Commit 5311f248 authored by Herbert Xu's avatar Herbert Xu
Browse files

[CRYPTO] ctr: Refactor into ctr and rfc3686 



As discussed previously, this patch moves the basic CTR functionality
into a chainable algorithm called ctr.  The IPsec-specific variant of
it is now placed on top with the name rfc3686.

So ctr(aes) gives a chainable cipher with IV size 16 while the IPsec
variant will be called rfc3686(ctr(aes)).  This patch also adjusts
gcm accordingly.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 653ebd9c

crypto/ctr.c

+206 −128
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
 */



#include <crypto/algapi.h>

#include <crypto/ctr.h>

#include <linux/err.h>

#include <linux/init.h>

#include <linux/kernel.h>
@@ -19,16 +20,13 @@ 
#include <linux/scatterlist.h>

#include <linux/slab.h>



struct ctr_instance_ctx {

	struct crypto_spawn alg;

	unsigned int noncesize;

	unsigned int ivsize;

	unsigned int countersize;

};



struct crypto_ctr_ctx {

	struct crypto_cipher *child;

	u8 *nonce;

};



struct crypto_rfc3686_ctx {

	struct crypto_blkcipher *child;

	u8 nonce[CTR_RFC3686_NONCE_SIZE];

};



static int crypto_ctr_setkey(struct crypto_tfm *parent, const u8 *key,
@@ -36,18 +34,7 @@ static int crypto_ctr_setkey(struct crypto_tfm *parent, const u8 *key, 
{

	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(parent);

	struct crypto_cipher *child = ctx->child;

	struct ctr_instance_ctx *ictx =

		crypto_instance_ctx(crypto_tfm_alg_instance(parent));

	unsigned int noncelen = ictx->noncesize;

	int err = 0;



	/* the nonce is stored in bytes at end of key */

	if (keylen < noncelen)

		return  -EINVAL;



	memcpy(ctx->nonce, key + (keylen - noncelen), noncelen);



	keylen -=  noncelen;

	int err;



	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);

	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
@@ -60,11 +47,13 @@ static int crypto_ctr_setkey(struct crypto_tfm *parent, const u8 *key, 
}



static void crypto_ctr_crypt_final(struct blkcipher_walk *walk,

				   struct crypto_cipher *tfm, u8 *ctrblk,

				   unsigned int countersize)

				   struct crypto_cipher *tfm)

{

	unsigned int bsize = crypto_cipher_blocksize(tfm);

	u8 *keystream = ctrblk + bsize;

	unsigned long alignmask = crypto_cipher_alignmask(tfm);

	u8 *ctrblk = walk->iv;

	u8 tmp[bsize + alignmask];

	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);

	u8 *src = walk->src.virt.addr;

	u8 *dst = walk->dst.virt.addr;

	unsigned int nbytes = walk->nbytes;
@@ -72,15 +61,17 @@ static void crypto_ctr_crypt_final(struct blkcipher_walk *walk, 
	crypto_cipher_encrypt_one(tfm, keystream, ctrblk);

	crypto_xor(keystream, src, nbytes);

	memcpy(dst, keystream, nbytes);



	crypto_inc(ctrblk, bsize);

}



static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,

				    struct crypto_cipher *tfm, u8 *ctrblk,

				    unsigned int countersize)

				    struct crypto_cipher *tfm)

{

	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =

		   crypto_cipher_alg(tfm)->cia_encrypt;

	unsigned int bsize = crypto_cipher_blocksize(tfm);

	u8 *ctrblk = walk->iv;

	u8 *src = walk->src.virt.addr;

	u8 *dst = walk->dst.virt.addr;

	unsigned int nbytes = walk->nbytes;
@@ -91,7 +82,7 @@ static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk, 
		crypto_xor(dst, src, bsize);



		/* increment counter in counterblock */

		crypto_inc(ctrblk + bsize - countersize, countersize);

		crypto_inc(ctrblk, bsize);



		src += bsize;

		dst += bsize;
@@ -101,15 +92,17 @@ static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk, 
}



static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,

				    struct crypto_cipher *tfm, u8 *ctrblk,

				    unsigned int countersize)

				    struct crypto_cipher *tfm)

