1 /* 2 * Copyright (c) 2014, Linaro Limited 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 11 * 2. Redistributions in binary form must reproduce the above copyright notice, 12 * this list of conditions and the following disclaimer in the documentation 13 * and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25 * POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <crypto/crypto.h> 29 #include <stdlib.h> 30 #include <string.h> 31 #include <tee/tee_cryp_concat_kdf.h> 32 #include <tee/tee_cryp_utl.h> 33 #include <utee_defines.h> 34 35 TEE_Result tee_cryp_concat_kdf(uint32_t hash_id, const uint8_t *shared_secret, 36 size_t shared_secret_len, 37 const uint8_t *other_info, 38 size_t other_info_len, uint8_t *derived_key, 39 size_t derived_key_len) 40 { 41 TEE_Result res; 42 size_t ctx_size, hash_len, i, n, sz; 43 void *ctx = NULL; 44 uint8_t tmp[TEE_MAX_HASH_SIZE]; 45 uint32_t be_count; 46 uint8_t *out = derived_key; 47 uint32_t hash_algo = TEE_ALG_HASH_ALGO(hash_id); 48 49 res = crypto_hash_get_ctx_size(hash_algo, &ctx_size); 50 if (res != TEE_SUCCESS) 51 goto out; 52 53 ctx = malloc(ctx_size); 54 if (!ctx) { 55 res = TEE_ERROR_OUT_OF_MEMORY; 56 goto out; 57 } 58 59 res = tee_hash_get_digest_size(hash_algo, &hash_len); 60 if (res != TEE_SUCCESS) 61 goto out; 62 63 n = derived_key_len / hash_len; 64 sz = hash_len; 65 for (i = 1; i <= n + 1; i++) { 66 be_count = TEE_U32_TO_BIG_ENDIAN(i); 67 68 res = crypto_hash_init(ctx, hash_algo); 69 if (res != TEE_SUCCESS) 70 goto out; 71 res = crypto_hash_update(ctx, hash_algo, (uint8_t *)&be_count, 72 sizeof(be_count)); 73 if (res != TEE_SUCCESS) 74 goto out; 75 res = crypto_hash_update(ctx, hash_algo, shared_secret, 76 shared_secret_len); 77 if (res != TEE_SUCCESS) 78 goto out; 79 if (other_info && other_info_len) { 80 res = crypto_hash_update(ctx, hash_algo, other_info, 81 other_info_len); 82 if (res != TEE_SUCCESS) 83 goto out; 84 } 85 res = crypto_hash_final(ctx, hash_algo, tmp, sizeof(tmp)); 86 if (res != TEE_SUCCESS) 87 goto out; 88 89 if (i == n + 1) 90 sz = derived_key_len % hash_len; 91 memcpy(out, tmp, sz); 92 out += sz; 93 } 94 res = TEE_SUCCESS; 95 out: 96 free(ctx); 97 return res; 98 } 99