xref: /openbmc/linux/crypto/shash.c (revision 0883c2c0)
1  /*
2   * Synchronous Cryptographic Hash operations.
3   *
4   * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
5   *
6   * This program is free software; you can redistribute it and/or modify it
7   * under the terms of the GNU General Public License as published by the Free
8   * Software Foundation; either version 2 of the License, or (at your option)
9   * any later version.
10   *
11   */
12  
13  #include <crypto/scatterwalk.h>
14  #include <crypto/internal/hash.h>
15  #include <linux/err.h>
16  #include <linux/kernel.h>
17  #include <linux/module.h>
18  #include <linux/slab.h>
19  #include <linux/seq_file.h>
20  #include <linux/cryptouser.h>
21  #include <net/netlink.h>
22  
23  #include "internal.h"
24  
25  static const struct crypto_type crypto_shash_type;
26  
27  static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
28  			   unsigned int keylen)
29  {
30  	return -ENOSYS;
31  }
32  
33  static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
34  				  unsigned int keylen)
35  {
36  	struct shash_alg *shash = crypto_shash_alg(tfm);
37  	unsigned long alignmask = crypto_shash_alignmask(tfm);
38  	unsigned long absize;
39  	u8 *buffer, *alignbuffer;
40  	int err;
41  
42  	absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
43  	buffer = kmalloc(absize, GFP_KERNEL);
44  	if (!buffer)
45  		return -ENOMEM;
46  
47  	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
48  	memcpy(alignbuffer, key, keylen);
49  	err = shash->setkey(tfm, alignbuffer, keylen);
50  	kzfree(buffer);
51  	return err;
52  }
53  
54  int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
55  			unsigned int keylen)
56  {
57  	struct shash_alg *shash = crypto_shash_alg(tfm);
58  	unsigned long alignmask = crypto_shash_alignmask(tfm);
59  
60  	if ((unsigned long)key & alignmask)
61  		return shash_setkey_unaligned(tfm, key, keylen);
62  
63  	return shash->setkey(tfm, key, keylen);
64  }
65  EXPORT_SYMBOL_GPL(crypto_shash_setkey);
66  
67  static inline unsigned int shash_align_buffer_size(unsigned len,
68  						   unsigned long mask)
69  {
70  	typedef u8 __attribute__ ((aligned)) u8_aligned;
71  	return len + (mask & ~(__alignof__(u8_aligned) - 1));
72  }
73  
74  static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
75  				  unsigned int len)
76  {
77  	struct crypto_shash *tfm = desc->tfm;
78  	struct shash_alg *shash = crypto_shash_alg(tfm);
79  	unsigned long alignmask = crypto_shash_alignmask(tfm);
80  	unsigned int unaligned_len = alignmask + 1 -
81  				     ((unsigned long)data & alignmask);
82  	u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
83  		__attribute__ ((aligned));
84  	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
85  	int err;
86  
87  	if (unaligned_len > len)
88  		unaligned_len = len;
89  
90  	memcpy(buf, data, unaligned_len);
91  	err = shash->update(desc, buf, unaligned_len);
92  	memset(buf, 0, unaligned_len);
93  
94  	return err ?:
95  	       shash->update(desc, data + unaligned_len, len - unaligned_len);
96  }
97  
98  int crypto_shash_update(struct shash_desc *desc, const u8 *data,
99  			unsigned int len)
100  {
101  	struct crypto_shash *tfm = desc->tfm;
102  	struct shash_alg *shash = crypto_shash_alg(tfm);
103  	unsigned long alignmask = crypto_shash_alignmask(tfm);
104  
105  	if ((unsigned long)data & alignmask)
106  		return shash_update_unaligned(desc, data, len);
107  
108  	return shash->update(desc, data, len);
109  }
110  EXPORT_SYMBOL_GPL(crypto_shash_update);
111  
112  static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
113  {
114  	struct crypto_shash *tfm = desc->tfm;
115  	unsigned long alignmask = crypto_shash_alignmask(tfm);
116  	struct shash_alg *shash = crypto_shash_alg(tfm);
117  	unsigned int ds = crypto_shash_digestsize(tfm);
118  	u8 ubuf[shash_align_buffer_size(ds, alignmask)]
119  		__attribute__ ((aligned));
120  	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
