| /* |
| * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved. |
| * |
| * Licensed under the Apache License 2.0 (the "License"). You may not use |
| * this file except in compliance with the License. You can obtain a copy |
| * in the file LICENSE in the source distribution or at |
| * https://www.openssl.org/source/license.html |
| */ |
| |
| #include <stdlib.h> |
| #include "ssl_locl.h" |
| #include "internal/cryptlib.h" |
| #include <openssl/evp.h> |
| #include <openssl/kdf.h> |
| |
| #define TLS13_MAX_LABEL_LEN 249 |
| |
| /* Always filled with zeros */ |
| static const unsigned char default_zeros[EVP_MAX_MD_SIZE]; |
| |
| /* |
| * Given a |secret|; a |label| of length |labellen|; and |data| of length |
| * |datalen| (e.g. typically a hash of the handshake messages), derive a new |
| * secret |outlen| bytes long and store it in the location pointed to be |out|. |
| * The |data| value may be zero length. Any errors will be treated as fatal if |
| * |fatal| is set. Returns 1 on success 0 on failure. |
| */ |
| int tls13_hkdf_expand(SSL *s, const EVP_MD *md, const unsigned char *secret, |
| const unsigned char *label, size_t labellen, |
| const unsigned char *data, size_t datalen, |
| unsigned char *out, size_t outlen, int fatal) |
| { |
| static const unsigned char label_prefix[] = "tls13 "; |
| EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); |
| int ret; |
| size_t hkdflabellen; |
| size_t hashlen; |
| /* |
| * 2 bytes for length of derived secret + 1 byte for length of combined |
| * prefix and label + bytes for the label itself + 1 byte length of hash |
| * + bytes for the hash itself |
| */ |
| unsigned char hkdflabel[sizeof(uint16_t) + sizeof(uint8_t) + |
| + (sizeof(label_prefix) - 1) + TLS13_MAX_LABEL_LEN |
| + 1 + EVP_MAX_MD_SIZE]; |
| WPACKET pkt; |
| |
| if (pctx == NULL) |
| return 0; |
| |
| if (labellen > TLS13_MAX_LABEL_LEN) { |
| if (fatal) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, |
| ERR_R_INTERNAL_ERROR); |
| } else { |
| /* |
| * Probably we have been called from SSL_export_keying_material(), |
| * or SSL_export_keying_material_early(). |
| */ |
| SSLerr(SSL_F_TLS13_HKDF_EXPAND, SSL_R_TLS_ILLEGAL_EXPORTER_LABEL); |
| } |
| EVP_PKEY_CTX_free(pctx); |
| return 0; |
| } |
| |
| hashlen = EVP_MD_size(md); |
| |
| if (!WPACKET_init_static_len(&pkt, hkdflabel, sizeof(hkdflabel), 0) |
| || !WPACKET_put_bytes_u16(&pkt, outlen) |
| || !WPACKET_start_sub_packet_u8(&pkt) |
| || !WPACKET_memcpy(&pkt, label_prefix, sizeof(label_prefix) - 1) |
| || !WPACKET_memcpy(&pkt, label, labellen) |
| || !WPACKET_close(&pkt) |
| || !WPACKET_sub_memcpy_u8(&pkt, data, (data == NULL) ? 0 : datalen) |
| || !WPACKET_get_total_written(&pkt, &hkdflabellen) |
| || !WPACKET_finish(&pkt)) { |
| EVP_PKEY_CTX_free(pctx); |
| WPACKET_cleanup(&pkt); |
| if (fatal) |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, |
| ERR_R_INTERNAL_ERROR); |
| else |
| SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| |
| ret = EVP_PKEY_derive_init(pctx) <= 0 |
| || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXPAND_ONLY) |
| <= 0 |
| || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0 |
| || EVP_PKEY_CTX_set1_hkdf_key(pctx, secret, hashlen) <= 0 |
| || EVP_PKEY_CTX_add1_hkdf_info(pctx, hkdflabel, hkdflabellen) <= 0 |
| || EVP_PKEY_derive(pctx, out, &outlen) <= 0; |
| |
| EVP_PKEY_CTX_free(pctx); |
| |
| if (ret != 0) { |
| if (fatal) |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_HKDF_EXPAND, |
| ERR_R_INTERNAL_ERROR); |
| else |
| SSLerr(SSL_F_TLS13_HKDF_EXPAND, ERR_R_INTERNAL_ERROR); |
| } |
| |
| return ret == 0; |
| } |
| |
| /* |
| * Given a |secret| generate a |key| of length |keylen| bytes. Returns 1 on |
| * success 0 on failure. |
| */ |
| int tls13_derive_key(SSL *s, const EVP_MD *md, const unsigned char *secret, |
| unsigned char *key, size_t keylen) |
| { |
| static const unsigned char keylabel[] = "key"; |
