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  1/*
  2 * Asynchronous block chaining cipher operations.
  3 *
  4 * This is the asynchronous version of blkcipher.c indicating completion
  5 * via a callback.
  6 *
  7 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
  8 *
  9 * This program is free software; you can redistribute it and/or modify it
 10 * under the terms of the GNU General Public License as published by the Free
 11 * Software Foundation; either version 2 of the License, or (at your option)
 12 * any later version.
 13 *
 14 */
 15
 16#include <crypto/internal/skcipher.h>
 17#include <linux/err.h>
 18#include <linux/kernel.h>
 19#include <linux/slab.h>
 20#include <linux/seq_file.h>
 21#include <linux/cryptouser.h>
 22#include <net/netlink.h>
 23
 24#include <crypto/scatterwalk.h>
 25
 26#include "internal.h"
 27
 28struct ablkcipher_buffer {
 29	struct list_head	entry;
 30	struct scatter_walk	dst;
 31	unsigned int		len;
 32	void			*data;
 33};
 34
 35enum {
 36	ABLKCIPHER_WALK_SLOW = 1 << 0,
 37};
 38
 39static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
 40{
 41	scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
 42}
 43
 44void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
 45{
 46	struct ablkcipher_buffer *p, *tmp;
 47
 48	list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
 49		ablkcipher_buffer_write(p);
 50		list_del(&p->entry);
 51		kfree(p);
 52	}
 53}
 54EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
 55
 56static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
 57					  struct ablkcipher_buffer *p)
 58{
 59	p->dst = walk->out;
 60	list_add_tail(&p->entry, &walk->buffers);
 61}
 62
 63/* Get a spot of the specified length that does not straddle a page.
 64 * The caller needs to ensure that there is enough space for this operation.
 65 */
 66static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
 67{
 68	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
 69
 70	return max(start, end_page);
 71}
 72
 73static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
 74						unsigned int bsize)
 75{
 76	unsigned int n = bsize;
 77
 78	for (;;) {
 79		unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
 80
 81		if (len_this_page > n)
 82			len_this_page = n;
 83		scatterwalk_advance(&walk->out, n);
 84		if (n == len_this_page)
 85			break;
 86		n -= len_this_page;
 87		scatterwalk_start(&walk->out, sg_next(walk->out.sg));
 88	}
 89
 90	return bsize;
 91}
 92
 93static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
 94						unsigned int n)
 95{
 96	scatterwalk_advance(&walk->in, n);
 97	scatterwalk_advance(&walk->out, n);
 98
 99	return n;
100}
101
102static int ablkcipher_walk_next(struct ablkcipher_request *req,
103				struct ablkcipher_walk *walk);
104
105int ablkcipher_walk_done(struct ablkcipher_request *req,
106			 struct ablkcipher_walk *walk, int err)
107{
108	struct crypto_tfm *tfm = req->base.tfm;
109	unsigned int nbytes = 0;
110
111	if (likely(err >= 0)) {
112		unsigned int n = walk->nbytes - err;
113
114		if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
115			n = ablkcipher_done_fast(walk, n);
116		else if (WARN_ON(err)) {
117			err = -EINVAL;
118			goto err;
119		} else
120			n = ablkcipher_done_slow(walk, n);
121
122		nbytes = walk->total - n;
123		err = 0;
124	}
125
126	scatterwalk_done(&walk->in, 0, nbytes);
127	scatterwalk_done(&walk->out, 1, nbytes);
128
129err:
130	walk->total = nbytes;
131	walk->nbytes = nbytes;
132
133	if (nbytes) {
134		crypto_yield(req->base.flags);
135		return ablkcipher_walk_next(req, walk);
136	}
137
138	if (walk->iv != req->info)
139		memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
140	kfree(walk->iv_buffer);
141
142	return err;
143}
144EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
145
146static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
147				       struct ablkcipher_walk *walk,
148				       unsigned int bsize,
149				       unsigned int alignmask,
150				       void **src_p, void **dst_p)
151{
152	unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
153	struct ablkcipher_buffer *p;
154	void *src, *dst, *base;
155	unsigned int n;
156
157	n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
158	n += (aligned_bsize * 3 - (alignmask + 1) +
159	      (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
160
161	p = kmalloc(n, GFP_ATOMIC);
162	if (!p)
163		return ablkcipher_walk_done(req, walk, -ENOMEM);
164
165	base = p + 1;
166
167	dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
168	src = dst = ablkcipher_get_spot(dst, bsize);
169
170	p->len = bsize;
171	p->data = dst;
172
173	scatterwalk_copychunks(src, &walk->in, bsize, 0);
174
175	ablkcipher_queue_write(walk, p);
176
177	walk->nbytes = bsize;
