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Diffstat (limited to 'lib/cryptopp/authenc.cpp')
| -rw-r--r-- | lib/cryptopp/authenc.cpp | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/lib/cryptopp/authenc.cpp b/lib/cryptopp/authenc.cpp new file mode 100644 index 000000000..f93662efb --- /dev/null +++ b/lib/cryptopp/authenc.cpp @@ -0,0 +1,180 @@ +// authenc.cpp - written and placed in the public domain by Wei Dai + +#include "pch.h" + +#ifndef CRYPTOPP_IMPORTS + +#include "authenc.h" + +NAMESPACE_BEGIN(CryptoPP) + +void AuthenticatedSymmetricCipherBase::AuthenticateData(const byte *input, size_t len) +{ + unsigned int blockSize = AuthenticationBlockSize(); + unsigned int &num = m_bufferedDataLength; + byte* data = m_buffer.begin(); + + if (num != 0) // process left over data + { + if (num+len >= blockSize) + { + memcpy(data+num, input, blockSize-num); + AuthenticateBlocks(data, blockSize); + input += (blockSize-num); + len -= (blockSize-num); + num = 0; + // drop through and do the rest + } + else + { + memcpy(data+num, input, len); + num += (unsigned int)len; + return; + } + } + + // now process the input data in blocks of blockSize bytes and save the leftovers to m_data + if (len >= blockSize) + { + size_t leftOver = AuthenticateBlocks(input, len); + input += (len - leftOver); + len = leftOver; + } + + memcpy(data, input, len); + num = (unsigned int)len; +} + +void AuthenticatedSymmetricCipherBase::SetKey(const byte *userKey, size_t keylength, const NameValuePairs ¶ms) +{ + m_bufferedDataLength = 0; + m_state = State_Start; + + SetKeyWithoutResync(userKey, keylength, params); + m_state = State_KeySet; + + size_t length; + const byte *iv = GetIVAndThrowIfInvalid(params, length); + if (iv) + Resynchronize(iv, (int)length); +} + +void AuthenticatedSymmetricCipherBase::Resynchronize(const byte *iv, int length) +{ + if (m_state < State_KeySet) + throw BadState(AlgorithmName(), "Resynchronize", "key is set"); + + m_bufferedDataLength = 0; + m_totalHeaderLength = m_totalMessageLength = m_totalFooterLength = 0; + m_state = State_KeySet; + + Resync(iv, this->ThrowIfInvalidIVLength(length)); + m_state = State_IVSet; +} + +void AuthenticatedSymmetricCipherBase::Update(const byte *input, size_t length) +{ + if (length == 0) + return; + + switch (m_state) + { + case State_Start: + case State_KeySet: + throw BadState(AlgorithmName(), "Update", "setting key and IV"); + case State_IVSet: + AuthenticateData(input, length); + m_totalHeaderLength += length; + break; + case State_AuthUntransformed: + case State_AuthTransformed: + AuthenticateLastConfidentialBlock(); + m_bufferedDataLength = 0; + m_state = State_AuthFooter; + // fall through + case State_AuthFooter: + AuthenticateData(input, length); + m_totalFooterLength += length; + break; + default: + assert(false); + } +} + +void AuthenticatedSymmetricCipherBase::ProcessData(byte *outString, const byte *inString, size_t length) +{ + m_totalMessageLength += length; + if (m_state >= State_IVSet && m_totalMessageLength > MaxMessageLength()) + throw InvalidArgument(AlgorithmName() + ": message length exceeds maximum"); + +reswitch: + switch (m_state) + { + case State_Start: + case State_KeySet: + throw BadState(AlgorithmName(), "ProcessData", "setting key and IV"); + case State_AuthFooter: + throw BadState(AlgorithmName(), "ProcessData was called after footer input has started"); + case State_IVSet: + AuthenticateLastHeaderBlock(); + m_bufferedDataLength = 0; + m_state = AuthenticationIsOnPlaintext()==IsForwardTransformation() ? State_AuthUntransformed : State_AuthTransformed; + goto reswitch; + case State_AuthUntransformed: + AuthenticateData(inString, length); + AccessSymmetricCipher().ProcessData(outString, inString, length); + break; + case State_AuthTransformed: + AccessSymmetricCipher().ProcessData(outString, inString, length); + AuthenticateData(outString, length); + break; + default: + assert(false); + } +} + +void AuthenticatedSymmetricCipherBase::TruncatedFinal(byte *mac, size_t macSize) +{ + if (m_totalHeaderLength > MaxHeaderLength()) + throw InvalidArgument(AlgorithmName() + ": header length of " + IntToString(m_totalHeaderLength) + " exceeds the maximum of " + IntToString(MaxHeaderLength())); + + if (m_totalFooterLength > MaxFooterLength()) + { + if (MaxFooterLength() == 0) + throw InvalidArgument(AlgorithmName() + ": additional authenticated data (AAD) cannot be input after data to be encrypted or decrypted"); + else + throw InvalidArgument(AlgorithmName() + ": footer length of " + IntToString(m_totalFooterLength) + " exceeds the maximum of " + IntToString(MaxFooterLength())); + } + + switch (m_state) + { + case State_Start: + case State_KeySet: + throw BadState(AlgorithmName(), "TruncatedFinal", "setting key and IV"); + + case State_IVSet: + AuthenticateLastHeaderBlock(); + m_bufferedDataLength = 0; + // fall through + + case State_AuthUntransformed: + case State_AuthTransformed: + AuthenticateLastConfidentialBlock(); + m_bufferedDataLength = 0; + // fall through + + case State_AuthFooter: + AuthenticateLastFooterBlock(mac, macSize); + m_bufferedDataLength = 0; + break; + + default: + assert(false); + } + + m_state = State_KeySet; +} + +NAMESPACE_END + +#endif |