[linux.git] / crypto / cipher.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Cryptographic API.
 *
 * Single-block cipher operations.
 *
 * Copyright (c) 2002 James Morris <[email protected]>
 * Copyright (c) 2005 Herbert Xu <[email protected]>
 */

#include <crypto/algapi.h>
#include <linux/kernel.h>
#include <linux/crypto.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "internal.h"

static int setkey_unaligned(struct crypto_cipher *tfm, const u8 *key,
			    unsigned int keylen)
{
	struct cipher_alg *cia = crypto_cipher_alg(tfm);
	unsigned long alignmask = crypto_cipher_alignmask(tfm);
	int ret;
	u8 *buffer, *alignbuffer;
	unsigned long absize;

	absize = keylen + alignmask;
	buffer = kmalloc(absize, GFP_ATOMIC);
	if (!buffer)
		return -ENOMEM;

	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	memcpy(alignbuffer, key, keylen);
	ret = cia->cia_setkey(crypto_cipher_tfm(tfm), alignbuffer, keylen);
	memset(alignbuffer, 0, keylen);
	kfree(buffer);
	return ret;

}

int crypto_cipher_setkey(struct crypto_cipher *tfm,
			 const u8 *key, unsigned int keylen)
{
	struct cipher_alg *cia = crypto_cipher_alg(tfm);
	unsigned long alignmask = crypto_cipher_alignmask(tfm);

	if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize)
		return -EINVAL;

	if ((unsigned long)key & alignmask)
		return setkey_unaligned(tfm, key, keylen);

	return cia->cia_setkey(crypto_cipher_tfm(tfm), key, keylen);
}
EXPORT_SYMBOL_GPL(crypto_cipher_setkey);

static inline void cipher_crypt_one(struct crypto_cipher *tfm,
				    u8 *dst, const u8 *src, bool enc)
{
	unsigned long alignmask = crypto_cipher_alignmask(tfm);
	struct cipher_alg *cia = crypto_cipher_alg(tfm);
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
		enc ? cia->cia_encrypt : cia->cia_decrypt;

	if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
		unsigned int bs = crypto_cipher_blocksize(tfm);
		u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
		u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);

		memcpy(tmp, src, bs);
		fn(crypto_cipher_tfm(tfm), tmp, tmp);
		memcpy(dst, tmp, bs);
	} else {
		fn(crypto_cipher_tfm(tfm), dst, src);
	}
}

void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
			       u8 *dst, const u8 *src)
{
	cipher_crypt_one(tfm, dst, src, true);
}
EXPORT_SYMBOL_GPL(crypto_cipher_encrypt_one);

void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
			       u8 *dst, const u8 *src)
{
	cipher_crypt_one(tfm, dst, src, false);
}
EXPORT_SYMBOL_GPL(crypto_cipher_decrypt_one);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* Cryptographic API.
	4	*
e8cfed5e	5	* Single-block cipher operations.
1da177e4 LT	6	*
1da177e4 LT	7	* Copyright (c) 2002 James Morris <[email protected]>
c774e93e	8	* Copyright (c) 2005 Herbert Xu <[email protected]>
1da177e4	9	*/
f1ddcaf3	10
6650c4de	11	#include <crypto/algapi.h>
1da177e4 LT	12	#include <linux/kernel.h>
	13	#include <linux/crypto.h>
	14	#include <linux/errno.h>
791b4d5f	15	#include <linux/slab.h>
1da177e4	16	#include <linux/string.h>
1da177e4	17	#include "internal.h"
1da177e4	18
e8cfed5e	19	static int setkey_unaligned(struct crypto_cipher tfm, const u8 key,
791b4d5f	20	unsigned int keylen)
ca7c3938	21	{
e8cfed5e EB	22	struct cipher_alg *cia = crypto_cipher_alg(tfm);
e8cfed5e EB	23	unsigned long alignmask = crypto_cipher_alignmask(tfm);
ca7c3938 SS	24	int ret;
	25	u8 buffer, alignbuffer;
	26	unsigned long absize;
	27
	28	absize = keylen + alignmask;
	29	buffer = kmalloc(absize, GFP_ATOMIC);
	30	if (!buffer)
	31	return -ENOMEM;
	32
	33	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	34	memcpy(alignbuffer, key, keylen);
e8cfed5e	35	ret = cia->cia_setkey(crypto_cipher_tfm(tfm), alignbuffer, keylen);
06817176	36	memset(alignbuffer, 0, keylen);
ca7c3938 SS	37	kfree(buffer);
	38	return ret;
	39
	40	}
	41
e8cfed5e EB	42	int crypto_cipher_setkey(struct crypto_cipher *tfm,
e8cfed5e EB	43	const u8 *key, unsigned int keylen)
1da177e4	44	{
e8cfed5e EB	45	struct cipher_alg *cia = crypto_cipher_alg(tfm);
e8cfed5e EB	46	unsigned long alignmask = crypto_cipher_alignmask(tfm);
ca7c3938	47
674f368a	48	if (keylen < cia->cia_min_keysize \|\| keylen > cia->cia_max_keysize)
1da177e4	49	return -EINVAL;
ca7c3938 SS	50
	51	if ((unsigned long)key & alignmask)
	52	return setkey_unaligned(tfm, key, keylen);
	53
e8cfed5e	54	return cia->cia_setkey(crypto_cipher_tfm(tfm), key, keylen);
1da177e4	55	}
e8cfed5e	56	EXPORT_SYMBOL_GPL(crypto_cipher_setkey);
1da177e4	57
e8cfed5e EB	58	static inline void cipher_crypt_one(struct crypto_cipher *tfm,
e8cfed5e EB	59	u8 dst, const u8 src, bool enc)
f28776a3	60	{
e8cfed5e EB	61	unsigned long alignmask = crypto_cipher_alignmask(tfm);
	62	struct cipher_alg *cia = crypto_cipher_alg(tfm);
	63	void (fn)(struct crypto_tfm , u8 , const u8 ) =
	64	enc ? cia->cia_encrypt : cia->cia_decrypt;
f28776a3 HX	65
f28776a3 HX	66	if (unlikely(((unsigned long)dst \| (unsigned long)src) & alignmask)) {
e8cfed5e EB	67	unsigned int bs = crypto_cipher_blocksize(tfm);
	68	u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
	69	u8 tmp = (u8 )ALIGN((unsigned long)buffer, alignmask + 1);
	70
	71	memcpy(tmp, src, bs);
	72	fn(crypto_cipher_tfm(tfm), tmp, tmp);
	73	memcpy(dst, tmp, bs);
	74	} else {
	75	fn(crypto_cipher_tfm(tfm), dst, src);
f28776a3	76	}
f28776a3 HX	77	}
f28776a3 HX	78
e8cfed5e EB	79	void crypto_cipher_encrypt_one(struct crypto_cipher *tfm,
e8cfed5e EB	80	u8 dst, const u8 src)
f28776a3	81	{
e8cfed5e	82	cipher_crypt_one(tfm, dst, src, true);
f28776a3	83	}
e8cfed5e	84	EXPORT_SYMBOL_GPL(crypto_cipher_encrypt_one);
f28776a3	85
e8cfed5e EB	86	void crypto_cipher_decrypt_one(struct crypto_cipher *tfm,
e8cfed5e EB	87	u8 dst, const u8 src)
1da177e4	88	{
e8cfed5e	89	cipher_crypt_one(tfm, dst, src, false);
1da177e4	90	}
e8cfed5e	91	EXPORT_SYMBOL_GPL(crypto_cipher_decrypt_one);