Subversion Repositories or1k

/*

 * Cryptographic API.

 *

 * SHA1 Secure Hash Algorithm.

 *

 * Derived from cryptoapi implementation, adapted for in-place

 * scatterlist interface.  Originally based on the public domain

 * implementation written by Steve Reid.

 *

 * 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 <asm/scatterlist.h>

#include <asm/byteorder.h>

#define SHA1_DIGEST_SIZE        20

#define SHA1_HMAC_BLOCK_SIZE    64

static inline u32 rol(u32 value, u32 bits)

{

        return (((value) << (bits)) | ((value) >> (32 - (bits))));

}

/* blk0() and blk() perform the initial expand. */

/* I got the idea of expanding during the round function from SSLeay */

# define blk0(i) block32[i]

#define blk(i) (block32[i&15] = rol(block32[(i+13)&15]^block32[(i+8)&15] \

    ^block32[(i+2)&15]^block32[i&15],1))

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */

#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5); \

                        w=rol(w,30);

#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5); \

                        w=rol(w,30);

#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);

#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5); \

                        w=rol(w,30);

#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);

struct sha1_ctx {

        u64 count;

        u32 state[5];

        u8 buffer[64];

};

/* Hash a single 512-bit block. This is the core of the algorithm. */

static void sha1_transform(u32 *state, const u8 *in)

{

        u32 a, b, c, d, e;

        u32 block32[16];

        /* convert/copy data to workspace */

        for (a = 0; a < sizeof(block32)/sizeof(u32); a++)

          block32[a] = be32_to_cpu (((const u32 *)in)[a]);

        /* Copy context->state[] to working vars */

        a = state[0];

        b = state[1];

        c = state[2];

        d = state[3];

        e = state[4];

        /* 4 rounds of 20 operations each. Loop unrolled. */

        R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);

        R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);

        R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);

        R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);

        R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);

        R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);

        R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);

        R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);

        R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);

        R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);

        R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);

        R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);

        R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);

        R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);

        R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);

        R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);

        R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);

        R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);

        R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);

        R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);

        /* Add the working vars back into context.state[] */

        state[0] += a;

        state[1] += b;

        state[2] += c;

        state[3] += d;

        state[4] += e;

        /* Wipe variables */

        a = b = c = d = e = 0;

        memset (block32, 0x00, sizeof block32);

}

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;

        j = (sctx->count >> 3) & 0x3f;

        sctx->count += len << 3;

        if ((j + len) > 63) {

                memcpy(&sctx->buffer[j], data, (i = 64-j));

                sha1_transform(sctx->state, sctx->buffer);

                for ( ; i + 63 < len; i += 64) {

                        sha1_transform(sctx->state, &data[i]);

                }

                j = 0;

        }

        else i = 0;

        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");