xref: /openbmc/linux/crypto/ccm.c (revision 285e74ab4f94d921a56fcf66320b3cd65e35b6bc)
1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /*
3   * CCM: Counter with CBC-MAC
4   *
5   * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
6   */
7  
8  #include <crypto/internal/aead.h>
9  #include <crypto/internal/hash.h>
10  #include <crypto/internal/skcipher.h>
11  #include <crypto/scatterwalk.h>
12  #include <linux/err.h>
13  #include <linux/init.h>
14  #include <linux/kernel.h>
15  #include <linux/module.h>
16  #include <linux/slab.h>
17  
18  struct ccm_instance_ctx {
19  	struct crypto_skcipher_spawn ctr;
20  	struct crypto_ahash_spawn mac;
21  };
22  
23  struct crypto_ccm_ctx {
24  	struct crypto_ahash *mac;
25  	struct crypto_skcipher *ctr;
26  };
27  
28  struct crypto_rfc4309_ctx {
29  	struct crypto_aead *child;
30  	u8 nonce[3];
31  };
32  
33  struct crypto_rfc4309_req_ctx {
34  	struct scatterlist src[3];
35  	struct scatterlist dst[3];
36  	struct aead_request subreq;
37  };
38  
39  struct crypto_ccm_req_priv_ctx {
40  	u8 odata[16];
41  	u8 idata[16];
42  	u8 auth_tag[16];
43  	u32 flags;
44  	struct scatterlist src[3];
45  	struct scatterlist dst[3];
46  	union {
47  		struct ahash_request ahreq;
48  		struct skcipher_request skreq;
49  	};
50  };
51  
52  struct cbcmac_tfm_ctx {
53  	struct crypto_cipher *child;
54  };
55  
56  struct cbcmac_desc_ctx {
57  	unsigned int len;
58  };
59  
60  static inline struct crypto_ccm_req_priv_ctx *crypto_ccm_reqctx(
61  	struct aead_request *req)
62  {
63  	unsigned long align = crypto_aead_alignmask(crypto_aead_reqtfm(req));
64  
65  	return (void *)PTR_ALIGN((u8 *)aead_request_ctx(req), align + 1);
66  }
67  
68  static int set_msg_len(u8 *block, unsigned int msglen, int csize)
69  {
70  	__be32 data;
71  
72  	memset(block, 0, csize);
73  	block += csize;
74  
75  	if (csize >= 4)
76  		csize = 4;
77  	else if (msglen > (1 << (8 * csize)))
78  		return -EOVERFLOW;
79  
80  	data = cpu_to_be32(msglen);
81  	memcpy(block - csize, (u8 *)&data + 4 - csize, csize);
82  
83  	return 0;
84  }
85  
86  static int crypto_ccm_setkey(struct crypto_aead *aead, const u8 *key,
87  			     unsigned int keylen)
88  {
89  	struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
90  	struct crypto_skcipher *ctr = ctx->ctr;
91  	struct crypto_ahash *mac = ctx->mac;
92  	int err;
93  
94  	crypto_skcipher_clear_flags(ctr, CRYPTO_TFM_REQ_MASK);
95  	crypto_skcipher_set_flags(ctr, crypto_aead_get_flags(aead) &
96  				       CRYPTO_TFM_REQ_MASK);
97  	err = crypto_skcipher_setkey(ctr, key, keylen);
98  	if (err)
99  		return err;
100  
101  	crypto_ahash_clear_flags(mac, CRYPTO_TFM_REQ_MASK);
102  	crypto_ahash_set_flags(mac, crypto_aead_get_flags(aead) &
103  				    CRYPTO_TFM_REQ_MASK);
104  	return crypto_ahash_setkey(mac, key, keylen);
105  }
106  
107  static int crypto_ccm_setauthsize(struct crypto_aead *tfm,
108  				  unsigned int authsize)
109  {
110  	switch (authsize) {
111  	case 4:
112  	case 6:
113  	case 8:
114  	case 10:
115  	case 12:
116  	case 14:
117  	case 16:
118  		break;
119  	default:
120  		return -EINVAL;
121  	}
122  
123  	return 0;
124  }
125  
126  static int format_input(u8 *info, struct aead_request *req,
127  			unsigned int cryptlen)
128  {
129  	struct crypto_aead *aead = crypto_aead_reqtfm(req);
130  	unsigned int lp = req->iv[0];
131  	unsigned int l = lp + 1;
132  	unsigned int m;
133  
134  	m = crypto_aead_authsize(aead);
135  
136  	memcpy(info, req->iv, 16);
137  
138  	/* format control info per RFC 3610 and
139  	 * NIST Special Publication 800-38C
