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Diffstat (limited to 'CryptoPP/basecode.cpp')
| -rw-r--r-- | CryptoPP/basecode.cpp | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/CryptoPP/basecode.cpp b/CryptoPP/basecode.cpp new file mode 100644 index 000000000..0c98b2271 --- /dev/null +++ b/CryptoPP/basecode.cpp @@ -0,0 +1,238 @@ +// basecode.cpp - written and placed in the public domain by Wei Dai + +#include "pch.h" + +#ifndef CRYPTOPP_IMPORTS + +#include "basecode.h" +#include "fltrimpl.h" +#include <ctype.h> + +NAMESPACE_BEGIN(CryptoPP) + +void BaseN_Encoder::IsolatedInitialize(const NameValuePairs ¶meters) +{ + parameters.GetRequiredParameter("BaseN_Encoder", Name::EncodingLookupArray(), m_alphabet); + + parameters.GetRequiredIntParameter("BaseN_Encoder", Name::Log2Base(), m_bitsPerChar); + if (m_bitsPerChar <= 0 || m_bitsPerChar >= 8) + throw InvalidArgument("BaseN_Encoder: Log2Base must be between 1 and 7 inclusive"); + + byte padding; + bool pad; + if (parameters.GetValue(Name::PaddingByte(), padding)) + pad = parameters.GetValueWithDefault(Name::Pad(), true); + else + pad = false; + m_padding = pad ? padding : -1; + + m_bytePos = m_bitPos = 0; + + int i = 8; + while (i%m_bitsPerChar != 0) + i += 8; + m_outputBlockSize = i/m_bitsPerChar; + + m_outBuf.New(m_outputBlockSize); +} + +size_t BaseN_Encoder::Put2(const byte *begin, size_t length, int messageEnd, bool blocking) +{ + FILTER_BEGIN; + while (m_inputPosition < length) + { + if (m_bytePos == 0) + memset(m_outBuf, 0, m_outputBlockSize); + + { + unsigned int b = begin[m_inputPosition++], bitsLeftInSource = 8; + while (true) + { + assert(m_bitPos < m_bitsPerChar); + unsigned int bitsLeftInTarget = m_bitsPerChar-m_bitPos; + m_outBuf[m_bytePos] |= b >> (8-bitsLeftInTarget); + if (bitsLeftInSource >= bitsLeftInTarget) + { + m_bitPos = 0; + ++m_bytePos; + bitsLeftInSource -= bitsLeftInTarget; + if (bitsLeftInSource == 0) + break; + b <<= bitsLeftInTarget; + b &= 0xff; + } + else + { + m_bitPos += bitsLeftInSource; + break; + } + } + } + + assert(m_bytePos <= m_outputBlockSize); + if (m_bytePos == m_outputBlockSize) + { + int i; + for (i=0; i<m_bytePos; i++) + { + assert(m_outBuf[i] < (1 << m_bitsPerChar)); + m_outBuf[i] = m_alphabet[m_outBuf[i]]; + } + FILTER_OUTPUT(1, m_outBuf, m_outputBlockSize, 0); + + m_bytePos = m_bitPos = 0; + } + } + if (messageEnd) + { + if (m_bitPos > 0) + ++m_bytePos; + + int i; + for (i=0; i<m_bytePos; i++) + m_outBuf[i] = m_alphabet[m_outBuf[i]]; + + if (m_padding != -1 && m_bytePos > 0) + { + memset(m_outBuf+m_bytePos, m_padding, m_outputBlockSize-m_bytePos); + m_bytePos = m_outputBlockSize; + } + FILTER_OUTPUT(2, m_outBuf, m_bytePos, messageEnd); + m_bytePos = m_bitPos = 0; + } + FILTER_END_NO_MESSAGE_END; +} + +void BaseN_Decoder::IsolatedInitialize(const NameValuePairs ¶meters) +{ + parameters.GetRequiredParameter("BaseN_Decoder", Name::DecodingLookupArray(), m_lookup); + + parameters.GetRequiredIntParameter("BaseN_Decoder", Name::Log2Base(), m_bitsPerChar); + if (m_bitsPerChar <= 0 || m_bitsPerChar >= 8) + throw InvalidArgument("BaseN_Decoder: Log2Base must be between 1 and 7 inclusive"); + + m_bytePos = m_bitPos = 0; + + int i = m_bitsPerChar; + while (i%8 != 0) + i += m_bitsPerChar; + m_outputBlockSize = i/8; + + m_outBuf.New(m_outputBlockSize); +} + +size_t BaseN_Decoder::Put2(const byte *begin, size_t length, int messageEnd, bool blocking) +{ + FILTER_BEGIN; + while (m_inputPosition < length) + { + unsigned int value; + value = m_lookup[begin[m_inputPosition++]]; + if (value >= 256) + continue; + + if (m_bytePos == 0 && m_bitPos == 0) + memset(m_outBuf, 0, m_outputBlockSize); + + { + int newBitPos = m_bitPos + m_bitsPerChar; + if (newBitPos <= 8) + m_outBuf[m_bytePos] |= value << (8-newBitPos); + else + { + m_outBuf[m_bytePos] |= value >> (newBitPos-8); + m_outBuf[m_bytePos+1] |= value << (16-newBitPos); + } + + m_bitPos = newBitPos; + while (m_bitPos >= 8) + { + m_bitPos -= 8; + ++m_bytePos; + } + } + + if (m_bytePos == m_outputBlockSize) + { + FILTER_OUTPUT(1, m_outBuf, m_outputBlockSize, 0); + m_bytePos = m_bitPos = 0; + } + } + if (messageEnd) + { + FILTER_OUTPUT(2, m_outBuf, m_bytePos, messageEnd); + m_bytePos = m_bitPos = 0; + } + FILTER_END_NO_MESSAGE_END; +} + +void BaseN_Decoder::InitializeDecodingLookupArray(int *lookup, const byte *alphabet, unsigned int base, bool caseInsensitive) +{ + std::fill(lookup, lookup+256, -1); + + for (unsigned int i=0; i<base; i++) + { + if (caseInsensitive && isalpha(alphabet[i])) + { + assert(lookup[toupper(alphabet[i])] == -1); + lookup[toupper(alphabet[i])] = i; + assert(lookup[tolower(alphabet[i])] == -1); + lookup[tolower(alphabet[i])] = i; + } + else + { + assert(lookup[alphabet[i]] == -1); + lookup[alphabet[i]] = i; + } + } +} + +void Grouper::IsolatedInitialize(const NameValuePairs ¶meters) +{ + m_groupSize = parameters.GetIntValueWithDefault(Name::GroupSize(), 0); + ConstByteArrayParameter separator, terminator; + if (m_groupSize) + parameters.GetRequiredParameter("Grouper", Name::Separator(), separator); + else + parameters.GetValue(Name::Separator(), separator); + parameters.GetValue(Name::Terminator(), terminator); + + m_separator.Assign(separator.begin(), separator.size()); + m_terminator.Assign(terminator.begin(), terminator.size()); + m_counter = 0; +} + +size_t Grouper::Put2(const byte *begin, size_t length, int messageEnd, bool blocking) +{ + FILTER_BEGIN; + if (m_groupSize) + { + while (m_inputPosition < length) + { + if (m_counter == m_groupSize) + { + FILTER_OUTPUT(1, m_separator, m_separator.size(), 0); + m_counter = 0; + } + + size_t len; + FILTER_OUTPUT2(2, len = STDMIN(length-m_inputPosition, m_groupSize-m_counter), + begin+m_inputPosition, len, 0); + m_inputPosition += len; + m_counter += len; + } + } + else + FILTER_OUTPUT(3, begin, length, 0); + + if (messageEnd) + { + FILTER_OUTPUT(4, m_terminator, m_terminator.size(), messageEnd); + m_counter = 0; + } + FILTER_END_NO_MESSAGE_END +} + +NAMESPACE_END + +#endif |