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Diffstat (limited to 'CryptoPP/esign.cpp')
| -rw-r--r-- | CryptoPP/esign.cpp | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/CryptoPP/esign.cpp b/CryptoPP/esign.cpp new file mode 100644 index 000000000..8b42c1fa4 --- /dev/null +++ b/CryptoPP/esign.cpp @@ -0,0 +1,210 @@ +// 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 ¶m) +{ + 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 |