1 /* 2 * QEMU Crypto cipher algorithms 3 * 4 * Copyright (c) 2015 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 "crypto/cipher.h" 22 23 24 static size_t alg_key_len[QCRYPTO_CIPHER_ALG__MAX] = { 25 [QCRYPTO_CIPHER_ALG_AES_128] = 16, 26 [QCRYPTO_CIPHER_ALG_AES_192] = 24, 27 [QCRYPTO_CIPHER_ALG_AES_256] = 32, 28 [QCRYPTO_CIPHER_ALG_DES_RFB] = 8, 29 }; 30 31 static size_t alg_block_len[QCRYPTO_CIPHER_ALG__MAX] = { 32 [QCRYPTO_CIPHER_ALG_AES_128] = 16, 33 [QCRYPTO_CIPHER_ALG_AES_192] = 16, 34 [QCRYPTO_CIPHER_ALG_AES_256] = 16, 35 [QCRYPTO_CIPHER_ALG_DES_RFB] = 8, 36 }; 37 38 static bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = { 39 [QCRYPTO_CIPHER_MODE_ECB] = false, 40 [QCRYPTO_CIPHER_MODE_CBC] = true, 41 }; 42 43 44 size_t qcrypto_cipher_get_block_len(QCryptoCipherAlgorithm alg) 45 { 46 if (alg >= G_N_ELEMENTS(alg_key_len)) { 47 return 0; 48 } 49 return alg_block_len[alg]; 50 } 51 52 53 size_t qcrypto_cipher_get_key_len(QCryptoCipherAlgorithm alg) 54 { 55 if (alg >= G_N_ELEMENTS(alg_key_len)) { 56 return 0; 57 } 58 return alg_key_len[alg]; 59 } 60 61 62 size_t qcrypto_cipher_get_iv_len(QCryptoCipherAlgorithm alg, 63 QCryptoCipherMode mode) 64 { 65 if (alg >= G_N_ELEMENTS(alg_block_len)) { 66 return 0; 67 } 68 if (mode >= G_N_ELEMENTS(mode_need_iv)) { 69 return 0; 70 } 71 72 if (mode_need_iv[mode]) { 73 return alg_block_len[alg]; 74 } 75 return 0; 76 } 77 78 79 static bool 80 qcrypto_cipher_validate_key_length(QCryptoCipherAlgorithm alg, 81 size_t nkey, 82 Error **errp) 83 { 84 if ((unsigned)alg >= QCRYPTO_CIPHER_ALG__MAX) { 85 error_setg(errp, "Cipher algorithm %d out of range", 86 alg); 87 return false; 88 } 89 90 if (alg_key_len[alg] != nkey) { 91 error_setg(errp, "Cipher key length %zu should be %zu", 92 nkey, alg_key_len[alg]); 93 return false; 94 } 95 return true; 96 } 97 98 #if defined(CONFIG_GCRYPT) || defined(CONFIG_NETTLE) 99 static uint8_t * 100 qcrypto_cipher_munge_des_rfb_key(const uint8_t *key, 101 size_t nkey) 102 { 103 uint8_t *ret = g_new0(uint8_t, nkey); 104 size_t i; 105 for (i = 0; i < nkey; i++) { 106 uint8_t r = key[i]; 107 r = (r & 0xf0) >> 4 | (r & 0x0f) << 4; 108 r = (r & 0xcc) >> 2 | (r & 0x33) << 2; 109 r = (r & 0xaa) >> 1 | (r & 0x55) << 1; 110 ret[i] = r; 111 } 112 return ret; 113 } 114 #endif /* CONFIG_GCRYPT || CONFIG_NETTLE */ 115 116 #ifdef CONFIG_GCRYPT 117 #include "crypto/cipher-gcrypt.c" 118 #elif defined CONFIG_NETTLE 119 #include "crypto/cipher-nettle.c" 120 #else 121 #include "crypto/cipher-builtin.c" 122 #endif 123