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Commit eb772f37 authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: salsa20 - export generic helpers 



Export the Salsa20 constants, transform context, and initialization
functions so that they can be reused by the x86 implementation.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent b62b3db7

crypto/salsa20_generic.c

+7 −13
Original line number Diff line number Diff line
@@ -21,17 +21,9 @@ 


#include <asm/unaligned.h>

#include <crypto/internal/skcipher.h>

#include <crypto/salsa20.h>

#include <linux/module.h>



#define SALSA20_IV_SIZE        8

#define SALSA20_MIN_KEY_SIZE  16

#define SALSA20_MAX_KEY_SIZE  32

#define SALSA20_BLOCK_SIZE    64



struct salsa20_ctx {

	u32 initial_state[16];

};



static void salsa20_block(u32 *state, __le32 *stream)

{

	u32 x[16];
@@ -101,15 +93,16 @@ static void salsa20_docrypt(u32 *state, u8 *dst, const u8 *src, 
	}

}



static void salsa20_init(u32 *state, const struct salsa20_ctx *ctx,

void crypto_salsa20_init(u32 *state, const struct salsa20_ctx *ctx,

			 const u8 *iv)

{

	memcpy(state, ctx->initial_state, sizeof(ctx->initial_state));

	state[6] = get_unaligned_le32(iv + 0);

	state[7] = get_unaligned_le32(iv + 4);

}

EXPORT_SYMBOL_GPL(crypto_salsa20_init);



static int salsa20_setkey(struct crypto_skcipher *tfm, const u8 *key,

int crypto_salsa20_setkey(struct crypto_skcipher *tfm, const u8 *key,

			  unsigned int keysize)

{

	static const char sigma[16] = "expand 32-byte k";
@@ -150,6 +143,7 @@ static int salsa20_setkey(struct crypto_skcipher *tfm, const u8 *key, 


	return 0;

}

EXPORT_SYMBOL_GPL(crypto_salsa20_setkey);



static int salsa20_crypt(struct skcipher_request *req)

{
@@ -161,7 +155,7 @@ static int salsa20_crypt(struct skcipher_request *req) 


	err = skcipher_walk_virt(&walk, req, true);



	salsa20_init(state, ctx, walk.iv);

	crypto_salsa20_init(state, ctx, walk.iv);



	while (walk.nbytes > 0) {

		unsigned int nbytes = walk.nbytes;
@@ -189,7 +183,7 @@ static struct skcipher_alg alg = { 
	.max_keysize		= SALSA20_MAX_KEY_SIZE,

	.ivsize			= SALSA20_IV_SIZE,

	.chunksize		= SALSA20_BLOCK_SIZE,

	.setkey			= salsa20_setkey,

	.setkey			= crypto_salsa20_setkey,

	.encrypt		= salsa20_crypt,

	.decrypt		= salsa20_crypt,

};

include/crypto/salsa20.h

0 → 100644
+27 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

/*

 * Common values for the Salsa20 algorithm

 */



#ifndef _CRYPTO_SALSA20_H

#define _CRYPTO_SALSA20_H



#include <linux/types.h>



#define SALSA20_IV_SIZE		8

#define SALSA20_MIN_KEY_SIZE	16

#define SALSA20_MAX_KEY_SIZE	32

#define SALSA20_BLOCK_SIZE	64



struct crypto_skcipher;



struct salsa20_ctx {

	u32 initial_state[16];

};



void crypto_salsa20_init(u32 *state, const struct salsa20_ctx *ctx,

			 const u8 *iv);

int crypto_salsa20_setkey(struct crypto_skcipher *tfm, const u8 *key,

			  unsigned int keysize);



#endif /* _CRYPTO_SALSA20_H */