[deliverable/linux.git] / crypto / cipher.c

/*
 * Cryptographic API.
 *
 * Cipher operations.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version.
 *
 */
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/crypto.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <asm/scatterlist.h>
#include "internal.h"
#include "scatterwalk.h"

static inline void xor_64(u8 *a, const u8 *b)
{
	((u32 *)a)[0] ^= ((u32 *)b)[0];
	((u32 *)a)[1] ^= ((u32 *)b)[1];
}

static inline void xor_128(u8 *a, const u8 *b)
{
	((u32 *)a)[0] ^= ((u32 *)b)[0];
	((u32 *)a)[1] ^= ((u32 *)b)[1];
	((u32 *)a)[2] ^= ((u32 *)b)[2];
	((u32 *)a)[3] ^= ((u32 *)b)[3];
}

static unsigned int crypt_slow(const struct cipher_desc *desc,
			       struct scatter_walk *in,
			       struct scatter_walk *out, unsigned int bsize)
{
	u8 src[bsize];
	u8 dst[bsize];
	unsigned int n;

	n = scatterwalk_copychunks(src, in, bsize, 0);
	scatterwalk_advance(in, n);

	desc->prfn(desc, dst, src, bsize);

	n = scatterwalk_copychunks(dst, out, bsize, 1);
	scatterwalk_advance(out, n);

	return bsize;
}

static inline unsigned int crypt_fast(const struct cipher_desc *desc,
				      struct scatter_walk *in,
				      struct scatter_walk *out,
				      unsigned int nbytes)
{
	u8 *src, *dst;

	src = in->data;
	dst = scatterwalk_samebuf(in, out) ? src : out->data;

	nbytes = desc->prfn(desc, dst, src, nbytes);

	scatterwalk_advance(in, nbytes);
	scatterwalk_advance(out, nbytes);

	return nbytes;
}

/* 
 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
 * multiple page boundaries by using temporary blocks.  In user context,
 * the kernel is given a chance to schedule us once per page.
 */
static int crypt(const struct cipher_desc *desc,
		 struct scatterlist *dst,
		 struct scatterlist *src,
		 unsigned int nbytes)
{
	struct scatter_walk walk_in, walk_out;
	struct crypto_tfm *tfm = desc->tfm;
	const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);

	if (!nbytes)
		return 0;

	if (nbytes % bsize) {
		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
		return -EINVAL;
	}

	scatterwalk_start(&walk_in, src);
	scatterwalk_start(&walk_out, dst);

	for(;;) {
		unsigned int n;

		scatterwalk_map(&walk_in, 0);
		scatterwalk_map(&walk_out, 1);

		n = scatterwalk_clamp(&walk_in, nbytes);
		n = scatterwalk_clamp(&walk_out, n);

		if (likely(n >= bsize))
			n = crypt_fast(desc, &walk_in, &walk_out, n);
		else
			n = crypt_slow(desc, &walk_in, &walk_out, bsize);

		nbytes -= n;

		scatterwalk_done(&walk_in, 0, nbytes);
		scatterwalk_done(&walk_out, 1, nbytes);

		if (!nbytes)
			return 0;

		crypto_yield(tfm);
	}
}

static unsigned int cbc_process_encrypt(const struct cipher_desc *desc,
					u8 *dst, const u8 *src,
					unsigned int nbytes)
{
	struct crypto_tfm *tfm = desc->tfm;
	void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
	int bsize = crypto_tfm_alg_blocksize(tfm);

	void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
	u8 *iv = desc->info;
	unsigned int done = 0;

	do {
		xor(iv, src);
		fn(crypto_tfm_ctx(tfm), dst, iv);
		memcpy(iv, dst, bsize);

		src += bsize;
		dst += bsize;
	} while ((done += bsize) < nbytes);

	return done;
}

static unsigned int cbc_process_decrypt(const struct cipher_desc *desc,
					u8 *dst, const u8 *src,
					unsigned int nbytes)
{
	struct crypto_tfm *tfm = desc->tfm;
	void (*xor)(u8 *, const u8 *) = tfm->crt_u.cipher.cit_xor_block;
	int bsize = crypto_tfm_alg_blocksize(tfm);

	u8 stack[src == dst ? bsize : 0];
	u8 *buf = stack;
	u8 **dst_p = src == dst ? &buf : &dst;

	void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
	u8 *iv = desc->info;
	unsigned int done = 0;

	do {
		u8 *tmp_dst = *dst_p;

