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/*
* Cryptographic API.
*
* SHA1 Secure Hash Algorithm.
*
* Derived from cryptoapi implementation, adapted for in-place
* scatterlist interface.
*
* Copyright (c) Alan Smithee.
* Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
* Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
*
* 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/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/crypto.h>
#include <linux/cryptohash.h>
#include <linux/types.h>
#include <asm/scatterlist.h>
#include <asm/byteorder.h>
#define SHA1_DIGEST_SIZE 20
#define SHA1_HMAC_BLOCK_SIZE 64
struct sha1_ctx {
u64 count;
u32 state[5];
u8 buffer[64];
};
static void sha1_init(void *ctx)
{
struct sha1_ctx *sctx = ctx;
static const struct sha1_ctx initstate = {
0,
{ 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0 },
{ 0, }
};
*sctx = initstate;
}
static void sha1_update(void *ctx, const u8 *data, unsigned int len)
{
struct sha1_ctx *sctx = ctx;
unsigned int partial, done;
const u8 *src;
partial = sctx->count & 0x3f;
sctx->count += len;
done = 0;
src = data;
if ((partial + len) > 63) {
u32 temp[SHA_WORKSPACE_WORDS];
if (partial) {
done = 64 - partial;
memcpy(sctx->buffer + partial, data, done);
src = sctx->buffer;
}
do {
sha_transform(sctx->state, src, temp);
done += 64;
src = data + done;
} while (done + 63 < len);
memset(temp, 0, sizeof(temp));
partial = 0;
}
memcpy(sctx->buffer + partial, src, len - done);
}
/* Add padding and return the message digest. */
static void sha1_final(void* ctx, u8 *out)
{
struct sha1_ctx *sctx = ctx;
__be32 *dst = (__be32 *)out;
u32 i, index, padlen;
__be64 bits;
static const u8 padding[64] = { 0x80, };
bits = cpu_to_be64(sctx->count << 3);
/* Pad out to 56 mod 64 */
index = sctx->count & 0x3f;
padlen = (index < 56) ? (56 - index) : ((64+56) - index);
sha1_update(sctx, padding, padlen);
/* Append length */
sha1_update(sctx, (const u8 *)&bits, sizeof(bits));
/* Store state in digest */
for (i = 0; i < 5; i++)
dst[i] = cpu_to_be32(sctx->state[i]);
/* Wipe context */
memset(sctx, 0, sizeof *sctx);
}
static struct crypto_alg alg = {
.cra_name = "sha1",
.cra_flags = CRYPTO_ALG_TYPE_DIGEST,
.cra_blocksize = SHA1_HMAC_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct sha1_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(alg.cra_list),
.cra_u = { .digest = {
.dia_digestsize = SHA1_DIGEST_SIZE,
.dia_init = sha1_init,
.dia_update = sha1_update,
.dia_final = sha1_final } }
};
static int __init init(void)
{
return crypto_register_alg(&alg);
}
static void __exit fini(void)
{
crypto_unregister_alg(&alg);
}
module_init(init);
module_exit(fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
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