1 // SPDX-License-Identifier: GPL-2.0-or-later <<
2 /* 1 /*
3 * CMAC: Cipher Block Mode for Authentication 2 * CMAC: Cipher Block Mode for Authentication
4 * 3 *
5 * Copyright © 2013 Jussi Kivilinna <jussi.ki 4 * Copyright © 2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>
6 * 5 *
7 * Based on work by: 6 * Based on work by:
8 * Copyright © 2013 Tom St Denis <tstdenis@e 7 * Copyright © 2013 Tom St Denis <tstdenis@elliptictech.com>
9 * Based on crypto/xcbc.c: 8 * Based on crypto/xcbc.c:
10 * Copyright © 2006 USAGI/WIDE Project, 9 * Copyright © 2006 USAGI/WIDE Project,
11 * Author: Kazunori Miyazawa <miyazawa@linux 10 * Author: Kazunori Miyazawa <miyazawa@linux-ipv6.org>
>> 11 *
>> 12 * This program is free software; you can redistribute it and/or modify
>> 13 * it under the terms of the GNU General Public License as published by
>> 14 * the Free Software Foundation; either version 2 of the License, or
>> 15 * (at your option) any later version.
>> 16 *
12 */ 17 */
13 18
14 #include <crypto/internal/cipher.h> <<
15 #include <crypto/internal/hash.h> 19 #include <crypto/internal/hash.h>
16 #include <linux/err.h> 20 #include <linux/err.h>
17 #include <linux/kernel.h> 21 #include <linux/kernel.h>
18 #include <linux/module.h> 22 #include <linux/module.h>
19 23
20 /* 24 /*
21 * +------------------------ 25 * +------------------------
22 * | <parent tfm> 26 * | <parent tfm>
23 * +------------------------ 27 * +------------------------
24 * | cmac_tfm_ctx 28 * | cmac_tfm_ctx
25 * +------------------------ 29 * +------------------------
26 * | consts (block size * 2) 30 * | consts (block size * 2)
27 * +------------------------ 31 * +------------------------
28 */ 32 */
29 struct cmac_tfm_ctx { 33 struct cmac_tfm_ctx {
30 struct crypto_cipher *child; 34 struct crypto_cipher *child;
31 __be64 consts[]; !! 35 u8 ctx[];
32 }; 36 };
33 37
34 /* 38 /*
35 * +------------------------ 39 * +------------------------
36 * | <shash desc> 40 * | <shash desc>
37 * +------------------------ 41 * +------------------------
38 * | cmac_desc_ctx 42 * | cmac_desc_ctx
39 * +------------------------ 43 * +------------------------
40 * | odds (block size) 44 * | odds (block size)
41 * +------------------------ 45 * +------------------------
42 * | prev (block size) 46 * | prev (block size)
43 * +------------------------ 47 * +------------------------
44 */ 48 */
45 struct cmac_desc_ctx { 49 struct cmac_desc_ctx {
46 unsigned int len; 50 unsigned int len;
47 u8 odds[]; !! 51 u8 ctx[];
48 }; 52 };
49 53
50 static int crypto_cmac_digest_setkey(struct cr 54 static int crypto_cmac_digest_setkey(struct crypto_shash *parent,
51 const u8 55 const u8 *inkey, unsigned int keylen)
52 { 56 {
>> 57 unsigned long alignmask = crypto_shash_alignmask(parent);
53 struct cmac_tfm_ctx *ctx = crypto_shas 58 struct cmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
54 unsigned int bs = crypto_shash_blocksi 59 unsigned int bs = crypto_shash_blocksize(parent);
55 __be64 *consts = ctx->consts; !! 60 __be64 *consts = PTR_ALIGN((void *)ctx->ctx, alignmask + 1);
56 u64 _const[2]; 61 u64 _const[2];
57 int i, err = 0; 62 int i, err = 0;
58 u8 msb_mask, gfmask; 63 u8 msb_mask, gfmask;
59 64
