Initial revision

1 files changed, 99 insertions, 0 deletions

diff --git a/blowfish.cpp b/blowfish.cpp
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+++ b/blowfish.cpp
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+// blowfish.cpp - written and placed in the public domain by Wei Dai
+
+#include "pch.h"
+#include "blowfish.h"
+#include "misc.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+void Blowfish::Base::UncheckedSetKey(CipherDir dir, const byte *key_string, unsigned int keylength)
+{
+	AssertValidKeyLength(keylength);
+
+	unsigned i, j=0, k;
+	word32 data, dspace[2] = {0, 0};
+
+	memcpy(pbox, p_init, sizeof(p_init));
+	memcpy(sbox, s_init, sizeof(s_init));
+
+	// Xor key string into encryption key vector
+	for (i=0 ; i<ROUNDS+2 ; ++i)
+	{
+		data = 0 ;
+		for (k=0 ; k<4 ; ++k )
+			data = (data << 8) | key_string[j++ % keylength];
+		pbox[i] ^= data;
+	}
+
+	crypt_block(dspace, pbox);
+
+	for (i=0; i<ROUNDS; i+=2)
+		crypt_block(pbox+i, pbox+i+2);
+
+	crypt_block(pbox+ROUNDS, sbox);
+
+	for (i=0; i<4*256-2; i+=2)
+		crypt_block(sbox+i, sbox+i+2);
+
+	if (dir==DECRYPTION)
+		for (i=0; i<(ROUNDS+2)/2; i++)
+			std::swap(pbox[i], pbox[ROUNDS+1-i]);
+}
+
+// this version is only used to make pbox and sbox
+void Blowfish::Base::crypt_block(const word32 in[2], word32 out[2]) const
+{
+	word32 left = in[0];
+	word32 right = in[1];
+
+	const word32 *const s=sbox;
+	const word32 *p=pbox;
+
+	left ^= p[0];
+
+	for (unsigned i=0; i<ROUNDS/2; i++)
+	{
+		right ^= (((s[GETBYTE(left,3)] + s[256+GETBYTE(left,2)])
+			  ^ s[2*256+GETBYTE(left,1)]) + s[3*256+GETBYTE(left,0)])
+			  ^ p[2*i+1];
+
+		left ^= (((s[GETBYTE(right,3)] + s[256+GETBYTE(right,2)])
+			 ^ s[2*256+GETBYTE(right,1)]) + s[3*256+GETBYTE(right,0)])
+			 ^ p[2*i+2];
+	}
+
+	right ^= p[ROUNDS+1];
+
+	out[0] = right;
+	out[1] = left;
+}
+
+void Blowfish::Base::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
+{
+	typedef BlockGetAndPut<word32, BigEndian> Block;
+
+	word32 left, right;
+	Block::Get(inBlock)(left)(right);
+
+	const word32 *const s=sbox;
+	const word32 *p=pbox;
+
+	left ^= p[0];
+
+	for (unsigned i=0; i<ROUNDS/2; i++)
+	{
+		right ^= (((s[GETBYTE(left,3)] + s[256+GETBYTE(left,2)])
+			  ^ s[2*256+GETBYTE(left,1)]) + s[3*256+GETBYTE(left,0)])
+			  ^ p[2*i+1];
+
+		left ^= (((s[GETBYTE(right,3)] + s[256+GETBYTE(right,2)])
+			 ^ s[2*256+GETBYTE(right,1)]) + s[3*256+GETBYTE(right,0)])
+			 ^ p[2*i+2];
+	}
+
+	right ^= p[ROUNDS+1];
+
+	Block::Put(xorBlock, outBlock)(right)(left);
+}
+
+NAMESPACE_END