X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Ftls13_enc.c;h=db8de1d1ca29c64d966364d5efd00eacb860e7ff;hp=0ac54bbfb5be1fa7e63557074afebf2591d8ab65;hb=c117af6765928f3fc61585b01f5d722162914d80;hpb=34574f193bf9961256d5b8bdb6950dcc890e0336 diff --git a/ssl/tls13_enc.c b/ssl/tls13_enc.c index 0ac54bbfb5..db8de1d1ca 100644 --- a/ssl/tls13_enc.c +++ b/ssl/tls13_enc.c @@ -17,23 +17,18 @@ /* Always filled with zeros */ static const unsigned char default_zeros[EVP_MAX_MD_SIZE]; -const unsigned char keylabel[] = "key"; -const unsigned char ivlabel[] = "iv"; - /* * Given a |secret|; a |label| of length |labellen|; and a |hash| of the * handshake messages, derive a new secret |outlen| bytes long and store it in - * the location pointed to be |out|. The |hash| value may be NULL. - * - * Returns 1 on success 0 on failure. + * the location pointed to be |out|. The |hash| value may be NULL. Returns 1 on + * success 0 on failure. */ -static int tls13_hkdf_expand(SSL *s, const unsigned char *secret, +int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, const unsigned char *label, size_t labellen, const unsigned char *hash, unsigned char *out, size_t outlen) { const unsigned char label_prefix[] = "TLS 1.3, "; - const EVP_MD *md = ssl_handshake_md(s); EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); int ret; size_t hkdflabellen; @@ -61,6 +56,7 @@ static int tls13_hkdf_expand(SSL *s, const unsigned char *secret, || !WPACKET_sub_memcpy_u8(&pkt, hash, (hash == NULL) ? 0 : hashlen) || !WPACKET_get_total_written(&pkt, &hkdflabellen) || !WPACKET_finish(&pkt)) { + EVP_PKEY_CTX_free(pctx); WPACKET_cleanup(&pkt); return 0; } @@ -79,66 +75,52 @@ static int tls13_hkdf_expand(SSL *s, const unsigned char *secret, } /* - * Given a input secret |insecret| and a |label| of length |labellen|, derive a - * new |secret|. This will be the length of the current hash output size and - * will be based on the current state of the handshake hashes. - * - * Returns 1 on success 0 on failure. + * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on + * success 0 on failure. */ -int tls13_derive_secret(SSL *s, const unsigned char *insecret, - const unsigned char *label, size_t labellen, - unsigned char *secret) +int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret, + unsigned char *key, size_t keylen) { - unsigned char hash[EVP_MAX_MD_SIZE]; - size_t hashlen; - - if (!ssl3_digest_cached_records(s, 1)) - return 0; + static const unsigned char keylabel[] = "key"; - if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) - return 0; - - return tls13_hkdf_expand(s, insecret, label, labellen, hash, secret, - hashlen); + return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1, + NULL, key, keylen); } /* - * Given a |secret| generate a |key| of length |keylen| bytes. - * - * Returns 1 on success 0 on failure. + * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on + * success 0 on failure. */ -int tls13_derive_key(SSL *s, const unsigned char *secret, unsigned char *key, - size_t keylen) +int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret, + unsigned char *iv, size_t ivlen) { - return tls13_hkdf_expand(s, secret, keylabel, sizeof(keylabel) - 1, NULL, - key, keylen); + static const unsigned char ivlabel[] = "iv"; + + return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1, + NULL, iv, ivlen); } -/* - * Given a |secret| generate an |iv| of length |ivlen| bytes. - * - * Returns 1 on success 0 on failure. - */ -int tls13_derive_iv(SSL *s, const unsigned char *secret, unsigned char *iv, - size_t ivlen) +int tls13_derive_finishedkey(SSL *s, const