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253 lines
7.0 KiB
253 lines
7.0 KiB
![]()
4 years ago
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// strciphr.cpp - written and placed in the public domain by Wei Dai
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#include "pch.h"
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#ifndef CRYPTOPP_IMPORTS
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#include "strciphr.h"
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NAMESPACE_BEGIN(CryptoPP)
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template <class S>
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void AdditiveCipherTemplate<S>::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms)
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{
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PolicyInterface &policy = this->AccessPolicy();
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policy.CipherSetKey(params, key, length);
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m_leftOver = 0;
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unsigned int bufferByteSize = policy.CanOperateKeystream() ? GetBufferByteSize(policy) : RoundUpToMultipleOf(1024U, GetBufferByteSize(policy));
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m_buffer.New(bufferByteSize);
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if (this->IsResynchronizable())
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{
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size_t ivLength;
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const byte *iv = this->GetIVAndThrowIfInvalid(params, ivLength);
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policy.CipherResynchronize(m_buffer, iv, ivLength);
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}
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}
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template <class S>
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void AdditiveCipherTemplate<S>::GenerateBlock(byte *outString, size_t length)
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{
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if (m_leftOver > 0)
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{
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size_t len = STDMIN(m_leftOver, length);
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memcpy(outString, KeystreamBufferEnd()-m_leftOver, len);
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length -= len;
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m_leftOver -= len;
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outString += len;
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if (!length)
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return;
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}
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assert(m_leftOver == 0);
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PolicyInterface &policy = this->AccessPolicy();
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unsigned int bytesPerIteration = policy.GetBytesPerIteration();
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if (length >= bytesPerIteration)
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{
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size_t iterations = length / bytesPerIteration;
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policy.WriteKeystream(outString, iterations);
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outString += iterations * bytesPerIteration;
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length -= iterations * bytesPerIteration;
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}
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if (length > 0)
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{
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size_t bufferByteSize = RoundUpToMultipleOf(length, bytesPerIteration);
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size_t bufferIterations = bufferByteSize / bytesPerIteration;
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policy.WriteKeystream(KeystreamBufferEnd()-bufferByteSize, bufferIterations);
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memcpy(outString, KeystreamBufferEnd()-bufferByteSize, length);
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m_leftOver = bufferByteSize - length;
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}
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}
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template <class S>
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void AdditiveCipherTemplate<S>::ProcessData(byte *outString, const byte *inString, size_t length)
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{
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if (m_leftOver > 0)
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{
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size_t len = STDMIN(m_leftOver, length);
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xorbuf(outString, inString, KeystreamBufferEnd()-m_leftOver, len);
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length -= len;
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m_leftOver -= len;
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inString += len;
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outString += len;
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if (!length)
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return;
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}
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assert(m_leftOver == 0);
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PolicyInterface &policy = this->AccessPolicy();
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unsigned int bytesPerIteration = policy.GetBytesPerIteration();
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if (policy.CanOperateKeystream() && length >= bytesPerIteration)
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{
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size_t iterations = length / bytesPerIteration;
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unsigned int alignment = policy.GetAlignment();
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KeystreamOperation operation = KeystreamOperation((IsAlignedOn(inString, alignment) * 2) | (int)IsAlignedOn(outString, alignment));
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policy.OperateKeystream(operation, outString, inString, iterations);
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inString += iterations * bytesPerIteration;
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outString += iterations * bytesPerIteration;
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length -= iterations * bytesPerIteration;
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if (!length)
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return;
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}
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size_t bufferByteSize = m_buffer.size();
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size_t bufferIterations = bufferByteSize / bytesPerIteration;
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while (length >= bufferByteSize)
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{
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policy.WriteKeystream(m_buffer, bufferIterations);
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xorbuf(outString, inString, KeystreamBufferBegin(), bufferByteSize);
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length -= bufferByteSize;
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inString += bufferByteSize;
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outString += bufferByteSize;
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}
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if (length > 0)
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{
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bufferByteSize = RoundUpToMultipleOf(length, bytesPerIteration);
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bufferIterations = bufferByteSize / bytesPerIteration;
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policy.WriteKeystream(KeystreamBufferEnd()-bufferByteSize, bufferIterations);
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xorbuf(outString, inString, KeystreamBufferEnd()-bufferByteSize, length);
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m_leftOver = bufferByteSize - length;
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}
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}
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template <class S>
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void AdditiveCipherTemplate<S>::Resynchronize(const byte *iv, int length)
