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22#include <crypto/scatterwalk.h>
23#include <linux/crypto.h>
24#include <linux/err.h>
25#include <linux/hardirq.h>
26#include <linux/kernel.h>
27#include <linux/mm.h>
28#include <linux/rtnetlink.h>
29#include <linux/slab.h>
30#include <linux/scatterlist.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
120 for (;;) {
121 struct page *pg = sg_page(sg);
122 unsigned int offset = sg->offset;
123 unsigned int slen = sg->length;
124
125 if (unlikely(slen > nbytes))
126 slen = nbytes;
127
128 nbytes -= slen;
129
130 while (slen > 0) {
131 unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
132 char *p = crypto_kmap(pg, 0) + offset;
133
134
135 if ((ctx->len + len) <= bs) {
136 memcpy(ctx->odds + ctx->len, p, len);
137 ctx->len += len;
138 slen -= len;
139
140
141 if (len + offset >= PAGE_SIZE) {
142 offset = 0;
143 pg++;
144 } else
145 offset += len;
146
147 crypto_kunmap(p, 0);
148 crypto_yield(pdesc->flags);
149 continue;
150 }
151
152
153 memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
154 len -= bs - ctx->len;
155 p += bs - ctx->len;
156
157 ctx->xor(ctx->prev, ctx->odds, bs);
158 crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
159
160
161 ctx->len = 0;
162
163
164 while (len > bs) {
165 ctx->xor(ctx->prev, p, bs);
166 crypto_cipher_encrypt_one(tfm, ctx->prev,
167 ctx->prev);
168 p += bs;
169 len -= bs;
170 }
171
172
173 if (len) {
174 memcpy(ctx->odds, p, len);
175 ctx->len = len;
176 }
177 crypto_kunmap(p, 0);
178 crypto_yield(pdesc->flags);
179 slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
180 offset = 0;
181 pg++;
182 }
183
184 if (!nbytes)
185 break;
186 sg = scatterwalk_sg_next(sg);
187 }
188
189 return 0;
190}
191
192static int crypto_xcbc_digest_update(struct hash_desc *pdesc,
193 struct scatterlist *sg,
194 unsigned int nbytes)
195{
196 if (WARN_ON_ONCE(in_irq()))
197 return -EDEADLK;
198 return crypto_xcbc_digest_update2(pdesc, sg, nbytes);
199}
200
201static int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out)
202{
203 struct crypto_hash *parent = pdesc->tfm;
204 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
205 struct crypto_cipher *tfm = ctx->child;
206 int bs = crypto_hash_blocksize(parent);
207 int err = 0;
208
209 if (ctx->len == bs) {
210 u8 key2[bs];
211
212 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
213 return err;
214
215 crypto_cipher_encrypt_one(tfm, key2,
216 (u8 *)(ctx->consts + bs));
217
218 ctx->xor(ctx->prev, ctx->odds, bs);
219 ctx->xor(ctx->prev, key2, bs);
220 _crypto_xcbc_digest_setkey(parent, ctx);
221
222 crypto_cipher_encrypt_one(tfm, out, ctx->prev);
223 } else {
224 u8 key3[bs];
225 unsigned int rlen;
226 u8 *p = ctx->odds + ctx->len;
227 *p = 0x80;
228 p++;
229
230 rlen = bs - ctx->len -1;
231 if (rlen)
232 memset(p, 0, rlen);
233
234 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
235 return err;
236
237 crypto_cipher_encrypt_one(tfm, key3,
238 (u8 *)(ctx->consts + bs * 2));
239
240 ctx->xor(ctx->prev, ctx->odds, bs);
241 ctx->xor(ctx->prev, key3, bs);
242
243 _crypto_xcbc_digest_setkey(parent, ctx);
244
245 crypto_cipher_encrypt_one(tfm, out, ctx->prev);
246 }
247
248 return 0;
249}
250
251static int crypto_xcbc_digest(struct hash_desc *pdesc,
