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