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 __FBSDID("$FreeBSD$"); 52 53 #include <opencrypto/xform_enc.h> 54 55 static int aes_icm_setkey(void *, const uint8_t *, int); 56 static void aes_icm_crypt(void *, const uint8_t *, uint8_t *); 57 static void aes_icm_crypt_last(void *, const uint8_t *, uint8_t *, size_t); 58 static void aes_icm_reinit(void *, const uint8_t *, size_t); 59 static void aes_gcm_reinit(void *, const uint8_t *, size_t); 60 static void aes_ccm_reinit(void *, const uint8_t *, size_t); 61 62 /* Encryption instances */ 63 const struct enc_xform enc_xform_aes_icm = { 64 .type = CRYPTO_AES_ICM, 65 .name = "AES-ICM", 66 .ctxsize = sizeof(struct aes_icm_ctx), 67 .blocksize = 1, 68 .native_blocksize = AES_BLOCK_LEN, 69 .ivsize = AES_BLOCK_LEN, 70 .minkey = AES_MIN_KEY, 71 .maxkey = AES_MAX_KEY, 72 .encrypt = aes_icm_crypt, 73 .decrypt = aes_icm_crypt, 74 .setkey = aes_icm_setkey, 75 .reinit = aes_icm_reinit, 76 .encrypt_last = aes_icm_crypt_last, 77 .decrypt_last = aes_icm_crypt_last, 78 }; 79 80 const struct enc_xform enc_xform_aes_nist_gcm = { 81 .type = CRYPTO_AES_NIST_GCM_16, 82 .name = "AES-GCM", 83 .ctxsize = sizeof(struct aes_icm_ctx), 84 .blocksize = 1, 85 .native_blocksize = AES_BLOCK_LEN, 86 .ivsize = AES_GCM_IV_LEN, 87 .minkey = AES_MIN_KEY, 88 .maxkey = AES_MAX_KEY, 89 .encrypt = aes_icm_crypt, 90 .decrypt = aes_icm_crypt, 91 .setkey = aes_icm_setkey, 92 .reinit = aes_gcm_reinit, 93 .encrypt_last = aes_icm_crypt_last, 94 .decrypt_last = aes_icm_crypt_last, 95 }; 96 97 const struct enc_xform enc_xform_ccm = { 98 .type = CRYPTO_AES_CCM_16, 99 .name = "AES-CCM", 100 .ctxsize = sizeof(struct aes_icm_ctx), 101 .blocksize = 1, 102 .native_blocksize = AES_BLOCK_LEN, 103 .ivsize = AES_CCM_IV_LEN, 104 .minkey = AES_MIN_KEY, .maxkey = AES_MAX_KEY, 105 .encrypt = aes_icm_crypt, 106 .decrypt = aes_icm_crypt, 107 .setkey = aes_icm_setkey, 108 .reinit = aes_ccm_reinit, 109 .encrypt_last = aes_icm_crypt_last, 110 .decrypt_last = aes_icm_crypt_last, 111 }; 112 113 /* 114 * Encryption wrapper routines. 115 */ 116 static void 117 aes_icm_reinit(void *key, const uint8_t *iv, size_t ivlen) 118 { 119 struct aes_icm_ctx *ctx; 120 121 ctx = key; 122 KASSERT(ivlen <= sizeof(ctx->ac_block), 123 ("%s: ivlen too large", __func__)); 124 bcopy(iv, ctx->ac_block, ivlen); 125 } 126 127 static void 128 aes_gcm_reinit(void *key, const uint8_t *iv, size_t ivlen) 129 { 130 struct aes_icm_ctx *ctx; 131 132 KASSERT(ivlen == AES_GCM_IV_LEN, 133 ("%s: invalid IV length", __func__)); 134 aes_icm_reinit(key, iv, ivlen); 135 136 ctx = key; 137 /* GCM starts with 2 as counter 1 is used for final xor of tag. */ 138 bzero(&ctx->ac_block[AESICM_BLOCKSIZE - 4], 4); 139 ctx->ac_block[AESICM_BLOCKSIZE - 1] = 2; 140 } 141 142 static void 143 aes_ccm_reinit(void *key, const uint8_t *iv, size_t ivlen) 144 { 145 struct aes_icm_ctx *ctx; 146 147 KASSERT(ivlen >= 7 && ivlen <= 13, 148 ("%s: invalid IV length", __func__)); 149 ctx = key; 150 151 /* CCM has flags, then the IV, then the counter, which starts at 1 */ 152 bzero(ctx->ac_block, sizeof(ctx->ac_block)); 153 ctx->ac_block[0] = (15 - ivlen) - 1; 154 bcopy(iv, ctx->ac_block + 1, ivlen); 155 ctx->ac_block[AESICM_BLOCKSIZE - 1] = 1; 156 } 157 158 static void 159 aes_icm_crypt(void *key, const uint8_t *in, uint8_t *out) 160 { 161 struct aes_icm_ctx *ctx; 162 int i; 163 164 ctx = key; 165 aes_icm_crypt_last(key, in, out, AESICM_BLOCKSIZE); 166 167 /* increment counter */ 168 for (i = AESICM_BLOCKSIZE - 1; 169 i >= 0; i--) 170 if (++ctx->ac_block[i]) /* continue on overflow */ 171 break; 172 } 173 174 static void 175 aes_icm_crypt_last(void *key, const uint8_t *in, uint8_t *out, size_t len) 176 { 177 struct aes_icm_ctx *ctx; 178 uint8_t keystream[AESICM_BLOCKSIZE]; 179 int i; 180 181 ctx = key; 182 rijndaelEncrypt(ctx->ac_ek, ctx->ac_nr, ctx->ac_block, keystream); 183 for (i = 0; i < len; i++) 184 out[i] = in[i] ^ keystream[i]; 185 explicit_bzero(keystream, sizeof(keystream)); 186 } 187 188 static int 189 aes_icm_setkey(void *sched, const uint8_t *key, int len) 190 { 191 struct aes_icm_ctx *ctx; 192 193 if (len != 16 && len != 24 && len != 32) 194 return (EINVAL); 195 196 ctx = sched; 197 ctx->ac_nr = rijndaelKeySetupEnc(ctx->ac_ek, key, len * 8); 198 return (0); 199 } 200