60 err = crypto_cipher_setkey(ctx->child, 65 err = crypto_cipher_setkey(ctx->child, inkey, keylen);
61 if (err) 66 if (err)
62 return err; 67 return err;
63 68
64 /* encrypt the zero block */ 69 /* encrypt the zero block */
65 memset(consts, 0, bs); 70 memset(consts, 0, bs);
66 crypto_cipher_encrypt_one(ctx->child, 71 crypto_cipher_encrypt_one(ctx->child, (u8 *)consts, (u8 *)consts);
67 72
68 switch (bs) { 73 switch (bs) {
69 case 16: 74 case 16:
70 gfmask = 0x87; 75 gfmask = 0x87;
71 _const[0] = be64_to_cpu(consts 76 _const[0] = be64_to_cpu(consts[1]);
72 _const[1] = be64_to_cpu(consts 77 _const[1] = be64_to_cpu(consts[0]);
73 78
74 /* gf(2^128) multiply zero-cip 79 /* gf(2^128) multiply zero-ciphertext with u and u^2 */
75 for (i = 0; i < 4; i += 2) { 80 for (i = 0; i < 4; i += 2) {
76 msb_mask = ((s64)_cons 81 msb_mask = ((s64)_const[1] >> 63) & gfmask;
77 _const[1] = (_const[1] 82 _const[1] = (_const[1] << 1) | (_const[0] >> 63);
78 _const[0] = (_const[0] 83 _const[0] = (_const[0] << 1) ^ msb_mask;
79 84
80 consts[i + 0] = cpu_to 85 consts[i + 0] = cpu_to_be64(_const[1]);
81 consts[i + 1] = cpu_to 86 consts[i + 1] = cpu_to_be64(_const[0]);
82 } 87 }
83 88
84 break; 89 break;
85 case 8: 90 case 8:
86 gfmask = 0x1B; 91 gfmask = 0x1B;
87 _const[0] = be64_to_cpu(consts 92 _const[0] = be64_to_cpu(consts[0]);
88 93
89 /* gf(2^64) multiply zero-ciph 94 /* gf(2^64) multiply zero-ciphertext with u and u^2 */
90 for (i = 0; i < 2; i++) { 95 for (i = 0; i < 2; i++) {
91 msb_mask = ((s64)_cons 96 msb_mask = ((s64)_const[0] >> 63) & gfmask;
92 _const[0] = (_const[0] 97 _const[0] = (_const[0] << 1) ^ msb_mask;
93 98
94 consts[i] = cpu_to_be6 99 consts[i] = cpu_to_be64(_const[0]);
95 } 100 }
96 101
97 break; 102 break;
98 } 103 }
99 104
100 return 0; 105 return 0;
101 } 106 }
102 107
103 static int crypto_cmac_digest_init(struct shas 108 static int crypto_cmac_digest_init(struct shash_desc *pdesc)
104 { 109 {
>> 110 unsigned long alignmask = crypto_shash_alignmask(pdesc->tfm);
105 struct cmac_desc_ctx *ctx = shash_desc 111 struct cmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
106 int bs = crypto_shash_blocksize(pdesc- 112 int bs = crypto_shash_blocksize(pdesc->tfm);
107 u8 *prev = &ctx->odds[bs]; !! 113 u8 *prev = PTR_ALIGN((void *)ctx->ctx, alignmask + 1) + bs;
108 114
109 ctx->len = 0; 115 ctx->len = 0;
110 memset(prev, 0, bs); 116 memset(prev, 0, bs);
111 117
112 return 0; 118 return 0;
113 } 119 }
114 120
115 static int crypto_cmac_digest_update(struct sh 121 static int crypto_cmac_digest_update(struct shash_desc *pdesc, const u8 *p,
116 unsigned 122 unsigned int len)
117 { 123 {
118 struct crypto_shash *parent = pdesc->t 124 struct crypto_shash *parent = pdesc->tfm;
>> 125 unsigned long alignmask = crypto_shash_alignmask(parent);
119 struct cmac_tfm_ctx *tctx = crypto_sha 126 struct cmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
120 struct cmac_desc_ctx *ctx = shash_desc 127 struct cmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
121 struct crypto_cipher *tfm = tctx->chil 128 struct crypto_cipher *tfm = tctx->child;
122 int bs = crypto_shash_blocksize(parent 129 int bs = crypto_shash_blocksize(parent);
123 u8 *odds = ctx->odds; !! 130 u8 *odds = PTR_ALIGN((void *)ctx->ctx, alignmask + 1);
