From cb4a46e7fbe62d788e66ed6121c717a2d22a4d7c Mon Sep 17 00:00:00 2001 From: watcherhd Date: Thu, 21 Apr 2011 14:14:52 +0000 Subject: svn.miranda.im is moving to a new home! git-svn-id: http://miranda-plugins.googlecode.com/svn/trunk@7 e753b5eb-9565-29b2-b5c5-2cc6f99dfbcb --- cryptopp/crypto/blumshub.cpp | 63 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 cryptopp/crypto/blumshub.cpp (limited to 'cryptopp/crypto/blumshub.cpp') diff --git a/cryptopp/crypto/blumshub.cpp b/cryptopp/crypto/blumshub.cpp new file mode 100644 index 0000000..6ab2209 --- /dev/null +++ b/cryptopp/crypto/blumshub.cpp @@ -0,0 +1,63 @@ +// blumshub.cpp - written and placed in the public domain by Wei Dai + +#include "pch.h" +#include "blumshub.h" + +NAMESPACE_BEGIN(CryptoPP) + +PublicBlumBlumShub::PublicBlumBlumShub(const Integer &n, const Integer &seed) + : modn(n), + maxBits(BitPrecision(n.BitCount())-1) +{ + current = modn.Square(modn.Square(seed)); + bitsLeft = maxBits; +} + +unsigned int PublicBlumBlumShub::GenerateBit() +{ + if (bitsLeft==0) + { + current = modn.Square(current); + bitsLeft = maxBits; + } + + return current.GetBit(--bitsLeft); +} + +byte PublicBlumBlumShub::GenerateByte() +{ + byte b=0; + for (int i=0; i<8; i++) + b = (b << 1) | PublicBlumBlumShub::GenerateBit(); + return b; +} + +void PublicBlumBlumShub::GenerateBlock(byte *output, size_t size) +{ + while (size--) + *output++ = PublicBlumBlumShub::GenerateByte(); +} + +void PublicBlumBlumShub::ProcessData(byte *outString, const byte *inString, size_t length) +{ + while (length--) + *outString++ = *inString++ ^ PublicBlumBlumShub::GenerateByte(); +} + +BlumBlumShub::BlumBlumShub(const Integer &p, const Integer &q, const Integer &seed) + : PublicBlumBlumShub(p*q, seed), + p(p), q(q), + x0(modn.Square(seed)) +{ +} + +void BlumBlumShub::Seek(lword index) +{ + Integer i(Integer::POSITIVE, index); + i *= 8; + Integer e = a_exp_b_mod_c (2, i / maxBits + 1, (p-1)*(q-1)); + current = modn.Exponentiate(x0, e); + bitsLeft = maxBits - i % maxBits; +} + +NAMESPACE_END -- cgit v1.2.3