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
19int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
20		    unsigned int keylen)
21{
22	return -ENOSYS;
23}
24EXPORT_SYMBOL_GPL(shash_no_setkey);
25
26static 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
32int 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}
47EXPORT_SYMBOL_GPL(crypto_shash_setkey);
48
49int 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}
54EXPORT_SYMBOL_GPL(crypto_shash_update);
55
56int crypto_shash_final(struct shash_desc *desc, u8 *out)
57{
58	return crypto_shash_alg(desc->tfm)->final(desc, out);
59}
60EXPORT_SYMBOL_GPL(crypto_shash_final);
61
62static 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
71int 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}
76EXPORT_SYMBOL_GPL(crypto_shash_finup);
77
78static 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
87int 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}
97EXPORT_SYMBOL_GPL(crypto_shash_digest);
98
99int 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}
113EXPORT_SYMBOL_GPL(crypto_shash_tfm_digest);
114
115int 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}
126EXPORT_SYMBOL_GPL(crypto_shash_export);
127
128int 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}
142EXPORT_SYMBOL_GPL(crypto_shash_import);
143
144static 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
152static 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
182static 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
189static 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
205static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
206	__maybe_unused;
207static 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
216const 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
232int 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}
239EXPORT_SYMBOL_GPL(crypto_grab_shash);
240
241struct 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}
246EXPORT_SYMBOL_GPL(crypto_alloc_shash);
247
248int 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}
252EXPORT_SYMBOL_GPL(crypto_has_shash);
253
254struct 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}
288EXPORT_SYMBOL_GPL(crypto_clone_shash);
289
290int 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
306static 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
347int 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}
358EXPORT_SYMBOL_GPL(crypto_register_shash);
359
360void crypto_unregister_shash(struct shash_alg *alg)
361{
362	crypto_unregister_alg(&alg->base);
363}
364EXPORT_SYMBOL_GPL(crypto_unregister_shash);
365
366int 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
378err:
379	for (--i; i >= 0; --i)
380		crypto_unregister_shash(&algs[i]);
381
382	return ret;
383}
384EXPORT_SYMBOL_GPL(crypto_register_shashes);
385
386void 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}
393EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
394
395int 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}
409EXPORT_SYMBOL_GPL(shash_register_instance);
410
411void shash_free_singlespawn_instance(struct shash_instance *inst)
412{
413	crypto_drop_spawn(shash_instance_ctx(inst));
414	kfree(inst);
415}
416EXPORT_SYMBOL_GPL(shash_free_singlespawn_instance);
417
418MODULE_LICENSE("GPL");
419MODULE_DESCRIPTION("Synchronous cryptographic hash type");
420