140  	 */
141  	*info |= (8 * ((m - 2) / 2));
142  	if (req->assoclen)
143  		*info |= 64;
144  
145  	return set_msg_len(info + 16 - l, cryptlen, l);
146  }
147  
148  static int format_adata(u8 *adata, unsigned int a)
149  {
150  	int len = 0;
151  
152  	/* add control info for associated data
153  	 * RFC 3610 and NIST Special Publication 800-38C
154  	 */
155  	if (a < 65280) {
156  		*(__be16 *)adata = cpu_to_be16(a);
157  		len = 2;
158  	} else  {
159  		*(__be16 *)adata = cpu_to_be16(0xfffe);
160  		*(__be32 *)&adata[2] = cpu_to_be32(a);
161  		len = 6;
162  	}
163  
164  	return len;
165  }
166  
167  static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
168  			   unsigned int cryptlen)
169  {
170  	struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
171  	struct crypto_aead *aead = crypto_aead_reqtfm(req);
172  	struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
173  	struct ahash_request *ahreq = &pctx->ahreq;
174  	unsigned int assoclen = req->assoclen;
175  	struct scatterlist sg[3];
176  	u8 *odata = pctx->odata;
177  	u8 *idata = pctx->idata;
178  	int ilen, err;
179  
180  	/* format control data for input */
181  	err = format_input(odata, req, cryptlen);
182  	if (err)
183  		goto out;
184  
185  	sg_init_table(sg, 3);
186  	sg_set_buf(&sg[0], odata, 16);
187  
188  	/* format associated data and compute into mac */
189  	if (assoclen) {
190  		ilen = format_adata(idata, assoclen);
191  		sg_set_buf(&sg[1], idata, ilen);
192  		sg_chain(sg, 3, req->src);
193  	} else {
194  		ilen = 0;
195  		sg_chain(sg, 2, req->src);
196  	}
197  
198  	ahash_request_set_tfm(ahreq, ctx->mac);
199  	ahash_request_set_callback(ahreq, pctx->flags, NULL, NULL);
200  	ahash_request_set_crypt(ahreq, sg, NULL, assoclen + ilen + 16);
201  	err = crypto_ahash_init(ahreq);
202  	if (err)
203  		goto out;
204  	err = crypto_ahash_update(ahreq);
205  	if (err)
206  		goto out;
207  
208  	/* we need to pad the MAC input to a round multiple of the block size */
209  	ilen = 16 - (assoclen + ilen) % 16;
210  	if (ilen < 16) {
211  		memset(idata, 0, ilen);
212  		sg_init_table(sg, 2);
213  		sg_set_buf(&sg[0], idata, ilen);
214  		if (plain)
215  			sg_chain(sg, 2, plain);
216  		plain = sg;
217  		cryptlen += ilen;
218  	}
219  
220  	ahash_request_set_crypt(ahreq, plain, pctx->odata, cryptlen);
221  	err = crypto_ahash_finup(ahreq);
222  out:
223  	return err;
224  }
225  
226  static void crypto_ccm_encrypt_done(struct crypto_async_request *areq, int err)
227  {
228  	struct aead_request *req = areq->data;
229  	struct crypto_aead *aead = crypto_aead_reqtfm(req);
230  	struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
231  	u8 *odata = pctx->odata;
232  
233  	if (!err)
234  		scatterwalk_map_and_copy(odata, req->dst,
235  					 req->assoclen + req->cryptlen,
236  					 crypto_aead_authsize(aead), 1);
237  	aead_request_complete(req, err);
238  }
239  
240  static inline int crypto_ccm_check_iv(const u8 *iv)
241  {
242  	/* 2 <= L <= 8, so 1 <= L' <= 7. */
243  	if (1 > iv[0] || iv[0] > 7)
244  		return -EINVAL;
245  
246  	return 0;
247  }
248  
249  static int crypto_ccm_init_crypt(struct aead_request *req, u8 *tag)
250  {
251  	struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
252  	struct scatterlist *sg;
253  	u8 *iv = req->iv;
254  	int err;
255  
256  	err = crypto_ccm_check_iv(iv);
257  	if (err)
258  		return err;
259  
260  	pctx->flags = aead_request_flags(req);
261  
262  	 /* Note: rfc 3610 and NIST 800-38C require counter of
263  	 * zero to encrypt auth tag.