EVP_MD *md, + const unsigned char *secret, + unsigned char *fin, size_t finlen) { - return tls13_hkdf_expand(s, secret, ivlabel, sizeof(ivlabel) - 1, NULL, - iv, ivlen); + static const unsigned char finishedlabel[] = "finished"; + + return tls13_hkdf_expand(s, md, secret, finishedlabel, + sizeof(finishedlabel) - 1, NULL, fin, finlen); } /* * Given the previous secret |prevsecret| and a new input secret |insecret| of * length |insecretlen|, generate a new secret and store it in the location - * pointed to by |outsecret|. - * - * Returns 1 on success 0 on failure. + * pointed to by |outsecret|. Returns 1 on success 0 on failure. */ -static int tls13_generate_secret(SSL *s, const unsigned char *prevsecret, - const unsigned char *insecret, - size_t insecretlen, - unsigned char *outsecret) +int tls13_generate_secret(SSL *s, const EVP_MD *md, + const unsigned char *prevsecret, + const unsigned char *insecret, + size_t insecretlen, + unsigned char *outsecret) { - const EVP_MD *md = ssl_handshake_md(s); size_t mdlen, prevsecretlen; int ret; EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); @@ -173,45 +155,429 @@ static int tls13_generate_secret(SSL *s, const unsigned char *prevsecret, return ret == 0; } -/* - * Given an input secret |insecret| of length |insecretlen| generate the early - * secret. - * - * Returns 1 on success 0 on failure. - */ -int tls13_generate_early_secret(SSL *s, const unsigned char *insecret, - size_t insecretlen) -{ - return tls13_generate_secret(s, NULL, insecret, insecretlen, - (unsigned char *)&s->early_secret); -} - /* * Given an input secret |insecret| of length |insecretlen| generate the * handshake secret. This requires the early secret to already have been - * generated. - * - * Returns 1 on success 0 on failure. + * generated. Returns 1 on success 0 on failure. */ int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret, size_t insecretlen) { - return tls13_generate_secret(s, s->early_secret, insecret, insecretlen, + return tls13_generate_secret(s, ssl_handshake_md(s), s->early_secret, + insecret, insecretlen, (unsigned char *)&s->handshake_secret); } /* * Given the handshake secret |prev| of length |prevlen| generate the master - * secret and store its length in |*secret_size| - * - * Returns 1 on success 0 on failure. + * secret and store its length in |*secret_size|. Returns 1 on success 0 on + * failure. */ int tls13_generate_master_secret(SSL *s, unsigned char *out, unsigned char *prev, size_t prevlen, size_t *secret_size) { - *secret_size = EVP_MD_size(ssl_handshake_md(s)); - return tls13_generate_secret(s, prev, NULL, 0, out); + const EVP_MD *md = ssl_handshake_md(s); + + *secret_size = EVP_MD_size(md); + return tls13_generate_secret(s, md, prev, NULL, 0, out); +} + +/* + * Generates the mac for the Finished message. Returns the length of the MAC or + * 0 on error. + */ +size_t tls13_final_finish_mac(SSL *s, const char *str, size_t slen, + unsigned char *out) +{ + const EVP_MD *md = ssl_handshake_md(s); + unsigned char hash[EVP_MAX_MD_SIZE]; + size_t hashlen, ret = 0; + EVP_PKEY *key = NULL; + EVP_MD_CTX *ctx = EVP_MD_CTX_new(); + + if (!ssl_handshake_hash(s, hash, sizeof(hash), &hashlen)) + goto err; + + if (str == s->method->ssl3_enc->server_finished_label) + key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, + s->server_finished_secret, hashlen); + else + key = EVP_PKEY_new_mac_key(EVP_PKEY_HMAC, NULL, + s->client_finished_secret, hashlen); + + if (key == NULL + || ctx == NULL + || EVP_DigestSignInit(ctx, NULL, md, NULL, key) <= 0 + || EVP_DigestSignUpdate(ctx, hash, hashlen) <= 0 + || EVP_DigestSignFinal(ctx, out, &hashlen) <= 0) + goto err; + + ret = hashlen; + err: + EVP_PKEY_free(key); + EVP_MD_CTX_free(ctx); + return ret; +} + +/* + * There isn't really a key block in TLSv1.3, but we still need this function + * for initialising the cipher and hash. Returns 1 on success or 0 on failure. + */ +int tls13_setup_key_block(SSL *s) +{ + const EVP_CIPHER *c; + const EVP_MD *hash; + int mac_type = NID_undef; + + s->session->cipher = s->s3->tmp.new_cipher; + if (!ssl_cipher_get_evp + (s->session, &c, &hash, &mac_type, NULL, NULL, 0)) { + SSLerr(SSL_F_TLS13_SETUP_KEY_BLOCK, SSL_R_CIPHER_OR_HASH_UNAVAILABLE); + return 0; + } + + s->s3->tmp.new_sym_enc = c; + s->s3->tmp.new_hash = hash; + + return 1; } +static int derive_secret_key_and_iv(SSL *s, int send, const EVP_MD *md, + const EVP_CIPHER *ciph, + const unsigned char *insecret, + const unsigned char *hash, + const unsigned char *label, + size_t labellen, unsigned char *secret, + unsigned char *iv, EVP_CIPHER_CTX *ciph_ctx) +{ + unsigned char key[EVP_MAX_KEY_LENGTH]; + size_t ivlen, keylen, taglen; + size_t hashlen = EVP_MD_size(md); + if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, secret, + hashlen)) { + SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_INTERNAL_ERROR); + goto err; + } + + /* TODO(size_t): convert me */ + keylen = EVP_CIPHER_key_length(ciph); + if (EVP_CIPHER_mode(ciph) == EVP_CIPH_CCM_MODE) { + uint32_t algenc; + + ivlen = EVP_CCM_TLS_IV_LEN; + if (s->s3->tmp.new_cipher == NULL) { + /* We've not selected a cipher yet - we must be doing early data */ + algenc = s->session->cipher->algorithm_enc; + } else { + algenc = s->s3->tmp.new_cipher->algorithm_enc; + } + if (algenc & (SSL_AES128CCM8 | SSL_AES256CCM8)) + taglen = EVP_CCM8_TLS_TAG_LEN; + else + taglen = EVP_CCM_TLS_TAG_LEN; + } else { + ivlen = EVP_CIPHER_iv_length(ciph); + taglen = 0; + } + + if (!tls13_derive_key(s, md, secret, key, keylen) + || !tls13_derive_iv(s, md, secret, iv, ivlen)) { + SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_INTERNAL_ERROR); + goto err; + } + + if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, send) <= 0 + || !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_IVLEN, ivlen, NULL) + || (taglen != 0 && !EVP_CIPHER_CTX_ctrl(ciph_ctx, EVP_CTRL_AEAD_SET_TAG, + taglen, NULL)) + || EVP_CipherInit_ex(ciph_ctx, NULL, NULL, key, NULL, -1) <= 0) { + SSLerr(SSL_F_DERIVE_SECRET_KEY_AND_IV, ERR_R_EVP_LIB); + goto err; + } + +#ifdef OPENSSL_SSL_TRACE_CRYPTO + if (s->msg_callback) { + int wh = send ? TLS1_RT_CRYPTO_WRITE : 0; + + if (ciph->key_len) + s->msg_callback(2, s->version, wh | TLS1_RT_CRYPTO_KEY, + key, ciph->key_len, s, s->msg_callback_arg); + + wh |= TLS1_RT_CRYPTO_IV; + s->msg_callback(2, s->version, wh, iv, ivlen, s, + s->msg_callback_arg); + } +#endif + + return 1; + err: + OPENSSL_cleanse(key, sizeof(key)); + return 0; +} + +int tls13_change_cipher_state(SSL *s, int which) +{ + static const unsigned char client_early_traffic[] = + "client early traffic secret"; + static const unsigned char client_handshake_traffic[] = + "client handshake traffic secret"; + static const unsigned char client_application_traffic[] = + "client application traffic secret"; + static const unsigned char server_handshake_traffic[] = + "server handshake traffic secret"; + static const unsigned char server_application_traffic[] = + "server application traffic secret"; + static const unsigned char resumption_master_secret[] = + "resumption master secret"; + unsigned char *iv; + unsigned char secret[EVP_MAX_MD_SIZE]; + unsigned char hashval[EVP_MAX_MD_SIZE]; + unsigned