chromium/third_party/nasm/nasmlib/md5c.c

/*
 * This code implements the MD5 message-digest algorithm.
 * The algorithm is due to Ron Rivest.  This code was
 * written by Colin Plumb in 1993, no copyright is claimed.
 * This code is in the public domain; do with it what you wish.
 *
 * Equivalent code is available from RSA Data Security, Inc.
 * This code has been tested against that, and is equivalent,
 * except that you don't need to include two pages of legalese
 * with every copy.
 *
 * To compute the message digest of a chunk of bytes, declare an
 * MD5Context structure, pass it to MD5Init, call MD5Update as
 * needed on buffers full of bytes, and then call MD5Final, which
 * will fill a supplied 16-byte array with the digest.
 */

#include "md5.h"

#ifdef WORDS_LITTLEENDIAN
#define byteReverse(buf, len) …
#else
static void byteReverse(unsigned char *buf, unsigned longs);

/*
 * Note: this code is harmless on little-endian machines.
 */
static void byteReverse(unsigned char *buf, unsigned longs)
{
    uint32_t t;
    do {
	t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
	    ((unsigned) buf[1] << 8 | buf[0]);
	*(uint32_t *) buf = t;
	buf += 4;
    } while (--longs);
}
#endif

/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
void MD5Init(MD5_CTX *ctx)
{ … }

/*
 * Update context to reflect the concatenation of another buffer full
 * of bytes.
 */
void MD5Update(MD5_CTX *ctx, unsigned char const *buf, unsigned 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], MD5_CTX *ctx)
{ … }

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

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

/* This is the central step in the MD5 algorithm. */
#define MD5STEP(f, w, x, y, z, data, s) …

/*
 * 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_t buf[4], uint32_t const in[16])
{ … }