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eccrypto.h

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00001 #ifndef CRYPTOPP_ECCRYPTO_H
00002 #define CRYPTOPP_ECCRYPTO_H
00003 
00004 /*! \file
00005 */
00006 
00007 #include "pubkey.h"
00008 #include "integer.h"
00009 #include "asn.h"
00010 #include "hmac.h"
00011 #include "sha.h"
00012 #include "gfpcrypt.h"
00013 #include "dh.h"
00014 #include "mqv.h"
00015 #include "ecp.h"
00016 #include "ec2n.h"
00017 
00018 NAMESPACE_BEGIN(CryptoPP)
00019 
00020 //! Elliptic Curve Parameters
00021 /*! This class corresponds to the ASN.1 sequence of the same name
00022     in ANSI X9.62 (also SEC 1).
00023 */
00024 template <class EC>
00025 class DL_GroupParameters_EC : public DL_GroupParametersImpl<EcPrecomputation<EC> >
00026 {
00027         typedef DL_GroupParameters_EC<EC> ThisClass;
00028 
00029 public:
00030         typedef EC EllipticCurve;
00031         typedef typename EllipticCurve::Point Point;
00032         typedef Point Element;
00033         typedef IncompatibleCofactorMultiplication DefaultCofactorOption;
00034 
00035         DL_GroupParameters_EC() : m_compress(false), m_encodeAsOID(false) {}
00036         DL_GroupParameters_EC(const OID &oid)
00037                 : m_compress(false), m_encodeAsOID(false) {Initialize(oid);}
00038         DL_GroupParameters_EC(const EllipticCurve &ec, const Point &G, const Integer &n, const Integer &k = Integer::Zero())
00039                 : m_compress(false), m_encodeAsOID(false) {Initialize(ec, G, n, k);}
00040         DL_GroupParameters_EC(BufferedTransformation &bt)
00041                 : m_compress(false), m_encodeAsOID(false) {BERDecode(bt);}
00042 
00043         void Initialize(const EllipticCurve &ec, const Point &G, const Integer &n, const Integer &k = Integer::Zero())
00044         {
00045                 this->m_groupPrecomputation.SetCurve(ec);
00046                 SetSubgroupGenerator(G);
00047                 m_n = n;
00048                 m_k = k;
00049         }
00050         void Initialize(const OID &oid);
00051 
00052         // NameValuePairs
00053         bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const;
00054         void AssignFrom(const NameValuePairs &source);
00055 
00056         // GeneratibleCryptoMaterial interface
00057         //! this implementation doesn't actually generate a curve, it just initializes the parameters with existing values
00058         /*! parameters: (Curve, SubgroupGenerator, SubgroupOrder, Cofactor (optional)), or (GroupOID) */
00059         void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &alg);
00060 
00061         // DL_GroupParameters
00062         const DL_FixedBasePrecomputation<Element> & GetBasePrecomputation() const {return this->m_gpc;}
00063         DL_FixedBasePrecomputation<Element> & AccessBasePrecomputation() {return this->m_gpc;}
00064         const Integer & GetSubgroupOrder() const {return m_n;}
00065         Integer GetCofactor() const;
00066         bool ValidateGroup(RandomNumberGenerator &rng, unsigned int level) const;
00067         bool ValidateElement(unsigned int level, const Element &element, const DL_FixedBasePrecomputation<Element> *precomp) const;
00068         bool FastSubgroupCheckAvailable() const {return false;}
00069         void EncodeElement(bool reversible, const Element &element, byte *encoded) const
