00001
00002
00003 #include "pch.h"
00004 #include "rabin.h"
00005 #include "nbtheory.h"
00006 #include "asn.h"
00007 #include "sha.h"
00008 #include "modarith.h"
00009
00010 #include "oaep.cpp"
00011
00012 NAMESPACE_BEGIN(CryptoPP)
00013
00014 void RabinFunction::BERDecode(BufferedTransformation &bt)
00015 {
00016 BERSequenceDecoder seq(bt);
00017 m_n.BERDecode(seq);
00018 m_r.BERDecode(seq);
00019 m_s.BERDecode(seq);
00020 seq.MessageEnd();
00021 }
00022
00023 void RabinFunction::DEREncode(BufferedTransformation &bt) const
00024 {
00025 DERSequenceEncoder seq(bt);
00026 m_n.DEREncode(seq);
00027 m_r.DEREncode(seq);
00028 m_s.DEREncode(seq);
00029 seq.MessageEnd();
00030 }
00031
00032 Integer RabinFunction::ApplyFunction(const Integer &in) const
00033 {
00034 DoQuickSanityCheck();
00035
00036 Integer out = in.Squared()%m_n;
00037 if (in.IsOdd())
00038 out = out*m_r%m_n;
00039 if (Jacobi(in, m_n)==-1)
00040 out = out*m_s%m_n;
00041 return out;
00042 }
00043
00044 bool RabinFunction::Validate(RandomNumberGenerator &rng, unsigned int level) const
00045 {
00046 bool pass = true;
00047 pass = pass && m_n > Integer::One() && m_n%4 == 1;
00048 pass = pass && m_r > Integer::One() && m_r < m_n;
00049 pass = pass && m_s > Integer::One() && m_s < m_n;
00050 if (level >= 1)
00051 pass = pass && Jacobi(m_r, m_n) == -1 && Jacobi(m_s, m_n) == -1;
00052 return pass;
00053 }
00054
00055 bool RabinFunction::GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
00056 {
00057 return GetValueHelper(this, name, valueType, pValue).Assignable()
00058 CRYPTOPP_GET_FUNCTION_ENTRY(Modulus)
00059 CRYPTOPP_GET_FUNCTION_ENTRY(QuadraticResidueModPrime1)
00060 CRYPTOPP_GET_FUNCTION_ENTRY(QuadraticResidueModPrime2)
00061 ;
00062 }
00063
00064 void RabinFunction::AssignFrom(const NameValuePairs &source)
00065 {
00066 AssignFromHelper(this, source)
00067 CRYPTOPP_SET_FUNCTION_ENTRY(Modulus)
00068 CRYPTOPP_SET_FUNCTION_ENTRY(QuadraticResidueModPrime1)
00069 CRYPTOPP_SET_FUNCTION_ENTRY(QuadraticResidueModPrime2)
00070 ;
00071 }
00072
00073
00074
00075
00076
00077 void InvertibleRabinFunction::GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg)
00078 {
00079 int modulusSize = 2048;
00080 alg.GetIntValue("ModulusSize", modulusSize) || alg.GetIntValue("KeySize", modulusSize);
00081
00082 if (modulusSize < 16)
00083 throw InvalidArgument("InvertibleRabinFunction: specified modulus size is too small");
00084
00085
00086 bool rFound=false, sFound=false;
00087 Integer t=2;
00088
00089 const NameValuePairs &primeParam = MakeParametersForTwoPrimesOfEqualSize(modulusSize)
00090 ("EquivalentTo", 3)("Mod", 4);
00091 m_p.GenerateRandom(rng, primeParam);
00092 m_q.GenerateRandom(rng, primeParam);
00093
00094 while (!(rFound && sFound))
00095 {
00096 int jp = Jacobi(t, m_p);
00097 int jq = Jacobi(t, m_q);
00098
00099 if (!rFound && jp==1 && jq==-1)
00100 {
00101 m_r = t;
00102 rFound = true;
00103 }
00104
00105 if (!sFound && jp==-1 && jq==1)
00106 {
00107 m_s = t;
00108 sFound = true;
00109 }
00110
00111 ++t;
00112 }
00113
00114 m_n = m_p * m_q;
00115 m_u = m_q.InverseMod(m_p);
00116 }
00117
00118 void InvertibleRabinFunction::BERDecode(BufferedTransformation &bt)
