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Diffstat (limited to 'CryptoPP/pubkey.cpp')
| -rw-r--r-- | CryptoPP/pubkey.cpp | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/CryptoPP/pubkey.cpp b/CryptoPP/pubkey.cpp new file mode 100644 index 000000000..1159e5343 --- /dev/null +++ b/CryptoPP/pubkey.cpp @@ -0,0 +1,165 @@ +// pubkey.cpp - written and placed in the public domain by Wei Dai + +#include "pch.h" + +#ifndef CRYPTOPP_IMPORTS + +#include "pubkey.h" + +NAMESPACE_BEGIN(CryptoPP) + +void P1363_MGF1KDF2_Common(HashTransformation &hash, byte *output, size_t outputLength, const byte *input, size_t inputLength, const byte *derivationParams, size_t derivationParamsLength, bool mask, unsigned int counterStart) +{ + ArraySink *sink; + HashFilter filter(hash, sink = mask ? new ArrayXorSink(output, outputLength) : new ArraySink(output, outputLength)); + word32 counter = counterStart; + while (sink->AvailableSize() > 0) + { + filter.Put(input, inputLength); + filter.PutWord32(counter++); + filter.Put(derivationParams, derivationParamsLength); + filter.MessageEnd(); + } +} + +bool PK_DeterministicSignatureMessageEncodingMethod::VerifyMessageRepresentative( + HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty, + byte *representative, size_t representativeBitLength) const +{ + SecByteBlock computedRepresentative(BitsToBytes(representativeBitLength)); + ComputeMessageRepresentative(NullRNG(), NULL, 0, hash, hashIdentifier, messageEmpty, computedRepresentative, representativeBitLength); + return VerifyBufsEqual(representative, computedRepresentative, computedRepresentative.size()); +} + +bool PK_RecoverableSignatureMessageEncodingMethod::VerifyMessageRepresentative( + HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty, + byte *representative, size_t representativeBitLength) const +{ + SecByteBlock recoveredMessage(MaxRecoverableLength(representativeBitLength, hashIdentifier.second, hash.DigestSize())); + DecodingResult result = RecoverMessageFromRepresentative( + hash, hashIdentifier, messageEmpty, representative, representativeBitLength, recoveredMessage); + return result.isValidCoding && result.messageLength == 0; +} + +void TF_SignerBase::InputRecoverableMessage(PK_MessageAccumulator &messageAccumulator, const byte *recoverableMessage, size_t recoverableMessageLength) const +{ + PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator); + HashIdentifier id = GetHashIdentifier(); + const MessageEncodingInterface &encoding = GetMessageEncodingInterface(); + + if (MessageRepresentativeBitLength() < encoding.MinRepresentativeBitLength(id.second, ma.AccessHash().DigestSize())) + throw PK_SignatureScheme::KeyTooShort(); + + size_t maxRecoverableLength = encoding.MaxRecoverableLength(MessageRepresentativeBitLength(), GetHashIdentifier().second, ma.AccessHash().DigestSize()); + + if (maxRecoverableLength == 0) + {throw NotImplemented("TF_SignerBase: this algorithm does not support messsage recovery or the key is too short");} + if (recoverableMessageLength > maxRecoverableLength) + throw InvalidArgument("TF_SignerBase: the recoverable message part is too long for the given key and algorithm"); + + ma.m_recoverableMessage.Assign(recoverableMessage, recoverableMessageLength); + encoding.ProcessRecoverableMessage( + ma.AccessHash(), + recoverableMessage, recoverableMessageLength, + NULL, 0, ma.m_semisignature); +} + +size_t TF_SignerBase::SignAndRestart(RandomNumberGenerator &rng, PK_MessageAccumulator &messageAccumulator, byte *signature, bool restart) const +{ + PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator); + HashIdentifier id = GetHashIdentifier(); + const MessageEncodingInterface &encoding = GetMessageEncodingInterface(); + + if (MessageRepresentativeBitLength() < encoding.MinRepresentativeBitLength(id.second, ma.AccessHash().DigestSize())) + throw PK_SignatureScheme::KeyTooShort(); + + SecByteBlock representative(MessageRepresentativeLength()); + encoding.ComputeMessageRepresentative(rng, + ma.m_recoverableMessage, ma.m_recoverableMessage.size(), + ma.AccessHash(), id, ma.m_empty, + representative, MessageRepresentativeBitLength()); + ma.m_empty = true; + + Integer