| |
| return tls13_hkdf_expand(s, md, secret, keylabel, sizeof(keylabel) - 1, |
| NULL, 0, key, keylen, 1); |
| } |
| |
| /* |
| * Given a |secret| generate an |iv| of length |ivlen| bytes. Returns 1 on |
| * success 0 on failure. |
| */ |
| int tls13_derive_iv(SSL *s, const EVP_MD *md, const unsigned char *secret, |
| unsigned char *iv, size_t ivlen) |
| { |
| static const unsigned char ivlabel[] = "iv"; |
| |
| return tls13_hkdf_expand(s, md, secret, ivlabel, sizeof(ivlabel) - 1, |
| NULL, 0, iv, ivlen, 1); |
| } |
| |
| int tls13_derive_finishedkey(SSL *s, const EVP_MD *md, |
| const unsigned char *secret, |
| unsigned char *fin, size_t finlen) |
| { |
| static const unsigned char finishedlabel[] = "finished"; |
| |
| return tls13_hkdf_expand(s, md, secret, finishedlabel, |
| sizeof(finishedlabel) - 1, NULL, 0, fin, finlen, 1); |
| } |
| |
| /* |
| * 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. |
| */ |
| int tls13_generate_secret(SSL *s, const EVP_MD *md, |
| const unsigned char *prevsecret, |
| const unsigned char *insecret, |
| size_t insecretlen, |
| unsigned char *outsecret) |
| { |
| size_t mdlen, prevsecretlen; |
| int mdleni; |
| int ret; |
| EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL); |
| static const char derived_secret_label[] = "derived"; |
| unsigned char preextractsec[EVP_MAX_MD_SIZE]; |
| |
| if (pctx == NULL) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, |
| ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| |
| mdleni = EVP_MD_size(md); |
| /* Ensure cast to size_t is safe */ |
| if (!ossl_assert(mdleni >= 0)) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, |
| ERR_R_INTERNAL_ERROR); |
| return 0; |
| } |
| mdlen = (size_t)mdleni; |
| |
| if (insecret == NULL) { |
| insecret = default_zeros; |
| insecretlen = mdlen; |
| } |
| if (prevsecret == NULL) { |
| prevsecret = default_zeros; |
| prevsecretlen = 0; |
| } else { |
| EVP_MD_CTX *mctx = EVP_MD_CTX_new(); |
| unsigned char hash[EVP_MAX_MD_SIZE]; |
| |
| /* The pre-extract derive step uses a hash of no messages */ |
| if (mctx == NULL |
| || EVP_DigestInit_ex(mctx, md, NULL) <= 0 |
| || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, |
| ERR_R_INTERNAL_ERROR); |
| EVP_MD_CTX_free(mctx); |
| EVP_PKEY_CTX_free(pctx); |
| return 0; |
| } |
| EVP_MD_CTX_free(mctx); |
| |
| /* Generate the pre-extract secret */ |
| if (!tls13_hkdf_expand(s, md, prevsecret, |
| (unsigned char *)derived_secret_label, |
| sizeof(derived_secret_label) - 1, hash, mdlen, |
| preextractsec, mdlen, 1)) { |
| /* SSLfatal() already called */ |
| EVP_PKEY_CTX_free(pctx); |
| return 0; |
| } |
| |
| prevsecret = preextractsec; |
| prevsecretlen = mdlen; |
| } |
| |
| ret = EVP_PKEY_derive_init(pctx) <= 0 |
| || EVP_PKEY_CTX_hkdf_mode(pctx, EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY) |
| <= 0 |
| || EVP_PKEY_CTX_set_hkdf_md(pctx, md) <= 0 |
| || EVP_PKEY_CTX_set1_hkdf_key(pctx, insecret, insecretlen) <= 0 |
| || EVP_PKEY_CTX_set1_hkdf_salt(pctx, prevsecret, prevsecretlen) |
| <= 0 |
| || EVP_PKEY_derive(pctx, outsecret, &mdlen) |
| <= 0; |
| |
| if (ret != 0) |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_GENERATE_SECRET, |
| ERR_R_INTERNAL_ERROR); |
| |
| EVP_PKEY_CTX_free(pctx); |
| if (prevsecret == preextractsec) |
| OPENSSL_cleanse(preextractsec, mdlen); |
| return ret == 0; |
| } |
| |
| /* |
| * 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. |
| */ |
| int tls13_generate_handshake_secret(SSL *s, const unsigned char *insecret, |
| size_t insecretlen) |
| { |
| /* Calls SSLfatal() if required */ |
| 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. |
| */ |
| int tls13_generate_master_secret(SSL *s, unsigned char *out, |
| unsigned char *prev, size_t prevlen, |
| size_t *secret_size) |
| { |
| const EVP_MD *md = ssl_handshake_md(s); |
| |
| *secret_size = EVP_MD_size(md); |
