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/types.h>
26 #include <sys/systm.h>
27 #include <sys/param.h>
28 #include <sys/endian.h>
29 #include <opencrypto/cbc_mac.h>
30 #include <opencrypto/xform_auth.h>
31
32 /*
33 * Given two CCM_CBC_BLOCK_LEN blocks, xor
34 * them into dst, and then encrypt dst.
35 */
36 static void
xor_and_encrypt(struct aes_cbc_mac_ctx * ctx,const uint8_t * src,uint8_t * dst)37 xor_and_encrypt(struct aes_cbc_mac_ctx *ctx,
38 const uint8_t *src, uint8_t *dst)
39 {
40 #define NWORDS (CCM_CBC_BLOCK_LEN / sizeof(uint64_t))
41 uint64_t b1[NWORDS], b2[NWORDS], temp[NWORDS];
42
43 memcpy(b1, src, CCM_CBC_BLOCK_LEN);
44 memcpy(b2, dst, CCM_CBC_BLOCK_LEN);
45
46 for (size_t count = 0; count < NWORDS; count++)
47 temp[count] = b1[count] ^ b2[count];
48 rijndaelEncrypt(ctx->keysched, ctx->rounds, (void *)temp, dst);
49 #undef NWORDS
50 }
51
52 void
AES_CBC_MAC_Init(void * vctx)53 AES_CBC_MAC_Init(void *vctx)
54 {
55 struct aes_cbc_mac_ctx *ctx;
56
57 ctx = vctx;
58 bzero(ctx, sizeof(*ctx));
59 }
60
61 void
AES_CBC_MAC_Setkey(void * vctx,const uint8_t * key,u_int klen)62 AES_CBC_MAC_Setkey(void *vctx, const uint8_t *key, u_int klen)
63 {
64 struct aes_cbc_mac_ctx *ctx;
65
66 ctx = vctx;
67 ctx->rounds = rijndaelKeySetupEnc(ctx->keysched, key, klen * 8);
68 }
69
70 /*
71 * This is called to set the nonce, aka IV.
72 *
73 * Note that the caller is responsible for constructing b0 as well
74 * as the length and padding around the AAD and passing that data
75 * to _Update.
76 */
77 void
AES_CBC_MAC_Reinit(void * vctx,const uint8_t * nonce,u_int nonceLen)78 AES_CBC_MAC_Reinit(void *vctx, const uint8_t *nonce, u_int nonceLen)
79 {
80 struct aes_cbc_mac_ctx *ctx = vctx;
81
82 ctx->nonce = nonce;
83 ctx->nonceLength = nonceLen;
84
85 ctx->blockIndex = 0;
86
87 /* XOR b0 with all 0's on first call to _Update. */
88 memset(ctx->block, 0, CCM_CBC_BLOCK_LEN);
89 }
90
91 int
AES_CBC_MAC_Update(void * vctx,const void * vdata,u_int length)92 AES_CBC_MAC_Update(void *vctx, const void *vdata, u_int length)
93 {
94 struct aes_cbc_mac_ctx *ctx;
95 const uint8_t *data;
96 size_t copy_amt;
97
98 ctx = vctx;
99 data = vdata;
100
101 /*
102 * _Update can be called with non-aligned update lengths. Use
103 * the staging block when necessary.
104 */
105 while (length != 0) {
106 uint8_t *ptr;
107
108 /*
109 * If there is no partial block and the length is at
110 * least a full block, encrypt the full block without
111 * copying to the staging block.
112 */
113 if (ctx->blockIndex == 0 && length >= CCM_CBC_BLOCK_LEN) {
114 xor_and_encrypt(ctx, data, ctx->block);
115 length -= CCM_CBC_BLOCK_LEN;
116 data += CCM_CBC_BLOCK_LEN;
117 continue;
118 }
119
120 copy_amt = MIN(sizeof(ctx->staging_block) - ctx->blockIndex,
121 length);
122 ptr = ctx->staging_block + ctx->blockIndex;
123 bcopy(data, ptr, copy_amt);
124 data += copy_amt;
125 ctx->blockIndex += copy_amt;
126 length -= copy_amt;
127 if (ctx->blockIndex == sizeof(ctx->staging_block)) {
128 /* We've got a full block */
129 xor_and_encrypt(ctx, ctx->staging_block, ctx->block);
130 ctx->blockIndex = 0;
131 }
132 }
133 return (0);
134 }
135
136 void
AES_CBC_MAC_Final(uint8_t * buf,void * vctx)137 AES_CBC_MAC_Final(uint8_t *buf, void *vctx)
138 {
139 struct aes_cbc_mac_ctx *ctx;
140 uint8_t s0[CCM_CBC_BLOCK_LEN];
141
142 ctx = vctx;
143
144 /*
145 * We first need to check to see if we've got any data
146 * left over to encrypt.
147 */
148 if (ctx->blockIndex != 0) {
149 memset(ctx->staging_block + ctx->blockIndex, 0,
150 CCM_CBC_BLOCK_LEN - ctx->blockIndex);
151 xor_and_encrypt(ctx, ctx->staging_block, ctx->block);
152 }
153 explicit_bzero(ctx->staging_block, sizeof(ctx->staging_block));
154
155 bzero(s0, sizeof(s0));
156 s0[0] = (15 - ctx->nonceLength) - 1;
157 bcopy(ctx->nonce, s0 + 1, ctx->nonceLength);
158 rijndaelEncrypt(ctx->keysched, ctx->rounds, s0, s0);
159 for (size_t indx = 0; indx < AES_CBC_MAC_HASH_LEN; indx++)
160 buf[indx] = ctx->block[indx] ^ s0[indx];
161 explicit_bzero(s0, sizeof(s0));
162 }
163