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