00119 {
00120 BERSequenceDecoder seq(bt);
00121 m_n.BERDecode(seq);
00122 m_r.BERDecode(seq);
00123 m_s.BERDecode(seq);
00124 m_p.BERDecode(seq);
00125 m_q.BERDecode(seq);
00126 m_u.BERDecode(seq);
00127 seq.MessageEnd();
00128 }
00129
00130 void InvertibleRabinFunction::DEREncode(BufferedTransformation &bt) const
00131 {
00132 DERSequenceEncoder seq(bt);
00133 m_n.DEREncode(seq);
00134 m_r.DEREncode(seq);
00135 m_s.DEREncode(seq);
00136 m_p.DEREncode(seq);
00137 m_q.DEREncode(seq);
00138 m_u.DEREncode(seq);
00139 seq.MessageEnd();
00140 }
00141
00142 Integer InvertibleRabinFunction::CalculateInverse(RandomNumberGenerator &rng, const Integer &in) const
00143 {
00144 DoQuickSanityCheck();
00145
00146 ModularArithmetic modn(m_n);
00147 Integer r(rng, Integer::One(), m_n - Integer::One());
00148 r = modn.Square(r);
00149 Integer r2 = modn.Square(r);
00150 Integer c = modn.Multiply(in, r2);
00151
00152 Integer cp=c%m_p, cq=c%m_q;
00153
00154 int jp = Jacobi(cp, m_p);
00155 int jq = Jacobi(cq, m_q);
00156
00157 if (jq==-1)
00158 {
00159 cp = cp*EuclideanMultiplicativeInverse(m_r, m_p)%m_p;
00160 cq = cq*EuclideanMultiplicativeInverse(m_r, m_q)%m_q;
00161 }
00162
00163 if (jp==-1)
00164 {
00165 cp = cp*EuclideanMultiplicativeInverse(m_s, m_p)%m_p;
00166 cq = cq*EuclideanMultiplicativeInverse(m_s, m_q)%m_q;
00167 }
00168
00169 cp = ModularSquareRoot(cp, m_p);
00170 cq = ModularSquareRoot(cq, m_q);
00171
00172 if (jp==-1)
00173 cp = m_p-cp;
00174
00175 Integer out = CRT(cq, m_q, cp, m_p, m_u);
00176
00177 out = modn.Divide(out, r);
00178
00179 if ((jq==-1 && out.IsEven()) || (jq==1 && out.IsOdd()))
00180 out = m_n-out;
00181
00182 return out;
00183 }
00184
00185 bool InvertibleRabinFunction::Validate(RandomNumberGenerator &rng, unsigned int level) const
00186 {
00187 bool pass = RabinFunction::Validate(rng, level);
00188 pass = pass && m_p > Integer::One() && m_p%4 == 3 && m_p < m_n;
00189 pass = pass && m_q > Integer::One() && m_q%4 == 3 && m_q < m_n;
00190 pass = pass && m_u.IsPositive() && m_u < m_p;
00191 if (level >= 1)
00192 {
00193 pass = pass && m_p * m_q == m_n;
00194 pass = pass && m_u * m_q % m_p == 1;
00195 pass = pass && Jacobi(m_r, m_p) == 1;
00196 pass = pass && Jacobi(m_r, m_q) == -1;
00197 pass = pass && Jacobi(m_s, m_p) == -1;
00198 pass = pass && Jacobi(m_s, m_q) == 1;
00199 }
00200 if (level >= 2)
00201 pass = pass && VerifyPrime(rng, m_p, level-2) && VerifyPrime(rng, m_q, level-2);
00202 return pass;
00203 }
00204
00205 bool InvertibleRabinFunction::GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
00206 {
00207 return GetValueHelper<RabinFunction>(this, name, valueType, pValue).Assignable()
00208 CRYPTOPP_GET_FUNCTION_ENTRY(Prime1)
00209 CRYPTOPP_GET_FUNCTION_ENTRY(Prime2)
00210 CRYPTOPP_GET_FUNCTION_ENTRY(MultiplicativeInverseOfPrime2ModPrime1)
00211 ;
00212 }
00213
00214 void InvertibleRabinFunction::AssignFrom(const NameValuePairs &source)
00215 {
00216 AssignFromHelper<RabinFunction>(this, source)
00217 CRYPTOPP_SET_FUNCTION_ENTRY(Prime1)
00218 CRYPTOPP_SET_FUNCTION_ENTRY(Prime2)
00219 CRYPTOPP_SET_FUNCTION_ENTRY(MultiplicativeInverseOfPrime2ModPrime1)
00220 ;
00221 }
00222
00223 NAMESPACE_END