diff options
Diffstat (limited to 'crypto/sha1_generic.c')
-rw-r--r-- | crypto/sha1_generic.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/crypto/sha1_generic.c b/crypto/sha1_generic.c new file mode 100644 index 000000000000..70364dd5c45a --- /dev/null +++ b/crypto/sha1_generic.c @@ -0,0 +1,142 @@ +/* + * 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(struct crypto_tfm *tfm) +{ + struct sha1_ctx *sctx = crypto_tfm_ctx(tfm); + static const struct sha1_ctx initstate = { + 0, + { 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0 }, + { 0, } + }; + + *sctx = initstate; +} + +static void sha1_update(struct crypto_tfm *tfm, const u8 *data, + unsigned int len) +{ + struct sha1_ctx *sctx = crypto_tfm_ctx(tfm); + 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(struct crypto_tfm *tfm, u8 *out) +{ + struct sha1_ctx *sctx = crypto_tfm_ctx(tfm); + __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(tfm, padding, padlen); + + /* Append length */ + sha1_update(tfm, (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_driver_name= "sha1-generic", + .cra_flags = CRYPTO_ALG_TYPE_DIGEST, + .cra_blocksize = SHA1_HMAC_BLOCK_SIZE, + .cra_ctxsize = sizeof(struct sha1_ctx), + .cra_module = THIS_MODULE, + .cra_alignmask = 3, + .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"); + +MODULE_ALIAS("sha1"); |