/* * QEMU Crypto cipher algorithms * * Copyright (c) 2015 Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, see <http://www.gnu.org/licenses/>. * */ #include "qemu/osdep.h" #include "qemu/host-utils.h" #include "qapi/error.h" #include "crypto/cipher.h" #include "cipherpriv.h" static const size_t alg_key_len[QCRYPTO_CIPHER_ALG__MAX] = { [QCRYPTO_CIPHER_ALG_AES_128] = 16, [QCRYPTO_CIPHER_ALG_AES_192] = 24, [QCRYPTO_CIPHER_ALG_AES_256] = 32, [QCRYPTO_CIPHER_ALG_DES_RFB] = 8, [QCRYPTO_CIPHER_ALG_3DES] = 24, [QCRYPTO_CIPHER_ALG_CAST5_128] = 16, [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16, [QCRYPTO_CIPHER_ALG_SERPENT_192] = 24, [QCRYPTO_CIPHER_ALG_SERPENT_256] = 32, [QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16, [QCRYPTO_CIPHER_ALG_TWOFISH_192] = 24, [QCRYPTO_CIPHER_ALG_TWOFISH_256] = 32, }; static const size_t alg_block_len[QCRYPTO_CIPHER_ALG__MAX] = { [QCRYPTO_CIPHER_ALG_AES_128] = 16, [QCRYPTO_CIPHER_ALG_AES_192] = 16, [QCRYPTO_CIPHER_ALG_AES_256] = 16, [QCRYPTO_CIPHER_ALG_DES_RFB] = 8, [QCRYPTO_CIPHER_ALG_3DES] = 8, [QCRYPTO_CIPHER_ALG_CAST5_128] = 8, [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16, [QCRYPTO_CIPHER_ALG_SERPENT_192] = 16, [QCRYPTO_CIPHER_ALG_SERPENT_256] = 16, [QCRYPTO_CIPHER_ALG_TWOFISH_128] = 16, [QCRYPTO_CIPHER_ALG_TWOFISH_192] = 16, [QCRYPTO_CIPHER_ALG_TWOFISH_256] = 16, }; static const bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = { [QCRYPTO_CIPHER_MODE_ECB] = false, [QCRYPTO_CIPHER_MODE_CBC] = true, [QCRYPTO_CIPHER_MODE_XTS] = true, [QCRYPTO_CIPHER_MODE_CTR] = true, }; size_t qcrypto_cipher_get_block_len(QCryptoCipherAlgorithm alg) { assert(alg < G_N_ELEMENTS(alg_key_len)); return alg_block_len[alg]; } size_t qcrypto_cipher_get_key_len(QCryptoCipherAlgorithm alg) { assert(alg < G_N_ELEMENTS(alg_key_len)); return alg_key_len[alg]; } size_t qcrypto_cipher_get_iv_len(QCryptoCipherAlgorithm alg, QCryptoCipherMode mode) { if (alg >= G_N_ELEMENTS(alg_block_len)) { return 0; } if (mode >= G_N_ELEMENTS(mode_need_iv)) { return 0; } if (mode_need_iv[mode]) { return alg_block_len[alg]; } return 0; } static bool qcrypto_cipher_validate_key_length(QCryptoCipherAlgorithm alg, QCryptoCipherMode mode, size_t nkey, Error **errp) { if ((unsigned)alg >= QCRYPTO_CIPHER_ALG__MAX) { error_setg(errp, "Cipher algorithm %d out of range", alg); return false; } if (mode == QCRYPTO_CIPHER_MODE_XTS) { if (alg == QCRYPTO_CIPHER_ALG_DES_RFB || alg == QCRYPTO_CIPHER_ALG_3DES) { error_setg(errp, "XTS mode not compatible with DES-RFB/3DES"); return false; } if (nkey % 2) { error_setg(errp, "XTS cipher key length should be a multiple of 2"); return false; } if (alg_key_len[alg] != (nkey / 2)) { error_setg(errp, "Cipher key length %zu should be %zu", nkey, alg_key_len[alg] * 2); return false; } } else { if (alg_key_len[alg] != nkey) { error_setg(errp, "Cipher key length %zu should be %zu", nkey, alg_key_len[alg]); return false; } } return true; } #if defined(CONFIG_GCRYPT) || defined(CONFIG_NETTLE) static uint8_t * qcrypto_cipher_munge_des_rfb_key(const uint8_t *key, size_t nkey) { uint8_t *ret = g_new0(uint8_t, nkey); size_t i; for (i = 0; i < nkey; i++) { uint8_t r = key[i]; r = (r & 0xf0) >> 4 | (r & 0x0f) << 4; r = (r & 0xcc) >> 2 | (r & 0x33) << 2; r = (r & 0xaa) >> 1 | (r & 0x55) << 1; ret[i] = r; } return ret; } #endif /* CONFIG_GCRYPT || CONFIG_NETTLE */ #ifdef CONFIG_GCRYPT #include "cipher-gcrypt.c.inc" #elif defined CONFIG_NETTLE #include "cipher-nettle.c.inc" #else #include "cipher-builtin.c.inc" #endif QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg, QCryptoCipherMode mode, const uint8_t *key, size_t nkey, Error **errp) { QCryptoCipher *cipher = NULL; #ifdef CONFIG_AF_ALG cipher = qcrypto_afalg_cipher_ctx_new(alg, mode, key, nkey, NULL); #endif if (!cipher) { cipher = qcrypto_cipher_ctx_new(alg, mode, key, nkey, errp); if (!cipher) { return NULL; } } cipher->alg = alg; cipher->mode = mode; return cipher; } int qcrypto_cipher_encrypt(QCryptoCipher *cipher, const void *in, void *out, size_t len, Error **errp) { const QCryptoCipherDriver *drv = cipher->driver; return drv->cipher_encrypt(cipher, in, out, len, errp); } int qcrypto_cipher_decrypt(QCryptoCipher *cipher, const void *in, void *out, size_t len, Error **errp) { const QCryptoCipherDriver *drv = cipher->driver; return drv->cipher_decrypt(cipher, in, out, len, errp); } int qcrypto_cipher_setiv(QCryptoCipher *cipher, const uint8_t *iv, size_t niv, Error **errp) { const QCryptoCipherDriver *drv = cipher->driver; return drv->cipher_setiv(cipher, iv, niv, errp); } void qcrypto_cipher_free(QCryptoCipher *cipher) { if (cipher) { cipher->driver->cipher_free(cipher); } }