diff options
Diffstat (limited to 'src-cryptopp/strciphr.cpp')
| -rw-r--r-- | src-cryptopp/strciphr.cpp | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/src-cryptopp/strciphr.cpp b/src-cryptopp/strciphr.cpp new file mode 100644 index 0000000..53e0073 --- /dev/null +++ b/src-cryptopp/strciphr.cpp @@ -0,0 +1,252 @@ +// strciphr.cpp - written and placed in the public domain by Wei Dai + +#include "pch.h" + +#ifndef CRYPTOPP_IMPORTS + +#include "strciphr.h" + +NAMESPACE_BEGIN(CryptoPP) + +template <class S> +void AdditiveCipherTemplate<S>::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms) +{ + PolicyInterface &policy = this->AccessPolicy(); + policy.CipherSetKey(params, key, length); + m_leftOver = 0; + unsigned int bufferByteSize = policy.CanOperateKeystream() ? GetBufferByteSize(policy) : RoundUpToMultipleOf(1024U, GetBufferByteSize(policy)); + m_buffer.New(bufferByteSize); + + if (this->IsResynchronizable()) + { + size_t ivLength; + const byte *iv = this->GetIVAndThrowIfInvalid(params, ivLength); + policy.CipherResynchronize(m_buffer, iv, ivLength); + } +} + +template <class S> +void AdditiveCipherTemplate<S>::GenerateBlock(byte *outString, size_t length) +{ + if (m_leftOver > 0) + { + size_t len = STDMIN(m_leftOver, length); + memcpy(outString, KeystreamBufferEnd()-m_leftOver, len); + length -= len; + m_leftOver -= len; + outString += len; + + if (!length) + return; + } + assert(m_leftOver == 0); + + PolicyInterface &policy = this->AccessPolicy(); + unsigned int bytesPerIteration = policy.GetBytesPerIteration(); + + if (length >= bytesPerIteration) + { + size_t iterations = length / bytesPerIteration; + policy.WriteKeystream(outString, iterations); + outString += iterations * bytesPerIteration; + length -= iterations * bytesPerIteration; + } + + if (length > 0) + { + size_t bufferByteSize = RoundUpToMultipleOf(length, bytesPerIteration); + size_t bufferIterations = bufferByteSize / bytesPerIteration; + + policy.WriteKeystream(KeystreamBufferEnd()-bufferByteSize, bufferIterations); + memcpy(outString, KeystreamBufferEnd()-bufferByteSize, length); + m_leftOver = bufferByteSize - length; + } +} + +template <class S> +void AdditiveCipherTemplate<S>::ProcessData(byte *outString, const byte *inString, size_t length) +{ + if (m_leftOver > 0) + { + size_t len = STDMIN(m_leftOver, length); + xorbuf(outString, inString, KeystreamBufferEnd()-m_leftOver, len); + length -= len; + m_leftOver -= len; + inString += len; + outString += len; + + if (!length) + return; + } + assert(m_leftOver == 0); + + PolicyInterface &policy = this->AccessPolicy(); + unsigned int bytesPerIteration = policy.GetBytesPerIteration(); + + if (policy.CanOperateKeystream() && length >= bytesPerIteration) + { + size_t iterations = length / bytesPerIteration; + unsigned int alignment = policy.GetAlignment(); + KeystreamOperation operation = KeystreamOperation((IsAlignedOn(inString, alignment) * 2) | (int)IsAlignedOn(outString, alignment)); + + policy.OperateKeystream(operation, outString, inString, iterations); + + inString += iterations * bytesPerIteration; + outString += iterations * bytesPerIteration; + length -= iterations * bytesPerIteration; + + if (!length) + return; + } + + size_t bufferByteSize = m_buffer.size(); + size_t bufferIterations = bufferByteSize / bytesPerIteration; + + while (length >= bufferByteSize) + { + policy.WriteKeystream(m_buffer, bufferIterations); + xorbuf(outString, inString, KeystreamBufferBegin(), bufferByteSize); + length -= bufferByteSize; + inString += bufferByteSize; + outString += bufferByteSize; + } + + if (length > 0) + { + bufferByteSize = RoundUpToMultipleOf(length, bytesPerIteration); + bufferIterations = bufferByteSize / bytesPerIteration; + + policy.WriteKeystream(KeystreamBufferEnd()-bufferByteSize, bufferIterations); + xorbuf(outString, inString, KeystreamBufferEnd()-bufferByteSize, length); + m_leftOver = bufferByteSize - length; + } +} + +template <class S> +void AdditiveCipherTemplate<S>::Resynchronize(const byte *iv, int length) +{ + PolicyInterface &policy = this->AccessPolicy(); + m_leftOver = 0; + m_buffer.New(GetBufferByteSize(policy)); + policy.CipherResynchronize(m_buffer, iv, this->ThrowIfInvalidIVLength(length)); +} + +template <class BASE> +void AdditiveCipherTemplate<BASE>::Seek(lword position) +{ + PolicyInterface &policy = this->AccessPolicy(); + unsigned int bytesPerIteration = policy.GetBytesPerIteration(); + + policy.SeekToIteration(position / bytesPerIteration); + position %= bytesPerIteration; + + if (position > 0) + { + policy.WriteKeystream(KeystreamBufferEnd()-bytesPerIteration, 1); + m_leftOver = bytesPerIteration - (unsigned int)position; + } + else + m_leftOver = 0; +} + +template <class BASE> +void CFB_CipherTemplate<BASE>::UncheckedSetKey(const byte *key, unsigned int length, const NameValuePairs ¶ms) +{ + PolicyInterface &policy = this->AccessPolicy(); + policy.CipherSetKey(params, key, length); + + if (this->IsResynchronizable()) + { + size_t ivLength; + const byte *iv = this->GetIVAndThrowIfInvalid(params, ivLength); + policy.CipherResynchronize(iv, ivLength); + } + + m_leftOver = policy.GetBytesPerIteration(); +} + +template <class BASE> +void CFB_CipherTemplate<BASE>::Resynchronize(const byte *iv, int length) +{ + PolicyInterface &policy = this->AccessPolicy(); + policy.CipherResynchronize(iv, this->ThrowIfInvalidIVLength(length)); + m_leftOver = policy.GetBytesPerIteration(); +} + +template <class BASE> +void CFB_CipherTemplate<BASE>::ProcessData(byte *outString, const byte *inString, size_t length) +{ + assert(length % this->MandatoryBlockSize() == 0); + + PolicyInterface &policy = this->AccessPolicy(); + unsigned int bytesPerIteration = policy.GetBytesPerIteration(); + unsigned int alignment = policy.GetAlignment(); + byte *reg = policy.GetRegisterBegin(); + + if (m_leftOver) + { + size_t len = STDMIN(m_leftOver, length); + CombineMessageAndShiftRegister(outString, reg + bytesPerIteration - m_leftOver, inString, len); + m_leftOver -= len; + length -= len; + inString += len; + outString += len; + } + + if (!length) + return; + + assert(m_leftOver == 0); + + if (policy.CanIterate() && length >= bytesPerIteration && IsAlignedOn(outString, alignment)) + { + if (IsAlignedOn(inString, alignment)) + policy.Iterate(outString, inString, GetCipherDir(*this), length / bytesPerIteration); + else + { + memcpy(outString, inString, length); + policy.Iterate(outString, outString, GetCipherDir(*this), length / bytesPerIteration); + } + inString += length - length % bytesPerIteration; + outString += length - length % bytesPerIteration; + length %= bytesPerIteration; + } + + while (length >= bytesPerIteration) + { + policy.TransformRegister(); + CombineMessageAndShiftRegister(outString, reg, inString, bytesPerIteration); + length -= bytesPerIteration; + inString += bytesPerIteration; + outString += bytesPerIteration; + } + + if (length > 0) + { + policy.TransformRegister(); + CombineMessageAndShiftRegister(outString, reg, inString, length); + m_leftOver = bytesPerIteration - length; + } +} + +template <class BASE> +void CFB_EncryptionTemplate<BASE>::CombineMessageAndShiftRegister(byte *output, byte *reg, const byte *message, size_t length) +{ + xorbuf(reg, message, length); + memcpy(output, reg, length); +} + +template <class BASE> +void CFB_DecryptionTemplate<BASE>::CombineMessageAndShiftRegister(byte *output, byte *reg, const byte *message, size_t length) +{ + for (unsigned int i=0; i<length; i++) + { + byte b = message[i]; + output[i] = reg[i] ^ b; + reg[i] = b; + } +} + +NAMESPACE_END + +#endif |