264  	 */
265  	memset(iv + 15 - iv[0], 0, iv[0] + 1);
266  
267  	sg_init_table(pctx->src, 3);
268  	sg_set_buf(pctx->src, tag, 16);
269  	sg = scatterwalk_ffwd(pctx->src + 1, req->src, req->assoclen);
270  	if (sg != pctx->src + 1)
271  		sg_chain(pctx->src, 2, sg);
272  
273  	if (req->src != req->dst) {
274  		sg_init_table(pctx->dst, 3);
275  		sg_set_buf(pctx->dst, tag, 16);
276  		sg = scatterwalk_ffwd(pctx->dst + 1, req->dst, req->assoclen);
277  		if (sg != pctx->dst + 1)
278  			sg_chain(pctx->dst, 2, sg);
279  	}
280  
281  	return 0;
282  }
283  
284  static int crypto_ccm_encrypt(struct aead_request *req)
285  {
286  	struct crypto_aead *aead = crypto_aead_reqtfm(req);
287  	struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
288  	struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
289  	struct skcipher_request *skreq = &pctx->skreq;
290  	struct scatterlist *dst;
291  	unsigned int cryptlen = req->cryptlen;
292  	u8 *odata = pctx->odata;
293  	u8 *iv = req->iv;
294  	int err;
295  
296  	err = crypto_ccm_init_crypt(req, odata);
297  	if (err)
298  		return err;
299  
300  	err = crypto_ccm_auth(req, sg_next(pctx->src), cryptlen);
301  	if (err)
302  		return err;
303  
304  	dst = pctx->src;
305  	if (req->src != req->dst)
306  		dst = pctx->dst;
307  
308  	skcipher_request_set_tfm(skreq, ctx->ctr);
309  	skcipher_request_set_callback(skreq, pctx->flags,
310  				      crypto_ccm_encrypt_done, req);
311  	skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
312  	err = crypto_skcipher_encrypt(skreq);
313  	if (err)
314  		return err;
315  
316  	/* copy authtag to end of dst */
317  	scatterwalk_map_and_copy(odata, sg_next(dst), cryptlen,
318  				 crypto_aead_authsize(aead), 1);
319  	return err;
320  }
321  
322  static void crypto_ccm_decrypt_done(struct crypto_async_request *areq,
323  				   int err)
324  {
325  	struct aead_request *req = areq->data;
326  	struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
327  	struct crypto_aead *aead = crypto_aead_reqtfm(req);
328  	unsigned int authsize = crypto_aead_authsize(aead);
329  	unsigned int cryptlen = req->cryptlen - authsize;
330  	struct scatterlist *dst;
331  
332  	pctx->flags = 0;
333  
334  	dst = sg_next(req->src == req->dst ? pctx->src : pctx->dst);
335  
336  	if (!err) {
337  		err = crypto_ccm_auth(req, dst, cryptlen);
338  		if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize))
339  			err = -EBADMSG;
340  	}
341  	aead_request_complete(req, err);
342  }
343  
344  static int crypto_ccm_decrypt(struct aead_request *req)
345  {
346  	struct crypto_aead *aead = crypto_aead_reqtfm(req);
347  	struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
348  	struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
349  	struct skcipher_request *skreq = &pctx->skreq;
350  	struct scatterlist *dst;
351  	unsigned int authsize = crypto_aead_authsize(aead);
352  	unsigned int cryptlen = req->cryptlen;
353  	u8 *authtag = pctx->auth_tag;
354  	u8 *odata = pctx->odata;
355  	u8 *iv = pctx->idata;
356  	int err;
357  
358  	cryptlen -= authsize;
359  
360  	err = crypto_ccm_init_crypt(req, authtag);
361  	if (err)
362  		return err;
363  
364  	scatterwalk_map_and_copy(authtag, sg_next(pctx->src), cryptlen,
365  				 authsize, 0);
366  
367  	dst = pctx->src;
368  	if (req->src != req->dst)
369  		dst = pctx->dst;
370  
371  	memcpy(iv, req->iv, 16);
372  
373  	skcipher_request_set_tfm(skreq, ctx->ctr);
374  	skcipher_request_set_callback(skreq, pctx->flags,
375  				      crypto_ccm_decrypt_done, req);
376  	skcipher_request_set_crypt(skreq, pctx->src, dst, cryptlen + 16, iv);