		fn(crypto_tfm_ctx(tfm), tmp_dst, src);
		xor(tmp_dst, iv);
		memcpy(iv, src, bsize);
		if (tmp_dst != dst)
			memcpy(dst, tmp_dst, bsize);

		src += bsize;
		dst += bsize;
	} while ((done += bsize) < nbytes);

	return done;
}

static unsigned int ecb_process(const struct cipher_desc *desc, u8 *dst,
				const u8 *src, unsigned int nbytes)
{
	struct crypto_tfm *tfm = desc->tfm;
	int bsize = crypto_tfm_alg_blocksize(tfm);
	void (*fn)(void *, u8 *, const u8 *) = desc->crfn;
	unsigned int done = 0;

	do {
		fn(crypto_tfm_ctx(tfm), dst, src);

		src += bsize;
		dst += bsize;
	} while ((done += bsize) < nbytes);

	return done;
}

static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
{
	struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
	
	if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
		return -EINVAL;
	} else
		return cia->cia_setkey(crypto_tfm_ctx(tfm), key, keylen,
		                       &tfm->crt_flags);
}

static int ecb_encrypt(struct crypto_tfm *tfm,
		       struct scatterlist *dst,
                       struct scatterlist *src, unsigned int nbytes)
{
	struct cipher_desc desc;
	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;

	desc.tfm = tfm;
	desc.crfn = cipher->cia_encrypt;
	desc.prfn = cipher->cia_encrypt_ecb ?: ecb_process;

	return crypt(&desc, dst, src, nbytes);
}

static int ecb_decrypt(struct crypto_tfm *tfm,
                       struct scatterlist *dst,
                       struct scatterlist *src,
		       unsigned int nbytes)
{
	struct cipher_desc desc;
	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;

	desc.tfm = tfm;
	desc.crfn = cipher->cia_decrypt;
	desc.prfn = cipher->cia_decrypt_ecb ?: ecb_process;

	return crypt(&desc, dst, src, nbytes);
}

static int cbc_encrypt(struct crypto_tfm *tfm,
                       struct scatterlist *dst,
                       struct scatterlist *src,
		       unsigned int nbytes)
{
	struct cipher_desc desc;
	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;

	desc.tfm = tfm;
	desc.crfn = cipher->cia_encrypt;
	desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
	desc.info = tfm->crt_cipher.cit_iv;

	return crypt(&desc, dst, src, nbytes);
}

static int cbc_encrypt_iv(struct crypto_tfm *tfm,
                          struct scatterlist *dst,
                          struct scatterlist *src,
                          unsigned int nbytes, u8 *iv)
{
	struct cipher_desc desc;
	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;

	desc.tfm = tfm;
	desc.crfn = cipher->cia_encrypt;
	desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
	desc.info = iv;

	return crypt(&desc, dst, src, nbytes);
}

static int cbc_decrypt(struct crypto_tfm *tfm,
                       struct scatterlist *dst,
                       struct scatterlist *src,
		       unsigned int nbytes)
{
	struct cipher_desc desc;
	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;

	desc.tfm = tfm;
	desc.crfn = cipher->cia_decrypt;
	desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
	desc.info = tfm->crt_cipher.cit_iv;

	return crypt(&desc, dst, src, nbytes);
}

static int cbc_decrypt_iv(struct crypto_tfm *tfm,
                          struct scatterlist *dst,
                          struct scatterlist *src,
                          unsigned int nbytes, u8 *iv)
{
	struct cipher_desc desc;
	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;

	desc.tfm = tfm;
	desc.crfn = cipher->cia_decrypt;
	desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
	desc.info = iv;

	return crypt(&desc, dst, src, nbytes);
}

static int nocrypt(struct crypto_tfm *tfm,
                   struct scatterlist *dst,
                   struct scatterlist *src,
		   unsigned int nbytes)
{
	return -ENOSYS;
}

static int nocrypt_iv(struct crypto_tfm *tfm,
                      struct scatterlist *dst,
                      struct scatterlist *src,
                      unsigned int nbytes, u8 *iv)
{
	return -ENOSYS;
}

int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags)
{
	u32 mode = flags & CRYPTO_TFM_MODE_MASK;
	
	tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB;
	if (flags & CRYPTO_TFM_REQ_WEAK_KEY)
		tfm->crt_flags = CRYPTO_TFM_REQ_WEAK_KEY;
	
	return 0;
}

int crypto_init_cipher_ops(struct crypto_tfm *tfm)
{
	int ret = 0;
	struct cipher_tfm *ops = &tfm->crt_cipher;

