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Improved security

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Leonetienne
2022-05-22 20:13:41 +02:00
parent 19660fc696
commit 5677d94e6a
5 changed files with 22 additions and 11 deletions
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15
GCryptLib/src/Feistel.cpp
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@@ -54,12 +54,13 @@ namespace Leonetienne::GCrypt {
// Block has finished de*ciphering.
// Let's generate a new set of round keys.
GenerateRoundKeys((Block)roundKeys.back());
GenerateRoundKeys((Key)roundKeys.back());
return FeistelCombine(r, l);
}
Halfblock Feistel::F(Halfblock m, const Key& key) {
// Made-up F function
// Expand to full bitwidth
@@ -74,15 +75,13 @@ namespace Leonetienne::GCrypt {
// Non-linearly apply subsitution boxes
std::stringstream ss;
const std::string m_str = m_expanded.to_string();
for (std::size_t i = 0; i < BLOCK_SIZE; i += 4) {
ss << SBox(m_str.substr(i, 4));
}
m_expanded = Block(ss.str());
// Return the compressed version
return CompressionFunction(m_expanded);
// Return the compressed version, shifted by 3
return Shiftl(CompressionFunction(m_expanded), 3);
}
std::pair<Halfblock, Halfblock> Feistel::FeistelSplit(const Block& block) {
@@ -124,13 +123,13 @@ namespace Leonetienne::GCrypt {
std::unordered_map<std::string, std::string> compressionMap;
compressionMap["0000"] = "10";
compressionMap["0001"] = "01";
compressionMap["0010"] = "10";
compressionMap["0010"] = "11";
compressionMap["0011"] = "10";
compressionMap["0100"] = "11";
compressionMap["0101"] = "01";
compressionMap["0110"] = "00";
compressionMap["0111"] = "11";
compressionMap["1000"] = "01";
compressionMap["0111"] = "01";
compressionMap["1000"] = "11";
compressionMap["1001"] = "00";
compressionMap["1010"] = "11";
compressionMap["1011"] = "00";