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crypto: chacha20 - Export common ChaCha20 helpers

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As architecture specific drivers need a software fallback, export a
ChaCha20 en-/decryption function together with some helpers in a header
file.

Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Martin Willi 2015-07-16 19:14:00 +02:00 committed by Herbert Xu
parent 2dce063a31
commit 31d7247da5
3 changed files with 38 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
crypto/chacha20_generic.c
View File

@ -13,14 +13,7 @@
#include <linux/crypto.h> #include <linux/crypto.h>
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/module.h> #include <linux/module.h>
#include <crypto/chacha20.h>
#define CHACHA20_NONCE_SIZE 16
#define CHACHA20_KEY_SIZE 32
#define CHACHA20_BLOCK_SIZE 64
struct chacha20_ctx {
u32 key[8];
};
static inline u32 rotl32(u32 v, u8 n) static inline u32 rotl32(u32 v, u8 n)
{ {
@ -108,7 +101,7 @@ static void chacha20_docrypt(u32 *state, u8 *dst, const u8 *src,
} }
} }
static void chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv) void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv)
{ {
static const char constant[16] = "expand 32-byte k"; static const char constant[16] = "expand 32-byte k";
@ -129,8 +122,9 @@ static void chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv)
state[14] = le32_to_cpuvp(iv + 8); state[14] = le32_to_cpuvp(iv + 8);
state[15] = le32_to_cpuvp(iv + 12); state[15] = le32_to_cpuvp(iv + 12);
} }
EXPORT_SYMBOL_GPL(crypto_chacha20_init);
static int chacha20_setkey(struct crypto_tfm *tfm, const u8 *key, int crypto_chacha20_setkey(struct crypto_tfm *tfm, const u8 *key,
unsigned int keysize) unsigned int keysize)
{ {
struct chacha20_ctx *ctx = crypto_tfm_ctx(tfm); struct chacha20_ctx *ctx = crypto_tfm_ctx(tfm);
@ -144,8 +138,9 @@ static int chacha20_setkey(struct crypto_tfm *tfm, const u8 *key,
return 0; return 0;
} }
EXPORT_SYMBOL_GPL(crypto_chacha20_setkey);
static int chacha20_crypt(struct blkcipher_desc *desc, struct scatterlist *dst, int crypto_chacha20_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes) struct scatterlist *src, unsigned int nbytes)
{ {
struct blkcipher_walk walk; struct blkcipher_walk walk;
@ -155,7 +150,7 @@ static int chacha20_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
blkcipher_walk_init(&walk, dst, src, nbytes); blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt_block(desc, &walk, CHACHA20_BLOCK_SIZE); err = blkcipher_walk_virt_block(desc, &walk, CHACHA20_BLOCK_SIZE);
chacha20_init(state, crypto_blkcipher_ctx(desc->tfm), walk.iv); crypto_chacha20_init(state, crypto_blkcipher_ctx(desc->tfm), walk.iv);
while (walk.nbytes >= CHACHA20_BLOCK_SIZE) { while (walk.nbytes >= CHACHA20_BLOCK_SIZE) {
chacha20_docrypt(state, walk.dst.virt.addr, walk.src.virt.addr, chacha20_docrypt(state, walk.dst.virt.addr, walk.src.virt.addr,
@ -172,6 +167,7 @@ static int chacha20_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
return err; return err;
} }
EXPORT_SYMBOL_GPL(crypto_chacha20_crypt);
static struct crypto_alg alg = { static struct crypto_alg alg = {
.cra_name = "chacha20", .cra_name = "chacha20",
@ -187,11 +183,11 @@ static struct crypto_alg alg = {
.blkcipher = { .blkcipher = {
.min_keysize = CHACHA20_KEY_SIZE, .min_keysize = CHACHA20_KEY_SIZE,
.max_keysize = CHACHA20_KEY_SIZE, .max_keysize = CHACHA20_KEY_SIZE,
.ivsize = CHACHA20_NONCE_SIZE, .ivsize = CHACHA20_IV_SIZE,
.geniv = "seqiv", .geniv = "seqiv",
.setkey = chacha20_setkey, .setkey = crypto_chacha20_setkey,
.encrypt = chacha20_crypt, .encrypt = crypto_chacha20_crypt,
.decrypt = chacha20_crypt, .decrypt = crypto_chacha20_crypt,
}, },
}, },
}; };

3
crypto/chacha20poly1305.c
View File

@ -13,6 +13,7 @@
#include <crypto/internal/hash.h> #include <crypto/internal/hash.h>
#include <crypto/internal/skcipher.h> #include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h> #include <crypto/scatterwalk.h>
#include <crypto/chacha20.h>
#include <linux/err.h> #include <linux/err.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/kernel.h> #include <linux/kernel.h>
@ -23,8 +24,6 @@
#define POLY1305_BLOCK_SIZE 16 #define POLY1305_BLOCK_SIZE 16
#define POLY1305_DIGEST_SIZE 16 #define POLY1305_DIGEST_SIZE 16
#define POLY1305_KEY_SIZE 32 #define POLY1305_KEY_SIZE 32
#define CHACHA20_KEY_SIZE 32
#define CHACHA20_IV_SIZE 16
#define CHACHAPOLY_IV_SIZE 12 #define CHACHAPOLY_IV_SIZE 12
struct chachapoly_instance_ctx { struct chachapoly_instance_ctx {

25
include/crypto/chacha20.h Normal file
View File

@ -0,0 +1,25 @@
/*
* Common values for the ChaCha20 algorithm
*/
#ifndef _CRYPTO_CHACHA20_H
#define _CRYPTO_CHACHA20_H
#include <linux/types.h>
#include <linux/crypto.h>
#define CHACHA20_IV_SIZE 16
#define CHACHA20_KEY_SIZE 32
#define CHACHA20_BLOCK_SIZE 64
struct chacha20_ctx {
u32 key[8];
};
void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv);
int crypto_chacha20_setkey(struct crypto_tfm *tfm, const u8 *key,
unsigned int keysize);
int crypto_chacha20_crypt(struct blkcipher_desc *desc, struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes);
#endif