1 /* 2 * QEMU Crypto PBKDF support (Password-Based Key Derivation Function) 3 * 4 * Copyright (c) 2015-2016 Red Hat, Inc. 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 18 * 19 */ 20 21 #include "qemu/osdep.h" 22 #include <gcrypt.h> 23 #include "qapi/error.h" 24 #include "crypto/pbkdf.h" 25 26 bool qcrypto_pbkdf2_supports(QCryptoHashAlgorithm hash) 27 { 28 switch (hash) { 29 case QCRYPTO_HASH_ALG_MD5: 30 case QCRYPTO_HASH_ALG_SHA1: 31 case QCRYPTO_HASH_ALG_SHA224: 32 case QCRYPTO_HASH_ALG_SHA256: 33 case QCRYPTO_HASH_ALG_SHA384: 34 case QCRYPTO_HASH_ALG_SHA512: 35 case QCRYPTO_HASH_ALG_RIPEMD160: 36 return true; 37 default: 38 return false; 39 } 40 } 41 42 int qcrypto_pbkdf2(QCryptoHashAlgorithm hash, 43 const uint8_t *key, size_t nkey, 44 const uint8_t *salt, size_t nsalt, 45 uint64_t iterations, 46 uint8_t *out, size_t nout, 47 Error **errp) 48 { 49 static const int hash_map[QCRYPTO_HASH_ALG__MAX] = { 50 [QCRYPTO_HASH_ALG_MD5] = GCRY_MD_MD5, 51 [QCRYPTO_HASH_ALG_SHA1] = GCRY_MD_SHA1, 52 [QCRYPTO_HASH_ALG_SHA224] = GCRY_MD_SHA224, 53 [QCRYPTO_HASH_ALG_SHA256] = GCRY_MD_SHA256, 54 [QCRYPTO_HASH_ALG_SHA384] = GCRY_MD_SHA384, 55 [QCRYPTO_HASH_ALG_SHA512] = GCRY_MD_SHA512, 56 [QCRYPTO_HASH_ALG_RIPEMD160] = GCRY_MD_RMD160, 57 }; 58 int ret; 59 60 if (iterations > ULONG_MAX) { 61 error_setg_errno(errp, ERANGE, 62 "PBKDF iterations %llu must be less than %lu", 63 (long long unsigned)iterations, ULONG_MAX); 64 return -1; 65 } 66 67 if (hash >= G_N_ELEMENTS(hash_map) || 68 hash_map[hash] == GCRY_MD_NONE) { 69 error_setg_errno(errp, ENOSYS, 70 "PBKDF does not support hash algorithm %s", 71 QCryptoHashAlgorithm_lookup[hash]); 72 return -1; 73 } 74 75 ret = gcry_kdf_derive(key, nkey, GCRY_KDF_PBKDF2, 76 hash_map[hash], 77 salt, nsalt, iterations, 78 nout, out); 79 if (ret != 0) { 80 error_setg(errp, "Cannot derive password: %s", 81 gcry_strerror(ret)); 82 return -1; 83 } 84 85 return 0; 86 } 87