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{
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PolicyInterface &policy = this->AccessPolicy();
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m_leftOver = 0;
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m_buffer.New(GetBufferByteSize(policy));
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policy.CipherResynchronize(m_buffer, iv, this->ThrowIfInvalidIVLength(length));
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}
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template <class BASE>
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void AdditiveCipherTemplate<BASE>::Seek(lword position)
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{
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PolicyInterface &policy = this->AccessPolicy();
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unsigned int bytesPerIteration = policy.GetBytesPerIteration();
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policy.SeekToIteration(position / bytesPerIteration);
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position %= bytesPerIteration;
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if (position > 0)
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{
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policy.WriteKeystream(KeystreamBufferEnd()-bytesPerIteration, 1);
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m_leftOver = bytesPerIteration - (unsigned int)position;
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}
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else
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m_leftOver = 0;
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}
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template <class BASE>
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void CFB_CipherTemplate<BASE>::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms)
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{
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PolicyInterface &policy = this->AccessPolicy();
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policy.CipherSetKey(params, key, length);
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if (this->IsResynchronizable())
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{
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size_t ivLength;
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const byte *iv = this->GetIVAndThrowIfInvalid(params, ivLength);
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policy.CipherResynchronize(iv, ivLength);
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}
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m_leftOver = policy.GetBytesPerIteration();
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}
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template <class BASE>
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void CFB_CipherTemplate<BASE>::Resynchronize(const byte *iv, int length)
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{
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PolicyInterface &policy = this->AccessPolicy();
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policy.CipherResynchronize(iv, this->ThrowIfInvalidIVLength(length));
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m_leftOver = policy.GetBytesPerIteration();
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}
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template <class BASE>
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void CFB_CipherTemplate<BASE>::ProcessData(byte *outString, const byte *inString, size_t length)
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{
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assert(length % this->MandatoryBlockSize() == 0);
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PolicyInterface &policy = this->AccessPolicy();
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unsigned int bytesPerIteration = policy.GetBytesPerIteration();
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unsigned int alignment = policy.GetAlignment();
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byte *reg = policy.GetRegisterBegin();
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if (m_leftOver)
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{
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size_t len = STDMIN(m_leftOver, length);
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CombineMessageAndShiftRegister(outString, reg + bytesPerIteration - m_leftOver, inString, len);
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m_leftOver -= len;
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length -= len;
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inString += len;
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outString += len;
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}
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if (!length)
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return;
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assert(m_leftOver == 0);
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if (policy.CanIterate() && length >= bytesPerIteration && IsAlignedOn(outString, alignment))
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{
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if (IsAlignedOn(inString, alignment))
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policy.Iterate(outString, inString, GetCipherDir(*this), length / bytesPerIteration);
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else
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{
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memcpy(outString, inString, length);
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policy.Iterate(outString, outString, GetCipherDir(*this), length / bytesPerIteration);
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}
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inString += length - length % bytesPerIteration;
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outString += length - length % bytesPerIteration;
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length %= bytesPerIteration;
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}
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while (length >= bytesPerIteration)
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{
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policy.TransformRegister();
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CombineMessageAndShiftRegister(outString, reg, inString, bytesPerIteration);
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length -= bytesPerIteration;
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inString += bytesPerIteration;
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outString += bytesPerIteration;
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}
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if (length > 0)
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{
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policy.TransformRegister();
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CombineMessageAndShiftRegister(outString, reg, inString, length);
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m_leftOver = bytesPerIteration - length;
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}
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}
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template <class BASE>
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void CFB_EncryptionTemplate<BASE>::CombineMessageAndShiftRegister(byte *output, byte *reg, const byte *message, size_t length)
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{
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xorbuf(reg, message, length);
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memcpy(output, reg, length);
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}
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template <class BASE>
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void CFB_DecryptionTemplate<BASE>::CombineMessageAndShiftRegister(byte *output, byte *reg, const byte *message, size_t length)
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{
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for (unsigned int i=0; i<length; i++)
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{
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byte b = message[i];
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output[i] = reg[i] ^ b;
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reg[i] = b;
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}
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}
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NAMESPACE_END
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#endif
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