1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Synchronous Cryptographic Hash operations.
4 *
5 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
6 */
7
8 #include <crypto/scatterwalk.h>
9 #include <linux/cryptouser.h>
10 #include <linux/err.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/seq_file.h>
14 #include <linux/string.h>
15 #include <net/netlink.h>
16
17 #include "hash.h"
18
19 int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
20 unsigned int keylen)
21 {
22 return -ENOSYS;
23 }
24 EXPORT_SYMBOL_GPL(shash_no_setkey);
25
26 static void shash_set_needkey(struct crypto_shash *tfm, struct shash_alg *alg)
27 {
28 if (crypto_shash_alg_needs_key(alg))
29 crypto_shash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
30 }
31
32 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
33 unsigned int keylen)
34 {
35 struct shash_alg *shash = crypto_shash_alg(tfm);
36 int err;
37
38 err = shash->setkey(tfm, key, keylen);
39 if (unlikely(err)) {
40 shash_set_needkey(tfm, shash);
41 return err;
42 }
43
44 crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
45 return 0;
46 }
47 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
48
49 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
50 unsigned int len)
51 {
52 return crypto_shash_alg(desc->tfm)->update(desc, data, len);
53 }
54 EXPORT_SYMBOL_GPL(crypto_shash_update);
55
56 int crypto_shash_final(struct shash_desc *desc, u8 *out)
57 {
58 return crypto_shash_alg(desc->tfm)->final(desc, out);
59 }
60 EXPORT_SYMBOL_GPL(crypto_shash_final);
61
62 static int shash_default_finup(struct shash_desc *desc, const u8 *data,
63 unsigned int len, u8 *out)
64 {
65 struct shash_alg *shash = crypto_shash_alg(desc->tfm);
66
67 return shash->update(desc, data, len) ?:
68 shash->final(desc, out);
69 }
70
71 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
72 unsigned int len, u8 *out)
73 {
74 return crypto_shash_alg(desc->tfm)->finup(desc, data, len, out);
75 }
76 EXPORT_SYMBOL_GPL(crypto_shash_finup);
77
78 static int shash_default_digest(struct shash_desc *desc, const u8 *data,
79 unsigned int len, u8 *out)
80 {
81 struct shash_alg *shash = crypto_shash_alg(desc->tfm);
82
83 return shash->init(desc) ?:
84 shash->finup(desc, data, len, out);
85 }
86
87 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
88 unsigned int len, u8 *out)
89 {
90 struct crypto_shash *tfm = desc->tfm;
91
92 if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
93 return -ENOKEY;
94
95 return crypto_shash_alg(tfm)->digest(desc, data, len, out);
96 }
97 EXPORT_SYMBOL_GPL(crypto_shash_digest);
98
99 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
100 unsigned int len, u8 *out)
101 {
102 SHASH_DESC_ON_STACK(desc, tfm);
103 int err;
104
105 desc->tfm = tfm;
106
107 err = crypto_shash_digest(desc, data, len, out);
108
109 shash_desc_zero(desc);
110
111 return err;
112 }
113 EXPORT_SYMBOL_GPL(crypto_shash_tfm_digest);
114
115 int crypto_shash_export(struct shash_desc *desc, void *out)
116 {
117 struct crypto_shash *tfm = desc->tfm;
118 struct shash_alg *shash = crypto_shash_alg(tfm);
119
120 if (shash->export)
121 return shash->export(desc, out);
122
123 memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(tfm));
124 return 0;
125 }
126 EXPORT_SYMBOL_GPL(crypto_shash_export);
127
128 int crypto_shash_import(struct shash_desc *desc, const void *in)
129 {
130 struct crypto_shash *tfm = desc->tfm;
131 struct shash_alg *shash = crypto_shash_alg(tfm);
132
133 if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
134 return -ENOKEY;
135
136 if (shash->import)
137 return shash->import(desc, in);
138
139 memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));
140 return 0;
141 }
142 EXPORT_SYMBOL_GPL(crypto_shash_import);
143
