00001
00002
00003 #include "pch.h"
00004
00005 #ifndef CRYPTOPP_IMPORTS
00006
00007 #include "pubkey.h"
00008
00009 NAMESPACE_BEGIN(CryptoPP)
00010
00011 void TF_DigestSignerBase::SignDigest(RandomNumberGenerator &rng, const byte *digest, unsigned int digestLen, byte *signature) const
00012 {
00013 assert(digestLen <= MaxDigestLength());
00014
00015 SecByteBlock paddedBlock(PaddedBlockByteLength());
00016 GetPaddingAlgorithm().Pad(rng, digest, digestLen, paddedBlock, PaddedBlockBitLength());
00017 GetTrapdoorFunctionInterface().CalculateRandomizedInverse(rng, Integer(paddedBlock, paddedBlock.size())).Encode(signature, DigestSignatureLength());
00018 }
00019
00020 bool TF_DigestVerifierBase::VerifyDigest(const byte *digest, unsigned int digestLen, const byte *signature) const
00021 {
00022 SecByteBlock paddedBlock(PaddedBlockByteLength());
00023 Integer x = GetTrapdoorFunctionInterface().ApplyFunction(Integer(signature, DigestSignatureLength()));
00024 if (x.ByteCount() > paddedBlock.size())
00025 x = Integer::Zero();
00026 x.Encode(paddedBlock, paddedBlock.size());
00027 if (GetPaddingAlgorithm().IsReversible())
00028 {
00029 SecByteBlock recoveredDigest(MaxDigestLength());
00030 DecodingResult result = GetPaddingAlgorithm().Unpad(paddedBlock, PaddedBlockBitLength(), recoveredDigest);
00031 return result == DecodingResult(digestLen) && memcmp(digest, recoveredDigest, digestLen) == 0;
00032 }
00033 else
00034 {
00035 SecByteBlock paddedBlock2(PaddedBlockByteLength());
00036 GetPaddingAlgorithm().Pad(NullRNG(), digest, digestLen, paddedBlock2, PaddedBlockBitLength());
00037 return paddedBlock == paddedBlock2;
00038 }
00039 }
00040
00041 DecodingResult TF_DecryptorBase::FixedLengthDecrypt(const byte *cipherText, byte *plainText) const
00042 {
00043 SecByteBlock paddedBlock(PaddedBlockByteLength());
00044 Integer x = GetTrapdoorFunctionInterface().CalculateInverse(Integer(cipherText, FixedCiphertextLength()));
00045 if (x.ByteCount() > paddedBlock.size())
00046 x = Integer::Zero();
00047 x.Encode(paddedBlock, paddedBlock.size());
00048 return GetPaddingAlgorithm().Unpad(paddedBlock, PaddedBlockBitLength(), plainText);
00049 }
00050
00051 void TF_EncryptorBase::Encrypt(RandomNumberGenerator &rng, const byte *plainText, unsigned int plainTextLength, byte *cipherText) const
00052 {
00053 if (plainTextLength > FixedMaxPlaintextLength())
00054 throw InvalidArgument(AlgorithmName() + ": message too long for this public key");
00055
00056 SecByteBlock paddedBlock(PaddedBlockByteLength());
00057 GetPaddingAlgorithm().Pad(rng, plainText, plainTextLength, paddedBlock, PaddedBlockBitLength());
00058 GetTrapdoorFunctionInterface().ApplyRandomizedFunction(rng, Integer(paddedBlock, paddedBlock.size())).Encode(cipherText, FixedCiphertextLength());
00059 }
00060
00061 NAMESPACE_END
00062
00063 #endif