121  	int err;
122  
123  	err = shash->final(desc, buf);
124  	if (err)
125  		goto out;
126  
127  	memcpy(out, buf, ds);
128  
129  out:
130  	memset(buf, 0, ds);
131  	return err;
132  }
133  
134  int crypto_shash_final(struct shash_desc *desc, u8 *out)
135  {
136  	struct crypto_shash *tfm = desc->tfm;
137  	struct shash_alg *shash = crypto_shash_alg(tfm);
138  	unsigned long alignmask = crypto_shash_alignmask(tfm);
139  
140  	if ((unsigned long)out & alignmask)
141  		return shash_final_unaligned(desc, out);
142  
143  	return shash->final(desc, out);
144  }
145  EXPORT_SYMBOL_GPL(crypto_shash_final);
146  
147  static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
148  				 unsigned int len, u8 *out)
149  {
150  	return crypto_shash_update(desc, data, len) ?:
151  	       crypto_shash_final(desc, out);
152  }
153  
154  int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
155  		       unsigned int len, u8 *out)
156  {
157  	struct crypto_shash *tfm = desc->tfm;
158  	struct shash_alg *shash = crypto_shash_alg(tfm);
159  	unsigned long alignmask = crypto_shash_alignmask(tfm);
160  
161  	if (((unsigned long)data | (unsigned long)out) & alignmask)
162  		return shash_finup_unaligned(desc, data, len, out);
163  
164  	return shash->finup(desc, data, len, out);
165  }
166  EXPORT_SYMBOL_GPL(crypto_shash_finup);
167  
168  static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
169  				  unsigned int len, u8 *out)
170  {
171  	return crypto_shash_init(desc) ?:
172  	       crypto_shash_finup(desc, data, len, out);
173  }
174  
175  int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
176  			unsigned int len, u8 *out)
177  {
178  	struct crypto_shash *tfm = desc->tfm;
179  	struct shash_alg *shash = crypto_shash_alg(tfm);
180  	unsigned long alignmask = crypto_shash_alignmask(tfm);
181  
182  	if (((unsigned long)data | (unsigned long)out) & alignmask)
183  		return shash_digest_unaligned(desc, data, len, out);
184  
185  	return shash->digest(desc, data, len, out);
186  }
187  EXPORT_SYMBOL_GPL(crypto_shash_digest);
188  
189  static int shash_default_export(struct shash_desc *desc, void *out)
190  {
191  	memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
192  	return 0;
193  }
194  
195  static int shash_default_import(struct shash_desc *desc, const void *in)
196  {
197  	memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
198  	return 0;
199  }
200  
201  static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
202  			      unsigned int keylen)
203  {
204  	struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
205  
206  	return crypto_shash_setkey(*ctx, key, keylen);
207  }
208  
209  static int shash_async_init(struct ahash_request *req)
210  {
211  	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
212  	struct shash_desc *desc = ahash_request_ctx(req);
213  
214  	desc->tfm = *ctx;
215  	desc->flags = req->base.flags;
216  
217  	return crypto_shash_init(desc);
218  }
219  
220  int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
221  {
222  	struct crypto_hash_walk walk;
223  	int nbytes;
224  
225  	for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
226  	     nbytes = crypto_hash_walk_done(&walk, nbytes))
227  		nbytes = crypto_shash_update(desc, walk.data, nbytes);
228  
229  	return nbytes;
230  }
231  EXPORT_SYMBOL_GPL(shash_ahash_update);
232  
233  static int shash_async_update(struct ahash_request *req)
234  {
235  	return shash_ahash_update(req, ahash_request_ctx(req));
236  }
237  
238  static int shash_async_final(struct ahash_request *req)
239  {
240  	return crypto_shash_final(ahash_request_ctx(req), req->result);
241  }
242  
243  int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
244  {
245  	struct crypto_hash_walk walk;
246  	int nbytes;
247  
248  	nbytes = crypto_hash_walk_first(req, &walk);
249  	if (!nbytes)
250  		return crypto_shash_final(desc, req->result);
251  
252  	do {
253  		nbytes = crypto_hash_walk_last(&walk) ?