144 static void crypto_shash_exit_tfm(struct crypto_tfm *tfm)
145 {
146 struct crypto_shash *hash = __crypto_shash_cast(tfm);
147 struct shash_alg *alg = crypto_shash_alg(hash);
148
149 alg->exit_tfm(hash);
150 }
151
152 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
153 {
154 struct crypto_shash *hash = __crypto_shash_cast(tfm);
155 struct shash_alg *alg = crypto_shash_alg(hash);
156 int err;
157
158 hash->descsize = alg->descsize;
159
160 shash_set_needkey(hash, alg);
161
162 if (alg->exit_tfm)
163 tfm->exit = crypto_shash_exit_tfm;
164
165 if (!alg->init_tfm)
166 return 0;
167
168 err = alg->init_tfm(hash);
169 if (err)
170 return err;
171
172 /* ->init_tfm() may have increased the descsize. */
173 if (WARN_ON_ONCE(hash->descsize > HASH_MAX_DESCSIZE)) {
174 if (alg->exit_tfm)
175 alg->exit_tfm(hash);
176 return -EINVAL;
177 }
178
179 return 0;
180 }
181
182 static void crypto_shash_free_instance(struct crypto_instance *inst)
183 {
184 struct shash_instance *shash = shash_instance(inst);
185
186 shash->free(shash);
187 }
188
189 static int __maybe_unused crypto_shash_report(
190 struct sk_buff *skb, struct crypto_alg *alg)
191 {
192 struct crypto_report_hash rhash;
193 struct shash_alg *salg = __crypto_shash_alg(alg);
194
195 memset(&rhash, 0, sizeof(rhash));
196
197 strscpy(rhash.type, "shash", sizeof(rhash.type));
198
199 rhash.blocksize = alg->cra_blocksize;
200 rhash.digestsize = salg->digestsize;
201
202 return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
203 }
204
205 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
206 __maybe_unused;
207 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
208 {
209 struct shash_alg *salg = __crypto_shash_alg(alg);
210
211 seq_printf(m, "type : shash\n");
212 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
213 seq_printf(m, "digestsize : %u\n", salg->digestsize);
214 }
215
216 const struct crypto_type crypto_shash_type = {
217 .extsize = crypto_alg_extsize,
218 .init_tfm = crypto_shash_init_tfm,
219 .free = crypto_shash_free_instance,
220 #ifdef CONFIG_PROC_FS
221 .show = crypto_shash_show,
222 #endif
223 #if IS_ENABLED(CONFIG_CRYPTO_USER)
224 .report = crypto_shash_report,
225 #endif
226 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
227 .maskset = CRYPTO_ALG_TYPE_MASK,
228 .type = CRYPTO_ALG_TYPE_SHASH,
229 .tfmsize = offsetof(struct crypto_shash, base),
230 };
231
232 int crypto_grab_shash(struct crypto_shash_spawn *spawn,
233 struct crypto_instance *inst,
234 const char *name, u32 type, u32 mask)
235 {
236 spawn->base.frontend = &crypto_shash_type;
237 return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
238 }
239 EXPORT_SYMBOL_GPL(crypto_grab_shash);
240
241 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
242 u32 mask)
243 {
244 return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
245 }
246 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
247
248 int crypto_has_shash(const char *alg_name, u32 type, u32 mask)
249 {
250 return crypto_type_has_alg(alg_name, &crypto_shash_type, type, mask);
251 }
252 EXPORT_SYMBOL_GPL(crypto_has_shash);
253
254 struct crypto_shash *crypto_clone_shash(struct crypto_shash *hash)
255 {
256 struct crypto_tfm *tfm = crypto_shash_tfm(hash);
257 struct shash_alg *alg = crypto_shash_alg(hash);
258 struct crypto_shash *nhash;
259 int err;
260
261 if (!crypto_shash_alg_has_setkey(alg)) {
262 tfm = crypto_tfm_get(tfm);
263 if (IS_ERR(tfm))
264 return ERR_CAST(tfm);
265
266 return hash;
267 }
268
269 if (!alg->clone_tfm && (alg->init_tfm || alg->base.cra_init))
270 return ERR_PTR(-ENOSYS);
271
272 nhash = crypto_clone_tfm(&crypto_shash_type, tfm);
273 if (IS_ERR(nhash))
274 return nhash;
275
276 nhash->descsize = hash->descsize;
277
278 if (alg->clone_tfm) {
