00001
00002
00003 #include "pch.h"
00004 #include "pubkey.h"
00005
00006 NAMESPACE_BEGIN(CryptoPP)
00007
00008 void P1363_MGF1KDF2_Common(HashTransformation &hash, byte *output, unsigned int outputLength, const byte *input, unsigned int inputLength, bool mask, unsigned int counterStart)
00009 {
00010 ArraySink *sink;
00011 HashFilter filter(hash, sink = mask ? new ArrayXorSink(output, outputLength) : new ArraySink(output, outputLength));
00012 word32 counter = counterStart;
00013 while (sink->AvailableSize() > 0)
00014 {
00015 filter.Put(input, inputLength);
00016 filter.PutWord32(counter++);
00017 filter.MessageEnd();
00018 }
00019 }
00020
00021 bool PK_DeterministicSignatureMessageEncodingMethod::VerifyMessageRepresentative(
00022 HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
00023 byte *representative, unsigned int representativeBitLength) const
00024 {
00025 SecByteBlock computedRepresentative(BitsToBytes(representativeBitLength));
00026 ComputeMessageRepresentative(NullRNG(), NULL, 0, hash, hashIdentifier, messageEmpty, computedRepresentative, representativeBitLength);
00027 return memcmp(representative, computedRepresentative, computedRepresentative.size()) == 0;
00028 }
00029
00030 bool PK_RecoverableSignatureMessageEncodingMethod::VerifyMessageRepresentative(
00031 HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
00032 byte *representative, unsigned int representativeBitLength) const
00033 {
00034 SecByteBlock recoveredMessage(MaxRecoverableLength(representativeBitLength, hashIdentifier.second, hash.DigestSize()));
00035 DecodingResult result = RecoverMessageFromRepresentative(
00036 hash, hashIdentifier, messageEmpty, representative, representativeBitLength, recoveredMessage);
00037 return result.isValidCoding && result.messageLength == 0;
00038 }
00039
00040 void TF_SignerBase::InputRecoverableMessage(PK_MessageAccumulator &messageAccumulator, const byte *recoverableMessage, unsigned int recoverableMessageLength) const
00041 {
00042 PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator);
00043 const MessageEncodingInterface &mei = GetMessageEncodingInterface();
00044 unsigned int maxRecoverableLength = mei.MaxRecoverableLength(MessageRepresentativeBitLength(), GetHashIdentifier().second, ma.AccessHash().DigestSize());
00045
00046 if (maxRecoverableLength == 0)
00047 {throw NotImplemented("TF_SignerBase: this algorithm does not support messsage recovery or the key is too short");}
00048 if (recoverableMessageLength > maxRecoverableLength)
00049 throw InvalidArgument("TF_SignerBase: the recoverable message part is too long for the given key and algorithm");
00050
00051 ma.m_recoverableMessage.Assign(recoverableMessage, recoverableMessageLength);
00052 mei.ProcessRecoverableMessage(
00053 ma.AccessHash(),
00054 recoverableMessage, recoverableMessageLength,
00055 NULL, 0, ma.m_semisignature);
00056 }
00057
00058 unsigned int TF_SignerBase::SignAndRestart(RandomNumberGenerator &rng, PK_MessageAccumulator &messageAccumulator, byte *signature, bool restart) const
00059 {
00060 PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator);
00061 SecByteBlock representative(MessageRepresentativeLength());
00062 GetMessageEncodingInterface().ComputeMessageRepresentative(rng,
00063 ma.m_recoverableMessage, ma.m_recoverableMessage.size(),
00064 ma.AccessHash(), GetHashIdentifier(), ma.m_empty,
00065 representative, MessageRepresentativeBitLength());
00066 ma.m_empty = true;
00067
00068 Integer r(representative, representative.size());
00069 unsigned int signatureLength = SignatureLength();
00070 GetTrapdoorFunctionInterface().CalculateRandomizedInverse(rng, r).Encode(signature, signatureLength);
00071 return signatureLength;
00072 }
00073
00074 void TF_VerifierBase::InputSignature(PK_MessageAccumulator &messageAccumulator, const byte *signature, unsigned int signatureLength) const
00075 {
00076 PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator);
00077 ma.m_representative.New(MessageRepresentativeLength());
00078 Integer x = GetTrapdoorFunctionInterface().ApplyFunction(Integer(signature, signatureLength));
00079 if (x.BitCount() > MessageRepresentativeBitLength())
00080 x = Integer::Zero();
00081 x.Encode(ma.m_representative, ma.m_representative.size());
00082 }
00083
00084 bool TF_VerifierBase::VerifyAndRestart(PK_MessageAccumulator &messageAccumulator) const
00085 {
00086 PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator);
00087 bool result = GetMessageEncodingInterface().VerifyMessageRepresentative(
00088 ma.AccessHash(), GetHashIdentifier(), ma.m_empty, ma.m_representative, MessageRepresentativeBitLength());
00089 ma.m_empty = true;
00090 return result;
00091 }
00092
00093 DecodingResult TF_VerifierBase::RecoverAndRestart(byte *recoveredMessage, PK_MessageAccumulator &messageAccumulator) const
00094 {
00095 PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator);
00096 DecodingResult result = GetMessageEncodingInterface().RecoverMessageFromRepresentative(
00097 ma.AccessHash(), GetHashIdentifier(), ma.m_empty, ma.m_representative, MessageRepresentativeBitLength(), recoveredMessage);
00098 ma.m_empty = true;
00099 return result;
00100 }
00101
00102 DecodingResult TF_DecryptorBase::FixedLengthDecrypt(RandomNumberGenerator &rng, const byte *cipherText, byte *plainText) const
00103 {
00104 SecByteBlock paddedBlock(PaddedBlockByteLength());
00105 Integer x = GetTrapdoorFunctionInterface().CalculateInverse(rng, Integer(cipherText, FixedCiphertextLength()));
00106 if (x.ByteCount() > paddedBlock.size())
00107 x = Integer::Zero();
00108 x.Encode(paddedBlock, paddedBlock.size());
00109 return GetMessageEncodingInterface().Unpad(paddedBlock, PaddedBlockBitLength(), plainText);
00110 }
00111
00112 void TF_EncryptorBase::Encrypt(RandomNumberGenerator &rng, const byte *plainText, unsigned int plainTextLength, byte *cipherText) const
00113 {
00114 if (plainTextLength > FixedMaxPlaintextLength())
00115 throw InvalidArgument(AlgorithmName() + ": message too long for this public key");
00116
00117 SecByteBlock paddedBlock(PaddedBlockByteLength());
00118 GetMessageEncodingInterface().Pad(rng, plainText, plainTextLength, paddedBlock, PaddedBlockBitLength());
00119 GetTrapdoorFunctionInterface().ApplyRandomizedFunction(rng, Integer(paddedBlock, paddedBlock.size())).Encode(cipherText, FixedCiphertextLength());
00120 }
00121
00122 NAMESPACE_END