377  	err = crypto_skcipher_decrypt(skreq);
378  	if (err)
379  		return err;
380  
381  	err = crypto_ccm_auth(req, sg_next(dst), cryptlen);
382  	if (err)
383  		return err;
384  
385  	/* verify */
386  	if (crypto_memneq(authtag, odata, authsize))
387  		return -EBADMSG;
388  
389  	return err;
390  }
391  
392  static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
393  {
394  	struct aead_instance *inst = aead_alg_instance(tfm);
395  	struct ccm_instance_ctx *ictx = aead_instance_ctx(inst);
396  	struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
397  	struct crypto_ahash *mac;
398  	struct crypto_skcipher *ctr;
399  	unsigned long align;
400  	int err;
401  
402  	mac = crypto_spawn_ahash(&ictx->mac);
403  	if (IS_ERR(mac))
404  		return PTR_ERR(mac);
405  
406  	ctr = crypto_spawn_skcipher(&ictx->ctr);
407  	err = PTR_ERR(ctr);
408  	if (IS_ERR(ctr))
409  		goto err_free_mac;
410  
411  	ctx->mac = mac;
412  	ctx->ctr = ctr;
413  
414  	align = crypto_aead_alignmask(tfm);
415  	align &= ~(crypto_tfm_ctx_alignment() - 1);
416  	crypto_aead_set_reqsize(
417  		tfm,
418  		align + sizeof(struct crypto_ccm_req_priv_ctx) +
419  		max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));
420  
421  	return 0;
422  
423  err_free_mac:
424  	crypto_free_ahash(mac);
425  	return err;
426  }
427  
428  static void crypto_ccm_exit_tfm(struct crypto_aead *tfm)
429  {
430  	struct crypto_ccm_ctx *ctx = crypto_aead_ctx(tfm);
431  
432  	crypto_free_ahash(ctx->mac);
433  	crypto_free_skcipher(ctx->ctr);
434  }
435  
436  static void crypto_ccm_free(struct aead_instance *inst)
437  {
438  	struct ccm_instance_ctx *ctx = aead_instance_ctx(inst);
439  
440  	crypto_drop_ahash(&ctx->mac);
441  	crypto_drop_skcipher(&ctx->ctr);
442  	kfree(inst);
443  }
444  
445  static int crypto_ccm_create_common(struct crypto_template *tmpl,
446  				    struct rtattr **tb,
447  				    const char *ctr_name,
448  				    const char *mac_name)
449  {
450  	struct crypto_attr_type *algt;
451  	u32 mask;
452  	struct aead_instance *inst;
453  	struct ccm_instance_ctx *ictx;
454  	struct skcipher_alg *ctr;
455  	struct hash_alg_common *mac;
456  	int err;
457  
458  	algt = crypto_get_attr_type(tb);
459  	if (IS_ERR(algt))
460  		return PTR_ERR(algt);
461  
462  	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
463  		return -EINVAL;
464  
465  	mask = crypto_requires_sync(algt->type, algt->mask);
466  
467  	inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
468  	if (!inst)
469  		return -ENOMEM;
470  	ictx = aead_instance_ctx(inst);
471  
472  	err = crypto_grab_ahash(&ictx->mac, aead_crypto_instance(inst),
473  				mac_name, 0, CRYPTO_ALG_ASYNC);
474  	if (err)
475  		goto err_free_inst;
476  	mac = crypto_spawn_ahash_alg(&ictx->mac);
477  
478  	err = -EINVAL;
479  	if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
480  	    mac->digestsize != 16)
481  		goto err_free_inst;
482  
483  	err = crypto_grab_skcipher(&ictx->ctr, aead_crypto_instance(inst),
484  				   ctr_name, 0, mask);
485  	if (err)
486  		goto err_free_inst;
487  	ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
488  
489  	/* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
490  	err = -EINVAL;
491  	if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
492  	    crypto_skcipher_alg_ivsize(ctr) != 16 ||
493  	    ctr->base.cra_blocksize != 1)
494  		goto err_free_inst;
495  
496  	/* ctr and cbcmac must use the same underlying block cipher. */
497  	if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
498  		goto err_free_inst;
499  
500  	err = -ENAMETOOLONG;
501  	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
