md5.c

Skin, zip, unzip, md5, crc32, drag and drop

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>


typedef unsigned int word32;
typedef word32 uint32;


struct MD5Context {
	uint32 buf[4];
	uint32 bits[2];
	unsigned char in[64];
};

typedef struct MD5Context MD5_CTX;

void MD5Init(struct MD5Context *context);
void MD5Update(struct MD5Context *context, unsigned char const *buf,
	       unsigned len);
void MD5Final(unsigned char digest[16], struct MD5Context *context);
void MD5Transform(uint32 buf[4], const unsigned char in[64],
			struct MD5Context *ctx);



void debugStatus(char *m, struct MD5Context *ctx);
void dumpBytes(unsigned char *b, int len);



#define GET_32BIT_LSB_FIRST(cp) \
  (((unsigned long)(unsigned char)(cp)[0]) | \
  ((unsigned long)(unsigned char)(cp)[1] << 8) | \
  ((unsigned long)(unsigned char)(cp)[2] << 16) | \
  ((unsigned long)(unsigned char)(cp)[3] << 24))

#define PUT_32BIT_LSB_FIRST(cp, value) do { \
  (cp)[0] = (value); \
  (cp)[1] = (value) >> 8; \
  (cp)[2] = (value) >> 16; \
  (cp)[3] = (value) >> 24; } while (0)
/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
void MD5Init(struct MD5Context *ctx)
{
    ctx->buf[0] = 0x67452301;
    ctx->buf[1] = 0xefcdab89;
    ctx->buf[2] = 0x98badcfe;
    ctx->buf[3] = 0x10325476;

    ctx->bits[0] = 0;
    ctx->bits[1] = 0;

	memset(ctx->in, 0, 64);
	debugStatus("after init", ctx);
}



void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
{
    uint32 t;

    /* Update bitcount */

    t = ctx->bits[0];
    if ((ctx->bits[0] = (t + ((uint32)len << 3)) & 0xffffffff) < t)
	ctx->bits[1]++;		/* Carry from low to high */
    ctx->bits[1] += len >> 29;

    t = (t >> 3) & 0x3f;	/* Bytes already in shsInfo->data */

    /* Handle any leading odd-sized chunks */

    if (t) {
	unsigned char *p = ctx->in + t;

	t = 64 - t;
	if (len < t) {
	    memcpy(p, buf, len);
	    return;
	}
	memcpy(p, buf, t);
	MD5Transform(ctx->buf, ctx->in, ctx);
	buf += t;
	len -= t;
    }
    /* Process data in 64-byte chunks */

    while (len >= 64) {
	memcpy(ctx->in, buf, 64);
	MD5Transform(ctx->buf, ctx->in, ctx);
	buf += 64;
	len -= 64;
    }

    /* Handle any remaining bytes of data. */

    memcpy(ctx->in, buf, len);
}

/*
 * Final wrapup - pad to 64-byte boundary with the bit pattern 
 * 1 0* (64-bit count of bits processed, MSB-first)
 */
void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
{
    unsigned count;
    unsigned char *p;

    /* Compute number of bytes mod 64 */
    count = (ctx->bits[0] >> 3) & 0x3F;

    /* Set the first char of padding to 0x80.  This is safe since there is
       always at least one byte free */
    p = ctx->in + count;
    *p++ = 0x80;

    /* Bytes of padding needed to make 64 bytes */
    count = 64 - 1 - count;

    /* Pad out to 56 mod 64 */
    if (count < 8) {
	/* Two lots of padding:  Pad the first block to 64 bytes */
	memset(p, 0, count);
	MD5Transform(ctx->buf, ctx->in, ctx);

	/* Now fill the next block with 56 bytes */
	memset(ctx->in, 0, 56);
    } else {
	/* Pad block to 56 bytes */
	memset(p, 0, count - 8);
    }

    /* Append length in bits and transform */
    PUT_32BIT_LSB_FIRST(ctx->in + 56, ctx->bits[0]);
    PUT_32BIT_LSB_FIRST(ctx->in + 60, ctx->bits[1]);

    MD5Transform(ctx->buf, ctx->in, ctx);
    PUT_32BIT_LSB_FIRST(digest, ctx->buf[0]);
    PUT_32BIT_LSB_FIRST(digest + 4, ctx->buf[1]);
    PUT_32BIT_LSB_FIRST(digest + 8, ctx->buf[2]);
    PUT_32BIT_LSB_FIRST(digest + 12, ctx->buf[3]);
    memset(ctx, 0, sizeof(ctx));	/* In case it's sensitive */
}

#ifndef ASM_MD5

/* The four core functions - F1 is optimized somewhat */

/* #define F1(x, y, z) (x & y | ~x & z) */
#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

/* This is the central step in the MD5 algorithm. */
/* debugging version: */
/*
#define MD5STEP(f, w, x, y, z, data, s) \
	printf("MD5STEP:  w: %x x: %x y: %x z: %x data: %x s: %x\n", 	\
		w, x, y, z, data, s); 	\
	printf("f(x,y,z) = %x\n", f(x,y,z)+data); \
	( w += f(x, y, z) + data,  printf(" - w: %x ", w), \
	w = w<<s | w>>(32-s),  printf(" - w: %x\n", w), w += x )
*/
#define MD5STEP(f, w, x, y, z, data, s) \
	( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )

/*
 * The core of the MD5 algorithm, this alters an existing MD5 hash to
 * reflect the addition of 16 longwords of new data.  MD5Update blocks
 * the data and converts bytes into longwords for this routine.
 */
void MD5Transform(uint32 buf[4], const unsigned char inext[64],
	struct MD5Context *ctx)
{
    register word32 a, b, c, d, i;
    word32 in[16];
    
	debugStatus("Before transform", ctx);

    for (i = 0; i < 16; i++)
      in[i] = GET_32BIT_LSB_FIRST(inext + 4 * i);

    a = buf[0];
    b = buf[1];
    c = buf[2];
    d = buf[3];

	/*
	printf("a: %x\n", a);
	printf("in[0]: %x\n", in[0]);
	*/
    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
	/* printf("a: %x\n", a); */
    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);

    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);

    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);

    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);

    buf[0] += a;
    buf[1] += b;
    buf[2] += c;
    buf[3] += d;

	debugStatus("After transform", ctx);
}

void debugStatus(char *m, struct MD5Context *ctx)
{
	return;

	printf("%s:\n", m);
	printf("in: ");
	dumpBytes(ctx->in, 64);
	printf("bits: %d %d\n", ctx->bits[1], ctx->bits[0]);
	printf("buf: %x %x %x %x\n",
		ctx->buf[0],
		ctx->buf[1],
		ctx->buf[2],
		ctx->buf[3]);
}

void dumpBytes(unsigned char *b, int len)
{
	int i;
	for (i=0; i<len; i++) {
		if (i%32==0 && i!=0) {
			printf("\n");
		}
		printf("%02x", b[i]&0xff);
	}
	printf("\n");
}

#endif