+ 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 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;
+ size_t hashlen = EVP_MD_size(md);
+
+ if (!tls13_hkdf_expand(s, md, insecret, label, labellen, hash, hashlen,
+ 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, 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) {
+ SSLerr(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";
+ 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) {
+ 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 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)) {
+ 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 (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->session->master_key,
+ hashlen)) {
+ SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ s->session->master_key_length = 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)) {
+ SSLerr(SSL_F_TLS13_CHANGE_CIPHER_STATE, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
+ }
+
+ 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 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) {
+ 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))
+ goto err;
+
+ memcpy(insecret, secret, hashlen);
+
+ ret = 1;
+ err:
+ OPENSSL_cleanse(secret, sizeof(secret));
+ return ret;