178	walk->flags |= ABLKCIPHER_WALK_SLOW;
179
180	*src_p = src;
181	*dst_p = dst;
182
183	return 0;
184}
185
186static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
187				     struct crypto_tfm *tfm,
188				     unsigned int alignmask)
189{
190	unsigned bs = walk->blocksize;
191	unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
192	unsigned aligned_bs = ALIGN(bs, alignmask + 1);
193	unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
194			    (alignmask + 1);
195	u8 *iv;
196
197	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
198	walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
199	if (!walk->iv_buffer)
200		return -ENOMEM;
201
202	iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
203	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
204	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
205	iv = ablkcipher_get_spot(iv, ivsize);
206
207	walk->iv = memcpy(iv, walk->iv, ivsize);
208	return 0;
209}
210
211static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
212				       struct ablkcipher_walk *walk)
213{
214	walk->src.page = scatterwalk_page(&walk->in);
215	walk->src.offset = offset_in_page(walk->in.offset);
216	walk->dst.page = scatterwalk_page(&walk->out);
217	walk->dst.offset = offset_in_page(walk->out.offset);
218
219	return 0;
220}
221
222static int ablkcipher_walk_next(struct ablkcipher_request *req,
223				struct ablkcipher_walk *walk)
224{
225	struct crypto_tfm *tfm = req->base.tfm;
226	unsigned int alignmask, bsize, n;
227	void *src, *dst;
228	int err;
229
230	alignmask = crypto_tfm_alg_alignmask(tfm);
231	n = walk->total;
232	if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
233		req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
234		return ablkcipher_walk_done(req, walk, -EINVAL);
235	}
236
237	walk->flags &= ~ABLKCIPHER_WALK_SLOW;
238	src = dst = NULL;
239
240	bsize = min(walk->blocksize, n);
241	n = scatterwalk_clamp(&walk->in, n);
242	n = scatterwalk_clamp(&walk->out, n);
243
244	if (n < bsize ||
245	    !scatterwalk_aligned(&walk->in, alignmask) ||
246	    !scatterwalk_aligned(&walk->out, alignmask)) {
247		err = ablkcipher_next_slow(req, walk, bsize, alignmask,
248					   &src, &dst);
249		goto set_phys_lowmem;
250	}
251
252	walk->nbytes = n;
253
254	return ablkcipher_next_fast(req, walk);
255
256set_phys_lowmem:
257	if (err >= 0) {
258		walk->src.page = virt_to_page(src);
259		walk->dst.page = virt_to_page(dst);
260		walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
261		walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
262	}
263
264	return err;
265}
266
267static int ablkcipher_walk_first(struct ablkcipher_request *req,
268				 struct ablkcipher_walk *walk)
269{
270	struct crypto_tfm *tfm = req->base.tfm;
271	unsigned int alignmask;
272
273	alignmask = crypto_tfm_alg_alignmask(tfm);
274	if (WARN_ON_ONCE(in_irq()))
275		return -EDEADLK;
276
277	walk->iv = req->info;
278	walk->nbytes = walk->total;
279	if (unlikely(!walk->total))
280		return 0;
281
282	walk->iv_buffer = NULL;
283	if (unlikely(((unsigned long)walk->iv & alignmask))) {
284		int err = ablkcipher_copy_iv(walk, tfm, alignmask);
285
286		if (err)
287			return err;
288	}
289
290	scatterwalk_start(&walk->in, walk->in.sg);
291	scatterwalk_start(&walk->out, walk->out.sg);
292
293	return ablkcipher_walk_next(req, walk);
294}
295
296int ablkcipher_walk_phys(struct ablkcipher_request *req,
297			 struct ablkcipher_walk *walk)
298{
299	walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
300	return ablkcipher_walk_first(req, walk);
301}
302EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
303
304static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
305			    unsigned int keylen)
306{
307	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
308	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
309	int ret;
310	u8 *buffer, *alignbuffer;
311	unsigned long absize;
312
313	absize = keylen + alignmask;
314	buffer = kmalloc(absize, GFP_ATOMIC);
315	if (!buffer)
316		return -ENOMEM;
317
318	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
319	memcpy(alignbuffer, key, keylen);
320	ret = cipher->setkey(tfm, alignbuffer, keylen);
321	memset(alignbuffer, 0, keylen);
322	kfree(buffer);
323	return ret;
324}
325
326static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
327		  unsigned int keylen)
328{
329	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
330	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
331
332	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
333		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
334		return -EINVAL;
335	}
336
337	if ((unsigned long)key & alignmask)
338		return setkey_unaligned(tfm, key, keylen);
339
340	return cipher->setkey(tfm, key, keylen);
341}
342
