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-rw-r--r--CryptoPP/esign.cpp210
1 files changed, 210 insertions, 0 deletions
diff --git a/CryptoPP/esign.cpp b/CryptoPP/esign.cpp
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+++ b/CryptoPP/esign.cpp
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+// esign.cpp - written and placed in the public domain by Wei Dai
+
+#include "pch.h"
+#include "esign.h"
+#include "asn.h"
+#include "modarith.h"
+#include "nbtheory.h"
+#include "sha.h"
+#include "algparam.h"
+
+NAMESPACE_BEGIN(CryptoPP)
+
+void ESIGN_TestInstantiations()
+{
+ ESIGN<SHA>::Verifier x1(1, 1);
+ ESIGN<SHA>::Signer x2(NullRNG(), 1);
+ ESIGN<SHA>::Verifier x3(x2);
+ ESIGN<SHA>::Verifier x4(x2.GetKey());
+ ESIGN<SHA>::Verifier x5(x3);
+ ESIGN<SHA>::Signer x6 = x2;
+
+ x6 = x2;
+ x3 = ESIGN<SHA>::Verifier(x2);
+ x4 = x2.GetKey();
+}
+
+void ESIGNFunction::BERDecode(BufferedTransformation &bt)
+{
+ BERSequenceDecoder seq(bt);
+ m_n.BERDecode(seq);
+ m_e.BERDecode(seq);
+ seq.MessageEnd();
+}
+
+void ESIGNFunction::DEREncode(BufferedTransformation &bt) const
+{
+ DERSequenceEncoder seq(bt);
+ m_n.DEREncode(seq);
+ m_e.DEREncode(seq);
+ seq.MessageEnd();
+}
+
+Integer ESIGNFunction::ApplyFunction(const Integer &x) const
+{
+ DoQuickSanityCheck();
+ return STDMIN(a_exp_b_mod_c(x, m_e, m_n) >> (2*GetK()+2), MaxImage());
+}
+
+bool ESIGNFunction::Validate(RandomNumberGenerator &rng, unsigned int level) const
+{
+ bool pass = true;
+ pass = pass && m_n > Integer::One() && m_n.IsOdd();
+ pass = pass && m_e >= 8 && m_e < m_n;
+ return pass;
+}
+
+bool ESIGNFunction::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(PublicExponent)
+ ;
+}
+
+void ESIGNFunction::AssignFrom(const NameValuePairs &source)
+{
+ AssignFromHelper(this, source)
+ CRYPTOPP_SET_FUNCTION_ENTRY(Modulus)
+ CRYPTOPP_SET_FUNCTION_ENTRY(PublicExponent)
+ ;
+}
+
+// *****************************************************************************
+
+void InvertibleESIGNFunction::GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &param)
+{
+ int modulusSize = 1023*2;
+ param.GetIntValue("ModulusSize", modulusSize) || param.GetIntValue("KeySize", modulusSize);
+
+ if (modulusSize < 24)
+ throw InvalidArgument("InvertibleESIGNFunction: specified modulus size is too small");
+
+ if (modulusSize % 3 != 0)
+ throw InvalidArgument("InvertibleESIGNFunction: modulus size must be divisible by 3");
+
+ m_e = param.GetValueWithDefault("PublicExponent", Integer(32));
+
+ if (m_e < 8)
+ throw InvalidArgument("InvertibleESIGNFunction: public exponents less than 8 may not be secure");
+
+ // VC70 workaround: putting these after primeParam causes overlapped stack allocation
+ ConstByteArrayParameter seedParam;
+ SecByteBlock seed;
+
+ const Integer minP = Integer(204) << (modulusSize/3-8);
+ const Integer maxP = Integer::Power2(modulusSize/3)-1;
+ AlgorithmParameters primeParam = MakeParameters("Min", minP)("Max", maxP)("RandomNumberType", Integer::PRIME);
+
+ if (param.GetValue("Seed", seedParam))
+ {
