mirror of
https://github.com/torvalds/linux
synced 2024-10-04 18:33:42 +00:00
a1d9306409
Expose the existing generic Poly1305 code via a init/update/final library interface so that callers are not required to go through the crypto API's shash abstraction to access it. At the same time, make some preparations so that the library implementation can be superseded by an accelerated arch-specific version in the future. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
130 lines
3.1 KiB
C
130 lines
3.1 KiB
C
/*
|
|
* Poly1305 authenticator algorithm, RFC7539
|
|
*
|
|
* Copyright (C) 2015 Martin Willi
|
|
*
|
|
* Based on public domain code by Andrew Moon and Daniel J. Bernstein.
|
|
*
|
|
* 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 <crypto/algapi.h>
|
|
#include <crypto/internal/hash.h>
|
|
#include <crypto/internal/poly1305.h>
|
|
#include <linux/crypto.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <asm/unaligned.h>
|
|
|
|
int crypto_poly1305_init(struct shash_desc *desc)
|
|
{
|
|
struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
|
|
|
|
poly1305_core_init(&dctx->h);
|
|
dctx->buflen = 0;
|
|
dctx->rset = 0;
|
|
dctx->sset = false;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_poly1305_init);
|
|
|
|
static void poly1305_blocks(struct poly1305_desc_ctx *dctx, const u8 *src,
|
|
unsigned int srclen)
|
|
{
|
|
unsigned int datalen;
|
|
|
|
if (unlikely(!dctx->sset)) {
|
|
datalen = crypto_poly1305_setdesckey(dctx, src, srclen);
|
|
src += srclen - datalen;
|
|
srclen = datalen;
|
|
}
|
|
|
|
poly1305_core_blocks(&dctx->h, dctx->r, src,
|
|
srclen / POLY1305_BLOCK_SIZE, 1);
|
|
}
|
|
|
|
int crypto_poly1305_update(struct shash_desc *desc,
|
|
const u8 *src, unsigned int srclen)
|
|
{
|
|
struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
|
|
unsigned int bytes;
|
|
|
|
if (unlikely(dctx->buflen)) {
|
|
bytes = min(srclen, POLY1305_BLOCK_SIZE - dctx->buflen);
|
|
memcpy(dctx->buf + dctx->buflen, src, bytes);
|
|
src += bytes;
|
|
srclen -= bytes;
|
|
dctx->buflen += bytes;
|
|
|
|
if (dctx->buflen == POLY1305_BLOCK_SIZE) {
|
|
poly1305_blocks(dctx, dctx->buf,
|
|
POLY1305_BLOCK_SIZE);
|
|
dctx->buflen = 0;
|
|
}
|
|
}
|
|
|
|
if (likely(srclen >= POLY1305_BLOCK_SIZE)) {
|
|
poly1305_blocks(dctx, src, srclen);
|
|
src += srclen - (srclen % POLY1305_BLOCK_SIZE);
|
|
srclen %= POLY1305_BLOCK_SIZE;
|
|
}
|
|
|
|
if (unlikely(srclen)) {
|
|
dctx->buflen = srclen;
|
|
memcpy(dctx->buf, src, srclen);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_poly1305_update);
|
|
|
|
int crypto_poly1305_final(struct shash_desc *desc, u8 *dst)
|
|
{
|
|
struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);
|
|
|
|
if (unlikely(!dctx->sset))
|
|
return -ENOKEY;
|
|
|
|
poly1305_final_generic(dctx, dst);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(crypto_poly1305_final);
|
|
|
|
static struct shash_alg poly1305_alg = {
|
|
.digestsize = POLY1305_DIGEST_SIZE,
|
|
.init = crypto_poly1305_init,
|
|
.update = crypto_poly1305_update,
|
|
.final = crypto_poly1305_final,
|
|
.descsize = sizeof(struct poly1305_desc_ctx),
|
|
.base = {
|
|
.cra_name = "poly1305",
|
|
.cra_driver_name = "poly1305-generic",
|
|
.cra_priority = 100,
|
|
.cra_blocksize = POLY1305_BLOCK_SIZE,
|
|
.cra_module = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static int __init poly1305_mod_init(void)
|
|
{
|
|
return crypto_register_shash(&poly1305_alg);
|
|
}
|
|
|
|
static void __exit poly1305_mod_exit(void)
|
|
{
|
|
crypto_unregister_shash(&poly1305_alg);
|
|
}
|
|
|
|
subsys_initcall(poly1305_mod_init);
|
|
module_exit(poly1305_mod_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
|
|
MODULE_DESCRIPTION("Poly1305 authenticator");
|
|
MODULE_ALIAS_CRYPTO("poly1305");
|
|
MODULE_ALIAS_CRYPTO("poly1305-generic");
|