343static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
344					      u32 mask)
345{
346	return alg->cra_ctxsize;
347}
348
349static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
350				      u32 mask)
351{
352	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
353	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
354
355	if (alg->ivsize > PAGE_SIZE / 8)
356		return -EINVAL;
357
358	crt->setkey = setkey;
359	crt->encrypt = alg->encrypt;
360	crt->decrypt = alg->decrypt;
361	crt->base = __crypto_ablkcipher_cast(tfm);
362	crt->ivsize = alg->ivsize;
363
364	return 0;
365}
366
367#ifdef CONFIG_NET
368static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
369{
370	struct crypto_report_blkcipher rblkcipher;
371
372	strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
373	strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
374		sizeof(rblkcipher.geniv));
375
376	rblkcipher.blocksize = alg->cra_blocksize;
377	rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
378	rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
379	rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
380
381	if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
382		    sizeof(struct crypto_report_blkcipher), &rblkcipher))
383		goto nla_put_failure;
384	return 0;
385
386nla_put_failure:
387	return -EMSGSIZE;
388}
389#else
390static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
391{
392	return -ENOSYS;
393}
394#endif
395
396static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
397	__attribute__ ((unused));
398static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
399{
400	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
401
402	seq_printf(m, "type         : ablkcipher\n");
403	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
404					     "yes" : "no");
405	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
406	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
407	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
408	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
409	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
410}
411
412const struct crypto_type crypto_ablkcipher_type = {
413	.ctxsize = crypto_ablkcipher_ctxsize,
414	.init = crypto_init_ablkcipher_ops,
415#ifdef CONFIG_PROC_FS
416	.show = crypto_ablkcipher_show,
417#endif
418	.report = crypto_ablkcipher_report,
419};
420EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
421
422static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
423				      u32 mask)
424{
425	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
426	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
427
428	if (alg->ivsize > PAGE_SIZE / 8)
429		return -EINVAL;
430
431	crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
432		      alg->setkey : setkey;
433	crt->encrypt = alg->encrypt;
434	crt->decrypt = alg->decrypt;
435	crt->base = __crypto_ablkcipher_cast(tfm);
436	crt->ivsize = alg->ivsize;
437
438	return 0;
439}
440
441#ifdef CONFIG_NET
442static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
443{
444	struct crypto_report_blkcipher rblkcipher;
445
446	strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
447	strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
448		sizeof(rblkcipher.geniv));
449
450	rblkcipher.blocksize = alg->cra_blocksize;
451	rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
452	rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
453	rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
454
455	if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
456		    sizeof(struct crypto_report_blkcipher), &rblkcipher))
457		goto nla_put_failure;
458	return 0;
459
460nla_put_failure:
461	return -EMSGSIZE;
462}
463#else
464static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
465{
466	return -ENOSYS;
467}
468#endif
469
470static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
471	__attribute__ ((unused));
472static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
473{
474	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
475
476	seq_printf(m, "type         : givcipher\n");
477	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
478					     "yes" : "no");
479	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
480	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
481	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
482	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
483	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
484}
485
486const struct crypto_type crypto_givcipher_type = {
487	.ctxsize = crypto_ablkcipher_ctxsize,
488	.init = crypto_init_givcipher_ops,
489#ifdef CONFIG_PROC_FS
490	.show = crypto_givcipher_show,
491#endif
492	.report = crypto_givcipher_report,
493};
494EXPORT_SYMBOL_GPL(crypto_givcipher_type);