1 /* $OpenBSD: xform.c,v 1.16 2001/08/28 12:20:43 ben Exp $ */ 2 /*- 3 * The authors of this code are John Ioannidis (ji@tla.org), 4 * Angelos D. Keromytis (kermit@csd.uch.gr), 5 * Niels Provos (provos@physnet.uni-hamburg.de) and 6 * Damien Miller (djm@mindrot.org). 7 * 8 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 9 * in November 1995. 10 * 11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 12 * by Angelos D. Keromytis. 13 * 14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 15 * and Niels Provos. 16 * 17 * Additional features in 1999 by Angelos D. Keromytis. 18 * 19 * AES XTS implementation in 2008 by Damien Miller 20 * 21 * Copyright (C) 1995, 1996, 1997, 1998, 1999 by John Ioannidis, 22 * Angelos D. Keromytis and Niels Provos. 23 * 24 * Copyright (C) 2001, Angelos D. Keromytis. 25 * 26 * Copyright (C) 2008, Damien Miller 27 * Copyright (c) 2014 The FreeBSD Foundation 28 * All rights reserved. 29 * 30 * Portions of this software were developed by John-Mark Gurney 31 * under sponsorship of the FreeBSD Foundation and 32 * Rubicon Communications, LLC (Netgate). 33 * 34 * Permission to use, copy, and modify this software with or without fee 35 * is hereby granted, provided that this entire notice is included in 36 * all copies of any software which is or includes a copy or 37 * modification of this software. 38 * You may use this code under the GNU public license if you so wish. Please 39 * contribute changes back to the authors under this freer than GPL license 40 * so that we may further the use of strong encryption without limitations to 41 * all. 42 * 43 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 44 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 45 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 46 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 47 * PURPOSE. 48 */ 49 50 #include <sys/cdefs.h> 51 #include <sys/types.h> 52 #include <crypto/rijndael/rijndael.h> 53 #include <opencrypto/xform_enc.h> 54 55 struct aes_cbc_ctx { 56 rijndael_ctx key; 57 char iv[AES_BLOCK_LEN]; 58 }; 59 60 static int aes_cbc_setkey(void *, const uint8_t *, int); 61 static void aes_cbc_encrypt(void *, const uint8_t *, uint8_t *); 62 static void aes_cbc_decrypt(void *, const uint8_t *, uint8_t *); 63 static void aes_cbc_encrypt_multi(void *, const uint8_t *, uint8_t *, size_t); 64 static void aes_cbc_decrypt_multi(void *, const uint8_t *, uint8_t *, size_t); 65 static void aes_cbc_reinit(void *, const uint8_t *, size_t); 66 67 /* Encryption instances */ 68 const struct enc_xform enc_xform_aes_cbc = { 69 .type = CRYPTO_AES_CBC, 70 .name = "AES-CBC", 71 .ctxsize = sizeof(struct aes_cbc_ctx), 72 .blocksize = AES_BLOCK_LEN, 73 .ivsize = AES_BLOCK_LEN, 74 .minkey = AES_MIN_KEY, 75 .maxkey = AES_MAX_KEY, 76 .setkey = aes_cbc_setkey, 77 .reinit = aes_cbc_reinit, 78 .encrypt = aes_cbc_encrypt, 79 .decrypt = aes_cbc_decrypt, 80 .encrypt_multi = aes_cbc_encrypt_multi, 81 .decrypt_multi = aes_cbc_decrypt_multi, 82 }; 83 84 /* 85 * Encryption wrapper routines. 86 */ 87 static void 88 aes_cbc_encrypt(void *vctx, const uint8_t *in, uint8_t *out) 89 { 90 struct aes_cbc_ctx *ctx = vctx; 91 92 for (u_int i = 0; i < AES_BLOCK_LEN; i++) 93 out[i] = in[i] ^ ctx->iv[i]; 94 rijndael_encrypt(&ctx->key, out, out); 95 memcpy(ctx->iv, out, AES_BLOCK_LEN); 96 } 97 98 static void 99 aes_cbc_decrypt(void *vctx, const uint8_t *in, uint8_t *out) 100 { 101 struct aes_cbc_ctx *ctx = vctx; 102 char block[AES_BLOCK_LEN]; 103 104 memcpy(block, in, AES_BLOCK_LEN); 105 rijndael_decrypt(&ctx->key, in, out); 106 for (u_int i = 0; i < AES_BLOCK_LEN; i++) 107 out[i] ^= ctx->iv[i]; 108 memcpy(ctx->iv, block, AES_BLOCK_LEN); 109 explicit_bzero(block, sizeof(block)); 110 } 111 112 static void 113 aes_cbc_encrypt_multi(void *vctx, const uint8_t *in, uint8_t *out, size_t len) 114 { 115 struct aes_cbc_ctx *ctx = vctx; 116 117 KASSERT(len % AES_BLOCK_LEN == 0, ("%s: invalid length", __func__)); 118 while (len > 0) { 119 for (u_int i = 0; i < AES_BLOCK_LEN; i++) 120 out[i] = in[i] ^ ctx->iv[i]; 121 rijndael_encrypt(&ctx->key, out, out); 122 memcpy(ctx->iv, out, AES_BLOCK_LEN); 123 out += AES_BLOCK_LEN; 124 in += AES_BLOCK_LEN; 125 len -= AES_BLOCK_LEN; 126 } 127 } 128 129 static void 130 aes_cbc_decrypt_multi(void *vctx, const uint8_t *in, uint8_t *out, size_t len) 131 { 132 struct aes_cbc_ctx *ctx = vctx; 133 char block[AES_BLOCK_LEN]; 134 135 KASSERT(len % AES_BLOCK_LEN == 0, ("%s: invalid length", __func__)); 136 while (len > 0) { 137 memcpy(block, in, AES_BLOCK_LEN); 138 rijndael_decrypt(&ctx->key, in, out); 139 for (u_int i = 0; i < AES_BLOCK_LEN; i++) 140 out[i] ^= ctx->iv[i]; 141 memcpy(ctx->iv, block, AES_BLOCK_LEN); 142 out += AES_BLOCK_LEN; 143 in += AES_BLOCK_LEN; 144 len -= AES_BLOCK_LEN; 145 } 146 explicit_bzero(block, sizeof(block)); 147 } 148 149 static int 150 aes_cbc_setkey(void *vctx, const uint8_t *key, int len) 151 { 152 struct aes_cbc_ctx *ctx = vctx; 153 154 if (len != 16 && len != 24 && len != 32) 155 return (EINVAL); 156 157 rijndael_set_key(&ctx->key, key, len * 8); 158 return (0); 159 } 160 161 static void 162 aes_cbc_reinit(void *vctx, const uint8_t *iv, size_t iv_len) 163 { 164 struct aes_cbc_ctx *ctx = vctx; 165 166 KASSERT(iv_len == sizeof(ctx->iv), ("%s: bad IV length", __func__)); 167 memcpy(ctx->iv, iv, sizeof(ctx->iv)); 168 } 169