+/*
+ * Copyright (c) 2017 Thomas Pornin <pornin@bolet.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "inner.h"
+
+/*
+ * Supported cipher suites that use SHA-384 for the PRF when selected
+ * for TLS 1.2. All other cipher suites are deemed to use SHA-256.
+ */
+static const uint16_t suites_sha384[] = {
+ BR_TLS_RSA_WITH_AES_256_GCM_SHA384,
+ BR_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,
+ BR_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384,
+ BR_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,
+ BR_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384,
+ BR_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+ BR_TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384,
+ BR_TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+ BR_TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384
+};
+
+/* see bearssl_ssl.h */
+int
+br_ssl_key_export(br_ssl_engine_context *cc,
+ void *dst, size_t len, const char *label,
+ const void *context, size_t context_len)
+{
+ br_tls_prf_seed_chunk chunks[4];
+ br_tls_prf_impl iprf;
+ size_t num_chunks, u;
+ unsigned char tmp[2];
+ int prf_id;
+
+ if (cc->application_data != 1) {
+ return 0;
+ }
+ chunks[0].data = cc->client_random;
+ chunks[0].len = sizeof cc->client_random;
+ chunks[1].data = cc->server_random;
+ chunks[1].len = sizeof cc->server_random;
+ if (context != NULL) {
+ br_enc16be(tmp, (unsigned)context_len);
+ chunks[2].data = tmp;
+ chunks[2].len = 2;
+ chunks[3].data = context;
+ chunks[3].len = context_len;
+ num_chunks = 4;
+ } else {
+ num_chunks = 2;
+ }
+ prf_id = BR_SSLPRF_SHA256;
+ for (u = 0; u < (sizeof suites_sha384) / sizeof(uint16_t); u ++) {
+ if (suites_sha384[u] == cc->session.cipher_suite) {
+ prf_id = BR_SSLPRF_SHA384;
+ }
+ }
+ iprf = br_ssl_engine_get_PRF(cc, prf_id);
+ iprf(dst, len,
+ cc->session.master_secret, sizeof cc->session.master_secret,
+ label, num_chunks, chunks);
+ return 1;
+}
projects / BearSSL / commitdiff