00070         {
00071                 if (reversible)
00072                         GetCurve().EncodePoint(encoded, element, m_compress);
00073                 else
00074                         element.x.Encode(encoded, GetEncodedElementSize(false));
00075         }
00076         unsigned int GetEncodedElementSize(bool reversible) const
00077         {
00078                 if (reversible)
00079                         return GetCurve().EncodedPointSize(m_compress);
00080                 else
00081                         return GetCurve().GetField().MaxElementByteLength();
00082         }
00083         Element DecodeElement(const byte *encoded, bool checkForGroupMembership) const
00084         {
00085                 Point result;
00086                 if (!GetCurve().DecodePoint(result, encoded, GetEncodedElementSize(true)))
00087                         throw DL_BadElement();
00088                 if (checkForGroupMembership && !ValidateElement(1, result, NULL))
00089                         throw DL_BadElement();
00090                 return result;
00091         }
00092         Integer ConvertElementToInteger(const Element &element) const;
00093         Integer GetMaxExponent() const {return GetSubgroupOrder()-1;}
00094         bool IsIdentity(const Element &element) const {return element.identity;}
00095         void SimultaneousExponentiate(Element *results, const Element &base, const Integer *exponents, unsigned int exponentsCount) const;
00096         static std::string StaticAlgorithmNamePrefix() {return "EC";}
00097 
00098         // ASN1Key
00099         OID GetAlgorithmID() const;
00100 
00101         // used by MQV
00102         Element MultiplyElements(const Element &a, const Element &b) const;
00103         Element CascadeExponentiate(const Element &element1, const Integer &exponent1, const Element &element2, const Integer &exponent2) const;
00104 
00105         // non-inherited
00106 
00107         // enumerate OIDs for recommended parameters, use OID() to get first one
00108         static OID GetNextRecommendedParametersOID(const OID &oid);
00109 
00110         void BERDecode(BufferedTransformation &bt);
00111         void DEREncode(BufferedTransformation &bt) const;
00112 
00113         void SetPointCompression(bool compress) {m_compress = compress;}
00114         bool GetPointCompression() const {return m_compress;}
00115 
00116         void SetEncodeAsOID(bool encodeAsOID) {m_encodeAsOID = encodeAsOID;}
00117         bool GetEncodeAsOID() const {return m_encodeAsOID;}
00118 
00119         const EllipticCurve& GetCurve() const {return this->m_groupPrecomputation.GetCurve();}
00120 
00121         bool operator==(const ThisClass &rhs) const
00122                 {return this->m_groupPrecomputation.GetCurve() == rhs.m_groupPrecomputation.GetCurve() && this->m_gpc.GetBase(this->m_groupPrecomputation) == rhs.m_gpc.GetBase(rhs.m_groupPrecomputation);}
00123 
00124 #ifdef CRYPTOPP_MAINTAIN_BACKWARDS_COMPATIBILITY
00125         const Point& GetBasePoint() const {return GetSubgroupGenerator();}
00126         const Integer& GetBasePointOrder() const {return GetSubgroupOrder();}
00127         void LoadRecommendedParameters(const OID &oid) {Initialize(oid);}
00128 #endif
00129 
00130 protected:
00131         unsigned int FieldElementLength() const {return GetCurve().GetField().MaxElementByteLength();}
