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 "qemu/osdep.h" 22 #include "crypto/cipher.h" 23 24 25 static size_t alg_key_len[QCRYPTO_CIPHER_ALG__MAX] = { 26 [QCRYPTO_CIPHER_ALG_AES_128] = 16, 27 [QCRYPTO_CIPHER_ALG_AES_192] = 24, 28 [QCRYPTO_CIPHER_ALG_AES_256] = 32, 29 [QCRYPTO_CIPHER_ALG_DES_RFB] = 8, 30 [QCRYPTO_CIPHER_ALG_CAST5_128] = 16, 31 [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16, 32 [QCRYPTO_CIPHER_ALG_SERPENT_192] = 24, 33 [QCRYPTO_CIPHER_ALG_SERPENT_256] = 32, 34 }; 35 36 static size_t alg_block_len[QCRYPTO_CIPHER_ALG__MAX] = { 37 [QCRYPTO_CIPHER_ALG_AES_128] = 16, 38 [QCRYPTO_CIPHER_ALG_AES_192] = 16, 39 [QCRYPTO_CIPHER_ALG_AES_256] = 16, 40 [QCRYPTO_CIPHER_ALG_DES_RFB] = 8, 41 [QCRYPTO_CIPHER_ALG_CAST5_128] = 8, 42 [QCRYPTO_CIPHER_ALG_SERPENT_128] = 16, 43 [QCRYPTO_CIPHER_ALG_SERPENT_192] = 16, 44 [QCRYPTO_CIPHER_ALG_SERPENT_256] = 16, 45 }; 46 47 static bool mode_need_iv[QCRYPTO_CIPHER_MODE__MAX] = { 48 [QCRYPTO_CIPHER_MODE_ECB] = false, 49 [QCRYPTO_CIPHER_MODE_CBC] = true, 50 }; 51 52 53 size_t qcrypto_cipher_get_block_len(QCryptoCipherAlgorithm alg) 54 { 55 if (alg >= G_N_ELEMENTS(alg_key_len)) { 56 return 0; 57 } 58 return alg_block_len[alg]; 59 } 60 61 62 size_t qcrypto_cipher_get_key_len(QCryptoCipherAlgorithm alg) 63 { 64 if (alg >= G_N_ELEMENTS(alg_key_len)) { 65 return 0; 66 } 67 return alg_key_len[alg]; 68 } 69 70 71 size_t qcrypto_cipher_get_iv_len(QCryptoCipherAlgorithm alg, 72 QCryptoCipherMode mode) 73 { 74 if (alg >= G_N_ELEMENTS(alg_block_len)) { 75 return 0; 76 } 77 if (mode >= G_N_ELEMENTS(mode_need_iv)) { 78 return 0; 79 } 80 81 if (mode_need_iv[mode]) { 82 return alg_block_len[alg]; 83 } 84 return 0; 85 } 86 87 88 static bool 89 qcrypto_cipher_validate_key_length(QCryptoCipherAlgorithm alg, 90 size_t nkey, 91 Error **errp) 92 { 93 if ((unsigned)alg >= QCRYPTO_CIPHER_ALG__MAX) { 94 error_setg(errp, "Cipher algorithm %d out of range", 95 alg); 96 return false; 97 } 98 99 if (alg_key_len[alg] != nkey) { 100 error_setg(errp, "Cipher key length %zu should be %zu", 101 nkey, alg_key_len[alg]); 102 return false; 103 } 104 return true; 105 } 106 107 #if defined(CONFIG_GCRYPT) || defined(CONFIG_NETTLE) 108 static uint8_t * 109 qcrypto_cipher_munge_des_rfb_key(const uint8_t *key, 110 size_t nkey) 111 { 112 uint8_t *ret = g_new0(uint8_t, nkey); 113 size_t i; 114 for (i = 0; i < nkey; i++) { 115 uint8_t r = key[i]; 116 r = (r & 0xf0) >> 4 | (r & 0x0f) << 4; 117 r = (r & 0xcc) >> 2 | (r & 0x33) << 2; 118 r = (r & 0xaa) >> 1 | (r & 0x55) << 1; 119 ret[i] = r; 120 } 121 return ret; 122 } 123 #endif /* CONFIG_GCRYPT || CONFIG_NETTLE */ 124 125 #ifdef CONFIG_GCRYPT 126 #include "crypto/cipher-gcrypt.c" 127 #elif defined CONFIG_NETTLE 128 #include "crypto/cipher-nettle.c" 129 #else 130 #include "crypto/cipher-builtin.c" 131 #endif 132