502  		     "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
503  		goto err_free_inst;
504  
505  	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
506  		     "ccm_base(%s,%s)", ctr->base.cra_driver_name,
507  		     mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
508  		goto err_free_inst;
509  
510  	inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
511  	inst->alg.base.cra_priority = (mac->base.cra_priority +
512  				       ctr->base.cra_priority) / 2;
513  	inst->alg.base.cra_blocksize = 1;
514  	inst->alg.base.cra_alignmask = mac->base.cra_alignmask |
515  				       ctr->base.cra_alignmask;
516  	inst->alg.ivsize = 16;
517  	inst->alg.chunksize = crypto_skcipher_alg_chunksize(ctr);
518  	inst->alg.maxauthsize = 16;
519  	inst->alg.base.cra_ctxsize = sizeof(struct crypto_ccm_ctx);
520  	inst->alg.init = crypto_ccm_init_tfm;
521  	inst->alg.exit = crypto_ccm_exit_tfm;
522  	inst->alg.setkey = crypto_ccm_setkey;
523  	inst->alg.setauthsize = crypto_ccm_setauthsize;
524  	inst->alg.encrypt = crypto_ccm_encrypt;
525  	inst->alg.decrypt = crypto_ccm_decrypt;
526  
527  	inst->free = crypto_ccm_free;
528  
529  	err = aead_register_instance(tmpl, inst);
530  	if (err) {
531  err_free_inst:
532  		crypto_ccm_free(inst);
533  	}
534  	return err;
535  }
536  
537  static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)
538  {
539  	const char *cipher_name;
540  	char ctr_name[CRYPTO_MAX_ALG_NAME];
541  	char mac_name[CRYPTO_MAX_ALG_NAME];
542  
543  	cipher_name = crypto_attr_alg_name(tb[1]);
544  	if (IS_ERR(cipher_name))
545  		return PTR_ERR(cipher_name);
546  
547  	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
548  		     cipher_name) >= CRYPTO_MAX_ALG_NAME)
549  		return -ENAMETOOLONG;
550  
551  	if (snprintf(mac_name, CRYPTO_MAX_ALG_NAME, "cbcmac(%s)",
552  		     cipher_name) >= CRYPTO_MAX_ALG_NAME)
553  		return -ENAMETOOLONG;
554  
555  	return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
556  }
557  
558  static int crypto_ccm_base_create(struct crypto_template *tmpl,
559  				  struct rtattr **tb)
560  {
561  	const char *ctr_name;
562  	const char *mac_name;
563  
564  	ctr_name = crypto_attr_alg_name(tb[1]);
565  	if (IS_ERR(ctr_name))
566  		return PTR_ERR(ctr_name);
567  
568  	mac_name = crypto_attr_alg_name(tb[2]);
569  	if (IS_ERR(mac_name))
570  		return PTR_ERR(mac_name);
571  
572  	return crypto_ccm_create_common(tmpl, tb, ctr_name, mac_name);
573  }
574  
575  static int crypto_rfc4309_setkey(struct crypto_aead *parent, const u8 *key,
576  				 unsigned int keylen)
577  {
578  	struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
579  	struct crypto_aead *child = ctx->child;
580  
581  	if (keylen < 3)
582  		return -EINVAL;
583  
584  	keylen -= 3;
585  	memcpy(ctx->nonce, key + keylen, 3);
586  
587  	crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
588  	crypto_aead_set_flags(child, crypto_aead_get_flags(parent) &
589  				     CRYPTO_TFM_REQ_MASK);
590  	return crypto_aead_setkey(child, key, keylen);
591  }
592  
593  static int crypto_rfc4309_setauthsize(struct crypto_aead *parent,
594  				      unsigned int authsize)
595  {
596  	struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(parent);
597  
598  	switch (authsize) {
599  	case 8:
600  	case 12:
601  	case 16:
602  		break;
603  	default:
604  		return -EINVAL;
605  	}
606  
607  	return crypto_aead_setauthsize(ctx->child, authsize);
608  }
609  
610  static struct aead_request *crypto_rfc4309_crypt(struct aead_request *req)
611  {
612  	struct crypto_rfc4309_req_ctx *rctx = aead_request_ctx(req);