	ops->cit_setkey = setkey;

	switch (tfm->crt_cipher.cit_mode) {
	case CRYPTO_TFM_MODE_ECB:
		ops->cit_encrypt = ecb_encrypt;
		ops->cit_decrypt = ecb_decrypt;
		break;
		
	case CRYPTO_TFM_MODE_CBC:
		ops->cit_encrypt = cbc_encrypt;
		ops->cit_decrypt = cbc_decrypt;
		ops->cit_encrypt_iv = cbc_encrypt_iv;
		ops->cit_decrypt_iv = cbc_decrypt_iv;
		break;
		
	case CRYPTO_TFM_MODE_CFB:
		ops->cit_encrypt = nocrypt;
		ops->cit_decrypt = nocrypt;
		ops->cit_encrypt_iv = nocrypt_iv;
		ops->cit_decrypt_iv = nocrypt_iv;
		break;
	
	case CRYPTO_TFM_MODE_CTR:
		ops->cit_encrypt = nocrypt;
		ops->cit_decrypt = nocrypt;
		ops->cit_encrypt_iv = nocrypt_iv;
		ops->cit_decrypt_iv = nocrypt_iv;
		break;

	default:
		BUG();
	}
	
	if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {
	    	
	    	switch (crypto_tfm_alg_blocksize(tfm)) {
	    	case 8:
	    		ops->cit_xor_block = xor_64;
	    		break;
	    		
	    	case 16:
	    		ops->cit_xor_block = xor_128;
	    		break;
	    		
	    	default:
	    		printk(KERN_WARNING "%s: block size %u not supported\n",
	    		       crypto_tfm_alg_name(tfm),
	    		       crypto_tfm_alg_blocksize(tfm));
	    		ret = -EINVAL;
	    		goto out;
	    	}
	    	
		ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm);
	    	ops->cit_iv = kmalloc(ops->cit_ivsize, GFP_KERNEL);
		if (ops->cit_iv == NULL)
			ret = -ENOMEM;
	}

