c9a3ff8f22
Convert salsa20-asm from the deprecated "blkcipher" API to the "skcipher" API, in the process fixing it up to use the generic helpers. This allows removing the salsa20_keysetup() and salsa20_ivsetup() assembly functions, which aren't performance critical; the C versions do just fine. This also fixes the same bug that salsa20-generic had, where the state array was being maintained directly in the transform context rather than on the stack or in the request context. Thus, if multiple threads used the same Salsa20 transform concurrently they produced the wrong results. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
92 lines
2.6 KiB
C
92 lines
2.6 KiB
C
/*
|
|
* Glue code for optimized assembly version of Salsa20.
|
|
*
|
|
* Copyright (c) 2007 Tan Swee Heng <thesweeheng@gmail.com>
|
|
*
|
|
* The assembly codes are public domain assembly codes written by Daniel. J.
|
|
* Bernstein <djb@cr.yp.to>. The codes are modified to include indentation
|
|
* and to remove extraneous comments and functions that are not needed.
|
|
* - i586 version, renamed as salsa20-i586-asm_32.S
|
|
* available from <http://cr.yp.to/snuffle/salsa20/x86-pm/salsa20.s>
|
|
* - x86-64 version, renamed as salsa20-x86_64-asm_64.S
|
|
* available from <http://cr.yp.to/snuffle/salsa20/amd64-3/salsa20.s>
|
|
*
|
|
* Also modified to set up the initial state using the generic C code rather
|
|
* than in assembly.
|
|
*
|
|
* 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 <asm/unaligned.h>
|
|
#include <crypto/internal/skcipher.h>
|
|
#include <crypto/salsa20.h>
|
|
#include <linux/module.h>
|
|
|
|
asmlinkage void salsa20_encrypt_bytes(u32 state[16], const u8 *src, u8 *dst,
|
|
u32 bytes);
|
|
|
|
static int salsa20_asm_crypt(struct skcipher_request *req)
|
|
{
|
|
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
|
|
const struct salsa20_ctx *ctx = crypto_skcipher_ctx(tfm);
|
|
struct skcipher_walk walk;
|
|
u32 state[16];
|
|
int err;
|
|
|
|
err = skcipher_walk_virt(&walk, req, true);
|
|
|
|
crypto_salsa20_init(state, ctx, walk.iv);
|
|
|
|
while (walk.nbytes > 0) {
|
|
unsigned int nbytes = walk.nbytes;
|
|
|
|
if (nbytes < walk.total)
|
|
nbytes = round_down(nbytes, walk.stride);
|
|
|
|
salsa20_encrypt_bytes(state, walk.src.virt.addr,
|
|
walk.dst.virt.addr, nbytes);
|
|
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static struct skcipher_alg alg = {
|
|
.base.cra_name = "salsa20",
|
|
.base.cra_driver_name = "salsa20-asm",
|
|
.base.cra_priority = 200,
|
|
.base.cra_blocksize = 1,
|
|
.base.cra_ctxsize = sizeof(struct salsa20_ctx),
|
|
.base.cra_module = THIS_MODULE,
|
|
|
|
.min_keysize = SALSA20_MIN_KEY_SIZE,
|
|
.max_keysize = SALSA20_MAX_KEY_SIZE,
|
|
.ivsize = SALSA20_IV_SIZE,
|
|
.chunksize = SALSA20_BLOCK_SIZE,
|
|
.setkey = crypto_salsa20_setkey,
|
|
.encrypt = salsa20_asm_crypt,
|
|
.decrypt = salsa20_asm_crypt,
|
|
};
|
|
|
|
static int __init init(void)
|
|
{
|
|
return crypto_register_skcipher(&alg);
|
|
}
|
|
|
|
static void __exit fini(void)
|
|
{
|
|
crypto_unregister_skcipher(&alg);
|
|
}
|
|
|
|
module_init(init);
|
|
module_exit(fini);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION ("Salsa20 stream cipher algorithm (optimized assembly version)");
|
|
MODULE_ALIAS_CRYPTO("salsa20");
|
|
MODULE_ALIAS_CRYPTO("salsa20-asm");
|