252 struct scatterlist *sg, unsigned int nbytes, u8 *out)
253{
254 if (WARN_ON_ONCE(in_irq()))
255 return -EDEADLK;
256
257 crypto_xcbc_digest_init(pdesc);
258 crypto_xcbc_digest_update2(pdesc, sg, nbytes);
259 return crypto_xcbc_digest_final(pdesc, out);
260}
261
262static int xcbc_init_tfm(struct crypto_tfm *tfm)
263{
264 struct crypto_cipher *cipher;
265 struct crypto_instance *inst = (void *)tfm->__crt_alg;
266 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
267 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
268 int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm));
269
270 cipher = crypto_spawn_cipher(spawn);
271 if (IS_ERR(cipher))
272 return PTR_ERR(cipher);
273
274 switch(bs) {
275 case 16:
276 ctx->xor = xor_128;
277 break;
278 default:
279 return -EINVAL;
280 }
281
282 ctx->child = cipher;
283 ctx->odds = (u8*)(ctx+1);
284 ctx->prev = ctx->odds + bs;
285 ctx->key = ctx->prev + bs;
286
287 return 0;
288};
289
290static void xcbc_exit_tfm(struct crypto_tfm *tfm)
291{
292 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
293 crypto_free_cipher(ctx->child);
294}
295
296static struct crypto_instance *xcbc_alloc(struct rtattr **tb)
297{
298 struct crypto_instance *inst;
299 struct crypto_alg *alg;
300 int err;
301
302 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH);
303 if (err)
304 return ERR_PTR(err);
305
306 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
307 CRYPTO_ALG_TYPE_MASK);
308 if (IS_ERR(alg))
309 return ERR_CAST(alg);
310
311 switch(alg->cra_blocksize) {
312 case 16:
313 break;
314 default:
315 inst = ERR_PTR(-EINVAL);
316 goto out_put_alg;
317 }
318
319 inst = crypto_alloc_instance("xcbc", alg);
320 if (IS_ERR(inst))
321 goto out_put_alg;
322
323 inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
324 inst->alg.cra_priority = alg->cra_priority;
325 inst->alg.cra_blocksize = alg->cra_blocksize;
326 inst->alg.cra_alignmask = alg->cra_alignmask;
327 inst->alg.cra_type = &crypto_hash_type;
328
329 inst->alg.cra_hash.digestsize = alg->cra_blocksize;
330 inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
331 ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *));
332 inst->alg.cra_init = xcbc_init_tfm;
333 inst->alg.cra_exit = xcbc_exit_tfm;
334
335 inst->alg.cra_hash.init = crypto_xcbc_digest_init;
336 inst->alg.cra_hash.update = crypto_xcbc_digest_update;
337 inst->alg.cra_hash.final = crypto_xcbc_digest_final;
338 inst->alg.cra_hash.digest = crypto_xcbc_digest;
339 inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey;
340
341out_put_alg:
342 crypto_mod_put(alg);
343 return inst;
344}
345
346static void xcbc_free(struct crypto_instance *inst)
347{
348 crypto_drop_spawn(crypto_instance_ctx(inst));
349 kfree(inst);
350}
351
352static struct crypto_template crypto_xcbc_tmpl = {
353 .name = "xcbc",
354 .alloc = xcbc_alloc,
355 .free = xcbc_free,
356 .module = THIS_MODULE,
357};
358
359static int __init crypto_xcbc_module_init(void)
360{
361 return crypto_register_template(&crypto_xcbc_tmpl);
362}
363
364static void __exit crypto_xcbc_module_exit(void)
365{
366 crypto_unregister_template(&crypto_xcbc_tmpl);
367}
368
369module_init(crypto_xcbc_module_init);
370module_exit(crypto_xcbc_module_exit);
371
372MODULE_LICENSE("GPL");
373MODULE_DESCRIPTION("XCBC keyed hash algorithm");
374