out:	
	return ret;
}

void crypto_exit_cipher_ops(struct crypto_tfm *tfm)
{
	kfree(tfm->crt_cipher.cit_iv);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Cryptographic API.
	3	*
	4	* Cipher operations.
	5	*
	6	* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
c774e93e	7	* Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
1da177e4 LT	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	#include <linux/compiler.h>
	16	#include <linux/kernel.h>
	17	#include <linux/crypto.h>
	18	#include <linux/errno.h>
	19	#include <linux/mm.h>
	20	#include <linux/slab.h>
	21	#include <linux/string.h>
	22	#include <asm/scatterlist.h>
	23	#include "internal.h"
	24	#include "scatterwalk.h"
	25
1da177e4 LT	26	static inline void xor_64(u8 a, const u8 b)
	27	{
	28	((u32 )a)[0] ^= ((u32 )b)[0];
	29	((u32 )a)[1] ^= ((u32 )b)[1];
	30	}
	31
	32	static inline void xor_128(u8 a, const u8 b)
	33	{
	34	((u32 )a)[0] ^= ((u32 )b)[0];
	35	((u32 )a)[1] ^= ((u32 )b)[1];
	36	((u32 )a)[2] ^= ((u32 )b)[2];
	37	((u32 )a)[3] ^= ((u32 )b)[3];
	38	}
c774e93e HX	39
	40	static unsigned int crypt_slow(const struct cipher_desc *desc,
	41	struct scatter_walk *in,
	42	struct scatter_walk *out, unsigned int bsize)
1da177e4	43	{
c774e93e HX	44	u8 src[bsize];
	45	u8 dst[bsize];
	46	unsigned int n;
1da177e4	47
c774e93e HX	48	n = scatterwalk_copychunks(src, in, bsize, 0);
c774e93e HX	49	scatterwalk_advance(in, n);
1da177e4	50
c774e93e	51	desc->prfn(desc, dst, src, bsize);
1da177e4	52
c774e93e HX	53	n = scatterwalk_copychunks(dst, out, bsize, 1);
c774e93e HX	54	scatterwalk_advance(out, n);
1da177e4	55
c774e93e	56	return bsize;
1da177e4 LT	57	}
1da177e4 LT	58
c774e93e HX	59	static inline unsigned int crypt_fast(const struct cipher_desc *desc,
	60	struct scatter_walk *in,
	61	struct scatter_walk *out,
	62	unsigned int nbytes)
1da177e4	63	{
c774e93e HX	64	u8 src, dst;
	65
	66	src = in->data;
	67	dst = scatterwalk_samebuf(in, out) ? src : out->data;
	68
	69	nbytes = desc->prfn(desc, dst, src, nbytes);
	70
	71	scatterwalk_advance(in, nbytes);
	72	scatterwalk_advance(out, nbytes);
1da177e4	73
c774e93e	74	return nbytes;
1da177e4 LT	75	}
	76
	77	/*
	78	* Generic encrypt/decrypt wrapper for ciphers, handles operations across
	79	* multiple page boundaries by using temporary blocks. In user context,
c774e93e	80	* the kernel is given a chance to schedule us once per page.
1da177e4	81	*/
c774e93e	82	static int crypt(const struct cipher_desc *desc,
1da177e4 LT	83	struct scatterlist *dst,
1da177e4 LT	84	struct scatterlist *src,
c774e93e	85	unsigned int nbytes)
1da177e4 LT	86	{
1da177e4 LT	87	struct scatter_walk walk_in, walk_out;
c774e93e	88	struct crypto_tfm *tfm = desc->tfm;
1da177e4	89	const unsigned int bsize = crypto_tfm_alg_blocksize(tfm);
1da177e4 LT	90
	91	if (!nbytes)
	92	return 0;
	93
	94	if (nbytes % bsize) {
	95	tfm->crt_flags \|= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
	96	return -EINVAL;
	97	}
	98
	99	scatterwalk_start(&walk_in, src);
	100	scatterwalk_start(&walk_out, dst);
	101
	102	for(;;) {
c774e93e	103	unsigned int n;
1da177e4 LT	104
	105	scatterwalk_map(&walk_in, 0);
	106	scatterwalk_map(&walk_out, 1);
	107
c774e93e HX	108	n = scatterwalk_clamp(&walk_in, nbytes);
c774e93e HX	109	n = scatterwalk_clamp(&walk_out, n);
1da177e4	110
c774e93e HX	111	if (likely(n >= bsize))
	112	n = crypt_fast(desc, &walk_in, &walk_out, n);
	113	else
	114	n = crypt_slow(desc, &walk_in, &walk_out, bsize);
1da177e4	115
c774e93e	116	nbytes -= n;
1da177e4 LT	117
	118	scatterwalk_done(&walk_in, 0, nbytes);
	119	scatterwalk_done(&walk_out, 1, nbytes);
	120
	121	if (!nbytes)
	122	return 0;
	123
	124	crypto_yield(tfm);
	125	}
	126	}
	127
c774e93e HX	128	static unsigned int cbc_process_encrypt(const struct cipher_desc *desc,
	129	u8 dst, const u8 src,
	130	unsigned int nbytes)
1da177e4	131	{
c774e93e HX	132	struct crypto_tfm *tfm = desc->tfm;
	133	void (xor)(u8 , const u8 *) = tfm->crt_u.cipher.cit_xor_block;