00132         unsigned int ExponentLength() const {return m_n.ByteCount();}
00133 
00134         OID m_oid;                      // set if parameters loaded from a recommended curve
00135         Integer m_n;            // order of base point
00136         bool m_compress, m_encodeAsOID;
00137         mutable Integer m_k;            // cofactor
00138 };
00139 
00140 CRYPTOPP_DLL_TEMPLATE_CLASS DL_GroupParameters_EC<ECP>;
00141 CRYPTOPP_DLL_TEMPLATE_CLASS DL_GroupParameters_EC<EC2N>;
00142 CRYPTOPP_DLL_TEMPLATE_CLASS DL_PublicKeyImpl<DL_GroupParameters_EC<ECP> >;
00143 CRYPTOPP_DLL_TEMPLATE_CLASS DL_PublicKeyImpl<DL_GroupParameters_EC<EC2N> >;
00144 
00145 //! EC public key
00146 template <class EC>
00147 class DL_PublicKey_EC : public DL_PublicKeyImpl<DL_GroupParameters_EC<EC> >
00148 {
00149 public:
00150         typedef typename EC::Point Element;
00151 
00152         void Initialize(const DL_GroupParameters_EC<EC> &params, const Element &Q)
00153                 {this->AccessGroupParameters() = params; SetPublicElement(Q);}
00154         void Initialize(const EC &ec, const Element &G, const Integer &n, const Element &Q)
00155                 {this->AccessGroupParameters().Initialize(ec, G, n); SetPublicElement(Q);}
00156 
00157         // X509PublicKey
00158         void BERDecodeKey2(BufferedTransformation &bt, bool parametersPresent, unsigned int size);
00159         void DEREncodeKey(BufferedTransformation &bt) const;
00160 };
00161 
00162 CRYPTOPP_DLL_TEMPLATE_CLASS DL_PublicKey_EC<ECP>;
00163 CRYPTOPP_DLL_TEMPLATE_CLASS DL_PublicKey_EC<EC2N>;
00164 CRYPTOPP_DLL_TEMPLATE_CLASS DL_PrivateKeyImpl<DL_GroupParameters_EC<ECP> >;
00165 CRYPTOPP_DLL_TEMPLATE_CLASS DL_PrivateKeyImpl<DL_GroupParameters_EC<EC2N> >;
00166 
00167 //! EC private key
00168 template <class EC>
00169 class DL_PrivateKey_EC : public DL_PrivateKeyImpl<DL_GroupParameters_EC<EC> >
00170 {
00171 public:
00172         typedef typename EC::Point Element;
00173 
00174         void Initialize(const DL_GroupParameters_EC<EC> &params, const Integer &x)
00175                 {this->AccessGroupParameters() = params; this->SetPrivateExponent(x);}
00176         void Initialize(const EC &ec, const Element &G, const Integer &n, const Integer &x)
00177                 {this->AccessGroupParameters().Initialize(ec, G, n); this->SetPrivateExponent(x);}
00178         void Initialize(RandomNumberGenerator &rng, const DL_GroupParameters_EC<EC> &params)
00179                 {GenerateRandom(rng, params);}
00180         void Initialize(RandomNumberGenerator &rng, const EC &ec, const Element &G, const Integer &n)
00181                 {GenerateRandom(rng, DL_GroupParameters_EC<EC>(ec, G, n));}
00182 
00183         // PKCS8PrivateKey
00184         void BERDecodeKey2(BufferedTransformation &bt,  bool parametersPresent, unsigned int size);
00185         void DEREncodeKey(BufferedTransformation &bt) const;
00186 };
00187 
00188 CRYPTOPP_DLL_TEMPLATE_CLASS DL_PrivateKey_EC<ECP>;
00189 CRYPTOPP_DLL_TEMPLATE_CLASS DL_PrivateKey_EC<EC2N>;
00190 
00191 //! Elliptic Curve Diffie-Hellman, AKA <a href="http://www.weidai.com/scan-mirror/ka.html#ECDH">ECDH</a>
00192 template <class EC, class COFACTOR_OPTION = CPP_TYPENAME DL_GroupParameters_EC<EC>::DefaultCofactorOption>
00193 struct ECDH
00194 {
00195         typedef DH_Domain<DL_GroupParameters_EC<EC>, COFACTOR_OPTION> Domain;
