qemu

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/*
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 * QEMU Crypto cipher algorithms
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 *
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 * Copyright (c) 2015 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 "qemu/host-utils.h"
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#include "qapi/error.h"
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#include "crypto/cipher.h"
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#include "cipherpriv.h"
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static const size_t alg_key_len[QCRYPTO_CIPHER_ALG__MAX] = {
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    [QCRYPTO_CIPHER_ALG_AES_128] = 16,
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    [QCRYPTO_CIPHER_ALG_AES_192] = 24,
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    [QCRYPTO_CIPHER_ALG_AES_256] = 32,
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    [QCRYPTO_CIPHER_ALG_DES] = 8,
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    [QCRYPTO_CIPHER_ALG_3DES] = 24,
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    [QCRYPTO_CIPHER_ALG_CAST5_128] = 16,
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    [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16,
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    [QCRYPTO_CIPHER_ALG_SERPENT_192] = 24,
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    [QCRYPTO_CIPHER_ALG_SERPENT_256] = 32,
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    [QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16,
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    [QCRYPTO_CIPHER_ALG_TWOFISH_192] = 24,
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    [QCRYPTO_CIPHER_ALG_TWOFISH_256] = 32,
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#ifdef CONFIG_CRYPTO_SM4
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    [QCRYPTO_CIPHER_ALG_SM4] = 16,
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#endif
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};
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static const size_t alg_block_len[QCRYPTO_CIPHER_ALG__MAX] = {
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    [QCRYPTO_CIPHER_ALG_AES_128] = 16,
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    [QCRYPTO_CIPHER_ALG_AES_192] = 16,
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    [QCRYPTO_CIPHER_ALG_AES_256] = 16,
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    [QCRYPTO_CIPHER_ALG_DES] = 8,
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    [QCRYPTO_CIPHER_ALG_3DES] = 8,
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    [QCRYPTO_CIPHER_ALG_CAST5_128] = 8,
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    [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16,
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    [QCRYPTO_CIPHER_ALG_SERPENT_192] = 16,
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    [QCRYPTO_CIPHER_ALG_SERPENT_256] = 16,
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    [QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16,
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    [QCRYPTO_CIPHER_ALG_TWOFISH_192] = 16,
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    [QCRYPTO_CIPHER_ALG_TWOFISH_256] = 16,
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#ifdef CONFIG_CRYPTO_SM4
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    [QCRYPTO_CIPHER_ALG_SM4] = 16,
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#endif
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};
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static const bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = {
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    [QCRYPTO_CIPHER_MODE_ECB] = false,
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    [QCRYPTO_CIPHER_MODE_CBC] = true,
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    [QCRYPTO_CIPHER_MODE_XTS] = true,
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    [QCRYPTO_CIPHER_MODE_CTR] = true,
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};
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size_t qcrypto_cipher_get_block_len(QCryptoCipherAlgorithm alg)
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{
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    assert(alg < G_N_ELEMENTS(alg_key_len));
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    return alg_block_len[alg];
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}
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size_t qcrypto_cipher_get_key_len(QCryptoCipherAlgorithm alg)
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{
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    assert(alg < G_N_ELEMENTS(alg_key_len));
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    return alg_key_len[alg];
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}
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size_t qcrypto_cipher_get_iv_len(QCryptoCipherAlgorithm alg,
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                                 QCryptoCipherMode mode)
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{
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    if (alg >= G_N_ELEMENTS(alg_block_len)) {
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        return 0;
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    }
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    if (mode >= G_N_ELEMENTS(mode_need_iv)) {
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        return 0;
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    }
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    if (mode_need_iv[mode]) {
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        return alg_block_len[alg];
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    }
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    return 0;
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}
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static bool
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qcrypto_cipher_validate_key_length(QCryptoCipherAlgorithm alg,
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                                   QCryptoCipherMode mode,
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                                   size_t nkey,
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                                   Error **errp)
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{
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    if ((unsigned)alg >= QCRYPTO_CIPHER_ALG__MAX) {
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        error_setg(errp, "Cipher algorithm %d out of range",
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                   alg);
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        return false;
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    }
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    if (mode == QCRYPTO_CIPHER_MODE_XTS) {
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        if (alg == QCRYPTO_CIPHER_ALG_DES ||
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            alg == QCRYPTO_CIPHER_ALG_3DES) {
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            error_setg(errp, "XTS mode not compatible with DES/3DES");
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            return false;
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        }
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        if (nkey % 2) {
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            error_setg(errp, "XTS cipher key length should be a multiple of 2");
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            return false;
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        }
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        if (alg_key_len[alg] != (nkey / 2)) {
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            error_setg(errp, "Cipher key length %zu should be %zu",
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                       nkey, alg_key_len[alg] * 2);
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            return false;
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        }
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    } else {
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        if (alg_key_len[alg] != nkey) {
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            error_setg(errp, "Cipher key length %zu should be %zu",
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                       nkey, alg_key_len[alg]);
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            return false;
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        }
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    }
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    return true;
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}
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#ifdef CONFIG_GCRYPT
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#include "cipher-gcrypt.c.inc"
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#elif defined CONFIG_NETTLE
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#include "cipher-nettle.c.inc"
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#elif defined CONFIG_GNUTLS_CRYPTO
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#include "cipher-gnutls.c.inc"
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#else
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#include "cipher-builtin.c.inc"
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#endif
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QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
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                                  QCryptoCipherMode mode,
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                                  const uint8_t *key, size_t nkey,
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                                  Error **errp)
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{
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    QCryptoCipher *cipher = NULL;
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#ifdef CONFIG_AF_ALG
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    cipher = qcrypto_afalg_cipher_ctx_new(alg, mode, key, nkey, NULL);
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#endif
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    if (!cipher) {
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        cipher = qcrypto_cipher_ctx_new(alg, mode, key, nkey, errp);
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        if (!cipher) {
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            return NULL;
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        }
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    }
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    cipher->alg = alg;
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    cipher->mode = mode;
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    return cipher;
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}
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int qcrypto_cipher_encrypt(QCryptoCipher *cipher,
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                           const void *in,
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                           void *out,
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                           size_t len,
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                           Error **errp)
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{
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    const QCryptoCipherDriver *drv = cipher->driver;
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    return drv->cipher_encrypt(cipher, in, out, len, errp);
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}
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int qcrypto_cipher_decrypt(QCryptoCipher *cipher,
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                           const void *in,
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                           void *out,
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                           size_t len,
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                           Error **errp)
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{
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    const QCryptoCipherDriver *drv = cipher->driver;
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    return drv->cipher_decrypt(cipher, in, out, len, errp);
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}
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int qcrypto_cipher_setiv(QCryptoCipher *cipher,
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                         const uint8_t *iv, size_t niv,
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                         Error **errp)
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{
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    const QCryptoCipherDriver *drv = cipher->driver;
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    return drv->cipher_setiv(cipher, iv, niv, errp);
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}
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void qcrypto_cipher_free(QCryptoCipher *cipher)
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{
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    if (cipher) {
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        cipher->driver->cipher_free(cipher);
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    }
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}
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