chromium/third_party/flac/src/libFLAC/md5.c

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <stdlib.h>		/* for malloc() */
#include <string.h>		/* for memcpy() */

#include "private/md5.h"
#include "share/alloc.h"
#include "share/compat.h"
#include "share/endswap.h"

/*
 * 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.
 *
 * Changed so as no longer to depend on Colin Plumb's `usual.h' header
 * definitions; now uses stuff from dpkg's config.h.
 *  - Ian Jackson <[email protected]>.
 * Still in the public domain.
 *
 * Josh Coalson: made some changes to integrate with libFLAC.
 * Still in the public domain.
 */

/* 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,in,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.
 */
static void FLAC__MD5Transform(FLAC__uint32 buf[4], FLAC__uint32 const in[16])
{ … }

#if WORDS_BIGENDIAN
//@@@@@@ OPT: use bswap/intrinsics
static void byteSwap(FLAC__uint32 *buf, uint32_t words)
{
	register FLAC__uint32 x;
	do {
		x = *buf;
		x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff);
		*buf++ = (x >> 16) | (x << 16);
	} while (--words);
}
static void byteSwapX16(FLAC__uint32 *buf)
{
	register FLAC__uint32 x;

	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf++ = (x >> 16) | (x << 16);
	x = *buf; x = ((x << 8) & 0xff00ff00) | ((x >> 8) & 0x00ff00ff); *buf   = (x >> 16) | (x << 16);
}
#else
#define byteSwap(buf, words) …
#define byteSwapX16(buf) …
#endif

/*
 * Update context to reflect the concatenation of another buffer full
 * of bytes.
 */
static void FLAC__MD5Update(FLAC__MD5Context *ctx, FLAC__byte const *buf, uint32_t len)
{ … }

/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
void FLAC__MD5Init(FLAC__MD5Context *ctx)
{ … }

/*
 * Final wrapup - pad to 64-byte boundary with the bit pattern
 * 1 0* (64-bit count of bits processed, MSB-first)
 */
void FLAC__MD5Final(FLAC__byte digest[16], FLAC__MD5Context *ctx)
{ … }

/*
 * Convert the incoming audio signal to a byte stream
 */
static void format_input_(FLAC__multibyte *mbuf, const FLAC__int32 * const signal[], uint32_t channels, uint32_t samples, uint32_t bytes_per_sample)
{ … }

/*
 * Convert the incoming audio signal to a byte stream and FLAC__MD5Update it.
 */
FLAC__bool FLAC__MD5Accumulate(FLAC__MD5Context *ctx, const FLAC__int32 * const signal[], uint32_t channels, uint32_t samples, uint32_t bytes_per_sample)
{ … }