{

	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =

		   crypto_cipher_alg(tfm)->cia_encrypt;

	unsigned int bsize = crypto_cipher_blocksize(tfm);

	unsigned long alignmask = crypto_cipher_alignmask(tfm);

	unsigned int nbytes = walk->nbytes;

	u8 *ctrblk = walk->iv;

	u8 *src = walk->src.virt.addr;

	u8 *keystream = ctrblk + bsize;

	u8 tmp[bsize + alignmask];

	u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);



	do {

		/* create keystream */
@@ -117,7 +110,7 @@ static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk, 
		crypto_xor(src, keystream, bsize);



		/* increment counter in counterblock */

		crypto_inc(ctrblk + bsize - countersize, countersize);

		crypto_inc(ctrblk, bsize);



		src += bsize;

	} while ((nbytes -= bsize) >= bsize);
@@ -134,41 +127,22 @@ static int crypto_ctr_crypt(struct blkcipher_desc *desc, 
	struct crypto_ctr_ctx *ctx = crypto_blkcipher_ctx(tfm);

	struct crypto_cipher *child = ctx->child;

	unsigned int bsize = crypto_cipher_blocksize(child);

	struct ctr_instance_ctx *ictx =

		crypto_instance_ctx(crypto_tfm_alg_instance(&tfm->base));

	unsigned long alignmask = crypto_cipher_alignmask(child) |

				  (__alignof__(u32) - 1);

	u8 cblk[bsize * 2 + alignmask];

	u8 *counterblk = (u8 *)ALIGN((unsigned long)cblk, alignmask + 1);

	int err;



	blkcipher_walk_init(&walk, dst, src, nbytes);

	err = blkcipher_walk_virt_block(desc, &walk, bsize);



	/* set up counter block */

	memset(counterblk, 0 , bsize);

	memcpy(counterblk, ctx->nonce, ictx->noncesize);

	memcpy(counterblk + ictx->noncesize, walk.iv, ictx->ivsize);



	/* initialize counter portion of counter block */

	crypto_inc(counterblk + bsize - ictx->countersize, ictx->countersize);



	while (walk.nbytes >= bsize) {

		if (walk.src.virt.addr == walk.dst.virt.addr)

			nbytes = crypto_ctr_crypt_inplace(&walk, child,

							  counterblk,

							  ictx->countersize);

			nbytes = crypto_ctr_crypt_inplace(&walk, child);

		else

			nbytes = crypto_ctr_crypt_segment(&walk, child,

							  counterblk,

							  ictx->countersize);

			nbytes = crypto_ctr_crypt_segment(&walk, child);



		err = blkcipher_walk_done(desc, &walk, nbytes);

	}



	if (walk.nbytes) {

		crypto_ctr_crypt_final(&walk, child, counterblk,

				       ictx->countersize);

		crypto_ctr_crypt_final(&walk, child);

		err = blkcipher_walk_done(desc, &walk, 0);

	}
@@ -178,15 +152,11 @@ static int crypto_ctr_crypt(struct blkcipher_desc *desc, 
static int crypto_ctr_init_tfm(struct crypto_tfm *tfm)

{

	struct crypto_instance *inst = (void *)tfm->__crt_alg;

	struct ctr_instance_ctx *ictx = crypto_instance_ctx(inst);

	struct crypto_spawn *spawn = crypto_instance_ctx(inst);

	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);

	struct crypto_cipher *cipher;



	ctx->nonce = kzalloc(ictx->noncesize, GFP_KERNEL);

	if (!ctx->nonce)

		return -ENOMEM;



	cipher = crypto_spawn_cipher(&ictx->alg);

	cipher = crypto_spawn_cipher(spawn);

	if (IS_ERR(cipher))

		return PTR_ERR(cipher);
@@ -199,7 +169,6 @@ static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm) 
{

	struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);



	kfree(ctx->nonce);

	crypto_free_cipher(ctx->child);

}
@@ -207,10 +176,6 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb) 
{

	struct crypto_instance *inst;

	struct crypto_alg *alg;

	struct ctr_instance_ctx *ictx;

	unsigned int noncesize;

	unsigned int ivsize;

	unsigned int countersize;

	int err;



	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
@@ -222,71 +187,28 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb) 
	if (IS_ERR(alg))

		return ERR_PTR(PTR_ERR(alg));



	err = crypto_attr_u32(tb[2], &noncesize);

	if (err)

		goto out_put_alg;



	err = crypto_attr_u32(tb[3], &ivsize);

	if (err)

		goto out_put_alg;



	err = crypto_attr_u32(tb[4], &countersize);

	if (err)

		goto out_put_alg;



	/* verify size of nonce + iv + counter

	 * counter must be >= 4 bytes.