279 err = alg->clone_tfm(nhash, hash);
280 if (err) {
281 crypto_free_shash(nhash);
282 return ERR_PTR(err);
283 }
284 }
285
286 return nhash;
287 }
288 EXPORT_SYMBOL_GPL(crypto_clone_shash);
289
290 int hash_prepare_alg(struct hash_alg_common *alg)
291 {
292 struct crypto_alg *base = &alg->base;
293
294 if (alg->digestsize > HASH_MAX_DIGESTSIZE)
295 return -EINVAL;
296
297 /* alignmask is not useful for hashes, so it is not supported. */
298 if (base->cra_alignmask)
299 return -EINVAL;
300
301 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
302
303 return 0;
304 }
305
306 static int shash_prepare_alg(struct shash_alg *alg)
307 {
308 struct crypto_alg *base = &alg->halg.base;
309 int err;
310
311 if (alg->descsize > HASH_MAX_DESCSIZE)
312 return -EINVAL;
313
314 if ((alg->export && !alg->import) || (alg->import && !alg->export))
315 return -EINVAL;
316
317 err = hash_prepare_alg(&alg->halg);
318 if (err)
319 return err;
320
321 base->cra_type = &crypto_shash_type;
322 base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
323
324 /*
325 * Handle missing optional functions. For each one we can either
326 * install a default here, or we can leave the pointer as NULL and check
327 * the pointer for NULL in crypto_shash_*(), avoiding an indirect call
328 * when the default behavior is desired. For ->finup and ->digest we
329 * install defaults, since for optimal performance algorithms should
330 * implement these anyway. On the other hand, for ->import and
331 * ->export the common case and best performance comes from the simple
332 * memcpy of the shash_desc_ctx, so when those pointers are NULL we
333 * leave them NULL and provide the memcpy with no indirect call.
334 */
335 if (!alg->finup)
336 alg->finup = shash_default_finup;
337 if (!alg->digest)
338 alg->digest = shash_default_digest;
339 if (!alg->export)
340 alg->halg.statesize = alg->descsize;
341 if (!alg->setkey)
342 alg->setkey = shash_no_setkey;
343
344 return 0;
345 }
346
347 int crypto_register_shash(struct shash_alg *alg)
348 {
349 struct crypto_alg *base = &alg->base;
350 int err;
351
352 err = shash_prepare_alg(alg);
353 if (err)
354 return err;
355
356 return crypto_register_alg(base);
357 }
358 EXPORT_SYMBOL_GPL(crypto_register_shash);
359
360 void crypto_unregister_shash(struct shash_alg *alg)
361 {
362 crypto_unregister_alg(&alg->base);
363 }
364 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
365
366 int crypto_register_shashes(struct shash_alg *algs, int count)
367 {
368 int i, ret;
369
370 for (i = 0; i < count; i++) {
371 ret = crypto_register_shash(&algs[i]);
372 if (ret)
373 goto err;
374 }
375
376 return 0;
377
378 err:
379 for (--i; i >= 0; --i)
380 crypto_unregister_shash(&algs[i]);
381
382 return ret;
383 }
384 EXPORT_SYMBOL_GPL(crypto_register_shashes);
385
386 void crypto_unregister_shashes(struct shash_alg *algs, int count)
387 {
388 int i;
389
390 for (i = count - 1; i >= 0; --i)
391 crypto_unregister_shash(&algs[i]);
392 }
393 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
394
395 int shash_register_instance(struct crypto_template *tmpl,
396 struct shash_instance *inst)
397 {
398 int err;
399
400 if (WARN_ON(!inst->free))
401 return -EINVAL;
402
403 err = shash_prepare_alg(&inst->alg);
404 if (err)
405 return err;
406
407 return crypto_register_instance(tmpl, shash_crypto_instance(inst));
408 }
409 EXPORT_SYMBOL_GPL(shash_register_instance);
410
411 void shash_free_singlespawn_instance(struct shash_instance *inst)
412 {
413 crypto_drop_spawn(shash_instance_ctx(inst));
414 kfree(inst);
415 }
416 EXPORT_SYMBOL_GPL(shash_free_singlespawn_instance);
417
418 MODULE_LICENSE("GPL");
419 MODULE_DESCRIPTION("Synchronous cryptographic hash type");
420
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