qemu

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/*
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 * QEMU Crypto PBKDF support (Password-Based Key Derivation Function)
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 *
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 * Copyright (c) 2015-2016 Red Hat, Inc.
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 *
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 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
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 *
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 */
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#include "qemu/osdep.h"
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#include <gcrypt.h>
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#include "qapi/error.h"
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#include "crypto/pbkdf.h"
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bool qcrypto_pbkdf2_supports(QCryptoHashAlgorithm hash)
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{
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    switch (hash) {
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    case QCRYPTO_HASH_ALG_MD5:
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    case QCRYPTO_HASH_ALG_SHA1:
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    case QCRYPTO_HASH_ALG_SHA224:
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    case QCRYPTO_HASH_ALG_SHA256:
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    case QCRYPTO_HASH_ALG_SHA384:
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    case QCRYPTO_HASH_ALG_SHA512:
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    case QCRYPTO_HASH_ALG_RIPEMD160:
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        return true;
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    default:
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        return false;
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    }
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}
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int qcrypto_pbkdf2(QCryptoHashAlgorithm hash,
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                   const uint8_t *key, size_t nkey,
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                   const uint8_t *salt, size_t nsalt,
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                   uint64_t iterations,
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                   uint8_t *out, size_t nout,
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                   Error **errp)
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{
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    static const int hash_map[QCRYPTO_HASH_ALG__MAX] = {
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        [QCRYPTO_HASH_ALG_MD5] = GCRY_MD_MD5,
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        [QCRYPTO_HASH_ALG_SHA1] = GCRY_MD_SHA1,
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        [QCRYPTO_HASH_ALG_SHA224] = GCRY_MD_SHA224,
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        [QCRYPTO_HASH_ALG_SHA256] = GCRY_MD_SHA256,
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        [QCRYPTO_HASH_ALG_SHA384] = GCRY_MD_SHA384,
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        [QCRYPTO_HASH_ALG_SHA512] = GCRY_MD_SHA512,
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        [QCRYPTO_HASH_ALG_RIPEMD160] = GCRY_MD_RMD160,
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    };
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    int ret;
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    if (iterations > ULONG_MAX) {
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        error_setg_errno(errp, ERANGE,
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                         "PBKDF iterations %llu must be less than %lu",
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                         (long long unsigned)iterations, ULONG_MAX);
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        return -1;
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    }
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    if (hash >= G_N_ELEMENTS(hash_map) ||
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        hash_map[hash] == GCRY_MD_NONE) {
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        error_setg_errno(errp, ENOSYS,
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                         "PBKDF does not support hash algorithm %s",
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                         QCryptoHashAlgorithm_str(hash));
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        return -1;
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    }
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    ret = gcry_kdf_derive(key, nkey, GCRY_KDF_PBKDF2,
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                          hash_map[hash],
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                          salt, nsalt, iterations,
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                          nout, out);
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    if (ret != 0) {
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        error_setg(errp, "Cannot derive password: %s",
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                   gcry_strerror(ret));
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        return -1;
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    }
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    return 0;
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}
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