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/cbc_mac.h> 54 #include <opencrypto/gmac.h> 55 #include <opencrypto/xform_enc.h> 56 57 struct aes_gcm_ctx { 58 struct aes_icm_ctx cipher; 59 struct aes_gmac_ctx gmac; 60 }; 61 62 struct aes_ccm_ctx { 63 struct aes_icm_ctx cipher; 64 struct aes_cbc_mac_ctx cbc_mac; 65 }; 66 67 static int aes_icm_setkey(void *, const uint8_t *, int); 68 static void aes_icm_crypt(void *, const uint8_t *, uint8_t *); 69 static void aes_icm_crypt_last(void *, const uint8_t *, uint8_t *, size_t); 70 static void aes_icm_reinit(void *, const uint8_t *, size_t); 71 static int aes_gcm_setkey(void *, const uint8_t *, int); 72 static void aes_gcm_reinit(void *, const uint8_t *, size_t); 73 static int aes_gcm_update(void *, const void *, u_int); 74 static void aes_gcm_final(uint8_t *, void *); 75 static int aes_ccm_setkey(void *, const uint8_t *, int); 76 static void aes_ccm_reinit(void *, const uint8_t *, size_t); 77 static int aes_ccm_update(void *, const void *, u_int); 78 static void aes_ccm_final(uint8_t *, void *); 79 80 /* Encryption instances */ 81 const struct enc_xform enc_xform_aes_icm = { 82 .type = CRYPTO_AES_ICM, 83 .name = "AES-ICM", 84 .ctxsize = sizeof(struct aes_icm_ctx), 85 .blocksize = 1, 86 .native_blocksize = AES_BLOCK_LEN, 87 .ivsize = AES_BLOCK_LEN, 88 .minkey = AES_MIN_KEY, 89 .maxkey = AES_MAX_KEY, 90 .encrypt = aes_icm_crypt, 91 .decrypt = aes_icm_crypt, 92 .setkey = aes_icm_setkey, 93 .reinit = aes_icm_reinit, 94 .encrypt_last = aes_icm_crypt_last, 95 .decrypt_last = aes_icm_crypt_last, 96 }; 97 98 const struct enc_xform enc_xform_aes_nist_gcm = { 99 .type = CRYPTO_AES_NIST_GCM_16, 100 .name = "AES-GCM", 101 .ctxsize = sizeof(struct aes_gcm_ctx), 102 .blocksize = 1, 103 .native_blocksize = AES_BLOCK_LEN, 104 .ivsize = AES_GCM_IV_LEN, 105 .minkey = AES_MIN_KEY, 106 .maxkey = AES_MAX_KEY, 107 .macsize = AES_GMAC_HASH_LEN, 108 .encrypt = aes_icm_crypt, 109 .decrypt = aes_icm_crypt, 110 .setkey = aes_gcm_setkey, 111 .reinit = aes_gcm_reinit, 112 .encrypt_last = aes_icm_crypt_last, 113 .decrypt_last = aes_icm_crypt_last, 114 .update = aes_gcm_update, 115 .final = aes_gcm_final, 116 }; 117 118 const struct enc_xform enc_xform_ccm = { 119 .type = CRYPTO_AES_CCM_16, 120 .name = "AES-CCM", 121 .ctxsize = sizeof(struct aes_ccm_ctx), 122 .blocksize = 1, 123 .native_blocksize = AES_BLOCK_LEN, 124 .ivsize = AES_CCM_IV_LEN, 125 .minkey = AES_MIN_KEY, .maxkey = AES_MAX_KEY, 126 .macsize = AES_CBC_MAC_HASH_LEN, 127 .encrypt = aes_icm_crypt, 128 .decrypt = aes_icm_crypt, 129 .setkey = aes_ccm_setkey, 130 .reinit = aes_ccm_reinit, 131 .encrypt_last = aes_icm_crypt_last, 132 .decrypt_last = aes_icm_crypt_last, 133 .update = aes_ccm_update, 134 .final = aes_ccm_final, 135 }; 136 137 /* 138 * Encryption wrapper routines. 