xref: /linux/crypto/shash.c (revision 8b8eed05a1c650c27e78bc47d07f7d6c9ba779e8) 
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 static inline struct crypto_istat_hash *shash_get_stat(struct shash_alg *alg)
20 {
21 	return hash_get_stat(&alg->halg);
22 }
23 
24 static inline int crypto_shash_errstat(struct shash_alg *alg, int err)
25 {
26 	if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
27 		return err;
28 
29 	if (err && err != -EINPROGRESS && err != -EBUSY)
30 		atomic64_inc(&shash_get_stat(alg)->err_cnt);
31 
32 	return err;
33 }
34 
35 int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
36 		    unsigned int keylen)
37 {
38 	return -ENOSYS;
39 }
40 EXPORT_SYMBOL_GPL(shash_no_setkey);
41 
42 static void shash_set_needkey(struct crypto_shash *tfm, struct shash_alg *alg)
43 {
44 	if (crypto_shash_alg_needs_key(alg))
45 		crypto_shash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
46 }
47 
48 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
49 			unsigned int keylen)
50 {
51 	struct shash_alg *shash = crypto_shash_alg(tfm);
52 	int err;
53 
54 	err = shash->setkey(tfm, key, keylen);
55 	if (unlikely(err)) {
56 		shash_set_needkey(tfm, shash);
57 		return err;
58 	}
59 
60 	crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
61 	return 0;
62 }
63 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
64 
65 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
66 			unsigned int len)
67 {
68 	struct shash_alg *shash = crypto_shash_alg(desc->tfm);
69 	int err;
70 
71 	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
72 		atomic64_add(len, &shash_get_stat(shash)->hash_tlen);
73 
74 	err = shash->update(desc, data, len);
75 
76 	return crypto_shash_errstat(shash, err);
77 }
78 EXPORT_SYMBOL_GPL(crypto_shash_update);
79 
80 int crypto_shash_final(struct shash_desc *desc, u8 *out)
81 {
82 	struct shash_alg *shash = crypto_shash_alg(desc->tfm);
83 	int err;
84 
85 	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
86 		atomic64_inc(&shash_get_stat(shash)->hash_cnt);
87 
88 	err = shash->final(desc, out);
89 
90 	return crypto_shash_errstat(shash, err);
91 }
92 EXPORT_SYMBOL_GPL(crypto_shash_final);
93 
94 static int shash_default_finup(struct shash_desc *desc, const u8 *data,
95 			       unsigned int len, u8 *out)
96 {
97 	struct shash_alg *shash = crypto_shash_alg(desc->tfm);
98 
99 	return shash->update(desc, data, len) ?:
100 	       shash->final(desc, out);
101 }
102 
103 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
104 		       unsigned int len, u8 *out)
105 {
106 	struct crypto_shash *tfm = desc->tfm;
107 	struct shash_alg *shash = crypto_shash_alg(tfm);
108 	int err;
109 
110 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
111 		struct crypto_istat_hash *istat = shash_get_stat(shash);
112 
113 		atomic64_inc(&istat->hash_cnt);
114 		atomic64_add(len, &istat->hash_tlen);
115 	}
116 
117 	err = shash->finup(desc, data, len, out);
118 
119 	return crypto_shash_errstat(shash, err);
120 }
121 EXPORT_SYMBOL_GPL(crypto_shash_finup);
122 
123 static int shash_default_digest(struct shash_desc *desc, const u8 *data,
124 				unsigned int len, u8 *out)
125 {
126 	struct shash_alg *shash = crypto_shash_alg(desc->tfm);
127 
128 	return shash->init(desc) ?:
129 	       shash->finup(desc, data, len, out);
130 }
131 