char *hash = hashval; + unsigned char *insecret; + unsigned char *finsecret = NULL; + const char *log_label = NULL; + EVP_CIPHER_CTX *ciph_ctx; + size_t finsecretlen = 0; + const unsigned char *label; + size_t labellen, hashlen = 0; + int ret = 0; + const EVP_MD *md; + const EVP_CIPHER *cipher; + + if (which & SSL3_CC_READ) { + if (s->enc_read_ctx != NULL) { + EVP_CIPHER_CTX_reset(s->enc_read_ctx); + } else { + s->enc_read_ctx = EVP_CIPHER_CTX_new(); + if (s->enc_read_ctx == NULL) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); + goto err; + } + } + ciph_ctx = s->enc_read_ctx; + iv = s->read_iv; + + RECORD_LAYER_reset_read_sequence(&s->rlayer); + } else { + if (s->enc_write_ctx != NULL) { + EVP_CIPHER_CTX_reset(s->enc_write_ctx); + } else { + s->enc_write_ctx = EVP_CIPHER_CTX_new(); + if (s->enc_write_ctx == NULL) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); + goto err; + } + } + ciph_ctx = s->enc_write_ctx; + iv = s->write_iv; + + RECORD_LAYER_reset_write_sequence(&s->rlayer); + } + + if (((which & SSL3_CC_CLIENT) && (which & SSL3_CC_WRITE)) + || ((which & SSL3_CC_SERVER) && (which & SSL3_CC_READ))) { + if (which & SSL3_CC_EARLY) { + EVP_MD_CTX *mdctx = NULL; + long handlen; + void *hdata; + unsigned int hashlenui; + const SSL_CIPHER *sslcipher = SSL_SESSION_get0_cipher(s->session); + + insecret = s->early_secret; + label = client_early_traffic; + labellen = sizeof(client_early_traffic) - 1; + log_label = CLIENT_EARLY_LABEL; + + handlen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata); + if (handlen <= 0) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, + SSL_R_BAD_HANDSHAKE_LENGTH); + goto err; + } + if (sslcipher == NULL) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + goto err; + } + + /* + * We need to calculate the handshake digest using the digest from + * the session. We haven't yet selected our ciphersuite so we can't + * use ssl_handshake_md(). + */ + mdctx = EVP_MD_CTX_new(); + if (mdctx == NULL) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_MALLOC_FAILURE); + goto err; + } + cipher = EVP_get_cipherbynid(SSL_CIPHER_get_cipher_nid(sslcipher)); + md = ssl_md(sslcipher->algorithm2); + if (md == NULL || !EVP_DigestInit_ex(mdctx, md, NULL) + || !EVP_DigestUpdate(mdctx, hdata, handlen) + || !EVP_DigestFinal_ex(mdctx, hashval, &hashlenui)) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + EVP_MD_CTX_free(mdctx); + goto err; + } + hashlen = hashlenui; + EVP_MD_CTX_free(mdctx); + } else if (which & SSL3_CC_HANDSHAKE) { + insecret = s->handshake_secret; + finsecret = s->client_finished_secret; + finsecretlen = EVP_MD_size(ssl_handshake_md(s)); + label = client_handshake_traffic; + labellen = sizeof(client_handshake_traffic) - 1; + log_label = CLIENT_HANDSHAKE_LABEL; + /* + * The hanshake hash used for the server read handshake traffic + * secret is the same as the hash for the server write handshake + * traffic secret. However, if we processed early data then we delay + * changing the server read cipher state until later, and the + * handshake hashes have moved on. Therefore we use the value saved + * earlier when we did the server write change cipher state. + */ + if (s->server) + hash = s->handshake_traffic_hash; + } else { + insecret = s->master_secret; + label = client_application_traffic; + labellen = sizeof(client_application_traffic) - 1; + log_label = CLIENT_APPLICATION_LABEL; + /* + * For this we only use the handshake hashes up until the server + * Finished hash. We do not include the client's Finished, which is + * what ssl_handshake_hash() would give us. Instead we use