| /* Calls SSLfatal() if required */ |
| 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)) { |
| /* SSLfatal() already called */ |
| goto err; |
| } |
| |
| if (str == s->method->ssl3_enc->server_finished_label) { |
| key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, |
| s->server_finished_secret, hashlen); |
| } else if (SSL_IS_FIRST_HANDSHAKE(s)) { |
| key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, |
| s->client_finished_secret, hashlen); |
| } else { |
| unsigned char finsecret[EVP_MAX_MD_SIZE]; |
| |
| if (!tls13_derive_finishedkey(s, ssl_handshake_md(s), |
| s->client_app_traffic_secret, |
| finsecret, hashlen)) |
| goto err; |
| |
| key = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finsecret, |
| hashlen); |
| OPENSSL_cleanse(finsecret, sizeof(finsecret)); |
| } |
| |
| 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) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS13_FINAL_FINISH_MAC, |
| ERR_R_INTERNAL_ERROR); |
| 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; |
| |
| s->session->cipher = s->s3->tmp.new_cipher; |
| if (!ssl_cipher_get_evp(s->session, &c, &hash, NULL, NULL, NULL, 0)) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, 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 sending, 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; |
| int hashleni = EVP_MD_size(md); |
| size_t hashlen; |
| |
| /* Ensure cast to size_t is safe */ |
| if (!ossl_assert(hashleni >= 0)) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, |
| ERR_R_EVP_LIB); |
| goto err; |
| } |
| hashlen = (size_t)hashleni; |
| |
| if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen, |
| secret, hashlen, 1)) { |
| /* SSLfatal() already called */ |
| 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)) { |
| /* SSLfatal() already called */ |
| goto err; |
| } |
| |
| if (EVP_CipherInit_ex(ciph_ctx, ciph, NULL, NULL, NULL, sending) <= 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) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DERIVE_SECRET_KEY_AND_IV, |
| ERR_R_EVP_LIB); |
| goto err; |
| } |
| |
| 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[] = "c e traffic"; |
| static const unsigned char client_handshake_traffic[] = "c hs traffic"; |
| static const unsigned char client_application_traffic[] = "c ap traffic"; |
| static const unsigned char server_handshake_traffic[] = "s hs traffic"; |
| static const unsigned char server_application_traffic[] = "s ap traffic"; |
| static const unsigned char exporter_master_secret[] = "exp master"; |
| static const unsigned char resumption_master_secret[] = "res master"; |
| static const unsigned char early_exporter_master_secret[] = "e exp master"; |
| 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 = NULL; |
| const EVP_CIPHER *cipher = NULL; |
| |
| 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) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
| 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 { |
| s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; |
| 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) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
| 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) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
| SSL_F_TLS13_CHANGE_CIPHER_STATE, |
| SSL_R_BAD_HANDSHAKE_LENGTH); |
| goto err; |
| } |
| |
| if (s->early_data_state == SSL_EARLY_DATA_CONNECTING |
| && s->max_early_data > 0 |
| && s->session->ext.max_early_data == 0) { |
| /* |
| * If we are attempting to send early data, and we've decided to |
| * actually do it but max_early_data in s->session is 0 then we |
| * must be using an external PSK. |
| */ |
| if (!ossl_assert(s->psksession != NULL |
| && s->max_early_data == |
| s->psksession->ext.max_early_data)) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
| SSL_F_TLS13_CHANGE_CIPHER_STATE, |
| ERR_R_INTERNAL_ERROR); |