132 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
133 			unsigned int len, u8 *out)
134 {
135 	struct crypto_shash *tfm = desc->tfm;
136 	struct shash_alg *shash = crypto_shash_alg(tfm);
137 	int err;
138 
139 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
140 		struct crypto_istat_hash *istat = shash_get_stat(shash);
141 
142 		atomic64_inc(&istat->hash_cnt);
143 		atomic64_add(len, &istat->hash_tlen);
144 	}
145 
146 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
147 		err = -ENOKEY;
148 	else
149 		err = shash->digest(desc, data, len, out);
150 
151 	return crypto_shash_errstat(shash, err);
152 }
153 EXPORT_SYMBOL_GPL(crypto_shash_digest);
154 
155 int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
156 			    unsigned int len, u8 *out)
157 {
158 	SHASH_DESC_ON_STACK(desc, tfm);
159 	int err;
160 
161 	desc->tfm = tfm;
162 
163 	err = crypto_shash_digest(desc, data, len, out);
164 
165 	shash_desc_zero(desc);
166 
167 	return err;
168 }
169 EXPORT_SYMBOL_GPL(crypto_shash_tfm_digest);
170 
171 int crypto_shash_export(struct shash_desc *desc, void *out)
172 {
173 	struct crypto_shash *tfm = desc->tfm;
174 	struct shash_alg *shash = crypto_shash_alg(tfm);
175 
176 	if (shash->export)
177 		return shash->export(desc, out);
178 
179 	memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(tfm));
180 	return 0;
181 }
182 EXPORT_SYMBOL_GPL(crypto_shash_export);
183 
184 int crypto_shash_import(struct shash_desc *desc, const void *in)
185 {
186 	struct crypto_shash *tfm = desc->tfm;
187 	struct shash_alg *shash = crypto_shash_alg(tfm);
188 
189 	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
190 		return -ENOKEY;
191 
192 	if (shash->import)
193 		return shash->import(desc, in);
194 
195 	memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));
196 	return 0;
197 }
198 EXPORT_SYMBOL_GPL(crypto_shash_import);
199 
200 static void crypto_shash_exit_tfm(struct crypto_tfm *tfm)
201 {
202 	struct crypto_shash *hash = __crypto_shash_cast(tfm);
203 	struct shash_alg *alg = crypto_shash_alg(hash);
204 
205 	alg->exit_tfm(hash);
206 }
207 
208 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
209 {
210 	struct crypto_shash *hash = __crypto_shash_cast(tfm);
211 	struct shash_alg *alg = crypto_shash_alg(hash);
212 	int err;
213 
214 	hash->descsize = alg->descsize;
215 
216 	shash_set_needkey(hash, alg);
217 
218 	if (alg->exit_tfm)
219 		tfm->exit = crypto_shash_exit_tfm;
220 
221 	if (!alg->init_tfm)
222 		return 0;
223 
224 	err = alg->init_tfm(hash);
225 	if (err)
226 		return err;
227 
228 	/* ->init_tfm() may have increased the descsize. */
229 	if (WARN_ON_ONCE(hash->descsize > HASH_MAX_DESCSIZE)) {
230 		if (alg->exit_tfm)
231 			alg->exit_tfm(hash);
232 		return -EINVAL;
233 	}
234 
235 	return 0;
236 }
237 
238 static void crypto_shash_free_instance(struct crypto_instance *inst)
239 {
240 	struct shash_instance *shash = shash_instance(inst);
241 
242 	shash->free(shash);
243 }
244 
245 static int __maybe_unused crypto_shash_report(
246 	struct sk_buff *skb, struct crypto_alg *alg)
247 {
248 	struct crypto_report_hash rhash;
249 	struct shash_alg *salg = __crypto_shash_alg(alg);
250 
251 	memset(&rhash, 0, sizeof(rhash));
252 
253 	strscpy(rhash.type, "shash", sizeof(rhash.type));
254 
255 	rhash.blocksize = alg->cra_blocksize;
256 	rhash.digestsize = salg->digestsize;
257 