the + * previously saved value. + */ + hash = s->server_finished_hash; + } + } else { + /* Early data never applies to client-read/server-write */ + if (which & SSL3_CC_HANDSHAKE) { + insecret = s->handshake_secret; + finsecret = s->server_finished_secret; + finsecretlen = EVP_MD_size(ssl_handshake_md(s)); + label = server_handshake_traffic; + labellen = sizeof(server_handshake_traffic) - 1; + log_label = SERVER_HANDSHAKE_LABEL; + } else { + insecret = s->master_secret; + label = server_application_traffic; + labellen = sizeof(server_application_traffic) - 1; + log_label = SERVER_APPLICATION_LABEL; + } + } + + if (!(which & SSL3_CC_EARLY)) { + md = ssl_handshake_md(s); + cipher = s->s3->tmp.new_sym_enc; + if (!ssl3_digest_cached_records(s, 1) + || !ssl_handshake_hash(s, hashval, sizeof(hashval), &hashlen)) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + goto err; + } + } + + /* + * Save the hash of handshakes up to now for use when we calculate the + * client application traffic secret + */ + if (label == server_application_traffic) + memcpy(s->server_finished_hash, hashval, hashlen); + + if (s->server && label == server_handshake_traffic) + memcpy(s->handshake_traffic_hash, hashval, hashlen); + + if (label == client_application_traffic) { + /* + * We also create the resumption master secret, but this time use the + * hash for the whole handshake including the Client Finished + */ + if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, + resumption_master_secret, + sizeof(resumption_master_secret) - 1, + hashval, s->session->master_key, hashlen)) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + goto err; + } + s->session->master_key_length = hashlen; + } + + if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher, + insecret, hash, label, labellen, secret, iv, + ciph_ctx)) { + goto err; + } + + if (label == server_application_traffic) + memcpy(s->server_app_traffic_secret, secret, hashlen); + else if (label == client_application_traffic) + memcpy(s->client_app_traffic_secret, secret, hashlen); + + if (!ssl_log_secret(s, log_label, secret, hashlen)) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + goto err; + } + + if (finsecret != NULL + && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret, + finsecret, finsecretlen)) { + SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); + goto err; + } + + ret = 1; + err: + OPENSSL_cleanse(secret, sizeof(secret)); + return ret; +} + +int tls13_update_key(SSL *s, int send) +{ + static const unsigned char application_traffic[] = + "application traffic secret"; + const EVP_MD *md = ssl_handshake_md(s); + size_t hashlen = EVP_MD_size(md); + unsigned char *insecret, *iv; + unsigned char secret[EVP_MAX_MD_SIZE]; + EVP_CIPHER_CTX *ciph_ctx; + int ret = 0; + + if (s->server == send) + insecret = s->server_app_traffic_secret; + else + insecret = s->client_app_traffic_secret; + + if (send) { + iv = s->write_iv; + ciph_ctx = s->enc_write_ctx; + RECORD_LAYER_reset_write_sequence(&s->rlayer); + } else { + iv = s->read_iv; + ciph_ctx = s->enc_read_ctx; + RECORD_LAYER_reset_read_sequence(&s->rlayer); + } + + if (!derive_secret_key_and_iv(s, send, ssl_handshake_md(s), + s->s3->tmp.new_sym_enc, insecret, NULL, + application_traffic, + sizeof(application_traffic) - 1, secret, iv, + ciph_ctx)) + goto err; + + memcpy(insecret, secret, hashlen); + + ret = 1; + err: + OPENSSL_cleanse(secret, sizeof(secret)); + return ret; +} + +int tls13_alert_code(int code) +{ + if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_END_OF_EARLY_DATA) + return code; + + return tls1_alert_code(code); +}