source: flair-src/branches/mavlink/tools/Controller/Mavlink/src/mavlink_generated_messages/mavlink_sha256.h@ 46

#pragma once



/*

  sha-256 implementation for MAVLink based on Heimdal sources, with

  modifications to suit mavlink headers

 */

/*

 * Copyright (c) 1995 - 2001 Kungliga Tekniska Högskolan

 * (Royal Institute of Technology, Stockholm, Sweden).

 * 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 Institute 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 INSTITUTE 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 INSTITUTE 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.

 */



/*

  allow implementation to provide their own sha256 with the same API

*/

#ifndef HAVE_MAVLINK_SHA256



#ifndef MAVLINK_HELPER

#define MAVLINK_HELPER

#endif



typedef struct {

  unsigned int sz[2];

  uint32_t counter[8];

  union {

      unsigned char save_bytes[64];

      uint32_t save_u32[16];

  } u;

} mavlink_sha256_ctx;



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

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



#define ROTR(x,n)   (((x)>>(n)) | ((x) << (32 - (n))))



#define Sigma0(x)       (ROTR(x,2)  ^ ROTR(x,13) ^ ROTR(x,22))

#define Sigma1(x)       (ROTR(x,6)  ^ ROTR(x,11) ^ ROTR(x,25))

#define sigma0(x)       (ROTR(x,7)  ^ ROTR(x,18) ^ ((x)>>3))

#define sigma1(x)       (ROTR(x,17) ^ ROTR(x,19) ^ ((x)>>10))



#define A m->counter[0]

#define B m->counter[1]

#define C m->counter[2]

#define D m->counter[3]

#define E m->counter[4]

#define F m->counter[5]

#define G m->counter[6]

#define H m->counter[7]



static const uint32_t mavlink_sha256_constant_256[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

};



MAVLINK_HELPER void mavlink_sha256_init(mavlink_sha256_ctx *m)

{

    m->sz[0] = 0;

    m->sz[1] = 0;

    A = 0x6a09e667;

    B = 0xbb67ae85;

    C = 0x3c6ef372;

    D = 0xa54ff53a;

    E = 0x510e527f;

    F = 0x9b05688c;

    G = 0x1f83d9ab;

    H = 0x5be0cd19;

}



static inline void mavlink_sha256_calc(mavlink_sha256_ctx *m, uint32_t *in)

{

    uint32_t AA, BB, CC, DD, EE, FF, GG, HH;

    uint32_t data[64];

    int i;



    AA = A;

    BB = B;

    CC = C;

    DD = D;

    EE = E;

    FF = F;

    GG = G;

    HH = H;



    for (i = 0; i < 16; ++i)

        data[i] = in[i];

    for (i = 16; i < 64; ++i)

        data[i] = sigma1(data[i-2]) + data[i-7] + 

            sigma0(data[i-15]) + data[i - 16];



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

        uint32_t T1, T2;



        T1 = HH + Sigma1(EE) + Ch(EE, FF, GG) + mavlink_sha256_constant_256[i] + data[i];

        T2 = Sigma0(AA) + Maj(AA,BB,CC);

                             

        HH = GG;

        GG = FF;

        FF = EE;

        EE = DD + T1;

        DD = CC;

        CC = BB;

        BB = AA;

        AA = T1 + T2;

    }



    A += AA;

    B += BB;

    C += CC;

    D += DD;

    E += EE;

    F += FF;

    G += GG;

    H += HH;

}



MAVLINK_HELPER void mavlink_sha256_update(mavlink_sha256_ctx *m, const void *v, uint32_t len)

{

    const unsigned char *p = (const unsigned char *)v;

    uint32_t old_sz = m->sz[0];

    uint32_t offset;



    m->sz[0] += len * 8;

    if (m->sz[0] < old_sz)

        ++m->sz[1];

    offset = (old_sz / 8) % 64;

    while(len > 0){

        uint32_t l = 64 - offset;

        if (len < l) {

            l = len;

        }

        memcpy(m->u.save_bytes + offset, p, l);

        offset += l;

        p += l;

        len -= l;

        if(offset == 64){

            int i;

            uint32_t current[16];

            const uint32_t *u = m->u.save_u32;

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

                const uint8_t *p1 = (const uint8_t *)&u[i];

                uint8_t *p2 = (uint8_t *)&current[i];

                p2[0] = p1[3];

                p2[1] = p1[2];

                p2[2] = p1[1];

                p2[3] = p1[0];

            }

            mavlink_sha256_calc(m, current);

            offset = 0;

        }

    }

}



/*

  get first 48 bits of final sha256 hash

 */

MAVLINK_HELPER void mavlink_sha256_final_48(mavlink_sha256_ctx *m, uint8_t result[6])

{

    unsigned char zeros[72];

    unsigned offset = (m->sz[0] / 8) % 64;

    unsigned int dstart = (120 - offset - 1) % 64 + 1;

    uint8_t *p = (uint8_t *)&m->counter[0];

    

    *zeros = 0x80;

    memset (zeros + 1, 0, sizeof(zeros) - 1);

    zeros[dstart+7] = (m->sz[0] >> 0) & 0xff;

    zeros[dstart+6] = (m->sz[0] >> 8) & 0xff;

    zeros[dstart+5] = (m->sz[0] >> 16) & 0xff;

    zeros[dstart+4] = (m->sz[0] >> 24) & 0xff;

    zeros[dstart+3] = (m->sz[1] >> 0) & 0xff;

    zeros[dstart+2] = (m->sz[1] >> 8) & 0xff;

    zeros[dstart+1] = (m->sz[1] >> 16) & 0xff;

    zeros[dstart+0] = (m->sz[1] >> 24) & 0xff;



    mavlink_sha256_update(m, zeros, dstart + 8);



    // this ordering makes the result consistent with taking the first

    // 6 bytes of more conventional sha256 functions. It assumes

    // little-endian ordering of m->counter

    result[0] = p[3];

    result[1] = p[2];

    result[2] = p[1];

    result[3] = p[0];

    result[4] = p[7];

    result[5] = p[6];

}



// prevent conflicts with users of the header

#undef A

#undef B

#undef C

#undef D

#undef E

#undef F

#undef G

#undef H

#undef Ch

#undef ROTR

#undef Sigma0

#undef Sigma1

#undef sigma0

#undef sigma1



#endif // HAVE_MAVLINK_SHA256