	 */

	/* Block size must be >= 4 bytes. */

	err = -EINVAL;

	if (((noncesize + ivsize + countersize) < alg->cra_blocksize) ||

	    ((noncesize + ivsize) > alg->cra_blocksize) ||

	    (countersize > alg->cra_blocksize) || (countersize < 4))

	if (alg->cra_blocksize < 4)

		goto out_put_alg;



	/* If this is false we'd fail the alignment of crypto_inc. */

	if ((alg->cra_blocksize - countersize) % 4)

	if (alg->cra_blocksize % 4)

		goto out_put_alg;



	inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);

	err = -ENOMEM;

	if (!inst)

		goto out_put_alg;



	err = -ENAMETOOLONG;

	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,

		     "ctr(%s,%u,%u,%u)", alg->cra_name, noncesize,

		     ivsize, countersize) >= CRYPTO_MAX_ALG_NAME) {

		goto err_free_inst;

	}



	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,

		     "ctr(%s,%u,%u,%u)", alg->cra_driver_name, noncesize,

		     ivsize, countersize) >= CRYPTO_MAX_ALG_NAME) {

		goto err_free_inst;

	}



	ictx = crypto_instance_ctx(inst);

	ictx->noncesize = noncesize;

	ictx->ivsize = ivsize;

	ictx->countersize = countersize;



	err = crypto_init_spawn(&ictx->alg, alg, inst,

		CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);

	if (err)

		goto err_free_inst;

	inst = crypto_alloc_instance("ctr", alg);

	if (IS_ERR(inst))

		goto out;



	err = 0;

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;

	inst->alg.cra_priority = alg->cra_priority;

	inst->alg.cra_blocksize = 1;

	inst->alg.cra_alignmask = alg->cra_alignmask | (__alignof__(u32) - 1);

	inst->alg.cra_type = &crypto_blkcipher_type;



	inst->alg.cra_blkcipher.ivsize = ivsize;

	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize

					      + noncesize;

	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize

					      + noncesize;

	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;

	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;

	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;



	inst->alg.cra_ctxsize = sizeof(struct crypto_ctr_ctx);
@@ -297,24 +219,18 @@ static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb) 
	inst->alg.cra_blkcipher.encrypt = crypto_ctr_crypt;

	inst->alg.cra_blkcipher.decrypt = crypto_ctr_crypt;



err_free_inst:

	if (err)

		kfree(inst);



out_put_alg:

out:

	crypto_mod_put(alg);

	return inst;



	if (err)

out_put_alg:

	inst = ERR_PTR(err);



	return inst;

	goto out;

}



static void crypto_ctr_free(struct crypto_instance *inst)

{

	struct ctr_instance_ctx *ictx = crypto_instance_ctx(inst);



	crypto_drop_spawn(&ictx->alg);

	crypto_drop_spawn(crypto_instance_ctx(inst));

	kfree(inst);

}
@@ -325,13 +241,174 @@ static struct crypto_template crypto_ctr_tmpl = { 
	.module = THIS_MODULE,

};



static int crypto_rfc3686_setkey(struct crypto_tfm *parent, const u8 *key,

				 unsigned int keylen)

{

	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(parent);

	struct crypto_blkcipher *child = ctx->child;

	int err;



	/* the nonce is stored in bytes at end of key */

	if (keylen < CTR_RFC3686_NONCE_SIZE)

		return -EINVAL;



	memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),

	       CTR_RFC3686_NONCE_SIZE);



	keylen -= CTR_RFC3686_NONCE_SIZE;



	crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);

	crypto_blkcipher_set_flags(child, crypto_tfm_get_flags(parent) &

					  CRYPTO_TFM_REQ_MASK);

	err = crypto_blkcipher_setkey(child, key, keylen);

	crypto_tfm_set_flags(parent, crypto_blkcipher_get_flags(child) &

				     CRYPTO_TFM_RES_MASK);



	return err;

}



static int crypto_rfc3686_crypt(struct blkcipher_desc *desc,

				struct scatterlist *dst,

				struct scatterlist *src, unsigned int nbytes)

