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[Progress:] Completely re-done Block class to not use bitsets, and provide custom operators.

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Leonetienne
2022-05-24 01:02:06 +02:00
parent ed45b69342
commit 939df4731b
11 changed files with 619 additions and 191 deletions
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27
GCryptLib/src/Feistel.cpp
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@@ -68,25 +68,27 @@ namespace Leonetienne::GCrypt {
Block m_expanded = ExpansionFunction(m);
// Shift to left by 1
m_expanded = Shiftl(m_expanded, 1);
//m_expanded = Shiftl(m_expanded, 1);
m_expanded = (m_expanded);
// Matrix-mult with key
m_expanded = (BlockMatrix(m_expanded) * BlockMatrix(key)).ToBlock();
m_expanded *= key;
// Non-linearly apply subsitution boxes
std::stringstream ss;
const std::string m_str = m_expanded.to_string();
const std::string m_str = m_expanded.ToString();
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, shifted by 3
return Shiftl(CompressionFunction(m_expanded), 3);
//return Shiftl(CompressionFunction(m_expanded), 3);
return (CompressionFunction(m_expanded));
}
std::pair<Halfblock, Halfblock> Feistel::FeistelSplit(const Block& block) {
const std::string bits = block.to_string();
const std::string bits = block.ToString();
Halfblock l(bits.substr(0, bits.size() / 2));
Halfblock r(bits.substr(bits.size() / 2));
@@ -119,7 +121,7 @@ namespace Leonetienne::GCrypt {
Halfblock Feistel::CompressionFunction(const Block& block) {
std::stringstream ss;
const std::string bits = block.to_string();
const std::string bits = block.ToString();
std::unordered_map<std::string, std::string> compressionMap;
compressionMap["0000"] = "10";
@@ -184,7 +186,8 @@ namespace Leonetienne::GCrypt {
// Compress- substitute, and expand the seed key to form the initial and the second-initial round key
// This action is non-linear and irreversible, and thus strenghtens security.
Halfblock compressedSeed1 = CompressionFunction(seedKey);
Halfblock compressedSeed2 = CompressionFunction(Shiftl(seedKey, 1)); // Shifting one key by 1 will result in a completely different compression
//Halfblock compressedSeed2 = CompressionFunction(Shiftl(seedKey, 1)); // Shifting one key by 1 will result in a completely different compression
Halfblock compressedSeed2 = CompressionFunction((seedKey)); // Shifting one key by 1 will result in a completely different compression
// To add further confusion, let's shift seed1 by 1 aswell (after compression, but before substitution)
// but only if the total number of bits set are a multiple of 3
@@ -192,10 +195,11 @@ namespace Leonetienne::GCrypt {
const std::size_t setBits1 = compressedSeed1.count();
if (setBits1 % 4 == 0) {
compressedSeed1 = Shiftr(compressedSeed1, 1);
//compressedSeed1 = Shiftr(compressedSeed1, 1);
compressedSeed1 = (compressedSeed1);
}
else if (setBits1 % 3 == 0) {
compressedSeed1 = Shiftl(compressedSeed1, 1);
compressedSeed1 = (compressedSeed1);
}
// Now apply substitution
@@ -224,7 +228,8 @@ namespace Leonetienne::GCrypt {
Block newKey = roundKeys[i - 1];
// Shift to left by how many bits are set, modulo 8
newKey = Shiftl(newKey, newKey.count() % 8); // This action is irreversible
//newKey = Shiftl(newKey, newKey.count() % 8); // This action is irreversible
newKey = (newKey); // This action is irreversible
// Split into two halfblocks,
// apply F() to one halfblock with rk[i-2],
@@ -255,7 +260,7 @@ namespace Leonetienne::GCrypt {
#endif
void Feistel::ZeroKeyMemory() {
for (Key& key : roundKeys) {
key.reset();
key.Reset();
}
return;