258 	return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
259 }
260 
261 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
262 	__maybe_unused;
263 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
264 {
265 	struct shash_alg *salg = __crypto_shash_alg(alg);
266 
267 	seq_printf(m, "type         : shash\n");
268 	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
269 	seq_printf(m, "digestsize   : %u\n", salg->digestsize);
270 }
271 
272 static int __maybe_unused crypto_shash_report_stat(
273 	struct sk_buff *skb, struct crypto_alg *alg)
274 {
275 	return crypto_hash_report_stat(skb, alg, "shash");
276 }
277 
278 const struct crypto_type crypto_shash_type = {
279 	.extsize = crypto_alg_extsize,
280 	.init_tfm = crypto_shash_init_tfm,
281 	.free = crypto_shash_free_instance,
282 #ifdef CONFIG_PROC_FS
283 	.show = crypto_shash_show,
284 #endif
285 #if IS_ENABLED(CONFIG_CRYPTO_USER)
286 	.report = crypto_shash_report,
287 #endif
288 #ifdef CONFIG_CRYPTO_STATS
289 	.report_stat = crypto_shash_report_stat,
290 #endif
291 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
292 	.maskset = CRYPTO_ALG_TYPE_MASK,
293 	.type = CRYPTO_ALG_TYPE_SHASH,
294 	.tfmsize = offsetof(struct crypto_shash, base),
295 };
296 
297 int crypto_grab_shash(struct crypto_shash_spawn *spawn,
298 		      struct crypto_instance *inst,
299 		      const char *name, u32 type, u32 mask)
300 {
301 	spawn->base.frontend = &crypto_shash_type;
302 	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
303 }
304 EXPORT_SYMBOL_GPL(crypto_grab_shash);
305 
306 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
307 					u32 mask)
308 {
309 	return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
310 }
311 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
312 
313 int crypto_has_shash(const char *alg_name, u32 type, u32 mask)
314 {
315 	return crypto_type_has_alg(alg_name, &crypto_shash_type, type, mask);
316 }
317 EXPORT_SYMBOL_GPL(crypto_has_shash);
318 
319 struct crypto_shash *crypto_clone_shash(struct crypto_shash *hash)
320 {
321 	struct crypto_tfm *tfm = crypto_shash_tfm(hash);
322 	struct shash_alg *alg = crypto_shash_alg(hash);
323 	struct crypto_shash *nhash;
324 	int err;
325 
326 	if (!crypto_shash_alg_has_setkey(alg)) {
327 		tfm = crypto_tfm_get(tfm);
328 		if (IS_ERR(tfm))
329 			return ERR_CAST(tfm);
330 
331 		return hash;
332 	}
333 
334 	if (!alg->clone_tfm && (alg->init_tfm || alg->base.cra_init))
335 		return ERR_PTR(-ENOSYS);
336 
337 	nhash = crypto_clone_tfm(&crypto_shash_type, tfm);
338 	if (IS_ERR(nhash))
339 		return nhash;
340 
341 	nhash->descsize = hash->descsize;
342 
343 	if (alg->clone_tfm) {
344 		err = alg->clone_tfm(nhash, hash);
345 		if (err) {
346 			crypto_free_shash(nhash);
347 			return ERR_PTR(err);
348 		}
349 	}
350 
351 	return nhash;
352 }
353 EXPORT_SYMBOL_GPL(crypto_clone_shash);
354 
355 int hash_prepare_alg(struct hash_alg_common *alg)
356 {
357 	struct crypto_istat_hash *istat = hash_get_stat(alg);
358 	struct crypto_alg *base = &alg->base;
359 
360 	if (alg->digestsize > HASH_MAX_DIGESTSIZE)
361 		return -EINVAL;
362 
363 	/* alignmask is not useful for hashes, so it is not supported. */
364 	if (base->cra_alignmask)
365 		return -EINVAL;
366 
367 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
368 
369 	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
