提交 5311f248 编写于 作者: H Herbert Xu

[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: NHerbert Xu <herbert@gondor.apana.org.au>
上级 653ebd9c
......@@ -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);
if (err)
inst = ERR_PTR(err);
return inst;
out_put_alg:
inst = ERR_PTR(err);
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");
......@@ -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,
......
......@@ -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;
......
/*
* 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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