1 /* 2 * Copyright (c) 2017 Thomas Pornin <pornin@bolet.org> 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining 5 * a copy of this software and associated documentation files (the 6 * "Software"), to deal in the Software without restriction, including 7 * without limitation the rights to use, copy, modify, merge, publish, 8 * distribute, sublicense, and/or sell copies of the Software, and to 9 * permit persons to whom the Software is furnished to do so, subject to 10 * the following conditions: 11 * 12 * The above copyright notice and this permission notice shall be 13 * included in all copies or substantial portions of the Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 22 * SOFTWARE. 23 */ 24 25 #include "inner.h" 26 27 /* 28 * Supported cipher suites that use SHA-384 for the PRF when selected 29 * for TLS 1.2. All other cipher suites are deemed to use SHA-256. 30 */ 31 static const uint16_t suites_sha384[] = { 32 BR_TLS_RSA_WITH_AES_256_GCM_SHA384, 33 BR_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384, 34 BR_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384, 35 BR_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384, 36 BR_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384, 37 BR_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384, 38 BR_TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384, 39 BR_TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384, 40 BR_TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 41 }; 42 43 /* see bearssl_ssl.h */ 44 int 45 br_ssl_key_export(br_ssl_engine_context *cc, 46 void *dst, size_t len, const char *label, 47 const void *context, size_t context_len) 48 { 49 br_tls_prf_seed_chunk chunks[4]; 50 br_tls_prf_impl iprf; 51 size_t num_chunks, u; 52 unsigned char tmp[2]; 53 int prf_id; 54 55 if (cc->application_data != 1) { 56 return 0; 57 } 58 chunks[0].data = cc->client_random; 59 chunks[0].len = sizeof cc->client_random; 60 chunks[1].data = cc->server_random; 61 chunks[1].len = sizeof cc->server_random; 62 if (context != NULL) { 63 br_enc16be(tmp, (unsigned)context_len); 64 chunks[2].data = tmp; 65 chunks[2].len = 2; 66 chunks[3].data = context; 67 chunks[3].len = context_len; 68 num_chunks = 4; 69 } else { 70 num_chunks = 2; 71 } 72 prf_id = BR_SSLPRF_SHA256; 73 for (u = 0; u < (sizeof suites_sha384) / sizeof(uint16_t); u ++) { 74 if (suites_sha384[u] == cc->session.cipher_suite) { 75 prf_id = BR_SSLPRF_SHA384; 76 } 77 } 78 iprf = br_ssl_engine_get_PRF(cc, prf_id); 79 iprf(dst, len, 80 cc->session.master_secret, sizeof cc->session.master_secret, 81 label, num_chunks, chunks); 82 return 1; 83 } 84