{

	struct crypto_blkcipher *tfm = desc->tfm;

	struct crypto_rfc3686_ctx *ctx = crypto_blkcipher_ctx(tfm);

	struct crypto_blkcipher *child = ctx->child;

	unsigned long alignmask = crypto_blkcipher_alignmask(tfm);

	u8 ivblk[CTR_RFC3686_BLOCK_SIZE + alignmask];

	u8 *iv = PTR_ALIGN(ivblk + 0, alignmask + 1);

	u8 *info = desc->info;

	int err;



	/* set up counter block */

	memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);

	memcpy(iv + CTR_RFC3686_NONCE_SIZE, info, CTR_RFC3686_IV_SIZE);



	/* initialize counter portion of counter block */

	*(__be32 *)(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =

		cpu_to_be32(1);



	desc->tfm = child;

	desc->info = iv;

	err = crypto_blkcipher_encrypt_iv(desc, dst, src, nbytes);

	desc->tfm = tfm;

	desc->info = info;



	return err;

}



static int crypto_rfc3686_init_tfm(struct crypto_tfm *tfm)

{

	struct crypto_instance *inst = (void *)tfm->__crt_alg;

	struct crypto_spawn *spawn = crypto_instance_ctx(inst);

	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);

	struct crypto_blkcipher *cipher;



	cipher = crypto_spawn_blkcipher(spawn);

	if (IS_ERR(cipher))

		return PTR_ERR(cipher);



	ctx->child = cipher;



	return 0;

}



static void crypto_rfc3686_exit_tfm(struct crypto_tfm *tfm)

{

	struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);



	crypto_free_blkcipher(ctx->child);

}



static struct crypto_instance *crypto_rfc3686_alloc(struct rtattr **tb)

{

	struct crypto_instance *inst;

	struct crypto_alg *alg;

	int err;



	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);

	if (err)

		return ERR_PTR(err);



	alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_BLKCIPHER,

				  CRYPTO_ALG_TYPE_MASK);

	err = PTR_ERR(alg);

	if (IS_ERR(alg))

		return ERR_PTR(err);



	/* We only support 16-byte blocks. */

	err = -EINVAL;

	if (alg->cra_blkcipher.ivsize != CTR_RFC3686_BLOCK_SIZE)

		goto out_put_alg;



	/* Not a stream cipher? */

	if (alg->cra_blocksize != 1)

		goto out_put_alg;



	inst = crypto_alloc_instance("rfc3686", alg);

	if (IS_ERR(inst))

		goto out;



	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;

	inst->alg.cra_priority = alg->cra_priority;

	inst->alg.cra_blocksize = 1;

	inst->alg.cra_alignmask = alg->cra_alignmask;

	inst->alg.cra_type = &crypto_blkcipher_type;



	inst->alg.cra_blkcipher.ivsize = CTR_RFC3686_IV_SIZE;

	inst->alg.cra_blkcipher.min_keysize = alg->cra_blkcipher.min_keysize

					      + CTR_RFC3686_NONCE_SIZE;

	inst->alg.cra_blkcipher.max_keysize = alg->cra_blkcipher.max_keysize

					      + CTR_RFC3686_NONCE_SIZE;



	inst->alg.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);



	inst->alg.cra_init = crypto_rfc3686_init_tfm;

	inst->alg.cra_exit = crypto_rfc3686_exit_tfm;



	inst->alg.cra_blkcipher.setkey = crypto_rfc3686_setkey;

	inst->alg.cra_blkcipher.encrypt = crypto_rfc3686_crypt;

	inst->alg.cra_blkcipher.decrypt = crypto_rfc3686_crypt;



out:

	crypto_mod_put(alg);

	return inst;



out_put_alg:

	inst = ERR_PTR(err);

	goto out;

}



static struct crypto_template crypto_rfc3686_tmpl = {

	.name = "rfc3686",

	.alloc = crypto_rfc3686_alloc,

	.free = crypto_ctr_free,

	.module = THIS_MODULE,

};



static int __init crypto_ctr_module_init(void)

