/* * 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 <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 i, j; u32 temp[SHA_WORKSPACE_WORDS]; j = (sctx->count >> 3) & 0x3f; sctx->count += len << 3; if ((j + len) > 63) { memcpy(&sctx->buffer[j], data, (i = 64-j)); sha_transform(sctx->state, sctx->buffer, temp); for ( ; i + 63 < len; i += 64) { sha_transform(sctx->state, &data[i], temp); } j = 0; } else i = 0; memset(temp, 0, sizeof(temp)); memcpy(&sctx->buffer[j], &data[i], len - i); } /* Add padding and return the message digest. */ static void sha1_final(void* ctx, u8 *out) { struct sha1_ctx *sctx = ctx; u32 i, j, index, padlen; u64 t; u8 bits[8] = { 0, }; static const u8 padding[64] = { 0x80, }; t = sctx->count; bits[7] = 0xff & t; t>>=8; bits[6] = 0xff & t; t>>=8; bits[5] = 0xff & t; t>>=8; bits[4] = 0xff & t; t>>=8; bits[3] = 0xff & t; t>>=8; bits[2] = 0xff & t; t>>=8; bits[1] = 0xff & t; t>>=8; bits[0] = 0xff & t; /* Pad out to 56 mod 64 */ index = (sctx->count >> 3) & 0x3f; padlen = (index < 56) ? (56 - index) : ((64+56) - index); sha1_update(sctx, padding, padlen); /* Append length */ sha1_update(sctx, bits, sizeof bits); /* Store state in digest */ for (i = j = 0; i < 5; i++, j += 4) { u32 t2 = sctx->state[i]; out[j+3] = t2 & 0xff; t2>>=8; out[j+2] = t2 & 0xff; t2>>=8; out[j+1] = t2 & 0xff; t2>>=8; out[j ] = t2 & 0xff; } /* 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");