613  	struct aead_request *subreq = &rctx->subreq;
614  	struct crypto_aead *aead = crypto_aead_reqtfm(req);
615  	struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(aead);
616  	struct crypto_aead *child = ctx->child;
617  	struct scatterlist *sg;
618  	u8 *iv = PTR_ALIGN((u8 *)(subreq + 1) + crypto_aead_reqsize(child),
619  			   crypto_aead_alignmask(child) + 1);
620  
621  	/* L' */
622  	iv[0] = 3;
623  
624  	memcpy(iv + 1, ctx->nonce, 3);
625  	memcpy(iv + 4, req->iv, 8);
626  
627  	scatterwalk_map_and_copy(iv + 16, req->src, 0, req->assoclen - 8, 0);
628  
629  	sg_init_table(rctx->src, 3);
630  	sg_set_buf(rctx->src, iv + 16, req->assoclen - 8);
631  	sg = scatterwalk_ffwd(rctx->src + 1, req->src, req->assoclen);
632  	if (sg != rctx->src + 1)
633  		sg_chain(rctx->src, 2, sg);
634  
635  	if (req->src != req->dst) {
636  		sg_init_table(rctx->dst, 3);
637  		sg_set_buf(rctx->dst, iv + 16, req->assoclen - 8);
638  		sg = scatterwalk_ffwd(rctx->dst + 1, req->dst, req->assoclen);
639  		if (sg != rctx->dst + 1)
640  			sg_chain(rctx->dst, 2, sg);
641  	}
642  
643  	aead_request_set_tfm(subreq, child);
644  	aead_request_set_callback(subreq, req->base.flags, req->base.complete,
645  				  req->base.data);
646  	aead_request_set_crypt(subreq, rctx->src,
647  			       req->src == req->dst ? rctx->src : rctx->dst,
648  			       req->cryptlen, iv);
649  	aead_request_set_ad(subreq, req->assoclen - 8);
650  
651  	return subreq;
652  }
653  
654  static int crypto_rfc4309_encrypt(struct aead_request *req)
655  {
656  	if (req->assoclen != 16 && req->assoclen != 20)
657  		return -EINVAL;
658  
659  	req = crypto_rfc4309_crypt(req);
660  
661  	return crypto_aead_encrypt(req);
662  }
663  
664  static int crypto_rfc4309_decrypt(struct aead_request *req)
665  {
666  	if (req->assoclen != 16 && req->assoclen != 20)
667  		return -EINVAL;
668  
669  	req = crypto_rfc4309_crypt(req);
670  
671  	return crypto_aead_decrypt(req);
672  }
673  
674  static int crypto_rfc4309_init_tfm(struct crypto_aead *tfm)
675  {
676  	struct aead_instance *inst = aead_alg_instance(tfm);
677  	struct crypto_aead_spawn *spawn = aead_instance_ctx(inst);
678  	struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
679  	struct crypto_aead *aead;
680  	unsigned long align;
681  
682  	aead = crypto_spawn_aead(spawn);
683  	if (IS_ERR(aead))
684  		return PTR_ERR(aead);
685  
686  	ctx->child = aead;
687  
688  	align = crypto_aead_alignmask(aead);
689  	align &= ~(crypto_tfm_ctx_alignment() - 1);
690  	crypto_aead_set_reqsize(
691  		tfm,
692  		sizeof(struct crypto_rfc4309_req_ctx) +
693  		ALIGN(crypto_aead_reqsize(aead), crypto_tfm_ctx_alignment()) +
694  		align + 32);
695  
696  	return 0;
697  }
698  
699  static void crypto_rfc4309_exit_tfm(struct crypto_aead *tfm)
700  {
701  	struct crypto_rfc4309_ctx *ctx = crypto_aead_ctx(tfm);
702  
703  	crypto_free_aead(ctx->child);
704  }
705  
706  static void crypto_rfc4309_free(struct aead_instance *inst)
707  {
708  	crypto_drop_aead(aead_instance_ctx(inst));
709  	kfree(inst);
710  }
711  
712  static int crypto_rfc4309_create(struct crypto_template *tmpl,
713  				 struct rtattr **tb)
714  {
715  	struct crypto_attr_type *algt;
716  	u32 mask;
717  	struct aead_instance *inst;
718  	struct crypto_aead_spawn *spawn;
719  	struct aead_alg *alg;
720  	int err;
721  
722  	algt = crypto_get_attr_type(tb);
723  	if (IS_ERR(algt))
724  		return PTR_ERR(algt);
725  
726  	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
727  		return -EINVAL;
728  
729  	mask = crypto_requires_sync(algt->type, algt->mask);
730  
731  	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
