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22#include <linux/crypto.h>
23#include <linux/err.h>
24#include <linux/hardirq.h>
25#include <linux/kernel.h>
26#include <linux/mm.h>
27#include <linux/rtnetlink.h>
28#include <linux/slab.h>
29#include <linux/scatterlist.h>
30#include "internal.h"
31
32static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
33 0x02020202, 0x02020202, 0x02020202, 0x02020202,
34 0x03030303, 0x03030303, 0x03030303, 0x03030303};
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50struct crypto_xcbc_ctx {
51 struct crypto_cipher *child;
52 u8 *odds;
53 u8 *prev;
54 u8 *key;
55 u8 *consts;
56 void (*xor)(u8 *a, const u8 *b, unsigned int bs);
57 unsigned int keylen;
58 unsigned int len;
59};
60
61static void xor_128(u8 *a, const u8 *b, unsigned int bs)
62{
63 ((u32 *)a)[0] ^= ((u32 *)b)[0];
64 ((u32 *)a)[1] ^= ((u32 *)b)[1];
65 ((u32 *)a)[2] ^= ((u32 *)b)[2];
66 ((u32 *)a)[3] ^= ((u32 *)b)[3];
67}
68
69static int _crypto_xcbc_digest_setkey(struct crypto_hash *parent,
70 struct crypto_xcbc_ctx *ctx)
71{
72 int bs = crypto_hash_blocksize(parent);
73 int err = 0;
74 u8 key1[bs];
75
76 if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
77 return err;
78
79 crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts);
80
81 return crypto_cipher_setkey(ctx->child, key1, bs);
82}
83
84static int crypto_xcbc_digest_setkey(struct crypto_hash *parent,
85 const u8 *inkey, unsigned int keylen)
86{
87 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
88
89 if (keylen != crypto_cipher_blocksize(ctx->child))
90 return -EINVAL;
91
92 ctx->keylen = keylen;
93 memcpy(ctx->key, inkey, keylen);
94 ctx->consts = (u8*)ks;
95
96 return _crypto_xcbc_digest_setkey(parent, ctx);
97}
98
99static int crypto_xcbc_digest_init(struct hash_desc *pdesc)
100{
101 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(pdesc->tfm);
102 int bs = crypto_hash_blocksize(pdesc->tfm);
103
104 ctx->len = 0;
105 memset(ctx->odds, 0, bs);
106 memset(ctx->prev, 0, bs);
107
108 return 0;
109}
110
111static int crypto_xcbc_digest_update2(struct hash_desc *pdesc,
112 struct scatterlist *sg,
113 unsigned int nbytes)
114{
115 struct crypto_hash *parent = pdesc->tfm;
116 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
117 struct crypto_cipher *tfm = ctx->child;
118 int bs = crypto_hash_blocksize(parent);
119 unsigned int i = 0;
120
121 do {
122
123 struct page *pg = sg_page(&sg[i]);
124 unsigned int offset = sg[i].offset;
125 unsigned int slen = sg[i].length;
126
127 while (slen > 0) {
128 unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
129 char *p = crypto_kmap(pg, 0) + offset;
130
131
132 if ((ctx->len + len) <= bs) {
133 memcpy(ctx->odds + ctx->len, p, len);
134 ctx->len += len;
135 slen -= len;
136
137
138 if (len + offset >= PAGE_SIZE) {
139 offset = 0;
140 pg++;
141 } else
142 offset += len;
143
144 crypto_kunmap(p, 0);
145 crypto_yield(pdesc->flags);
146 continue;
147 }
148
149
150 memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
151 len -= bs - ctx->len;
152 p += bs - ctx->len;
153
154 ctx->xor(ctx->prev, ctx->odds, bs);
155 crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
156
157
158 ctx->len = 0;
159
160
161 while (len > bs) {
162 ctx->xor(ctx->prev, p, bs);
163 crypto_cipher_encrypt_one(tfm, ctx->prev,
164 ctx->prev);
165 p += bs;
166 len -= bs;
167 }
168
169
170 if (len) {
171 memcpy(ctx->odds, p, len);
172 ctx->len = len;
173 }
174 crypto_kunmap(p, 0);
175 crypto_yield(pdesc->flags);
176 slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
177 offset = 0;
178 pg++;
179 }
180 nbytes-=sg[i].length;
181 i++;
182 } while (nbytes>0);
183
184 return 0;
185}
186
187static int crypto_xcbc_digest_update(struct hash_desc *pdesc,
188 struct scatterlist *sg,
189 unsigned int nbytes)
190{
191 if (WARN_ON_ONCE(in_irq()))
192 return -EDEADLK;
193 return crypto_xcbc_digest_update2(pdesc, sg, nbytes);
194}
195
196static int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out)
197{
198 struct crypto_hash *parent = pdesc->tfm;
199 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
200 struct crypto_cipher *tfm = ctx->child;
201 int bs = crypto_hash_blocksize(parent);
202 int err = 0;
203
204 if (ctx->len == bs) {
205 u8 key2[bs];
206
207 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
