbc587fdc7a95e58f9632;hp=ee5b0d71a31e91f1c2e4e77c7b9d88d5c79647ab;hb=0dd7ba24e835fc66afc4997b376bc2a5e1f03992;hpb=3e6c1da82247567f619a53569080428a6eb5b4c6 diff --git a/ssl/statem/extensions.c b/ssl/statem/extensions.c index ee5b0d71a3..99326b2b55 100644 --- a/ssl/statem/extensions.c +++ b/ssl/statem/extensions.c @@ -35,6 +35,8 @@ static int init_srp(SSL *s, unsigned int context); 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); +static int final_key_share(SSL *s, unsigned int context, int sent, int *al); #ifndef OPENSSL_NO_SRTP static int init_srtp(SSL *s, unsigned int context); #endif @@ -55,15 +57,17 @@ typedef struct extensions_definition_st { */ 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); + int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, 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); + int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, 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); + int (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context, 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); + int (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context, 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 @@ -234,6 +238,12 @@ static const EXTENSION_DEFINITION ext_defs[] = { /* Processed inline as part of version selection */ NULL, NULL, NULL, tls_construct_ctos_supported_versions, NULL }, + { + 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 @@ -244,7 +254,8 @@ static const EXTENSION_DEFINITION ext_defs[] = { | EXT_TLS1_3_HELLO_RETRY_REQUEST | EXT_TLS_IMPLEMENTATION_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 + tls_construct_stoc_key_share, tls_construct_ctos_key_share, + final_key_share }, { /* @@ -256,12 +267,21 @@ static const EXTENSION_DEFINITION ext_defs[] = { NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL }, { - /* Last in the list because it must be added as the last extension */ + /* Must be immediately before pre_shared_key */ + /* TODO(TLS1.3): Fix me */ TLSEXT_TYPE_padding, EXT_CLIENT_HELLO, NULL, /* We send this, but don't read it */ NULL, NULL, NULL, tls_construct_ctos_padding, NULL + }, + { + /* Required by the TLSv1.3 spec to always be the last extension */ + TLSEXT_TYPE_psk, + EXT_CLIENT_HELLO | EXT_TLS1_3_SERVER_HELLO | EXT_TLS_IMPLEMENTATION_ONLY + | EXT_TLS1_3_ONLY, + NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk, + tls_construct_ctos_psk, NULL } }; @@ -452,7 +472,8 @@ int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context, RAW_EXTENSION *exts, X509 *x, size_t chainidx, int *al) { RAW_EXTENSION *currext = &exts[idx]; - int (*parser)(SSL *s, PACKET *pkt, X509 *x, size_t chainidx, int *al) = NULL; + int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x, + size_t chainidx, int *al) = NULL; /* Skip if the extension is not present */ if (!currext->present) @@ -481,7 +502,7 @@ int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context, parser = s->server ? extdef->parse_ctos : extdef->parse_stoc; if (parser != NULL) - return parser(s, &currext->data, x, chainidx, al); + return parser(s, &currext->data, context, x, chainidx, al); /* * If the parser is NULL we fall through to the custom extension @@ -615,8 +636,8 @@ int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context, } 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); + int (*construct)(SSL *s, WPACKET *pkt, unsigned int context, X509 *x, + size_t chainidx, int *al); /* Skip if not relevant for our context */ if ((thisexd->context & context) == 0) @@ -643,7 +664,7 @@ int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context, || construct == NULL) continue; - if (!construct(s, pkt, x, chainidx, &tmpal)) + if (!construct(s, pkt, context, x, chainidx, &tmpal)) goto err; } @@ -718,10 +739,10 @@ static int final_server_name(SSL *s, unsigned int context, int sent, 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); + else if (s->session_ctx != NULL + && s->session_ctx->ext.servername_cb != 0) + ret = s->session_ctx->ext.servername_cb(s, &altmp, + s->session_ctx->ext.servername_arg); switch (ret) { case SSL_TLSEXT_ERR_ALERT_FATAL: @@ -938,3 +959,254 @@ static int final_sig_algs(SSL *s, unsigned int context, int sent, int *al) return 1; } + + +static int final_key_share(SSL *s, unsigned int context, int sent, int *al) +{ + if (!SSL_IS_TLS13(s)) + return 1; + + /* + * If + * we are a client + * AND + * we have no key_share + * AND + * (we are not resuming + * OR the kex_mode doesn't allow non key_share resumes) + * THEN + * fail; + */ + if (!s->server + && !sent + && (!s->hit + || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) { + /* Nothing left we can do - just fail */ + *al = SSL_AD_HANDSHAKE_FAILURE; + SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE); + return 0; + } + /* + * If + * we are a server + * AND + * we have no key_share + * THEN + * If + * we didn't already send a HelloRetryRequest + * AND + * the client sent a key_share extension + * AND + * (we are not resuming + * OR the kex_mode allows key_share resumes) + * AND + * a shared group exists + * THEN + * send a HelloRetryRequest + * ELSE If + * we are not resuming + * OR + * the kex_mode doesn't allow non key_share resumes + * THEN + * fail; + */ + if (s->server && s->s3->peer_tmp == NULL) { + /* No