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70 lines
2.0 KiB
70 lines
2.0 KiB
// blumshub.h - originally written and placed in the public domain by Wei Dai |
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/// \file blumshub.h |
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/// \brief Classes for Blum Blum Shub generator |
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#ifndef CRYPTOPP_BLUMSHUB_H |
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#define CRYPTOPP_BLUMSHUB_H |
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#include "cryptlib.h" |
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#include "modarith.h" |
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#include "integer.h" |
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NAMESPACE_BEGIN(CryptoPP) |
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/// \brief BlumBlumShub without factorization of the modulus |
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/// \details You should reseed the generator after a fork() to avoid multiple generators |
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/// with the same internal state. |
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class PublicBlumBlumShub : public RandomNumberGenerator, |
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public StreamTransformation |
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{ |
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public: |
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virtual ~PublicBlumBlumShub() {} |
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/// \brief Construct a PublicBlumBlumShub |
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/// \param n the modulus |
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/// \param seed the seed for the generator |
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/// \details seed is the secret key and should be about as large as n. |
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PublicBlumBlumShub(const Integer &n, const Integer &seed); |
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unsigned int GenerateBit(); |
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byte GenerateByte(); |
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void GenerateBlock(byte *output, size_t size); |
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void ProcessData(byte *outString, const byte *inString, size_t length); |
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bool IsSelfInverting() const {return true;} |
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bool IsForwardTransformation() const {return true;} |
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protected: |
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ModularArithmetic modn; |
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Integer current; |
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word maxBits, bitsLeft; |
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}; |
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/// \brief BlumBlumShub with factorization of the modulus |
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/// \details You should reseed the generator after a fork() to avoid multiple generators |
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/// with the same internal state. |
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class BlumBlumShub : public PublicBlumBlumShub |
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{ |
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public: |
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virtual ~BlumBlumShub() {} |
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/// \brief Construct a BlumBlumShub |
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/// \param p the first prime factor |
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/// \param q the second prime factor |
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/// \param seed the seed for the generator |
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/// \details Esure p and q are both primes congruent to 3 mod 4 and at least 512 bits long. |
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/// seed is the secret key and should be about as large as p*q. |
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BlumBlumShub(const Integer &p, const Integer &q, const Integer &seed); |
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bool IsRandomAccess() const {return true;} |
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void Seek(lword index); |
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protected: |
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const Integer p, q; |
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const Integer x0; |
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}; |
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NAMESPACE_END |
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#endif
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