208 return err;
209
210 crypto_cipher_encrypt_one(tfm, key2,
211 (u8 *)(ctx->consts + bs));
212
213 ctx->xor(ctx->prev, ctx->odds, bs);
214 ctx->xor(ctx->prev, key2, bs);
215 _crypto_xcbc_digest_setkey(parent, ctx);
216
217 crypto_cipher_encrypt_one(tfm, out, ctx->prev);
218 } else {
219 u8 key3[bs];
220 unsigned int rlen;
221 u8 *p = ctx->odds + ctx->len;
222 *p = 0x80;
223 p++;
224
225 rlen = bs - ctx->len -1;
226 if (rlen)
227 memset(p, 0, rlen);
228
229 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
230 return err;
231
232 crypto_cipher_encrypt_one(tfm, key3,
233 (u8 *)(ctx->consts + bs * 2));
234
235 ctx->xor(ctx->prev, ctx->odds, bs);
236 ctx->xor(ctx->prev, key3, bs);
237
238 _crypto_xcbc_digest_setkey(parent, ctx);
239
240 crypto_cipher_encrypt_one(tfm, out, ctx->prev);
241 }
242
243 return 0;
244}
245
246static int crypto_xcbc_digest(struct hash_desc *pdesc,
247 struct scatterlist *sg, unsigned int nbytes, u8 *out)
248{
249 if (WARN_ON_ONCE(in_irq()))
250 return -EDEADLK;
251
252 crypto_xcbc_digest_init(pdesc);
253 crypto_xcbc_digest_update2(pdesc, sg, nbytes);
254 return crypto_xcbc_digest_final(pdesc, out);
255}
256
257static int xcbc_init_tfm(struct crypto_tfm *tfm)
258{
259 struct crypto_cipher *cipher;
260 struct crypto_instance *inst = (void *)tfm->__crt_alg;
261 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
262 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
263 int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm));
264
265 cipher = crypto_spawn_cipher(spawn);
266 if (IS_ERR(cipher))
267 return PTR_ERR(cipher);
268
269 switch(bs) {
270 case 16:
271 ctx->xor = xor_128;
272 break;
273 default:
274 return -EINVAL;
275 }
276
277 ctx->child = cipher;
278 ctx->odds = (u8*)(ctx+1);
279 ctx->prev = ctx->odds + bs;
280 ctx->key = ctx->prev + bs;
281
282 return 0;
283};
284
285static void xcbc_exit_tfm(struct crypto_tfm *tfm)
286{
287 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
288 crypto_free_cipher(ctx->child);
289}
290
291static struct crypto_instance *xcbc_alloc(struct rtattr **tb)
292{
293 struct crypto_instance *inst;
294 struct crypto_alg *alg;
295 int err;
296
297 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH);
298 if (err)
299 return ERR_PTR(err);
300
301 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
302 CRYPTO_ALG_TYPE_MASK);
303 if (IS_ERR(alg))
304 return ERR_PTR(PTR_ERR(alg));
305
306 switch(alg->cra_blocksize) {
307 case 16:
308 break;
309 default:
310 return ERR_PTR(PTR_ERR(alg));
311 }
312
313 inst = crypto_alloc_instance("xcbc", alg);
314 if (IS_ERR(inst))
315 goto out_put_alg;
316
317 inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
318 inst->alg.cra_priority = alg->cra_priority;
319 inst->alg.cra_blocksize = alg->cra_blocksize;
320 inst->alg.cra_alignmask = alg->cra_alignmask;
321 inst->alg.cra_type = &crypto_hash_type;
322
323 inst->alg.cra_hash.digestsize =
324 (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
325 CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize :
326 alg->cra_blocksize;
327 inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
328 ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *));
329 inst->alg.cra_init = xcbc_init_tfm;
330 inst->alg.cra_exit = xcbc_exit_tfm;
331
332 inst->alg.cra_hash.init = crypto_xcbc_digest_init;
333 inst->alg.cra_hash.update = crypto_xcbc_digest_update;
334 inst->alg.cra_hash.final = crypto_xcbc_digest_final;
335 inst->alg.cra_hash.digest = crypto_xcbc_digest;
336 inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey;
337
338out_put_alg:
339 crypto_mod_put(alg);
340 return inst;
341}
342
343static void xcbc_free(struct crypto_instance *inst)
344{
345 crypto_drop_spawn(crypto_instance_ctx(inst));
346 kfree(inst);
347}
348
349static struct crypto_template crypto_xcbc_tmpl = {
350 .name = "xcbc",
351 .alloc = xcbc_alloc,
352 .free = xcbc_free,
353 .module = THIS_MODULE,
354};
355
356static int __init crypto_xcbc_module_init(void)
357{
358 return crypto_register_template(&crypto_xcbc_tmpl);
359}
360
361static void __exit crypto_xcbc_module_exit(void)
362{
363 crypto_unregister_template(&crypto_xcbc_tmpl);
364}
365
366module_init(crypto_xcbc_module_init);
367module_exit(crypto_xcbc_module_exit);
368
369MODULE_LICENSE("GPL");
370MODULE_DESCRIPTION("XCBC keyed hash algorithm");
371