suitable share */ + if (s->hello_retry_request == 0 && sent + && (!s->hit + || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE) + != 0)) { + const unsigned char *pcurves, *pcurvestmp, *clntcurves; + size_t num_curves, clnt_num_curves, i; + unsigned int group_id; + + /* Check if a shared group exists */ + + /* Get the clients list of supported groups. */ + if (!tls1_get_curvelist(s, 1, &clntcurves, &clnt_num_curves)) { + *al = SSL_AD_INTERNAL_ERROR; + SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR); + return 0; + } + + /* Get our list of available groups */ + if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves)) { + *al = SSL_AD_INTERNAL_ERROR; + SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR); + return 0; + } + + /* Find the first group we allow that is also in client's list */ + for (i = 0, pcurvestmp = pcurves; i < num_curves; + i++, pcurvestmp += 2) { + group_id = bytestogroup(pcurvestmp); + + if (check_in_list(s, group_id, clntcurves, clnt_num_curves, 1)) + break; + } + + if (i < num_curves) { + /* A shared group exists so send a HelloRetryRequest */ + s->s3->group_id = group_id; + s->hello_retry_request = 1; + return 1; + } + } + if (!s->hit + || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) { + /* Nothing left we can do - just fail */ + *al = SSL_AD_HANDSHAKE_FAILURE; + SSLerr(SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE); + return 0; + } + } + + /* We have a key_share so don't send any more HelloRetryRequest messages */ + if (s->server) + s->hello_retry_request = 0; + + /* + * For a client side resumption with no key_share we need to generate + * the handshake secret (otherwise this is done during key_share + * processing). + */ + if (!sent && !s->server && !tls13_generate_handshake_secret(s, NULL, 0)) { + *al = SSL_AD_INTERNAL_ERROR; + SSLerr(SSL_F_FINAL_KEY_SHARE, ERR_R_INTERNAL_ERROR); + 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; +} + +int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart, + size_t binderoffset, const unsigned char *binderin, + unsigned char *binderout, + SSL_SESSION *sess, int sign) +{ + EVP_PKEY *mackey = NULL; + EVP_MD_CTX *mctx = NULL; + unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE]; + unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE]; + const char resumption_label[] = "resumption psk binder key"; + size_t bindersize, hashsize = EVP_MD_size(md); + int ret = -1; + + /* Generate the early_secret */ + if (!tls13_generate_secret(s, md, NULL, sess->master_key, + sess->master_key_length, + (unsigned char *)&s->early_secret)) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR); + goto err; + } + + /* + * Create the handshake hash for the binder key...the messages so far are + * empty! + */ + mctx = EVP_MD_CTX_new(); + if (mctx == NULL + || EVP_DigestInit_ex(mctx, md, NULL) <= 0 + || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR); + goto err; + } + + /* Generate the binder key */ + if (!tls13_hkdf_expand(s, md, s->early_secret, + (unsigned char *)resumption_label, + sizeof(resumption_label) - 1, hash, binderkey, + hashsize)) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR); + goto err; + } + + /* Generate the finished key */ + if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR); + goto err; + } + + if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR); + goto err; + } + + /* + * Get a hash of the ClientHello up to the start of the binders. If we are + * following a HelloRetryRequest then this includes the hash of the first + * ClientHello and the HelloRetryRequest itself. + */ + if (s->hello_retry_request) { + size_t hdatalen; + void *hdata; + + hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata); + if (hdatalen <= 0) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, SSL_R_BAD_HANDSHAKE_LENGTH); + goto err; + } + + /* + * For servers the handshake buffer data will include the second + * ClientHello - which we don't want - so we need to take that bit off. + */ + if (s->server) { + if (hdatalen < s->init_num + SSL3_HM_HEADER_LENGTH) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR); + goto err; + } + hdatalen -= s->init_num + SSL3_HM_HEADER_LENGTH; + } + + if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR); + goto err; + } + } + + if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0 + || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR); + goto err; + } + + mackey = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, finishedkey, hashsize); + if (mackey == NULL) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR); + goto err; + } + + if (!sign) + binderout = tmpbinder; + + bindersize = hashsize; + if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0 + || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0 + || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0 + || bindersize != hashsize) { + SSLerr(SSL_F_TLS_PSK_DO_BINDER, ERR_R_INTERNAL_ERROR); + goto err; + } + + if (sign) { + ret = 1; + } else { + /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */ + ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0); + } + + err: + OPENSSL_cleanse(binderkey, sizeof(binderkey)); + OPENSSL_cleanse(finishedkey, sizeof(finishedkey)); + EVP_PKEY_free(mackey); + EVP_MD_CTX_free(mctx); + + return ret; +}