732  	if (!inst)
733  		return -ENOMEM;
734  
735  	spawn = aead_instance_ctx(inst);
736  	err = crypto_grab_aead(spawn, aead_crypto_instance(inst),
737  			       crypto_attr_alg_name(tb[1]), 0, mask);
738  	if (err)
739  		goto err_free_inst;
740  
741  	alg = crypto_spawn_aead_alg(spawn);
742  
743  	err = -EINVAL;
744  
745  	/* We only support 16-byte blocks. */
746  	if (crypto_aead_alg_ivsize(alg) != 16)
747  		goto err_free_inst;
748  
749  	/* Not a stream cipher? */
750  	if (alg->base.cra_blocksize != 1)
751  		goto err_free_inst;
752  
753  	err = -ENAMETOOLONG;
754  	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
755  		     "rfc4309(%s)", alg->base.cra_name) >=
756  	    CRYPTO_MAX_ALG_NAME ||
757  	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
758  		     "rfc4309(%s)", alg->base.cra_driver_name) >=
759  	    CRYPTO_MAX_ALG_NAME)
760  		goto err_free_inst;
761  
762  	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
763  	inst->alg.base.cra_priority = alg->base.cra_priority;
764  	inst->alg.base.cra_blocksize = 1;
765  	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
766  
767  	inst->alg.ivsize = 8;
768  	inst->alg.chunksize = crypto_aead_alg_chunksize(alg);
769  	inst->alg.maxauthsize = 16;
770  
771  	inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc4309_ctx);
772  
773  	inst->alg.init = crypto_rfc4309_init_tfm;
774  	inst->alg.exit = crypto_rfc4309_exit_tfm;
775  
776  	inst->alg.setkey = crypto_rfc4309_setkey;
777  	inst->alg.setauthsize = crypto_rfc4309_setauthsize;
778  	inst->alg.encrypt = crypto_rfc4309_encrypt;
779  	inst->alg.decrypt = crypto_rfc4309_decrypt;
780  
781  	inst->free = crypto_rfc4309_free;
782  
783  	err = aead_register_instance(tmpl, inst);
784  	if (err) {
785  err_free_inst:
786  		crypto_rfc4309_free(inst);
787  	}
788  	return err;
789  }
790  
791  static int crypto_cbcmac_digest_setkey(struct crypto_shash *parent,
792  				     const u8 *inkey, unsigned int keylen)
793  {
794  	struct cbcmac_tfm_ctx *ctx = crypto_shash_ctx(parent);
795  
796  	return crypto_cipher_setkey(ctx->child, inkey, keylen);
797  }
798  
799  static int crypto_cbcmac_digest_init(struct shash_desc *pdesc)
800  {
801  	struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
802  	int bs = crypto_shash_digestsize(pdesc->tfm);
803  	u8 *dg = (u8 *)ctx + crypto_shash_descsize(pdesc->tfm) - bs;
804  
805  	ctx->len = 0;
806  	memset(dg, 0, bs);
807  
808  	return 0;
809  }
810  
811  static int crypto_cbcmac_digest_update(struct shash_desc *pdesc, const u8 *p,
812  				       unsigned int len)
813  {
814  	struct crypto_shash *parent = pdesc->tfm;
815  	struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
816  	struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
817  	struct crypto_cipher *tfm = tctx->child;
818  	int bs = crypto_shash_digestsize(parent);
819  	u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
820  
821  	while (len > 0) {
822  		unsigned int l = min(len, bs - ctx->len);
823  
824  		crypto_xor(dg + ctx->len, p, l);
825  		ctx->len +=l;
826  		len -= l;
827  		p += l;
828  
829  		if (ctx->len == bs) {
830  			crypto_cipher_encrypt_one(tfm, dg, dg);
831  			ctx->len = 0;
832  		}
833  	}
834  
835  	return 0;
836  }
837  
838  static int crypto_cbcmac_digest_final(struct shash_desc *pdesc, u8 *out)
839  {
840  	struct crypto_shash *parent = pdesc->tfm;
841  	struct cbcmac_tfm_ctx *tctx = crypto_shash_ctx(parent);
842  	struct cbcmac_desc_ctx *ctx = shash_desc_ctx(pdesc);
843  	struct crypto_cipher *tfm = tctx->child;
844  	int bs = crypto_shash_digestsize(parent);
