From 469bbcf0701e1eb8a6670c23145b0da87357e178 Mon Sep 17 00:00:00 2001
From: Mike Buland <eichlan@xagasoft.com>
Date: Sun, 25 Mar 2012 20:00:08 +0000
Subject: Code is all reorganized.  We're about ready to release.  I should
 write up a little explenation of the arrangement.

---
 src/stable/sha1.cpp | 194 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 194 insertions(+)
 create mode 100644 src/stable/sha1.cpp

(limited to 'src/stable/sha1.cpp')

diff --git a/src/stable/sha1.cpp b/src/stable/sha1.cpp
new file mode 100644
index 0000000..bfe4c5a
--- /dev/null
+++ b/src/stable/sha1.cpp
@@ -0,0 +1,194 @@
+/*
+ * Copyright (C) 2007-2011 Xagasoft, All rights reserved.
+ *
+ * This file is part of the libbu++ library and is released under the
+ * terms of the license contained in the file LICENSE.
+ */
+
+#include <string.h>
+
+#include "bu/stream.h"
+
+#include "bu/sha1.h"
+
+Bu::Sha1::Sha1() :
+	uH0( 0x67452301 ),
+	uH1( 0xefcdab89 ),
+	uH2( 0x98badcfe ),
+	uH3( 0x10325476 ),
+	uH4( 0xc3d2e1f0 ),
+	iUnprocessedBytes( 0 ),
+	uTotalBytes( 0 )
+{
+	reset();
+}
+
+Bu::Sha1::~Sha1()
+{
+}
+
+void Bu::Sha1::reset()
+{
+	uH0 = 0x67452301;
+	uH1 = 0xefcdab89;
+	uH2 = 0x98badcfe;
+	uH3 = 0x10325476;
+	uH4 = 0xc3d2e1f0;
+	iUnprocessedBytes = 0;
+	uTotalBytes = 0;
+}
+
+void Bu::Sha1::setSalt( const Bu::String & /*sSalt*/ )
+{
+}
+
+void Bu::Sha1::addData( const void *sDataRaw, int iSize )
+{
+	const unsigned char *sData = (const unsigned char *)sDataRaw;
+	// add these bytes to the running total
+	uTotalBytes += iSize;
+
+	// repeat until all data is processed
+	while( iSize > 0 )
+	{
+		// number of bytes required to complete block
+		int iNeeded = 64 - iUnprocessedBytes;
+
+		// number of bytes to copy (use smaller of two)
+		int iToCopy = (iSize < iNeeded) ? iSize : iNeeded;
+
+		// Copy the bytes
+		memcpy( uBytes + iUnprocessedBytes, sData, iToCopy );
+
+		// Bytes have been copied
+		iSize -= iToCopy;
+		sData += iToCopy;
+		iUnprocessedBytes += iToCopy;
+		
+		// there is a full block
+		if( iUnprocessedBytes == 64 )
+		{
+			process();
+		}
+	}
+}
+
+Bu::String Bu::Sha1::getResult()
+{
+	// save the message size
+	uint32_t totalBitsL = uTotalBytes << 3;
+	uint32_t totalBitsH = uTotalBytes >> 29;
+
+	// add 0x80 to the message
+	addData( "\x80", 1 );
+	
+	unsigned char footer[64] = {
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+		0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+
+	// block has no room for 8-byte filesize, so finish it
+	if( iUnprocessedBytes > 56 )
+		addData( (char*)footer, 64 - iUnprocessedBytes);
+
+	// how many zeros do we need
+	int iNeededZeros = 56 - iUnprocessedBytes;
+
+	// store file size (in bits) in big-endian format
+	toBigEndian( totalBitsH, footer + iNeededZeros );
+	toBigEndian( totalBitsL, footer + iNeededZeros + 4 );
+
+	// finish the final block
+	addData( (char*)footer, iNeededZeros + 8 );
+
+	Bu::String sRet( 20 );
+
+	unsigned char *digest = (unsigned char *)sRet.getStr();
+
+	// copy the digest bytes
+	toBigEndian( uH0, digest );
+	toBigEndian( uH1, digest + 4 );
+	toBigEndian( uH2, digest + 8 );
+	toBigEndian( uH3, digest + 12 );
+	toBigEndian( uH4, digest + 16 );
+
+	// return the digest
+	return sRet;
+}
+
+void Bu::Sha1::writeResult( Bu::Stream &sOut )
+{
+	sOut.write( getResult() );
+}
+
+void Bu::Sha1::process()
+{
+	int t;
+	uint32_t a, b, c, d, e, K, f, W[80];
+
+	// starting values
+	a = uH0;
+	b = uH1;
+	c = uH2;
+	d = uH3;
+	e = uH4;
+
+	// copy and expand the message block
+	for( t = 0; t < 16; t++ ) W[t] = (uBytes[t*4] << 24)
+									+(uBytes[t*4 + 1] << 16)
+									+(uBytes[t*4 + 2] << 8)
+									+ uBytes[t*4 + 3];
+	for(; t< 80; t++ ) W[t] = lrot( W[t-3]^W[t-8]^W[t-14]^W[t-16], 1 );
+	
+	/* main loop */
+	uint32_t temp;
+	for( t = 0; t < 80; t++ )
+	{
+		if( t < 20 ) {
+			K = 0x5a827999;
+			f = (b & c) | ((~b) & d);
+		} else if( t < 40 ) {
+			K = 0x6ed9eba1;
+			f = b ^ c ^ d;
+		} else if( t < 60 ) {
+			K = 0x8f1bbcdc;
+			f = (b & c) | (b & d) | (c & d);
+		} else {
+			K = 0xca62c1d6;
+			f = b ^ c ^ d;
+		}
+		temp = lrot(a,5) + f + e + W[t] + K;
+		e = d;
+		d = c;
+		c = lrot(b,30);
+		b = a;
+		a = temp;
+		//printf( "t=%d %08x %08x %08x %08x %08x\n",t,a,b,c,d,e );
+	}
+
+	/* add variables */
+	uH0 += a;
+	uH1 += b;
+	uH2 += c;
+	uH3 += d;
+	uH4 += e;
+
+	//printf( "Current: %08x %08x %08x %08x %08x\n",H0,H1,H2,H3,H4 );
+	/* all bytes have been processed */
+	iUnprocessedBytes = 0;
+}
+
+uint32_t Bu::Sha1::lrot( uint32_t x, int bits )
+{
+	return (x<<bits) | (x>>(32 - bits));
+}
+
+void Bu::Sha1::toBigEndian( uint32_t num, unsigned char* byte )
+{
+	byte[0] = (unsigned char)(num>>24);
+	byte[1] = (unsigned char)(num>>16);
+	byte[2] = (unsigned char)(num>>8);
+	byte[3] = (unsigned char)num;
+}
+
-- 
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