/* * 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 = -partial;			memcpy(sctx->buffer + partial, data, done + 64);			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");