CVS: crypto/src SHA256.c,NONE,1.1

Update of /cvsroot/pycrypto/crypto/src
In directory sc8-pr-cvs1:/tmp/cvs-serv14245

Added Files:
	SHA256.c 
Log Message:
Add SHA256.c file

--- NEW FILE ---
/*

 * An implementation of the SHA-256 hash function, this is endian neutral

 * so should work just about anywhere.

 *

 * This code works much like the MD5 code provided by RSA.  You sha_init()

 * a "sha_state" then sha_process() the bytes you want and sha_done() to get

 * the output.

 *

 * Revised Code:  Complies to SHA-256 standard now.

 *

 * Tom St Denis -- http://tomstdenis.home.dhs.org

 * */

#include "Python.h"

#define MODULE_NAME SHA256
#define DIGEST_SIZE 32



typedef unsigned char U8;
typedef unsigned int U32;



typedef struct {

    unsigned long state[8], length, curlen;

    unsigned char buf[64];

}

hash_state;



/* the K array */

static const unsigned long K[64] = {

    0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,

    0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,

    0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,

    0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,

    0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,

    0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,

    0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,

    0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,

    0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,

    0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,

    0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,

    0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,

    0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL

};



/* Various logical functions */

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

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

#define S(x, n)        (((x)>>((n)&31))|((x)<<(32-((n)&31))))

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

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

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

#define Gamma0(x)    (S(x, 7) ^ S(x, 18) ^ R(x, 3))

#define Gamma1(x)    (S(x, 17) ^ S(x, 19) ^ R(x, 10))



/* compress 512-bits */

static void sha_compress(hash_state * md)

{

    unsigned long S[8], W[64], t0, t1;

    int i;



    /* copy state into S */

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

        S[i] = md->state[i];



    /* copy the state into 512-bits into W[0..15] */

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

        W[i] = (((unsigned long) md->buf[(4 * i) + 0]) << 24) |

            (((unsigned long) md->buf[(4 * i) + 1]) << 16) |

            (((unsigned long) md->buf[(4 * i) + 2]) << 8) |

            (((unsigned long) md->buf[(4 * i) + 3]));



    /* fill W[16..63] */

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

        W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) + W[i - 16];



    /* Compress */

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

        t0 = S[7] + Sigma1(S[4]) + Ch(S[4], S[5], S[6]) + K[i] + W[i];

        t1 = Sigma0(S[0]) + Maj(S[0], S[1], S[2]);

        S[7] = S[6];

        S[6] = S[5];

        S[5] = S[4];

        S[4] = S[3] + t0;

        S[3] = S[2];

        S[2] = S[1];

        S[1] = S[0];

        S[0] = t0 + t1;

    }



    /* feedback */

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

        md->state[i] += S[i];

}



/* init the SHA state */

void sha_init(hash_state * md)

{

    md->curlen = md->length = 0;

    md->state[0] = 0x6A09E667UL;

    md->state[1] = 0xBB67AE85UL;

    md->state[2] = 0x3C6EF372UL;

    md->state[3] = 0xA54FF53AUL;

    md->state[4] = 0x510E527FUL;

    md->state[5] = 0x9B05688CUL;

    md->state[6] = 0x1F83D9ABUL;

    md->state[7] = 0x5BE0CD19UL;

}



void sha_process(hash_state * md, unsigned char *buf, int len)

{

    while (len--) {

        /* copy byte */

        md->buf[md->curlen++] = *buf++;



        /* is 64 bytes full? */

        if (md->curlen == 64) {

            sha_compress(md);

            md->length += 512;

            md->curlen = 0;

        }

    }

}



void sha_done(hash_state * md, unsigned char *hash)

{

    int i;



    /* increase the length of the message */

    md->length += md->curlen * 8;



    /* append the '1' bit */

    md->buf[md->curlen++] = 0x80;



    /* if the length is currenlly above 56 bytes we append zeros

                               * then compress.  Then we can fall back to padding zeros and length

                               * encoding like normal.

                             */

    if (md->curlen >= 56) {

        for (; md->curlen < 64;)

            md->buf[md->curlen++] = 0;

        sha_compress(md);

        md->curlen = 0;

    }



    /* pad upto 56 bytes of zeroes */

    for (; md->curlen < 56;)

        md->buf[md->curlen++] = 0;



    /* since all messages are under 2^32 bits we mark the top bits zero */

    for (i = 56; i < 60; i++)

        md->buf[i] = 0;



    /* append length */

    for (i = 60; i < 64; i++)

        md->buf[i] = (md->length >> ((63 - i) * 8)) & 255;

    sha_compress(md);



    /* copy output */

    for (i = 0; i < 32; i++)

        hash[i] = (md->state[i >> 2] >> (((3 - i) & 3) << 3)) & 255;

}



// Done

static void hash_init (hash_state *ptr)

{

	sha_init(ptr);

}



// Done

static void 

hash_update (hash_state *self, const U8 *buf, U32 len)

{

	sha_process(self,(unsigned char *)buf,len);

}



// Done

static void
hash_copy(hash_state *src, hash_state *dest)

{

	memcpy(dest,src,sizeof(hash_state));

}



// Done

static PyObject *
hash_digest (const hash_state *self)

{

	unsigned char digest[32];

	hash_state temp;



	hash_copy((hash_state*)self,&temp);

	sha_done(&temp,digest);

	return PyString_FromStringAndSize(digest, 32);

}



#include "hash_template.c"




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