diff options
Diffstat (limited to 'crypto/sha1.c')
-rw-r--r-- | crypto/sha1.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/crypto/sha1.c b/crypto/sha1.c new file mode 100644 index 0000000..4016f3b --- /dev/null +++ b/crypto/sha1.c @@ -0,0 +1,139 @@ +/* + * 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"); |