bcachefs-tools/linux/crypto/poly1305_generic.c
2018-05-17 07:24:39 -04:00

89 lines
2.1 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 <linux/byteorder.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <asm/unaligned.h>
#include <linux/crypto.h>
#include <crypto/algapi.h>
#include <crypto/hash.h>
#include <crypto/poly1305.h>
static struct shash_alg poly1305_alg;
struct poly1305_desc_ctx {
bool key_done;
crypto_onetimeauth_poly1305_state s;
};
static int poly1305_init(struct shash_desc *desc)
{
struct poly1305_desc_ctx *state = (void *) desc->ctx;
state->key_done = false;
return 0;
}
static int poly1305_update(struct shash_desc *desc,
const u8 *src, unsigned len)
{
struct poly1305_desc_ctx *state = (void *) desc->ctx;
if (!state->key_done) {
BUG_ON(len != crypto_onetimeauth_poly1305_KEYBYTES);
state->key_done = true;
return crypto_onetimeauth_poly1305_init(&state->s, src);
}
return crypto_onetimeauth_poly1305_update(&state->s, src, len);
}
static int poly1305_final(struct shash_desc *desc, u8 *out)
{
struct poly1305_desc_ctx *state = (void *) desc->ctx;
return crypto_onetimeauth_poly1305_final(&state->s, out);
}
static void *poly1305_alloc_tfm(void)
{
struct crypto_shash *tfm = kzalloc(sizeof(*tfm), GFP_KERNEL);
if (!tfm)
return NULL;
tfm->base.alg = &poly1305_alg.base;
tfm->descsize = sizeof(struct poly1305_desc_ctx);
return tfm;
}
static struct shash_alg poly1305_alg = {
.digestsize = crypto_onetimeauth_poly1305_BYTES,
.init = poly1305_init,
.update = poly1305_update,
.final = poly1305_final,
.descsize = sizeof(struct poly1305_desc_ctx),
.base.cra_name = "poly1305",
.base.alloc_tfm = poly1305_alloc_tfm,
};
__attribute__((constructor(110)))
static int poly1305_mod_init(void)
{
return crypto_register_shash(&poly1305_alg);
}