	134	int bsize = crypto_tfm_alg_blocksize(tfm);
	135
	136	void (fn)(void , u8 , const u8 ) = desc->crfn;
	137	u8 *iv = desc->info;
	138	unsigned int done = 0;
	139
	140	do {
	141	xor(iv, src);
	142	fn(crypto_tfm_ctx(tfm), dst, iv);
	143	memcpy(iv, dst, bsize);
1da177e4	144
c774e93e HX	145	src += bsize;
	146	dst += bsize;
	147	} while ((done += bsize) < nbytes);
	148
	149	return done;
1da177e4 LT	150	}
1da177e4 LT	151
c774e93e HX	152	static unsigned int cbc_process_decrypt(const struct cipher_desc *desc,
	153	u8 dst, const u8 src,
	154	unsigned int nbytes)
1da177e4	155	{
c774e93e HX	156	struct crypto_tfm *tfm = desc->tfm;
	157	void (xor)(u8 , const u8 *) = tfm->crt_u.cipher.cit_xor_block;
	158	int bsize = crypto_tfm_alg_blocksize(tfm);
	159
	160	u8 stack[src == dst ? bsize : 0];
	161	u8 *buf = stack;
	162	u8 **dst_p = src == dst ? &buf : &dst;
	163
	164	void (fn)(void , u8 , const u8 ) = desc->crfn;
	165	u8 *iv = desc->info;
	166	unsigned int done = 0;
	167
	168	do {
	169	u8 tmp_dst = dst_p;
1da177e4	170
c774e93e HX	171	fn(crypto_tfm_ctx(tfm), tmp_dst, src);
	172	xor(tmp_dst, iv);
	173	memcpy(iv, src, bsize);
	174	if (tmp_dst != dst)
	175	memcpy(dst, tmp_dst, bsize);
	176
	177	src += bsize;
	178	dst += bsize;
	179	} while ((done += bsize) < nbytes);
	180
	181	return done;
1da177e4 LT	182	}
1da177e4 LT	183
c774e93e HX	184	static unsigned int ecb_process(const struct cipher_desc desc, u8 dst,
c774e93e HX	185	const u8 *src, unsigned int nbytes)
1da177e4	186	{
c774e93e HX	187	struct crypto_tfm *tfm = desc->tfm;
	188	int bsize = crypto_tfm_alg_blocksize(tfm);
	189	void (fn)(void , u8 , const u8 ) = desc->crfn;
	190	unsigned int done = 0;
	191
	192	do {
	193	fn(crypto_tfm_ctx(tfm), dst, src);
	194
	195	src += bsize;
	196	dst += bsize;
	197	} while ((done += bsize) < nbytes);
	198
	199	return done;
1da177e4 LT	200	}
	201
	202	static int setkey(struct crypto_tfm tfm, const u8 key, unsigned int keylen)
	203	{
	204	struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
	205
	206	if (keylen < cia->cia_min_keysize \|\| keylen > cia->cia_max_keysize) {
	207	tfm->crt_flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
	208	return -EINVAL;
	209	} else
	210	return cia->cia_setkey(crypto_tfm_ctx(tfm), key, keylen,
	211	&tfm->crt_flags);
	212	}
	213
	214	static int ecb_encrypt(struct crypto_tfm *tfm,
	215	struct scatterlist *dst,
	216	struct scatterlist *src, unsigned int nbytes)
	217	{
c774e93e	218	struct cipher_desc desc;
40725181	219	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e HX	220
c774e93e HX	221	desc.tfm = tfm;
40725181 HX	222	desc.crfn = cipher->cia_encrypt;
40725181 HX	223	desc.prfn = cipher->cia_encrypt_ecb ?: ecb_process;
c774e93e HX	224
c774e93e HX	225	return crypt(&desc, dst, src, nbytes);
1da177e4 LT	226	}
	227
	228	static int ecb_decrypt(struct crypto_tfm *tfm,
	229	struct scatterlist *dst,
	230	struct scatterlist *src,
	231	unsigned int nbytes)
	232	{
c774e93e	233	struct cipher_desc desc;
40725181	234	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e HX	235
c774e93e HX	236	desc.tfm = tfm;
40725181 HX	237	desc.crfn = cipher->cia_decrypt;
40725181 HX	238	desc.prfn = cipher->cia_decrypt_ecb ?: ecb_process;
c774e93e HX	239
c774e93e HX	240	return crypt(&desc, dst, src, nbytes);
1da177e4 LT	241	}
	242
	243	static int cbc_encrypt(struct crypto_tfm *tfm,
	244	struct scatterlist *dst,
	245	struct scatterlist *src,
	246	unsigned int nbytes)
	247	{
c774e93e	248	struct cipher_desc desc;
40725181	249	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e HX	250
c774e93e HX	251	desc.tfm = tfm;
40725181 HX	252	desc.crfn = cipher->cia_encrypt;
40725181 HX	253	desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
c774e93e HX	254	desc.info = tfm->crt_cipher.cit_iv;
	255
	256	return crypt(&desc, dst, src, nbytes);
1da177e4 LT	257	}
	258
	259	static int cbc_encrypt_iv(struct crypto_tfm *tfm,
	260	struct scatterlist *dst,