00196 };
00197 
00198 /// Elliptic Curve Menezes-Qu-Vanstone, AKA <a href="http://www.weidai.com/scan-mirror/ka.html#ECMQV">ECMQV</a>
00199 template <class EC, class COFACTOR_OPTION = CPP_TYPENAME DL_GroupParameters_EC<EC>::DefaultCofactorOption>
00200 struct ECMQV
00201 {
00202         typedef MQV_Domain<DL_GroupParameters_EC<EC>, COFACTOR_OPTION> Domain;
00203 };
00204 
00205 //! EC keys
00206 template <class EC>
00207 struct DL_Keys_EC
00208 {
00209         typedef DL_PublicKey_EC<EC> PublicKey;
00210         typedef DL_PrivateKey_EC<EC> PrivateKey;
00211 };
00212 
00213 template <class EC, class H = SHA>
00214 struct ECDSA;
00215 
00216 //! ECDSA keys
00217 template <class EC>
00218 struct DL_Keys_ECDSA
00219 {
00220         typedef DL_PublicKey_EC<EC> PublicKey;
00221         typedef DL_PrivateKey_WithSignaturePairwiseConsistencyTest<DL_PrivateKey_EC<EC>, ECDSA<EC> > PrivateKey;
00222 };
00223 
00224 CRYPTOPP_DLL_TEMPLATE_CLASS DL_Algorithm_GDSA<ECP::Point>;
00225 CRYPTOPP_DLL_TEMPLATE_CLASS DL_Algorithm_GDSA<EC2N::Point>;
00226 
00227 //! ECDSA algorithm
00228 template <class EC>
00229 class DL_Algorithm_ECDSA : public DL_Algorithm_GDSA<typename EC::Point>
00230 {
00231 public:
00232         static const char * StaticAlgorithmName() {return "ECDSA";}
00233 };
00234 
00235 //! ECNR algorithm
00236 template <class EC>
00237 class DL_Algorithm_ECNR : public DL_Algorithm_NR<typename EC::Point>
00238 {
00239 public:
00240         static const char * StaticAlgorithmName() {return "ECNR";}
00241 };
00242 
00243 //! <a href="http://www.weidai.com/scan-mirror/sig.html#ECDSA">ECDSA</a>
00244 template <class EC, class H>
00245 struct ECDSA : public DL_SS<DL_Keys_ECDSA<EC>, DL_Algorithm_ECDSA<EC>, DL_SignatureMessageEncodingMethod_DSA, H>
00246 {
00247 };
00248 
00249 CRYPTOPP_DLL_TEMPLATE_CLASS DL_PrivateKey_WithSignaturePairwiseConsistencyTest<DL_PrivateKey_EC<ECP>, ECDSA<ECP> >;
00250 CRYPTOPP_DLL_TEMPLATE_CLASS DL_PrivateKey_WithSignaturePairwiseConsistencyTest<DL_PrivateKey_EC<EC2N>, ECDSA<EC2N> >;
00251 
00252 //! ECNR
00253 template <class EC, class H = SHA>
00254 struct ECNR : public DL_SS<DL_Keys_EC<EC>, DL_Algorithm_ECNR<EC>, DL_SignatureMessageEncodingMethod_NR, H>
00255 {
00256 };
00257 
00258 //! Elliptic Curve Integrated Encryption Scheme, AKA <a href="http://www.weidai.com/scan-mirror/ca.html#ECIES">ECIES</a>
00259 /*! Default to (NoCofactorMultiplication and DHAES_MODE = false) for compatibilty with SEC1 and Crypto++ 4.2.
00260         The combination of (IncompatibleCofactorMultiplication and DHAES_MODE = true) is recommended for best
00261         efficiency and security. */
00262 template <class EC, class COFACTOR_OPTION = NoCofactorMultiplication, bool DHAES_MODE = false>
00263 struct ECIES
00264         : public DL_ES<
00265                 DL_Keys_EC<EC>,
00266                 DL_KeyAgreementAlgorithm_DH<typename EC::Point, COFACTOR_OPTION>,
00267                 DL_KeyDerivationAlgorithm_P1363<typename EC::Point, DHAES_MODE, P1363_KDF2<SHA1> >,
00268                 DL_EncryptionAlgorithm_Xor<HMAC<SHA1>, DHAES_MODE>,
00269                 ECIES<EC> >
00270 {
00271         static std::string StaticAlgorithmName() {return "ECIES";}      // TODO: fix this after name is standardized
00272 };
00273 
00274 NAMESPACE_END
00275 
00276 #endif

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