254  			 crypto_shash_finup(desc, walk.data, nbytes,
255  					    req->result) :
256  			 crypto_shash_update(desc, walk.data, nbytes);
257  		nbytes = crypto_hash_walk_done(&walk, nbytes);
258  	} while (nbytes > 0);
259  
260  	return nbytes;
261  }
262  EXPORT_SYMBOL_GPL(shash_ahash_finup);
263  
264  static int shash_async_finup(struct ahash_request *req)
265  {
266  	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
267  	struct shash_desc *desc = ahash_request_ctx(req);
268  
269  	desc->tfm = *ctx;
270  	desc->flags = req->base.flags;
271  
272  	return shash_ahash_finup(req, desc);
273  }
274  
275  int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
276  {
277  	struct scatterlist *sg = req->src;
278  	unsigned int offset = sg->offset;
279  	unsigned int nbytes = req->nbytes;
280  	int err;
281  
282  	if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
283  		void *data;
284  
285  		data = kmap_atomic(sg_page(sg));
286  		err = crypto_shash_digest(desc, data + offset, nbytes,
287  					  req->result);
288  		kunmap_atomic(data);
289  		crypto_yield(desc->flags);
290  	} else
291  		err = crypto_shash_init(desc) ?:
292  		      shash_ahash_finup(req, desc);
293  
294  	return err;
295  }
296  EXPORT_SYMBOL_GPL(shash_ahash_digest);
297  
298  static int shash_async_digest(struct ahash_request *req)
299  {
300  	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
301  	struct shash_desc *desc = ahash_request_ctx(req);
302  
303  	desc->tfm = *ctx;
304  	desc->flags = req->base.flags;
305  
306  	return shash_ahash_digest(req, desc);
307  }
308  
309  static int shash_async_export(struct ahash_request *req, void *out)
310  {
311  	return crypto_shash_export(ahash_request_ctx(req), out);
312  }
313  
314  static int shash_async_import(struct ahash_request *req, const void *in)
315  {
316  	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
317  	struct shash_desc *desc = ahash_request_ctx(req);
318  
319  	desc->tfm = *ctx;
320  	desc->flags = req->base.flags;
321  
322  	return crypto_shash_import(desc, in);
323  }
324  
325  static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
326  {
327  	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
328  
329  	crypto_free_shash(*ctx);
330  }
331  
332  int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
333  {
334  	struct crypto_alg *calg = tfm->__crt_alg;
335  	struct shash_alg *alg = __crypto_shash_alg(calg);
336  	struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
337  	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
338  	struct crypto_shash *shash;
339  
340  	if (!crypto_mod_get(calg))
341  		return -EAGAIN;
342  
343  	shash = crypto_create_tfm(calg, &crypto_shash_type);
344  	if (IS_ERR(shash)) {
345  		crypto_mod_put(calg);
346  		return PTR_ERR(shash);
347  	}
348  
349  	*ctx = shash;
350  	tfm->exit = crypto_exit_shash_ops_async;
351  
352  	crt->init = shash_async_init;
353  	crt->update = shash_async_update;
354  	crt->final = shash_async_final;
355  	crt->finup = shash_async_finup;
356  	crt->digest = shash_async_digest;
357  	crt->setkey = shash_async_setkey;
358  
359  	crt->has_setkey = alg->setkey != shash_no_setkey;
360  
361  	if (alg->export)
362  		crt->export = shash_async_export;
363  	if (alg->import)
364  		crt->import = shash_async_import;
365  
366  	crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
367  
368  	return 0;
369  }
370  
371  static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
372  {
373  	struct crypto_shash *hash = __crypto_shash_cast(tfm);
374  
375  	hash->descsize = crypto_shash_alg(hash)->descsize;
376  	return 0;
377  }
378  
379  #ifdef CONFIG_NET
380  static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
381  {
382  	struct crypto_report_hash rhash;
383  	struct shash_alg *salg = __crypto_shash_alg(alg);
384  
385  	strncpy(rhash.type, "shash", sizeof(rhash.type));
386  
387  	rhash.blocksize = alg->cra_blocksize;
388  	rhash.digestsize = salg->digestsize;
389  
390  	if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
391  		    sizeof(struct crypto_report_hash), &rhash))
392  		goto nla_put_failure;
393  	return 0;
394  
395  nla_put_failure:
396  	return -EMSGSIZE;
397  }
398  #else
399  static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
400  {
401  	return -ENOSYS;
402  }
403  #endif
404  
405  static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
406  	__attribute__ ((unused));
