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