124 u8 *prev = odds + bs; 131 u8 *prev = odds + bs;
125 132
126 /* checking the data can fill the bloc 133 /* checking the data can fill the block */
127 if ((ctx->len + len) <= bs) { 134 if ((ctx->len + len) <= bs) {
128 memcpy(odds + ctx->len, p, len 135 memcpy(odds + ctx->len, p, len);
129 ctx->len += len; 136 ctx->len += len;
130 return 0; 137 return 0;
131 } 138 }
132 139
133 /* filling odds with new data and encr 140 /* filling odds with new data and encrypting it */
134 memcpy(odds + ctx->len, p, bs - ctx->l 141 memcpy(odds + ctx->len, p, bs - ctx->len);
135 len -= bs - ctx->len; 142 len -= bs - ctx->len;
136 p += bs - ctx->len; 143 p += bs - ctx->len;
137 144
138 crypto_xor(prev, odds, bs); 145 crypto_xor(prev, odds, bs);
139 crypto_cipher_encrypt_one(tfm, prev, p 146 crypto_cipher_encrypt_one(tfm, prev, prev);
140 147
141 /* clearing the length */ 148 /* clearing the length */
142 ctx->len = 0; 149 ctx->len = 0;
143 150
144 /* encrypting the rest of data */ 151 /* encrypting the rest of data */
145 while (len > bs) { 152 while (len > bs) {
146 crypto_xor(prev, p, bs); 153 crypto_xor(prev, p, bs);
147 crypto_cipher_encrypt_one(tfm, 154 crypto_cipher_encrypt_one(tfm, prev, prev);
148 p += bs; 155 p += bs;
149 len -= bs; 156 len -= bs;
150 } 157 }
151 158
152 /* keeping the surplus of blocksize */ 159 /* keeping the surplus of blocksize */
153 if (len) { 160 if (len) {
154 memcpy(odds, p, len); 161 memcpy(odds, p, len);
155 ctx->len = len; 162 ctx->len = len;
156 } 163 }
157 164
158 return 0; 165 return 0;
159 } 166 }
160 167
161 static int crypto_cmac_digest_final(struct sha 168 static int crypto_cmac_digest_final(struct shash_desc *pdesc, u8 *out)
162 { 169 {
163 struct crypto_shash *parent = pdesc->t 170 struct crypto_shash *parent = pdesc->tfm;
>> 171 unsigned long alignmask = crypto_shash_alignmask(parent);
164 struct cmac_tfm_ctx *tctx = crypto_sha 172 struct cmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
165 struct cmac_desc_ctx *ctx = shash_desc 173 struct cmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
166 struct crypto_cipher *tfm = tctx->chil 174 struct crypto_cipher *tfm = tctx->child;
167 int bs = crypto_shash_blocksize(parent 175 int bs = crypto_shash_blocksize(parent);
168 u8 *odds = ctx->odds; !! 176 u8 *consts = PTR_ALIGN((void *)tctx->ctx, alignmask + 1);
>> 177 u8 *odds = PTR_ALIGN((void *)ctx->ctx, alignmask + 1);
169 u8 *prev = odds + bs; 178 u8 *prev = odds + bs;
170 unsigned int offset = 0; 179 unsigned int offset = 0;
171 180
172 if (ctx->len != bs) { 181 if (ctx->len != bs) {
173 unsigned int rlen; 182 unsigned int rlen;
174 u8 *p = odds + ctx->len; 183 u8 *p = odds + ctx->len;
175 184
176 *p = 0x80; 185 *p = 0x80;
177 p++; 186 p++;
178 187
179 rlen = bs - ctx->len - 1; 188 rlen = bs - ctx->len - 1;
180 if (rlen) 189 if (rlen)
181 memset(p, 0, rlen); 190 memset(p, 0, rlen);
182 191
183 offset += bs; 192 offset += bs;
184 } 193 }
185 194
186 crypto_xor(prev, odds, bs); 195 crypto_xor(prev, odds, bs);
187 crypto_xor(prev, (const u8 *)tctx->con !! 196 crypto_xor(prev, consts + offset, bs);
188 197
189 crypto_cipher_encrypt_one(tfm, out, pr 198 crypto_cipher_encrypt_one(tfm, out, prev);