139 */ 140 static void 141 aes_icm_reinit(void *key, const uint8_t *iv, size_t ivlen) 142 { 143 struct aes_icm_ctx *ctx; 144 145 ctx = key; 146 KASSERT(ivlen <= sizeof(ctx->ac_block), 147 ("%s: ivlen too large", __func__)); 148 bcopy(iv, ctx->ac_block, ivlen); 149 } 150 151 static void 152 aes_gcm_reinit(void *vctx, const uint8_t *iv, size_t ivlen) 153 { 154 struct aes_gcm_ctx *ctx = vctx; 155 156 KASSERT(ivlen == AES_GCM_IV_LEN, 157 ("%s: invalid IV length", __func__)); 158 aes_icm_reinit(&ctx->cipher, iv, ivlen); 159 160 /* GCM starts with 2 as counter 1 is used for final xor of tag. */ 161 bzero(&ctx->cipher.ac_block[AESICM_BLOCKSIZE - 4], 4); 162 ctx->cipher.ac_block[AESICM_BLOCKSIZE - 1] = 2; 163 164 AES_GMAC_Reinit(&ctx->gmac, iv, ivlen); 165 } 166 167 static void 168 aes_ccm_reinit(void *vctx, const uint8_t *iv, size_t ivlen) 169 { 170 struct aes_ccm_ctx *ctx = vctx; 171 172 KASSERT(ivlen >= 7 && ivlen <= 13, 173 ("%s: invalid IV length", __func__)); 174 175 /* CCM has flags, then the IV, then the counter, which starts at 1 */ 176 bzero(ctx->cipher.ac_block, sizeof(ctx->cipher.ac_block)); 177 ctx->cipher.ac_block[0] = (15 - ivlen) - 1; 178 bcopy(iv, ctx->cipher.ac_block + 1, ivlen); 179 ctx->cipher.ac_block[AESICM_BLOCKSIZE - 1] = 1; 180 181 AES_CBC_MAC_Reinit(&ctx->cbc_mac, iv, ivlen); 182 } 183 184 static void 185 aes_icm_crypt(void *key, const uint8_t *in, uint8_t *out) 186 { 187 struct aes_icm_ctx *ctx; 188 int i; 189 190 ctx = key; 191 aes_icm_crypt_last(key, in, out, AESICM_BLOCKSIZE); 192 193 /* increment counter */ 194 for (i = AESICM_BLOCKSIZE - 1; 195 i >= 0; i--) 196 if (++ctx->ac_block[i]) /* continue on overflow */ 197 break; 198 } 199 200 static void 201 aes_icm_crypt_last(void *key, const uint8_t *in, uint8_t *out, size_t len) 202 { 203 struct aes_icm_ctx *ctx; 204 uint8_t keystream[AESICM_BLOCKSIZE]; 205 int i; 206 207 ctx = key; 208 rijndaelEncrypt(ctx->ac_ek, ctx->ac_nr, ctx->ac_block, keystream); 209 for (i = 0; i < len; i++) 210 out[i] = in[i] ^ keystream[i]; 211 explicit_bzero(keystream, sizeof(keystream)); 212 } 213 214 static int 215 aes_icm_setkey(void *sched, const uint8_t *key, int len) 216 { 217 struct aes_icm_ctx *ctx; 218 219 if (len != 16 && len != 24 && len != 32) 220 return (EINVAL); 221 222 ctx = sched; 223 ctx->ac_nr = rijndaelKeySetupEnc(ctx->ac_ek, key, len * 8); 224 return (0); 225 } 226 227 static int 228 aes_gcm_setkey(void *vctx, const uint8_t *key, int len) 229 { 230 struct aes_gcm_ctx *ctx = vctx; 231 int error; 232 233 error = aes_icm_setkey(&ctx->cipher, key, len); 234 if (error != 0) 235 return (error); 236 237 AES_GMAC_Setkey(&ctx->gmac, key, len); 238 return (0); 239 } 240 241 static int 242 aes_ccm_setkey(void *vctx, const uint8_t *key, int len) 243 { 244 struct aes_ccm_ctx *ctx = vctx; 245 int error; 246 247 error = aes_icm_setkey(&ctx->cipher, key, len); 248 if (error != 0) 249 return (error); 250 251 AES_CBC_MAC_Setkey(&ctx->cbc_mac, key, len); 252 return (0); 253 } 254 255 static int 256 aes_gcm_update(void *vctx, const void *buf, u_int len) 257 { 258 struct aes_gcm_ctx *ctx = vctx; 259 260 return (AES_GMAC_Update(&ctx->gmac, buf, len)); 261 } 262 263 static int 264 aes_ccm_update(void *vctx, const void *buf, u_int len) 265 { 266 struct aes_ccm_ctx *ctx = vctx; 267 268 return (AES_CBC_MAC_Update(&ctx->cbc_mac, buf, len)); 269 } 270 271 static void 272 aes_gcm_final(uint8_t *tag, void *vctx) 273 { 274 struct aes_gcm_ctx *ctx = vctx; 275 276 AES_GMAC_Final(tag, &ctx->gmac); 277 } 278 279 static void 280 aes_ccm_final(uint8_t *tag, void *vctx) 281 { 282 struct aes_ccm_ctx *ctx = vctx; 283 284 AES_CBC_MAC_Final(tag, &ctx->cbc_mac); 285 } 286