+ seed.resize(seedParam.size() + 4);
+ memcpy(seed + 4, seedParam.begin(), seedParam.size());
+
+ PutWord(false, BIG_ENDIAN_ORDER, seed, (word32)0);
+ m_p.GenerateRandom(rng, CombinedNameValuePairs(primeParam, MakeParameters("Seed", ConstByteArrayParameter(seed))));
+ PutWord(false, BIG_ENDIAN_ORDER, seed, (word32)1);
+ m_q.GenerateRandom(rng, CombinedNameValuePairs(primeParam, MakeParameters("Seed", ConstByteArrayParameter(seed))));
+ }
+ else
+ {
+ m_p.GenerateRandom(rng, primeParam);
+ m_q.GenerateRandom(rng, primeParam);
+ }
+
+ m_n = m_p * m_p * m_q;
+
+ assert(m_n.BitCount() == modulusSize);
+}
+
+void InvertibleESIGNFunction::BERDecode(BufferedTransformation &bt)
+{
+ BERSequenceDecoder privateKey(bt);
+ m_n.BERDecode(privateKey);
+ m_e.BERDecode(privateKey);
+ m_p.BERDecode(privateKey);
+ m_q.BERDecode(privateKey);
+ privateKey.MessageEnd();
+}
+
+void InvertibleESIGNFunction::DEREncode(BufferedTransformation &bt) const
+{
+ DERSequenceEncoder privateKey(bt);
+ m_n.DEREncode(privateKey);
+ m_e.DEREncode(privateKey);
+ m_p.DEREncode(privateKey);
+ m_q.DEREncode(privateKey);
+ privateKey.MessageEnd();
+}
+
+Integer InvertibleESIGNFunction::CalculateRandomizedInverse(RandomNumberGenerator &rng, const Integer &x) const
+{
+ DoQuickSanityCheck();
+
+ Integer pq = m_p * m_q;
+ Integer p2 = m_p * m_p;
+ Integer r, z, re, a, w0, w1;
+
+ do
+ {
+ r.Randomize(rng, Integer::Zero(), pq);
+ z = x << (2*GetK()+2);
+ re = a_exp_b_mod_c(r, m_e, m_n);
+ a = (z - re) % m_n;
+ Integer::Divide(w1, w0, a, pq);
+ if (w1.NotZero())
+ {
+ ++w0;
+ w1 = pq - w1;
+ }
+ }
+ while ((w1 >> 2*GetK()+1).IsPositive());
+
+ ModularArithmetic modp(m_p);
+ Integer t = modp.Divide(w0 * r % m_p, m_e * re % m_p);
+ Integer s = r + t*pq;
+ assert(s < m_n);
+/*
+ using namespace std;
+ cout << "f = " << x << endl;
+ cout << "r = " << r << endl;
+ cout << "z = " << z << endl;
+ cout << "a = " << a << endl;
+ cout << "w0 = " << w0 << endl;
+ cout << "w1 = " << w1 << endl;
+ cout << "t = " << t << endl;
+ cout << "s = " << s << endl;
+*/
+ return s;
+}
+
+bool InvertibleESIGNFunction::Validate(RandomNumberGenerator &rng, unsigned int level) const
+{
+ bool pass = ESIGNFunction::Validate(rng, level);
+ pass = pass && m_p > Integer::One() && m_p.IsOdd() && m_p < m_n;
+ pass = pass && m_q > Integer::One() && m_q.IsOdd() && m_q < m_n;
+ pass = pass && m_p.BitCount() == m_q.BitCount();
+ if (level >= 1)
+ pass = pass && m_p * m_p * m_q == m_n;
+ if (level >= 2)
+ pass = pass && VerifyPrime(rng, m_p, level-2) && VerifyPrime(rng, m_q, level-2);
+ return pass;
+}
+
+bool InvertibleESIGNFunction::GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
+{
+ return GetValueHelper<ESIGNFunction>(this, name, valueType, pValue).Assignable()
+ CRYPTOPP_GET_FUNCTION_ENTRY(Prime1)
+ CRYPTOPP_GET_FUNCTION_ENTRY(Prime2)
+ ;
+}
+
+void InvertibleESIGNFunction::AssignFrom(const NameValuePairs &source)
+{
+ AssignFromHelper<ESIGNFunction>(this, source)
+ CRYPTOPP_SET_FUNCTION_ENTRY(Prime1)
+ CRYPTOPP_SET_FUNCTION_ENTRY(Prime2)
+ ;
+}
+
+NAMESPACE_END