r(representative, representative.size()); + size_t signatureLength = SignatureLength(); + GetTrapdoorFunctionInterface().CalculateRandomizedInverse(rng, r).Encode(signature, signatureLength); + return signatureLength; +} + +void TF_VerifierBase::InputSignature(PK_MessageAccumulator &messageAccumulator, const byte *signature, size_t signatureLength) const +{ + PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator); + HashIdentifier id = GetHashIdentifier(); + const MessageEncodingInterface &encoding = GetMessageEncodingInterface(); + + if (MessageRepresentativeBitLength() < encoding.MinRepresentativeBitLength(id.second, ma.AccessHash().DigestSize())) + throw PK_SignatureScheme::KeyTooShort(); + + ma.m_representative.New(MessageRepresentativeLength()); + Integer x = GetTrapdoorFunctionInterface().ApplyFunction(Integer(signature, signatureLength)); + if (x.BitCount() > MessageRepresentativeBitLength()) + x = Integer::Zero(); // don't return false here to prevent timing attack + x.Encode(ma.m_representative, ma.m_representative.size()); +} + +bool TF_VerifierBase::VerifyAndRestart(PK_MessageAccumulator &messageAccumulator) const +{ + PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator); + HashIdentifier id = GetHashIdentifier(); + const MessageEncodingInterface &encoding = GetMessageEncodingInterface(); + + if (MessageRepresentativeBitLength() < encoding.MinRepresentativeBitLength(id.second, ma.AccessHash().DigestSize())) + throw PK_SignatureScheme::KeyTooShort(); + + bool result = encoding.VerifyMessageRepresentative( + ma.AccessHash(), id, ma.m_empty, ma.m_representative, MessageRepresentativeBitLength()); + ma.m_empty = true; + return result; +} + +DecodingResult TF_VerifierBase::RecoverAndRestart(byte *recoveredMessage, PK_MessageAccumulator &messageAccumulator) const +{ + PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator); + HashIdentifier id = GetHashIdentifier(); + const MessageEncodingInterface &encoding = GetMessageEncodingInterface(); + + if (MessageRepresentativeBitLength() < encoding.MinRepresentativeBitLength(id.second, ma.AccessHash().DigestSize())) + throw PK_SignatureScheme::KeyTooShort(); + + DecodingResult result = encoding.RecoverMessageFromRepresentative( + ma.AccessHash(), id, ma.m_empty, ma.m_representative, MessageRepresentativeBitLength(), recoveredMessage); + ma.m_empty = true; + return result; +} + +DecodingResult TF_DecryptorBase::Decrypt(RandomNumberGenerator &rng, const byte *ciphertext, size_t ciphertextLength, byte *plaintext, const NameValuePairs ¶meters) const +{ + if (ciphertextLength != FixedCiphertextLength()) + throw InvalidArgument(AlgorithmName() + ": ciphertext length of " + IntToString(ciphertextLength) + " doesn't match the required length of " + IntToString(FixedCiphertextLength()) + " for this key"); + + SecByteBlock paddedBlock(PaddedBlockByteLength()); + Integer x = GetTrapdoorFunctionInterface().CalculateInverse(rng, Integer(ciphertext, ciphertextLength)); + if (x.ByteCount() > paddedBlock.size()) + x = Integer::Zero(); // don't return false here to prevent timing attack + x.Encode(paddedBlock, paddedBlock.size()); + return GetMessageEncodingInterface().Unpad(paddedBlock, PaddedBlockBitLength(), plaintext, parameters); +} + +void TF_EncryptorBase::Encrypt(RandomNumberGenerator &rng, const byte *plaintext, size_t plaintextLength, byte *ciphertext, const NameValuePairs ¶meters) const +{ + if (plaintextLength > FixedMaxPlaintextLength()) + { + if (FixedMaxPlaintextLength() < 1) + throw InvalidArgument(AlgorithmName() + ": this key is too short to encrypt any messages"); + else + throw InvalidArgument(AlgorithmName() + ": message length of " + IntToString(plaintextLength) + " exceeds the maximum of " + IntToString(FixedMaxPlaintextLength()) + " for this public key"); + } + + SecByteBlock paddedBlock(PaddedBlockByteLength()); + GetMessageEncodingInterface().Pad(rng, plaintext, plaintextLength, paddedBlock, PaddedBlockBitLength(), parameters); + GetTrapdoorFunctionInterface().ApplyRandomizedFunction(rng, Integer(paddedBlock, paddedBlock.size())).Encode(ciphertext, FixedCiphertextLength()); +} + +NAMESPACE_END + +#endif |