You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
109 lines
3.1 KiB
109 lines
3.1 KiB
5 years ago
|
// xtrcrypt.cpp - written and placed in the public domain by Wei Dai
|
||
|
|
|
||
|
|
#include "pch.h"
|
||
|
|
#include "xtrcrypt.h"
|
||
|
|
#include "nbtheory.h"
|
||
|
|
#include "asn.h"
|
||
|
|
#include "argnames.h"
|
||
|
|
|
||
|
|
NAMESPACE_BEGIN(CryptoPP)
|
||
|
|
|
||
|
|
XTR_DH::XTR_DH(const Integer &p, const Integer &q, const GFP2Element &g)
|
||
|
|
: m_p(p), m_q(q), m_g(g)
|
||
|
|
{
|
||
|
|
}
|
||
|
|
|
||
|
|
XTR_DH::XTR_DH(RandomNumberGenerator &rng, unsigned int pbits, unsigned int qbits)
|
||
|
|
{
|
||
|
|
XTR_FindPrimesAndGenerator(rng, m_p, m_q, m_g, pbits, qbits);
|
||
|
|
}
|
||
|
|
|
||
|
|
XTR_DH::XTR_DH(BufferedTransformation &bt)
|
||
|
|
{
|
||
|
|
BERSequenceDecoder seq(bt);
|
||
|
|
m_p.BERDecode(seq);
|
||
|
|
m_q.BERDecode(seq);
|
||
|
|
m_g.c1.BERDecode(seq);
|
||
|
|
m_g.c2.BERDecode(seq);
|
||
|
|
seq.MessageEnd();
|
||
|
|
}
|
||
|
|
|
||
|
|
void XTR_DH::DEREncode(BufferedTransformation &bt) const
|
||
|
|
{
|
||
|
|
DERSequenceEncoder seq(bt);
|
||
|
|
m_p.DEREncode(seq);
|
||
|
|
m_q.DEREncode(seq);
|
||
|
|
m_g.c1.DEREncode(seq);
|
||
|
|
m_g.c2.DEREncode(seq);
|
||
|
|
seq.MessageEnd();
|
||
|
|
}
|
||
|
|
|
||
|
|
bool XTR_DH::Validate(RandomNumberGenerator &rng, unsigned int level) const
|
||
|
|
{
|
||
|
|
bool pass = true;
|
||
|
|
pass = pass && m_p > Integer::One() && m_p.IsOdd();
|
||
|
|
pass = pass && m_q > Integer::One() && m_q.IsOdd();
|
||
|
|
GFP2Element three = GFP2_ONB<ModularArithmetic>(m_p).ConvertIn(3);
|
||
|
|
pass = pass && !(m_g.c1.IsNegative() || m_g.c2.IsNegative() || m_g.c1 >= m_p || m_g.c2 >= m_p || m_g == three);
|
||
|
|
if (level >= 1)
|
||
|
|
pass = pass && ((m_p.Squared()-m_p+1)%m_q).IsZero();
|
||
|
|
if (level >= 2)
|
||
|
|
{
|
||
|
|
pass = pass && VerifyPrime(rng, m_p, level-2) && VerifyPrime(rng, m_q, level-2);
|
||
|
|
pass = pass && XTR_Exponentiate(m_g, (m_p.Squared()-m_p+1)/m_q, m_p) != three;
|
||
|
|
pass = pass && XTR_Exponentiate(m_g, m_q, m_p) == three;
|
||
|
|
}
|
||
|
|
return pass;
|
||
|
|
}
|
||
|
|
|
||
|
|
bool XTR_DH::GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
|
||
|
|
{
|
||
|
|
return GetValueHelper(this, name, valueType, pValue).Assignable()
|
||
|
|
CRYPTOPP_GET_FUNCTION_ENTRY(Modulus)
|
||
|
|
CRYPTOPP_GET_FUNCTION_ENTRY(SubgroupOrder)
|
||
|
|
CRYPTOPP_GET_FUNCTION_ENTRY(SubgroupGenerator)
|
||
|
|
;
|
||
|
|
}
|
||
|
|
|
||
|
|
void XTR_DH::AssignFrom(const NameValuePairs &source)
|
||
|
|
{
|
||
|
|
AssignFromHelper(this, source)
|
||
|
|
CRYPTOPP_SET_FUNCTION_ENTRY(Modulus)
|
||
|
|
CRYPTOPP_SET_FUNCTION_ENTRY(SubgroupOrder)
|
||
|
|
CRYPTOPP_SET_FUNCTION_ENTRY(SubgroupGenerator)
|
||
|
|
;
|
||
|
|
}
|
||
|
|
|
||
|
|
void XTR_DH::GeneratePrivateKey(RandomNumberGenerator &rng, byte *privateKey) const
|
||
|
|
{
|
||
|
|
Integer x(rng, Integer::Zero(), m_q-1);
|
||
|
|
x.Encode(privateKey, PrivateKeyLength());
|
||
|
|
}
|
||
|
|
|
||
|
|
void XTR_DH::GeneratePublicKey(RandomNumberGenerator &rng, const byte *privateKey, byte *publicKey) const
|
||
|
|
{
|
||
|
|
Integer x(privateKey, PrivateKeyLength());
|
||
|
|
GFP2Element y = XTR_Exponentiate(m_g, x, m_p);
|
||
|
|
y.Encode(publicKey, PublicKeyLength());
|
||
|
|
}
|
||
|
|
|
||
|
|
bool XTR_DH::Agree(byte *agreedValue, const byte *privateKey, const byte *otherPublicKey, bool validateOtherPublicKey) const
|
||
|
|
{
|
||
|
|
GFP2Element w(otherPublicKey, PublicKeyLength());
|
||
|
|
if (validateOtherPublicKey)
|
||
|
|
{
|
||
|
|
GFP2_ONB<ModularArithmetic> gfp2(m_p);
|
||
|
|
GFP2Element three = gfp2.ConvertIn(3);
|
||
|
|
if (w.c1.IsNegative() || w.c2.IsNegative() || w.c1 >= m_p || w.c2 >= m_p || w == three)
|
||
|
|
return false;
|
||
|
|
if (XTR_Exponentiate(w, m_q, m_p) != three)
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
Integer s(privateKey, PrivateKeyLength());
|
||
|
|
GFP2Element z = XTR_Exponentiate(w, s, m_p);
|
||
|
|
z.Encode(agreedValue, AgreedValueLength());
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
NAMESPACE_END
|