190 199
191 return 0; 200 return 0;
192 } 201 }
193 202
194 static int cmac_init_tfm(struct crypto_shash * !! 203 static int cmac_init_tfm(struct crypto_tfm *tfm)
195 { 204 {
196 struct shash_instance *inst = shash_al <<
197 struct cmac_tfm_ctx *ctx = crypto_shas <<
198 struct crypto_cipher_spawn *spawn; <<
199 struct crypto_cipher *cipher; 205 struct crypto_cipher *cipher;
>> 206 struct crypto_instance *inst = (void *)tfm->__crt_alg;
>> 207 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
>> 208 struct cmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
200 209
201 spawn = shash_instance_ctx(inst); <<
202 cipher = crypto_spawn_cipher(spawn); 210 cipher = crypto_spawn_cipher(spawn);
203 if (IS_ERR(cipher)) 211 if (IS_ERR(cipher))
204 return PTR_ERR(cipher); 212 return PTR_ERR(cipher);
205 213
206 ctx->child = cipher; 214 ctx->child = cipher;
207 215
208 return 0; 216 return 0;
209 } !! 217 };
210 <<
211 static int cmac_clone_tfm(struct crypto_shash <<
212 { <<
213 struct cmac_tfm_ctx *octx = crypto_sha <<
214 struct cmac_tfm_ctx *ctx = crypto_shas <<
215 struct crypto_cipher *cipher; <<
216 <<
217 cipher = crypto_clone_cipher(octx->chi <<
218 if (IS_ERR(cipher)) <<
219 return PTR_ERR(cipher); <<
220 <<
221 ctx->child = cipher; <<
222 <<
223 return 0; <<
224 } <<
225 218
226 static void cmac_exit_tfm(struct crypto_shash !! 219 static void cmac_exit_tfm(struct crypto_tfm *tfm)
227 { 220 {
228 struct cmac_tfm_ctx *ctx = crypto_shas !! 221 struct cmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
229 crypto_free_cipher(ctx->child); 222 crypto_free_cipher(ctx->child);
230 } 223 }
231 224
232 static int cmac_create(struct crypto_template 225 static int cmac_create(struct crypto_template *tmpl, struct rtattr **tb)
233 { 226 {
234 struct shash_instance *inst; 227 struct shash_instance *inst;
235 struct crypto_cipher_spawn *spawn; <<
236 struct crypto_alg *alg; 228 struct crypto_alg *alg;
237 u32 mask; !! 229 unsigned long alignmask;
238 int err; 230 int err;
239 231
240 err = crypto_check_attr_type(tb, CRYPT !! 232 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
241 if (err) 233 if (err)
242 return err; 234 return err;
243 235
244 inst = kzalloc(sizeof(*inst) + sizeof( !! 236 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
245 if (!inst) !! 237 CRYPTO_ALG_TYPE_MASK);
246 return -ENOMEM; !! 238 if (IS_ERR(alg))
247 spawn = shash_instance_ctx(inst); !! 239 return PTR_ERR(alg);
248 <<
249 err = crypto_grab_cipher(spawn, shash_ <<
250 crypto_attr_a <<
251 if (err) <<
252 goto err_free_inst; <<
253 alg = crypto_spawn_cipher_alg(spawn); <<
254 240
255 switch (alg->cra_blocksize) { 241 switch (alg->cra_blocksize) {
256 case 16: 242 case 16:
257 case 8: 243 case 8:
258 break; 244 break;
259 default: 245 default:
260 err = -EINVAL; !! 246 goto out_put_alg;
261 goto err_free_inst; <<
262 } 247 }
263 248
264 err = crypto_inst_setname(shash_crypto !! 249 inst = shash_alloc_instance("cmac", alg);
>> 250 err = PTR_ERR(inst);
>> 251 if (IS_ERR(inst))
>> 252 goto out_put_alg;
>> 253
>> 254 err = crypto_init_spawn(shash_instance_ctx(inst), alg,
>> 255 shash_crypto_instance(inst),
>> 256 CRYPTO_ALG_TYPE_MASK);
265 if (err) 257 if (err)
