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esign.h
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    00001 #ifndef CRYPTOPP_ESIGN_H
    00002 #define CRYPTOPP_ESIGN_H
    00003
    00004 /** \file
    00005     This file contains classes that implement the
    00006     ESIGN signature schemes as defined in IEEE P1363a.
    00007 */
    00008
    00009 #include "pubkey.h"
    00010 #include "integer.h"
    00011 #include "asn.h"
    00012
    00013 NAMESPACE_BEGIN(CryptoPP)
    00014
    00015 //! _
    00016 class ESIGNFunction : public TrapdoorFunction, public ASN1CryptoMaterial<PublicKey>
    00017 {
    00018     typedef ESIGNFunction ThisClass;
    00019
    00020 public:
    00021     void Initialize(const Integer &n, const Integer &e)
    00022         {m_n = n; m_e = e;}
    00023
    00024     // PublicKey
    00025     void BERDecode(BufferedTransformation &bt);
    00026     void DEREncode(BufferedTransformation &bt) const;
    00027
    00028     // CryptoMaterial
    00029     bool Validate(RandomNumberGenerator &rng, unsigned int level) const;
    00030     bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const;
    00031     void AssignFrom(const NameValuePairs &source);
    00032
    00033     // TrapdoorFunction
    00034     Integer ApplyFunction(const Integer &x) const;
    00035     Integer PreimageBound() const {return m_n;}
    00036     Integer ImageBound() const {return Integer::Power2(GetK());}
    00037
    00038     // non-derived
    00039     const Integer & GetModulus() const {return m_n;}
    00040     const Integer & GetPublicExponent() const {return m_e;}
    00041
    00042     void SetModulus(const Integer &n) {m_n = n;}
    00043     void SetPublicExponent(const Integer &e) {m_e = e;}
    00044
    00045 protected:
    00046     unsigned int GetK() const {return m_n.BitCount()/3-1;}
    00047
    00048     Integer m_n, m_e;
    00049 };
    00050
    00051 //! _
    00052 class InvertibleESIGNFunction : public ESIGNFunction, public RandomizedTrapdoorFunctionInverse, public PrivateKey
    00053 {
    00054     typedef InvertibleESIGNFunction ThisClass;
    00055
    00056 public:
    00057     void Initialize(const Integer &n, const Integer &e, const Integer &p, const Integer &q)
    00058         {m_n = n; m_e = e; m_p = p; m_q = q;}
    00059     // generate a random private key
    00060     void Initialize(RandomNumberGenerator &rng, unsigned int modulusBits)
    00061         {GenerateRandomWithKeySize(rng, modulusBits);}
    00062
    00063     void BERDecode(BufferedTransformation &bt);
    00064     void DEREncode(BufferedTransformation &bt) const;
    00065
    00066     Integer CalculateRandomizedInverse(RandomNumberGenerator &rng, const Integer &x) const;
    00067
    00068     // GeneratibleCryptoMaterial
    00069     bool Validate(RandomNumberGenerator &rng, unsigned int level) const;
    00070     bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const;
    00071     void AssignFrom(const NameValuePairs &source);
    00072     /*! parameters: (ModulusSize) */
    00073     void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg);
    00074
    00075     const Integer& GetPrime1() const {return m_p;}
    00076     const Integer& GetPrime2() const {return m_q;}
    00077
    00078     void SetPrime1(const Integer &p) {m_p = p;}
    00079     void SetPrime2(const Integer &q) {m_q = q;}
    00080
    00081 protected:
    00082     Integer m_p, m_q;
    00083 };
    00084
    00085 //! _
    00086 template <class T>
    00087 class EMSA5Pad : public PK_DeterministicSignatureMessageEncodingMethod
    00088 {
    00089 public:
    00090     static const char *StaticAlgorithmName() {return "EMSA5";}
    00091
    00092     void ComputeMessageRepresentative(RandomNumberGenerator &rng,
    00093         const byte *recoverableMessage, size_t recoverableMessageLength,
    00094         HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
    00095         byte *representative, size_t representativeBitLength) const
    00096     {
    00097         SecByteBlock digest(hash.DigestSize());
    00098         hash.Final(digest);
    00099         size_t representativeByteLength = BitsToBytes(representativeBitLength);
    00100         T mgf;
    00101         mgf.GenerateAndMask(hash, representative, representativeByteLength, digest, digest.size(), false);
    00102         if (representativeBitLength % 8 != 0)
    00103             representative[0] = (byte)Crop(representative[0], representativeBitLength % 8);
    00104     }
    00105 };
    00106
    00107 //! EMSA5, for use with ESIGN
    00108 struct P1363_EMSA5 : public SignatureStandard
    00109 {
    00110     typedef EMSA5Pad<P1363_MGF1> SignatureMessageEncodingMethod;
    00111 };
    00112
    00113 struct ESIGN_Keys
    00114 {
    00115     static std::string StaticAlgorithmName() {return "ESIGN";}
    00116     typedef ESIGNFunction PublicKey;
    00117     typedef InvertibleESIGNFunction PrivateKey;
    00118 };
    00119
    00120 //! ESIGN, as defined in IEEE P1363a
    00121 template <class H, class STANDARD = P1363_EMSA5>
    00122 struct ESIGN : public TF_SS<STANDARD, H, ESIGN_Keys>
    00123 {
    00124 };
    00125
    00126 NAMESPACE_END
    00127
    00128 #endif