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 "crypto/pbkdf.h" 23 #include "gcrypt.h" 24 25 bool qcrypto_pbkdf2_supports(QCryptoHashAlgorithm hash) 26 { 27 switch (hash) { 28 case QCRYPTO_HASH_ALG_MD5: 29 case QCRYPTO_HASH_ALG_SHA1: 30 case QCRYPTO_HASH_ALG_SHA256: 31 return true; 32 default: 33 return false; 34 } 35 } 36 37 int qcrypto_pbkdf2(QCryptoHashAlgorithm hash, 38 const uint8_t *key, size_t nkey, 39 const uint8_t *salt, size_t nsalt, 40 unsigned int iterations, 41 uint8_t *out, size_t nout, 42 Error **errp) 43 { 44 static const int hash_map[QCRYPTO_HASH_ALG__MAX] = { 45 [QCRYPTO_HASH_ALG_MD5] = GCRY_MD_MD5, 46 [QCRYPTO_HASH_ALG_SHA1] = GCRY_MD_SHA1, 47 [QCRYPTO_HASH_ALG_SHA256] = GCRY_MD_SHA256, 48 }; 49 int ret; 50 51 if (hash >= G_N_ELEMENTS(hash_map) || 52 hash_map[hash] == GCRY_MD_NONE) { 53 error_setg(errp, "Unexpected hash algorithm %d", hash); 54 return -1; 55 } 56 57 ret = gcry_kdf_derive(key, nkey, GCRY_KDF_PBKDF2, 58 hash_map[hash], 59 salt, nsalt, iterations, 60 nout, out); 61 if (ret != 0) { 62 error_setg(errp, "Cannot derive password: %s", 63 gcry_strerror(ret)); 64 return -1; 65 } 66 67 return 0; 68 } 69