NRDigestVerifier::NRDigestVerifier(BufferedTransformation &bt)
{
BERSequenceDecoder seq(bt);
p.BERDecode(seq);
q.BERDecode(seq);
g.BERDecode(seq);
y.BERDecode(seq);
gpc.Precompute(p, g, ExponentBitLength(), 1);
ypc.Precompute(p, y, ExponentBitLength(), 1);
}
NRDigestSigner::NRDigestSigner(RandomNumberGenerator &rng, unsigned int pbits)
{
PrimeAndGenerator pg(1, rng, pbits, 2*DiscreteLogWorkFactor(pbits));
p = pg.Prime();
q = pg.SubPrime();
g = pg.Generator();
x.Randomize(rng, 2, q-2, Integer::ANY);
gpc.Precompute(p, g, ExponentBitLength(), 1);
y = gpc.Exponentiate(x);
ypc.Precompute(p, y, ExponentBitLength(), 1);
}
void DH::GenerateKeyPair(RandomNumberGenerator &rng, byte *privateKey, byte *publicKey) const
{
Integer x(rng, ExponentBitLength());
Integer y = gpc.Exponentiate(x);
x.Encode(privateKey, PrivateKeyLength());
y.Encode(publicKey, PublicKeyLength());
}
DH::DH(BufferedTransformation &bt)
{
BERSequenceDecoder seq(bt);
p.BERDecode(seq);
g.BERDecode(seq);
gpc.Precompute(p, g, ExponentBitLength(), 1);
}
DH::DH(RandomNumberGenerator &rng, unsigned int pbits)
{
PrimeAndGenerator pg(1, rng, pbits);
p = pg.Prime();
g = pg.Generator();
gpc.Precompute(p, g, ExponentBitLength(), 1);
}
ElGamalDecryptor::ElGamalDecryptor(RandomNumberGenerator &rng, const Integer &pIn, const Integer &gIn)
{
m_p = pIn;
m_g = gIn;
m_x.Randomize(rng, ExponentBitLength());
m_gpc.SetModulusAndBase(m_p, m_g);
m_y = m_gpc.Exponentiate(m_x);
m_ypc.SetModulusAndBase(m_p, m_y);
}
ElGamalDecryptor::ElGamalDecryptor(RandomNumberGenerator &rng, unsigned int pbits)
{
PrimeAndGenerator pg(1, rng, pbits);
m_p = pg.Prime();
m_g = pg.Generator();
m_x.Randomize(rng, ExponentBitLength());
m_gpc.SetModulusAndBase(m_p, m_g);
m_y = m_gpc.Exponentiate(m_x);
m_ypc.SetModulusAndBase(m_p, m_y);
}
void ElGamalEncryptor::Encrypt(RandomNumberGenerator &rng, const byte *plainText, unsigned int plainTextLength, byte *cipherText)
{
assert(plainTextLength <= MaxPlainTextLength());
SecByteBlock block(modulusLen-1);
rng.GetBlock(block, modulusLen-2-plainTextLength);
memcpy(block+modulusLen-2-plainTextLength, plainText, plainTextLength);
block[modulusLen-2] = plainTextLength;
Integer m(block, modulusLen-1);
Integer a,b;
RawEncrypt(Integer(rng, ExponentBitLength()), m, a, b);
a.Encode(cipherText, modulusLen);
b.Encode(cipherText+modulusLen, modulusLen);
}
void ElGamalEncryptor::Precompute(unsigned int precomputationStorage)
{
gpc.Precompute(p, g, ExponentBitLength(), precomputationStorage);
ypc.Precompute(p, y, ExponentBitLength(), precomputationStorage);
}
ElGamalEncryptor::ElGamalEncryptor(const Integer &p, const Integer &g, const Integer &y)
: p(p), g(g), y(y), modulusLen(p.ByteCount()),
gpc(p, g, ExponentBitLength(), 1), ypc(p, y, ExponentBitLength(), 1)
{
}
DH::DH(const Integer &p, const Integer &g)
: p(p), g(g), gpc(p, g, ExponentBitLength(), 1)
{
}
void DH::Precompute(unsigned int precomputationStorage)
{
gpc.Precompute(p, g, ExponentBitLength(), precomputationStorage);
}
void ElGamalEncryptor::Precompute(unsigned int precomputationStorage)
{
m_gpc.Precompute(ExponentBitLength(), precomputationStorage);
m_ypc.Precompute(ExponentBitLength(), precomputationStorage);
}
void NRDigestVerifier::Precompute(unsigned int precomputationStorage)
{
m_gpc.Precompute(ExponentBitLength(), precomputationStorage);
m_ypc.Precompute(ExponentBitLength(), precomputationStorage);
}
void NRDigestVerifier::Precompute(unsigned int precomputationStorage)
{
gpc.Precompute(p, g, ExponentBitLength(), precomputationStorage);
ypc.Precompute(p, y, ExponentBitLength(), precomputationStorage);
}