370 		memset(istat, 0, sizeof(*istat));
371 
372 	return 0;
373 }
374 
375 static int shash_prepare_alg(struct shash_alg *alg)
376 {
377 	struct crypto_alg *base = &alg->halg.base;
378 	int err;
379 
380 	if (alg->descsize > HASH_MAX_DESCSIZE)
381 		return -EINVAL;
382 
383 	if ((alg->export && !alg->import) || (alg->import && !alg->export))
384 		return -EINVAL;
385 
386 	err = hash_prepare_alg(&alg->halg);
387 	if (err)
388 		return err;
389 
390 	base->cra_type = &crypto_shash_type;
391 	base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
392 
393 	/*
394 	 * Handle missing optional functions.  For each one we can either
395 	 * install a default here, or we can leave the pointer as NULL and check
396 	 * the pointer for NULL in crypto_shash_*(), avoiding an indirect call
397 	 * when the default behavior is desired.  For ->finup and ->digest we
398 	 * install defaults, since for optimal performance algorithms should
399 	 * implement these anyway.  On the other hand, for ->import and
400 	 * ->export the common case and best performance comes from the simple
401 	 * memcpy of the shash_desc_ctx, so when those pointers are NULL we
402 	 * leave them NULL and provide the memcpy with no indirect call.
403 	 */
404 	if (!alg->finup)
405 		alg->finup = shash_default_finup;
406 	if (!alg->digest)
407 		alg->digest = shash_default_digest;
408 	if (!alg->export)
409 		alg->halg.statesize = alg->descsize;
410 	if (!alg->setkey)
411 		alg->setkey = shash_no_setkey;
412 
413 	return 0;
414 }
415 
416 int crypto_register_shash(struct shash_alg *alg)
417 {
418 	struct crypto_alg *base = &alg->base;
419 	int err;
420 
421 	err = shash_prepare_alg(alg);
422 	if (err)
423 		return err;
424 
425 	return crypto_register_alg(base);
426 }
427 EXPORT_SYMBOL_GPL(crypto_register_shash);
428 
429 void crypto_unregister_shash(struct shash_alg *alg)
430 {
431 	crypto_unregister_alg(&alg->base);
432 }
433 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
434 
435 int crypto_register_shashes(struct shash_alg *algs, int count)
436 {
437 	int i, ret;
438 
439 	for (i = 0; i < count; i++) {
440 		ret = crypto_register_shash(&algs[i]);
441 		if (ret)
442 			goto err;
443 	}
444 
445 	return 0;
446 
447 err:
448 	for (--i; i >= 0; --i)
449 		crypto_unregister_shash(&algs[i]);
450 
451 	return ret;
452 }
453 EXPORT_SYMBOL_GPL(crypto_register_shashes);
454 
455 void crypto_unregister_shashes(struct shash_alg *algs, int count)
456 {
457 	int i;
458 
459 	for (i = count - 1; i >= 0; --i)
460 		crypto_unregister_shash(&algs[i]);
461 }
462 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
463 
464 int shash_register_instance(struct crypto_template *tmpl,
465 			    struct shash_instance *inst)
466 {
467 	int err;
468 
469 	if (WARN_ON(!inst->free))
470 		return -EINVAL;
471 
472 	err = shash_prepare_alg(&inst->alg);
473 	if (err)
474 		return err;
475 
476 	return crypto_register_instance(tmpl, shash_crypto_instance(inst));
477 }
478 EXPORT_SYMBOL_GPL(shash_register_instance);
479 
480 void shash_free_singlespawn_instance(struct shash_instance *inst)
481 {
482 	crypto_drop_spawn(shash_instance_ctx(inst));
483 	kfree(inst);
484 }
485 EXPORT_SYMBOL_GPL(shash_free_singlespawn_instance);
486 
487 MODULE_LICENSE("GPL");
488 MODULE_DESCRIPTION("Synchronous cryptographic hash type");
489