845  	u8 *dg = (u8 *)ctx + crypto_shash_descsize(parent) - bs;
846  
847  	if (ctx->len)
848  		crypto_cipher_encrypt_one(tfm, dg, dg);
849  
850  	memcpy(out, dg, bs);
851  	return 0;
852  }
853  
854  static int cbcmac_init_tfm(struct crypto_tfm *tfm)
855  {
856  	struct crypto_cipher *cipher;
857  	struct crypto_instance *inst = (void *)tfm->__crt_alg;
858  	struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst);
859  	struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
860  
861  	cipher = crypto_spawn_cipher(spawn);
862  	if (IS_ERR(cipher))
863  		return PTR_ERR(cipher);
864  
865  	ctx->child = cipher;
866  
867  	return 0;
868  };
869  
870  static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
871  {
872  	struct cbcmac_tfm_ctx *ctx = crypto_tfm_ctx(tfm);
873  	crypto_free_cipher(ctx->child);
874  }
875  
876  static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
877  {
878  	struct shash_instance *inst;
879  	struct crypto_cipher_spawn *spawn;
880  	struct crypto_alg *alg;
881  	int err;
882  
883  	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
884  	if (err)
885  		return err;
886  
887  	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
888  	if (!inst)
889  		return -ENOMEM;
890  	spawn = shash_instance_ctx(inst);
891  
892  	err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
893  				 crypto_attr_alg_name(tb[1]), 0, 0);
894  	if (err)
895  		goto err_free_inst;
896  	alg = crypto_spawn_cipher_alg(spawn);
897  
898  	err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
899  	if (err)
900  		goto err_free_inst;
901  
902  	inst->alg.base.cra_priority = alg->cra_priority;
903  	inst->alg.base.cra_blocksize = 1;
904  
905  	inst->alg.digestsize = alg->cra_blocksize;
906  	inst->alg.descsize = ALIGN(sizeof(struct cbcmac_desc_ctx),
907  				   alg->cra_alignmask + 1) +
908  			     alg->cra_blocksize;
909  
910  	inst->alg.base.cra_ctxsize = sizeof(struct cbcmac_tfm_ctx);
911  	inst->alg.base.cra_init = cbcmac_init_tfm;
912  	inst->alg.base.cra_exit = cbcmac_exit_tfm;
913  
914  	inst->alg.init = crypto_cbcmac_digest_init;
915  	inst->alg.update = crypto_cbcmac_digest_update;
916  	inst->alg.final = crypto_cbcmac_digest_final;
917  	inst->alg.setkey = crypto_cbcmac_digest_setkey;
918  
919  	inst->free = shash_free_singlespawn_instance;
920  
921  	err = shash_register_instance(tmpl, inst);
922  	if (err) {
923  err_free_inst:
924  		shash_free_singlespawn_instance(inst);
925  	}
926  	return err;
927  }
928  
929  static struct crypto_template crypto_ccm_tmpls[] = {
930  	{
931  		.name = "cbcmac",
932  		.create = cbcmac_create,
933  		.module = THIS_MODULE,
934  	}, {
935  		.name = "ccm_base",
936  		.create = crypto_ccm_base_create,
937  		.module = THIS_MODULE,
938  	}, {
939  		.name = "ccm",
940  		.create = crypto_ccm_create,
941  		.module = THIS_MODULE,
942  	}, {
943  		.name = "rfc4309",
944  		.create = crypto_rfc4309_create,
945  		.module = THIS_MODULE,
946  	},
947  };
948  
949  static int __init crypto_ccm_module_init(void)
950  {
951  	return crypto_register_templates(crypto_ccm_tmpls,
952  					 ARRAY_SIZE(crypto_ccm_tmpls));
953  }
954  
955  static void __exit crypto_ccm_module_exit(void)
956  {
957  	crypto_unregister_templates(crypto_ccm_tmpls,
958  				    ARRAY_SIZE(crypto_ccm_tmpls));
959  }
960  
961  subsys_initcall(crypto_ccm_module_init);
962  module_exit(crypto_ccm_module_exit);
963  
964  MODULE_LICENSE("GPL");
965  MODULE_DESCRIPTION("Counter with CBC MAC");
966  MODULE_ALIAS_CRYPTO("ccm_base");
967  MODULE_ALIAS_CRYPTO("rfc4309");
968  MODULE_ALIAS_CRYPTO("ccm");
969  MODULE_ALIAS_CRYPTO("cbcmac");
970