| goto err; |
| } |
| sslcipher = SSL_SESSION_get0_cipher(s->psksession); |
| } |
| if (sslcipher == NULL) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
| SSL_F_TLS13_CHANGE_CIPHER_STATE, SSL_R_BAD_PSK); |
| 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) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
| 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)) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
| SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); |
| EVP_MD_CTX_free(mdctx); |
| goto err; |
| } |
| hashlen = hashlenui; |
| EVP_MD_CTX_free(mdctx); |
| |
| if (!tls13_hkdf_expand(s, md, insecret, |
| early_exporter_master_secret, |
| sizeof(early_exporter_master_secret) - 1, |
| hashval, hashlen, |
| s->early_exporter_master_secret, hashlen, |
| 1)) { |
| SSLfatal(s, SSL_AD_INTERNAL_ERROR, |
| SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR); |
| goto err; |
| } |
| |
| if (!ssl_log_secret(s, EARLY_EXPORTER_SECRET_LABEL, |
| s->early_exporter_master_secret, hashlen)) { |
| /* SSLfatal() already called */ |
| goto err; |
| } |
| } 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 handshake hash used for the server read/client write handshake |
| * traffic secret is the same as the hash for the server |
| * write/client read handshake traffic secret. However, if we |
| * processed early data then we delay changing the server |
| * read/client write cipher state until later, and the handshake |
| * hashes have moved on. Therefore we use the value saved earlier |
| * when we did the server write/client read change cipher state. |
| */ |
| 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)) { |
| /* SSLfatal() already called */; |
| 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 (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, hashlen, s->resumption_master_secret, |
| hashlen, 1)) { |
| /* SSLfatal() already called */ |
| goto err; |
| } |
| } |
| |
| if (!derive_secret_key_and_iv(s, which & SSL3_CC_WRITE, md, cipher, |
| insecret, hash, label, labellen, secret, iv, |
| ciph_ctx)) { |
| /* SSLfatal() already called */ |
| goto err; |
| } |
| |
| if (label == server_application_traffic) { |
| memcpy(s->server_app_traffic_secret, secret, hashlen); |
| /* Now we create the exporter master secret */ |
| if (!tls13_hkdf_expand(s, ssl_handshake_md(s), insecret, |
| exporter_master_secret, |
| sizeof(exporter_master_secret) - 1, |
| hash, hashlen, s->exporter_master_secret, |
| hashlen, 1)) { |
| /* SSLfatal() already called */ |
| goto err; |
| } |
| |
| if (!ssl_log_secret(s, EXPORTER_SECRET_LABEL, s->exporter_master_secret, |
| hashlen)) { |
| /* SSLfatal() already called */ |
| goto err; |
| } |
| } else if (label == client_application_traffic) |
| memcpy(s->client_app_traffic_secret, secret, hashlen); |
| |
| if (!ssl_log_secret(s, log_label, secret, hashlen)) { |
| /* SSLfatal() already called */ |
| goto err; |
| } |
| |
| if (finsecret != NULL |
| && !tls13_derive_finishedkey(s, ssl_handshake_md(s), secret, |
| finsecret, finsecretlen)) { |
| /* SSLfatal() already called */ |
| goto err; |
| } |
| |
| if (!s->server && label == client_early_traffic) |
| s->statem.enc_write_state = ENC_WRITE_STATE_WRITE_PLAIN_ALERTS; |
| else |
| s->statem.enc_write_state = ENC_WRITE_STATE_VALID; |
| ret = 1; |
| err: |
| OPENSSL_cleanse(secret, sizeof(secret)); |
| return ret; |
| } |
| |
| int tls13_update_key(SSL *s, int sending) |
| { |
| static const unsigned char application_traffic[] = "traffic upd"; |
| 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 == sending) |
| insecret = s->server_app_traffic_secret; |
| else |
| insecret = s->client_app_traffic_secret; |
| |
| if (sending) { |
| s->statem.enc_write_state = ENC_WRITE_STATE_INVALID; |
| 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, sending, ssl_handshake_md(s), |
| s->s3->tmp.new_sym_enc, insecret, NULL, |