266 goto err_free_inst; !! 258 goto out_free_inst;
267 259
>> 260 alignmask = alg->cra_alignmask | (sizeof(long) - 1);
>> 261 inst->alg.base.cra_alignmask = alignmask;
268 inst->alg.base.cra_priority = alg->cra 262 inst->alg.base.cra_priority = alg->cra_priority;
269 inst->alg.base.cra_blocksize = alg->cr 263 inst->alg.base.cra_blocksize = alg->cra_blocksize;
270 inst->alg.base.cra_ctxsize = sizeof(st <<
271 alg->cra_ <<
272 264
273 inst->alg.digestsize = alg->cra_blocks 265 inst->alg.digestsize = alg->cra_blocksize;
274 inst->alg.descsize = sizeof(struct cma !! 266 inst->alg.descsize =
275 alg->cra_blocksiz !! 267 ALIGN(sizeof(struct cmac_desc_ctx), crypto_tfm_ctx_alignment())
>> 268 + (alignmask & ~(crypto_tfm_ctx_alignment() - 1))
>> 269 + alg->cra_blocksize * 2;
>> 270
>> 271 inst->alg.base.cra_ctxsize =
>> 272 ALIGN(sizeof(struct cmac_tfm_ctx), alignmask + 1)
>> 273 + alg->cra_blocksize * 2;
>> 274
>> 275 inst->alg.base.cra_init = cmac_init_tfm;
>> 276 inst->alg.base.cra_exit = cmac_exit_tfm;
>> 277
276 inst->alg.init = crypto_cmac_digest_in 278 inst->alg.init = crypto_cmac_digest_init;
277 inst->alg.update = crypto_cmac_digest_ 279 inst->alg.update = crypto_cmac_digest_update;
278 inst->alg.final = crypto_cmac_digest_f 280 inst->alg.final = crypto_cmac_digest_final;
279 inst->alg.setkey = crypto_cmac_digest_ 281 inst->alg.setkey = crypto_cmac_digest_setkey;
280 inst->alg.init_tfm = cmac_init_tfm; <<
281 inst->alg.clone_tfm = cmac_clone_tfm; <<
282 inst->alg.exit_tfm = cmac_exit_tfm; <<
283 <<
284 inst->free = shash_free_singlespawn_in <<
285 282
286 err = shash_register_instance(tmpl, in 283 err = shash_register_instance(tmpl, inst);
287 if (err) { 284 if (err) {
288 err_free_inst: !! 285 out_free_inst:
289 shash_free_singlespawn_instanc !! 286 shash_free_instance(shash_crypto_instance(inst));
290 } 287 }
>> 288
>> 289 out_put_alg:
>> 290 crypto_mod_put(alg);
291 return err; 291 return err;
292 } 292 }
293 293
294 static struct crypto_template crypto_cmac_tmpl 294 static struct crypto_template crypto_cmac_tmpl = {
295 .name = "cmac", 295 .name = "cmac",
296 .create = cmac_create, 296 .create = cmac_create,
>> 297 .free = shash_free_instance,
297 .module = THIS_MODULE, 298 .module = THIS_MODULE,
298 }; 299 };
299 300
300 static int __init crypto_cmac_module_init(void 301 static int __init crypto_cmac_module_init(void)
301 { 302 {
302 return crypto_register_template(&crypt 303 return crypto_register_template(&crypto_cmac_tmpl);
303 } 304 }
304 305
305 static void __exit crypto_cmac_module_exit(voi 306 static void __exit crypto_cmac_module_exit(void)
306 { 307 {
307 crypto_unregister_template(&crypto_cma 308 crypto_unregister_template(&crypto_cmac_tmpl);
308 } 309 }
309 310
310 subsys_initcall(crypto_cmac_module_init); !! 311 module_init(crypto_cmac_module_init);
311 module_exit(crypto_cmac_module_exit); 312 module_exit(crypto_cmac_module_exit);
312 313
313 MODULE_LICENSE("GPL"); 314 MODULE_LICENSE("GPL");
314 MODULE_DESCRIPTION("CMAC keyed hash algorithm" 315 MODULE_DESCRIPTION("CMAC keyed hash algorithm");
315 MODULE_ALIAS_CRYPTO("cmac"); 316 MODULE_ALIAS_CRYPTO("cmac");
316 MODULE_IMPORT_NS(CRYPTO_INTERNAL); <<
317 317
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