407  static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
408  {
409  	struct shash_alg *salg = __crypto_shash_alg(alg);
410  
411  	seq_printf(m, "type         : shash\n");
412  	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
413  	seq_printf(m, "digestsize   : %u\n", salg->digestsize);
414  }
415  
416  static const struct crypto_type crypto_shash_type = {
417  	.extsize = crypto_alg_extsize,
418  	.init_tfm = crypto_shash_init_tfm,
419  #ifdef CONFIG_PROC_FS
420  	.show = crypto_shash_show,
421  #endif
422  	.report = crypto_shash_report,
423  	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
424  	.maskset = CRYPTO_ALG_TYPE_MASK,
425  	.type = CRYPTO_ALG_TYPE_SHASH,
426  	.tfmsize = offsetof(struct crypto_shash, base),
427  };
428  
429  struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
430  					u32 mask)
431  {
432  	return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
433  }
434  EXPORT_SYMBOL_GPL(crypto_alloc_shash);
435  
436  static int shash_prepare_alg(struct shash_alg *alg)
437  {
438  	struct crypto_alg *base = &alg->base;
439  
440  	if (alg->digestsize > PAGE_SIZE / 8 ||
441  	    alg->descsize > PAGE_SIZE / 8 ||
442  	    alg->statesize > PAGE_SIZE / 8)
443  		return -EINVAL;
444  
445  	base->cra_type = &crypto_shash_type;
446  	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
447  	base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
448  
449  	if (!alg->finup)
450  		alg->finup = shash_finup_unaligned;
451  	if (!alg->digest)
452  		alg->digest = shash_digest_unaligned;
453  	if (!alg->export) {
454  		alg->export = shash_default_export;
455  		alg->import = shash_default_import;
456  		alg->statesize = alg->descsize;
457  	}
458  	if (!alg->setkey)
459  		alg->setkey = shash_no_setkey;
460  
461  	return 0;
462  }
463  
464  int crypto_register_shash(struct shash_alg *alg)
465  {
466  	struct crypto_alg *base = &alg->base;
467  	int err;
468  
469  	err = shash_prepare_alg(alg);
470  	if (err)
471  		return err;
472  
473  	return crypto_register_alg(base);
474  }
475  EXPORT_SYMBOL_GPL(crypto_register_shash);
476  
477  int crypto_unregister_shash(struct shash_alg *alg)
478  {
479  	return crypto_unregister_alg(&alg->base);
480  }
481  EXPORT_SYMBOL_GPL(crypto_unregister_shash);
482  
483  int crypto_register_shashes(struct shash_alg *algs, int count)
484  {
485  	int i, ret;
486  
487  	for (i = 0; i < count; i++) {
488  		ret = crypto_register_shash(&algs[i]);
489  		if (ret)
490  			goto err;
491  	}
492  
493  	return 0;
494  
495  err:
496  	for (--i; i >= 0; --i)
497  		crypto_unregister_shash(&algs[i]);
498  
499  	return ret;
500  }
501  EXPORT_SYMBOL_GPL(crypto_register_shashes);
502  
503  int crypto_unregister_shashes(struct shash_alg *algs, int count)
504  {
505  	int i, ret;
506  
507  	for (i = count - 1; i >= 0; --i) {
508  		ret = crypto_unregister_shash(&algs[i]);
509  		if (ret)
510  			pr_err("Failed to unregister %s %s: %d\n",
511  			       algs[i].base.cra_driver_name,
512  			       algs[i].base.cra_name, ret);
513  	}
514  
515  	return 0;
516  }
517  EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
518  
519  int shash_register_instance(struct crypto_template *tmpl,
520  			    struct shash_instance *inst)
521  {
522  	int err;
523  
524  	err = shash_prepare_alg(&inst->alg);
525  	if (err)
526  		return err;
527  
528  	return crypto_register_instance(tmpl, shash_crypto_instance(inst));
529  }
530  EXPORT_SYMBOL_GPL(shash_register_instance);
531  
532  void shash_free_instance(struct crypto_instance *inst)
533  {
534  	crypto_drop_spawn(crypto_instance_ctx(inst));
535  	kfree(shash_instance(inst));
536  }
537  EXPORT_SYMBOL_GPL(shash_free_instance);
538  
539  int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
540  			    struct shash_alg *alg,
541  			    struct crypto_instance *inst)
542  {
543  	return crypto_init_spawn2(&spawn->base, &alg->base, inst,
544  				  &crypto_shash_type);
545  }
546  EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
547  
548  struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
549  {
550  	struct crypto_alg *alg;
551  
552  	alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
553  	return IS_ERR(alg) ? ERR_CAST(alg) :
554  	       container_of(alg, struct shash_alg, base);
555  }
556  EXPORT_SYMBOL_GPL(shash_attr_alg);
557  
558  MODULE_LICENSE("GPL");
559  MODULE_DESCRIPTION("Synchronous cryptographic hash type");
560