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(u_int8_t **, u_int8_t *, int); 56 static void aes_icm_crypt(caddr_t, u_int8_t *); 57 static void aes_icm_zerokey(u_int8_t **); 58 static void aes_icm_reinit(caddr_t, u_int8_t *); 59 static void aes_gcm_reinit(caddr_t, u_int8_t *); 60 61 /* Encryption instances */ 62 struct enc_xform enc_xform_aes_icm = { 63 CRYPTO_AES_ICM, "AES-ICM", 64 AES_BLOCK_LEN, AES_BLOCK_LEN, AES_MIN_KEY, AES_MAX_KEY, 65 aes_icm_crypt, 66 aes_icm_crypt, 67 aes_icm_setkey, 68 rijndael128_zerokey, 69 aes_icm_reinit, 70 }; 71 72 struct enc_xform enc_xform_aes_nist_gcm = { 73 CRYPTO_AES_NIST_GCM_16, "AES-GCM", 74 AES_ICM_BLOCK_LEN, AES_GCM_IV_LEN, AES_MIN_KEY, AES_MAX_KEY, 75 aes_icm_crypt, 76 aes_icm_crypt, 77 aes_icm_setkey, 78 aes_icm_zerokey, 79 aes_gcm_reinit, 80 }; 81 82 /* 83 * Encryption wrapper routines. 84 */ 85 static void 86 aes_icm_reinit(caddr_t key, u_int8_t *iv) 87 { 88 struct aes_icm_ctx *ctx; 89 90 ctx = (struct aes_icm_ctx *)key; 91 bcopy(iv, ctx->ac_block, AESICM_BLOCKSIZE); 92 } 93 94 static void 95 aes_gcm_reinit(caddr_t key, u_int8_t *iv) 96 { 97 struct aes_icm_ctx *ctx; 98 99 aes_icm_reinit(key, iv); 100 101 ctx = (struct aes_icm_ctx *)key; 102 /* GCM starts with 2 as counter 1 is used for final xor of tag. */ 103 bzero(&ctx->ac_block[AESICM_BLOCKSIZE - 4], 4); 104 ctx->ac_block[AESICM_BLOCKSIZE - 1] = 2; 105 } 106 107 static void 108 aes_icm_crypt(caddr_t key, u_int8_t *data) 109 { 110 struct aes_icm_ctx *ctx; 111 u_int8_t keystream[AESICM_BLOCKSIZE]; 112 int i; 113 114 ctx = (struct aes_icm_ctx *)key; 115 rijndaelEncrypt(ctx->ac_ek, ctx->ac_nr, ctx->ac_block, keystream); 116 for (i = 0; i < AESICM_BLOCKSIZE; i++) 117 data[i] ^= keystream[i]; 118 explicit_bzero(keystream, sizeof(keystream)); 119 120 /* increment counter */ 121 for (i = AESICM_BLOCKSIZE - 1; 122 i >= 0; i--) 123 if (++ctx->ac_block[i]) /* continue on overflow */ 124 break; 125 } 126 127 static int 128 aes_icm_setkey(u_int8_t **sched, u_int8_t *key, int len) 129 { 130 struct aes_icm_ctx *ctx; 131 132 if (len != 16 && len != 24 && len != 32) 133 return EINVAL; 134 135 *sched = KMALLOC(sizeof(struct aes_icm_ctx), M_CRYPTO_DATA, 136 M_NOWAIT | M_ZERO); 137 if (*sched == NULL) 138 return ENOMEM; 139 140 ctx = (struct aes_icm_ctx *)*sched; 141 ctx->ac_nr = rijndaelKeySetupEnc(ctx->ac_ek, (u_char *)key, len * 8); 142 return 0; 143 } 144 145 static void 146 aes_icm_zerokey(u_int8_t **sched) 147 { 148 149 bzero(*sched, sizeof(struct aes_icm_ctx)); 150 KFREE(*sched, M_CRYPTO_DATA); 151 *sched = NULL; 152 } 153