| application_traffic, |
| sizeof(application_traffic) - 1, secret, iv, |
| ciph_ctx)) { |
| /* SSLfatal() already called */ |
| goto err; |
| } |
| |
| memcpy(insecret, secret, hashlen); |
| |
| s->statem.enc_write_state = ENC_WRITE_STATE_VALID; |
| ret = 1; |
| err: |
| OPENSSL_cleanse(secret, sizeof(secret)); |
| return ret; |
| } |
| |
| int tls13_alert_code(int code) |
| { |
| /* There are 2 additional alerts in TLSv1.3 compared to TLSv1.2 */ |
| if (code == SSL_AD_MISSING_EXTENSION || code == SSL_AD_CERTIFICATE_REQUIRED) |
| return code; |
| |
| return tls1_alert_code(code); |
| } |
| |
| int tls13_export_keying_material(SSL *s, unsigned char *out, size_t olen, |
| const char *label, size_t llen, |
| const unsigned char *context, |
| size_t contextlen, int use_context) |
| { |
| unsigned char exportsecret[EVP_MAX_MD_SIZE]; |
| static const unsigned char exporterlabel[] = "exporter"; |
| unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; |
| const EVP_MD *md = ssl_handshake_md(s); |
| EVP_MD_CTX *ctx = EVP_MD_CTX_new(); |
| unsigned int hashsize, datalen; |
| int ret = 0; |
| |
| if (ctx == NULL || !ossl_statem_export_allowed(s)) |
| goto err; |
| |
| if (!use_context) |
| contextlen = 0; |
| |
| if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 |
| || EVP_DigestUpdate(ctx, context, contextlen) <= 0 |
| || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 |
| || EVP_DigestInit_ex(ctx, md, NULL) <= 0 |
| || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 |
| || !tls13_hkdf_expand(s, md, s->exporter_master_secret, |
| (const unsigned char *)label, llen, |
| data, datalen, exportsecret, hashsize, 0) |
| || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, |
| sizeof(exporterlabel) - 1, hash, hashsize, |
| out, olen, 0)) |
| goto err; |
| |
| ret = 1; |
| err: |
| EVP_MD_CTX_free(ctx); |
| return ret; |
| } |
| |
| int tls13_export_keying_material_early(SSL *s, unsigned char *out, size_t olen, |
| const char *label, size_t llen, |
| const unsigned char *context, |
| size_t contextlen) |
| { |
| static const unsigned char exporterlabel[] = "exporter"; |
| unsigned char exportsecret[EVP_MAX_MD_SIZE]; |
| unsigned char hash[EVP_MAX_MD_SIZE], data[EVP_MAX_MD_SIZE]; |
| const EVP_MD *md; |
| EVP_MD_CTX *ctx = EVP_MD_CTX_new(); |
| unsigned int hashsize, datalen; |
| int ret = 0; |
| const SSL_CIPHER *sslcipher; |
| |
| if (ctx == NULL || !ossl_statem_export_early_allowed(s)) |
| goto err; |
| |
| if (!s->server && s->max_early_data > 0 |
| && s->session->ext.max_early_data == 0) |
| sslcipher = SSL_SESSION_get0_cipher(s->psksession); |
| else |
| sslcipher = SSL_SESSION_get0_cipher(s->session); |
| |
| md = ssl_md(sslcipher->algorithm2); |
| |
| /* |
| * Calculate the hash value and store it in |data|. The reason why |
| * the empty string is used is that the definition of TLS-Exporter |
| * is like so: |
| * |
| * TLS-Exporter(label, context_value, key_length) = |
| * HKDF-Expand-Label(Derive-Secret(Secret, label, ""), |
| * "exporter", Hash(context_value), key_length) |
| * |
| * Derive-Secret(Secret, Label, Messages) = |
| * HKDF-Expand-Label(Secret, Label, |
| * Transcript-Hash(Messages), Hash.length) |
| * |
| * Here Transcript-Hash is the cipher suite hash algorithm. |
| */ |
| if (EVP_DigestInit_ex(ctx, md, NULL) <= 0 |
| || EVP_DigestUpdate(ctx, context, contextlen) <= 0 |
| || EVP_DigestFinal_ex(ctx, hash, &hashsize) <= 0 |
| || EVP_DigestInit_ex(ctx, md, NULL) <= 0 |
| || EVP_DigestFinal_ex(ctx, data, &datalen) <= 0 |
| || !tls13_hkdf_expand(s, md, s->early_exporter_master_secret, |
| (const unsigned char *)label, llen, |
| data, datalen, exportsecret, hashsize, 0) |
| || !tls13_hkdf_expand(s, md, exportsecret, exporterlabel, |
| sizeof(exporterlabel) - 1, hash, hashsize, |
| out, olen, 0)) |
| goto err; |
| |
| ret = 1; |
| err: |
| EVP_MD_CTX_free(ctx); |
| return ret; |
| } |