{

	return crypto_register_template(&crypto_ctr_tmpl);

	int err;



	err = crypto_register_template(&crypto_ctr_tmpl);

	if (err)

		goto out;



	err = crypto_register_template(&crypto_rfc3686_tmpl);

	if (err)

		goto out_drop_ctr;



out:

	return err;



out_drop_ctr:

	crypto_unregister_template(&crypto_ctr_tmpl);

	goto out;

}



static void __exit crypto_ctr_module_exit(void)

{

	crypto_unregister_template(&crypto_rfc3686_tmpl);

	crypto_unregister_template(&crypto_ctr_tmpl);

}
@@ -340,3 +417,4 @@ module_exit(crypto_ctr_module_exit); 


MODULE_LICENSE("GPL");

MODULE_DESCRIPTION("CTR Counter block mode");

MODULE_ALIAS("rfc3686");

crypto/gcm.c

+3 −4
Original line number Diff line number Diff line
@@ -160,7 +160,7 @@ static void crypto_gcm_ghash_final_xor(struct crypto_gcm_ghash_ctx *ctx, 


static inline void crypto_gcm_set_counter(u8 *counterblock, u32 value)

{

	*((u32 *)&counterblock[12]) = cpu_to_be32(value);

	*((u32 *)&counterblock[12]) = cpu_to_be32(value + 1);

}



static int crypto_gcm_encrypt_counter(struct crypto_aead *aead, u8 *block,
@@ -400,9 +400,8 @@ static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb) 
		return inst;



	inst = ERR_PTR(ENAMETOOLONG);

	if (snprintf(

		    ctr_name, CRYPTO_MAX_ALG_NAME,

		    "ctr(%s,0,16,4)", cipher->cra_name) >= CRYPTO_MAX_ALG_NAME)

	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",

		     cipher->cra_name) >= CRYPTO_MAX_ALG_NAME)

		return inst;



	ctr = crypto_alg_mod_lookup(ctr_name, CRYPTO_ALG_TYPE_BLKCIPHER,

crypto/tcrypt.c

+4 −4
Original line number Diff line number Diff line
@@ -1193,9 +1193,9 @@ static void do_test(void) 
			    AES_XTS_ENC_TEST_VECTORS);

		test_cipher("xts(aes)", DECRYPT, aes_xts_dec_tv_template,

			    AES_XTS_DEC_TEST_VECTORS);

		test_cipher("ctr(aes,4,8,4)", ENCRYPT, aes_ctr_enc_tv_template,

		test_cipher("rfc3686(ctr(aes))", ENCRYPT, aes_ctr_enc_tv_template,

			    AES_CTR_ENC_TEST_VECTORS);

		test_cipher("ctr(aes,4,8,4)", DECRYPT, aes_ctr_dec_tv_template,

		test_cipher("rfc3686(ctr(aes))", DECRYPT, aes_ctr_dec_tv_template,

			    AES_CTR_DEC_TEST_VECTORS);

		test_aead("gcm(aes)", ENCRYPT, aes_gcm_enc_tv_template,

			  AES_GCM_ENC_TEST_VECTORS);
@@ -1394,9 +1394,9 @@ static void do_test(void) 
			    AES_XTS_ENC_TEST_VECTORS);

		test_cipher("xts(aes)", DECRYPT, aes_xts_dec_tv_template,

			    AES_XTS_DEC_TEST_VECTORS);

		test_cipher("ctr(aes,4,8,4)", ENCRYPT, aes_ctr_enc_tv_template,

		test_cipher("rfc3686(ctr(aes))", ENCRYPT, aes_ctr_enc_tv_template,

			    AES_CTR_ENC_TEST_VECTORS);

		test_cipher("ctr(aes,4,8,4)", DECRYPT, aes_ctr_dec_tv_template,

		test_cipher("rfc3686(ctr(aes))", DECRYPT, aes_ctr_dec_tv_template,

			    AES_CTR_DEC_TEST_VECTORS);

		break;

include/crypto/ctr.h

0 → 100644
+20 −0
Original line number Diff line number Diff line 
/*

 * CTR: Counter mode

 *

 * Copyright (c) 2007 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.

 *

 */



#ifndef _CRYPTO_CTR_H

#define _CRYPTO_CTR_H



#define CTR_RFC3686_NONCE_SIZE 4

#define CTR_RFC3686_IV_SIZE 8

#define CTR_RFC3686_BLOCK_SIZE 16



#endif  /* _CRYPTO_CTR_H */

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