	261	struct scatterlist *src,
	262	unsigned int nbytes, u8 *iv)
	263	{
c774e93e	264	struct cipher_desc desc;
40725181	265	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e HX	266
c774e93e HX	267	desc.tfm = tfm;
40725181 HX	268	desc.crfn = cipher->cia_encrypt;
40725181 HX	269	desc.prfn = cipher->cia_encrypt_cbc ?: cbc_process_encrypt;
c774e93e HX	270	desc.info = iv;
	271
	272	return crypt(&desc, dst, src, nbytes);
1da177e4 LT	273	}
	274
	275	static int cbc_decrypt(struct crypto_tfm *tfm,
	276	struct scatterlist *dst,
	277	struct scatterlist *src,
	278	unsigned int nbytes)
	279	{
c774e93e	280	struct cipher_desc desc;
40725181	281	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e HX	282
c774e93e HX	283	desc.tfm = tfm;
40725181 HX	284	desc.crfn = cipher->cia_decrypt;
40725181 HX	285	desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
c774e93e HX	286	desc.info = tfm->crt_cipher.cit_iv;
	287
	288	return crypt(&desc, dst, src, nbytes);
1da177e4 LT	289	}
	290
	291	static int cbc_decrypt_iv(struct crypto_tfm *tfm,
	292	struct scatterlist *dst,
	293	struct scatterlist *src,
	294	unsigned int nbytes, u8 *iv)
	295	{
c774e93e	296	struct cipher_desc desc;
40725181	297	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
c774e93e HX	298
c774e93e HX	299	desc.tfm = tfm;
40725181 HX	300	desc.crfn = cipher->cia_decrypt;
40725181 HX	301	desc.prfn = cipher->cia_decrypt_cbc ?: cbc_process_decrypt;
c774e93e HX	302	desc.info = iv;
	303
	304	return crypt(&desc, dst, src, nbytes);
1da177e4 LT	305	}
	306
	307	static int nocrypt(struct crypto_tfm *tfm,
	308	struct scatterlist *dst,
	309	struct scatterlist *src,
	310	unsigned int nbytes)
	311	{
	312	return -ENOSYS;
	313	}
	314
	315	static int nocrypt_iv(struct crypto_tfm *tfm,
	316	struct scatterlist *dst,
	317	struct scatterlist *src,
	318	unsigned int nbytes, u8 *iv)
	319	{
	320	return -ENOSYS;
	321	}
	322
	323	int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags)
	324	{
	325	u32 mode = flags & CRYPTO_TFM_MODE_MASK;
	326
	327	tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB;
	328	if (flags & CRYPTO_TFM_REQ_WEAK_KEY)
	329	tfm->crt_flags = CRYPTO_TFM_REQ_WEAK_KEY;
	330
	331	return 0;
	332	}
	333
	334	int crypto_init_cipher_ops(struct crypto_tfm *tfm)
	335	{
	336	int ret = 0;
	337	struct cipher_tfm *ops = &tfm->crt_cipher;
	338
	339	ops->cit_setkey = setkey;
	340
	341	switch (tfm->crt_cipher.cit_mode) {
	342	case CRYPTO_TFM_MODE_ECB:
	343	ops->cit_encrypt = ecb_encrypt;
	344	ops->cit_decrypt = ecb_decrypt;
	345	break;
	346
	347	case CRYPTO_TFM_MODE_CBC:
	348	ops->cit_encrypt = cbc_encrypt;
	349	ops->cit_decrypt = cbc_decrypt;
	350	ops->cit_encrypt_iv = cbc_encrypt_iv;
	351	ops->cit_decrypt_iv = cbc_decrypt_iv;
	352	break;
	353
	354	case CRYPTO_TFM_MODE_CFB:
	355	ops->cit_encrypt = nocrypt;
	356	ops->cit_decrypt = nocrypt;
	357	ops->cit_encrypt_iv = nocrypt_iv;
	358	ops->cit_decrypt_iv = nocrypt_iv;
	359	break;
	360
	361	case CRYPTO_TFM_MODE_CTR:
	362	ops->cit_encrypt = nocrypt;
	363	ops->cit_decrypt = nocrypt;
	364	ops->cit_encrypt_iv = nocrypt_iv;
	365	ops->cit_decrypt_iv = nocrypt_iv;
	366	break;
	367
	368	default:
369	BUG();
370	}
371
372	if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) {
373
374	switch (crypto_tfm_alg_blocksize(tfm)) {
375	case 8:
376	ops->cit_xor_block = xor_64;
377	break;
378
379	case 16:
380	ops->cit_xor_block = xor_128;
381	break;
382
383	default:
384	printk(KERN_WARNING "%s: block size %u not supported\n",
385	crypto_tfm_alg_name(tfm),
386	crypto_tfm_alg_blocksize(tfm));
387	ret = -EINVAL;
388	goto out;
389	}
390
391	ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm);
392	ops->cit_iv = kmalloc(ops->cit_ivsize, GFP_KERNEL);
393	if (ops->cit_iv == NULL)
394	ret = -ENOMEM;
395	}
396
397	out:
398	return ret;
399	}
400
401	void crypto_exit_cipher_ops(struct crypto_tfm *tfm)
402	{
8279dd74	403	kfree(tfm->crt_cipher.cit_iv);
1da177e4	404	}