~ubuntu-branches/ubuntu/oneiric/znc/oneiric-backports

/*

 * FIPS 180-2 SHA-224/256/384/512 implementation

 * Last update: 02/02/2007

 * Issue date:  04/30/2005

 *

 * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch>

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the project nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

#include <string.h>

#include "SHA256.h"

#define SHFR(x, n)    (x >> n)

#define ROTR(x, n)   ((x >> n) | (x << ((sizeof(x) << 3) - n)))

#define ROTL(x, n)   ((x << n) | (x >> ((sizeof(x) << 3) - n)))

#define CH(x, y, z)  ((x & y) ^ (~x & z))

#define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z))

#define SHA256_F1(x) (ROTR(x,  2) ^ ROTR(x, 13) ^ ROTR(x, 22))

#define SHA256_F2(x) (ROTR(x,  6) ^ ROTR(x, 11) ^ ROTR(x, 25))

#define SHA256_F3(x) (ROTR(x,  7) ^ ROTR(x, 18) ^ SHFR(x,  3))

#define SHA256_F4(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10))

#define UNPACK32(x, str)                      \

{                                             \

    *((str) + 3) = (uint8_t) ((x)      );     \

    *((str) + 2) = (uint8_t) ((x) >>  8);     \

    *((str) + 1) = (uint8_t) ((x) >> 16);     \

    *((str) + 0) = (uint8_t) ((x) >> 24);     \

}

#define PACK32(str, x)                        \

{                                             \

    *(x) =   ((uint32_t) *((str) + 3)      )  \

           | ((uint32_t) *((str) + 2) <<  8)  \

           | ((uint32_t) *((str) + 1) << 16)  \

           | ((uint32_t) *((str) + 0) << 24); \

}

/* Macros used for loops unrolling */

#define SHA256_SCR(i)                         \

{                                             \

    w[i] =  SHA256_F4(w[i -  2]) + w[i -  7]  \

          + SHA256_F3(w[i - 15]) + w[i - 16]; \

}

#define SHA256_EXP(a, b, c, d, e, f, g, h, j)               \

{                                                           \

    t1 = wv[h] + SHA256_F2(wv[e]) + CH(wv[e], wv[f], wv[g]) \

         + sha256_k[j] + w[j];                              \

    t2 = SHA256_F1(wv[a]) + MAJ(wv[a], wv[b], wv[c]);       \

    wv[d] += t1;                                            \

    wv[h] = t1 + t2;                                        \

}

uint32_t sha256_h0[8] =

            {0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,

             0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};

uint32_t sha256_k[64] =

            {0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,

             0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,

             0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,

             0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,

             0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,

             0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,

             0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,

             0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,

             0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,

             0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,

             0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,

             0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,

             0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,

             0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,

             0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,

             0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2};

/* SHA-256 functions */

static void sha256_transf(sha256_ctx *ctx, const unsigned char *message,

                   unsigned int block_nb)

{

    uint32_t w[64];

    uint32_t wv[8];

    uint32_t t1, t2;

    const unsigned char *sub_block;

    int i;

    int j;

    for (i = 0; i < (int) block_nb; i++) {

        sub_block = message + (i << 6);

        for (j = 0; j < 16; j++) {

            PACK32(&sub_block[j << 2], &w[j]);

        }

        for (j = 16; j < 64; j++) {

            SHA256_SCR(j);

        }

        for (j = 0; j < 8; j++) {

            wv[j] = ctx->h[j];

        }

        for (j = 0; j < 64; j++) {

            t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6])

                + sha256_k[j] + w[j];

            t2 = SHA256_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]);

            wv[7] = wv[6];

            wv[6] = wv[5];

            wv[5] = wv[4];

            wv[4] = wv[3] + t1;

            wv[3] = wv[2];

            wv[2] = wv[1];

            wv[1] = wv[0];

            wv[0] = t1 + t2;

        }

        for (j = 0; j < 8; j++) {

            ctx->h[j] += wv[j];

        }

    }

}

void sha256(const unsigned char *message, unsigned int len, unsigned char *digest)

{

    sha256_ctx ctx;

    sha256_init(&ctx);

    sha256_update(&ctx, message, len);

    sha256_final(&ctx, digest);

}

void sha256_init(sha256_ctx *ctx)

{

    int i;

    for (i = 0; i < 8; i++) {

        ctx->h[i] = sha256_h0[i];

    }

    ctx->len = 0;

    ctx->tot_len = 0;

}

void sha256_update(sha256_ctx *ctx, const unsigned char *message,

                   unsigned int len)

{

    unsigned int block_nb;

    unsigned int new_len, rem_len, tmp_len;

    const unsigned char *shifted_message;

    tmp_len = SHA256_BLOCK_SIZE - ctx->len;

    rem_len = len < tmp_len ? len : tmp_len;

    memcpy(&ctx->block[ctx->len], message, rem_len);

    if (ctx->len + len < SHA256_BLOCK_SIZE) {

        ctx->len += len;

        return;

    }

    new_len = len - rem_len;

    block_nb = new_len / SHA256_BLOCK_SIZE;

    shifted_message = message + rem_len;

    sha256_transf(ctx, ctx->block, 1);

    sha256_transf(ctx, shifted_message, block_nb);

    rem_len = new_len % SHA256_BLOCK_SIZE;

    memcpy(ctx->block, &shifted_message[block_nb << 6],

           rem_len);

    ctx->len = rem_len;

    ctx->tot_len += (block_nb + 1) << 6;

}

void sha256_final(sha256_ctx *ctx, unsigned char *digest)

{

    unsigned int block_nb;

    unsigned int pm_len;

    unsigned int len_b;

    int i;

    block_nb = (1 + ((SHA256_BLOCK_SIZE - 9)

                     < (ctx->len % SHA256_BLOCK_SIZE)));

    len_b = (ctx->tot_len + ctx->len) << 3;

    pm_len = block_nb << 6;

    memset(ctx->block + ctx->len, 0, pm_len - ctx->len);

    ctx->block[ctx->len] = 0x80;

    UNPACK32(len_b, ctx->block + pm_len - 4);

    sha256_transf(ctx, ctx->block, block_nb);

    for (i = 0 ; i < 8; i++) {

        UNPACK32(ctx->h[i], &digest[i << 2]);

    }

}