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pssr.h

00001 #ifndef CRYPTOPP_PSSR_H
00002 #define CRYPTOPP_PSSR_H
00003 
00004 #include "pubkey.h"
00005 #include <functional>
00006 
00007 NAMESPACE_BEGIN(CryptoPP)
00008 
00009 class PSSR_MEM_Base : public PK_RecoverableSignatureMessageEncodingMethod
00010 {
00011         virtual bool AllowRecovery() const =0;
00012         virtual unsigned int SaltLen(unsigned int hashLen) const =0;
00013         virtual unsigned int MinPadLen(unsigned int hashLen) const =0;
00014         virtual const MaskGeneratingFunction & GetMGF() const =0;
00015 
00016 public:
00017         unsigned int MaxRecoverableLength(unsigned int representativeBitLength, unsigned int hashIdentifierLength, unsigned int digestLength) const;
00018         bool IsProbabilistic() const;
00019         bool AllowNonrecoverablePart() const;
00020         bool RecoverablePartFirst() const;
00021         void ComputeMessageRepresentative(RandomNumberGenerator &rng, 
00022                 const byte *recoverableMessage, unsigned int recoverableMessageLength,
00023                 HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
00024                 byte *representative, unsigned int representativeBitLength) const;
00025         DecodingResult RecoverMessageFromRepresentative(
00026                 HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
00027                 byte *representative, unsigned int representativeBitLength,
00028                 byte *recoverableMessage) const;
00029 };
00030 
00031 template <class H> struct EMSA2HashId
00032 {
00033         static const byte id;
00034 };
00035 
00036 // EMSA2HashId can be instantiated with the following two classes.
00037 class SHA;
00038 class RIPEMD160;
00039 
00040 template <class BASE>
00041 class EMSA2HashIdLookup : public BASE
00042 {
00043 public:
00044         struct HashIdentifierLookup
00045         {
00046                 template <class H> struct HashIdentifierLookup2
00047                 {
00048                         static HashIdentifier Lookup()
00049                         {
00050                                 return HashIdentifier(&EMSA2HashId<H>::id, 1);
00051                         }
00052                 };
00053         };
00054 };
00055 
00056 template <bool USE_HASH_ID> class PSSR_MEM_BaseWithHashId;
00057 template<> class PSSR_MEM_BaseWithHashId<true> : public EMSA2HashIdLookup<PSSR_MEM_Base> {};
00058 template<> class PSSR_MEM_BaseWithHashId<false> : public PSSR_MEM_Base {};
00059 
00060 template <bool ALLOW_RECOVERY, class MGF=P1363_MGF1, int SALT_LEN=-1, int MIN_PAD_LEN=0, bool USE_HASH_ID=false>
00061 class PSSR_MEM : public PSSR_MEM_BaseWithHashId<USE_HASH_ID>
00062 {
00063         virtual bool AllowRecovery() const {return ALLOW_RECOVERY;}
00064         virtual unsigned int SaltLen(unsigned int hashLen) const {return SALT_LEN < 0 ? hashLen : SALT_LEN;}
00065         virtual unsigned int MinPadLen(unsigned int hashLen) const {return MIN_PAD_LEN < 0 ? hashLen : MIN_PAD_LEN;}
00066         virtual const MaskGeneratingFunction & GetMGF() const {static MGF mgf; return mgf;}
00067 
00068 public:
00069         static std::string StaticAlgorithmName() {return std::string(ALLOW_RECOVERY ? "PSSR-" : "PSS-") + MGF::StaticAlgorithmName();}
00070 };
00071 
00072 //! <a href="http://www.weidai.com/scan-mirror/sig.html#sem_PSSR-MGF1">PSSR-MGF1</a>
00073 struct PSSR : public SignatureStandard
00074 {
00075         typedef PSSR_MEM<true> SignatureMessageEncodingMethod;
00076 };
00077 
00078 //! <a href="http://www.weidai.com/scan-mirror/sig.html#sem_PSS-MGF1">PSS-MGF1</a>
00079 struct PSS : public SignatureStandard
00080 {
00081         typedef PSSR_MEM<false> SignatureMessageEncodingMethod;
00082 };
00083 
00084 NAMESPACE_END
00085 
00086 #endif

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