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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