1 /*
2 * Copyright (c) 2018-2019 iXsystems Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25 #include <sys/cdefs.h>
26 #include <sys/types.h>
27 #include <sys/systm.h>
28 #include <sys/param.h>
29 #include <sys/endian.h>
30 #include <opencrypto/cbc_mac.h>
31 #include <opencrypto/xform_auth.h>
32
33 /*
34 * Given two CCM_CBC_BLOCK_LEN blocks, xor
35 * them into dst, and then encrypt dst.
36 */
37 static void
xor_and_encrypt(struct aes_cbc_mac_ctx * ctx,const uint8_t * src,uint8_t * dst)38 xor_and_encrypt(struct aes_cbc_mac_ctx *ctx,
39 const uint8_t *src, uint8_t *dst)
40 {
41 #define NWORDS (CCM_CBC_BLOCK_LEN / sizeof(uint64_t))
42 uint64_t b1[NWORDS], b2[NWORDS], temp[NWORDS];
43
44 memcpy(b1, src, CCM_CBC_BLOCK_LEN);
45 memcpy(b2, dst, CCM_CBC_BLOCK_LEN);
46
47 for (size_t count = 0; count < NWORDS; count++)
48 temp[count] = b1[count] ^ b2[count];
49 rijndaelEncrypt(ctx->keysched, ctx->rounds, (void *)temp, dst);
50 #undef NWORDS
51 }
52
53 void
AES_CBC_MAC_Init(void * vctx)54 AES_CBC_MAC_Init(void *vctx)
55 {
56 struct aes_cbc_mac_ctx *ctx;
57
58 ctx = vctx;
59 bzero(ctx, sizeof(*ctx));
60 }
61
62 void
AES_CBC_MAC_Setkey(void * vctx,const uint8_t * key,u_int klen)63 AES_CBC_MAC_Setkey(void *vctx, const uint8_t *key, u_int klen)
64 {
65 struct aes_cbc_mac_ctx *ctx;
66
67 ctx = vctx;
68 ctx->rounds = rijndaelKeySetupEnc(ctx->keysched, key, klen * 8);
69 }
70
71 /*
72 * This is called to set the nonce, aka IV.
73 *
74 * Note that the caller is responsible for constructing b0 as well
75 * as the length and padding around the AAD and passing that data
76 * to _Update.
77 */
78 void
AES_CBC_MAC_Reinit(void * vctx,const uint8_t * nonce,u_int nonceLen)79 AES_CBC_MAC_Reinit(void *vctx, const uint8_t *nonce, u_int nonceLen)
80 {
81 struct aes_cbc_mac_ctx *ctx = vctx;
82
83 ctx->nonce = nonce;
84 ctx->nonceLength = nonceLen;
85
86 ctx->blockIndex = 0;
87
88 /* XOR b0 with all 0's on first call to _Update. */
89 memset(ctx->block, 0, CCM_CBC_BLOCK_LEN);
90 }
91
92 int
AES_CBC_MAC_Update(void * vctx,const void * vdata,u_int length)93 AES_CBC_MAC_Update(void *vctx, const void *vdata, u_int length)
94 {
95 struct aes_cbc_mac_ctx *ctx;
96 const uint8_t *data;
97 size_t copy_amt;
98
99 ctx = vctx;
100 data = vdata;
101
102 /*
103 * _Update can be called with non-aligned update lengths. Use
104 * the staging block when necessary.
105 */
106 while (length != 0) {
107 uint8_t *ptr;
108
109 /*
110 * If there is no partial block and the length is at
111 * least a full block, encrypt the full block without
112 * copying to the staging block.
113 */
114 if (ctx->blockIndex == 0 && length >= CCM_CBC_BLOCK_LEN) {
115 xor_and_encrypt(ctx, data, ctx->block);
116 length -= CCM_CBC_BLOCK_LEN;
117 data += CCM_CBC_BLOCK_LEN;
118 continue;
119 }
120
121 copy_amt = MIN(sizeof(ctx->staging_block) - ctx->blockIndex,
122 length);
123 ptr = ctx->staging_block + ctx->blockIndex;
124 bcopy(data, ptr, copy_amt);
125 data += copy_amt;
126 ctx->blockIndex += copy_amt;
127 length -= copy_amt;
128 if (ctx->blockIndex == sizeof(ctx->staging_block)) {
129 /* We've got a full block */
130 xor_and_encrypt(ctx, ctx->staging_block, ctx->block);
131 ctx->blockIndex = 0;
132 }
133 }
134 return (0);
135 }
136
137 void
AES_CBC_MAC_Final(uint8_t * buf,void * vctx)138 AES_CBC_MAC_Final(uint8_t *buf, void *vctx)
139 {
140 struct aes_cbc_mac_ctx *ctx;
141 uint8_t s0[CCM_CBC_BLOCK_LEN];
142
143 ctx = vctx;
144
145 /*
146 * We first need to check to see if we've got any data
147 * left over to encrypt.
148 */
149 if (ctx->blockIndex != 0) {
150 memset(ctx->staging_block + ctx->blockIndex, 0,
151 CCM_CBC_BLOCK_LEN - ctx->blockIndex);
152 xor_and_encrypt(ctx, ctx->staging_block, ctx->block);
153 }
154 explicit_bzero(ctx->staging_block, sizeof(ctx->staging_block));
155
156 bzero(s0, sizeof(s0));
157 s0[0] = (15 - ctx->nonceLength) - 1;
158 bcopy(ctx->nonce, s0 + 1, ctx->nonceLength);
159 rijndaelEncrypt(ctx->keysched, ctx->rounds, s0, s0);
160 for (size_t indx = 0; indx < AES_CBC_MAC_HASH_LEN; indx++)
161 buf[indx] = ctx->block[indx] ^ s0[indx];
162 explicit_bzero(s0, sizeof(s0));
163 }
164