VICE.cpp

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#include <vcryptpp/VICE.h>
 
#include <cstring>
 
#include <IceKey.h>
 
using namespace vcryptpp;
 
namespace {
 
std::vector<std::byte> applyIce(std::span<const std::byte> data, std::string_view code, bool encrypt) {
    if (code.size() != IceKey::blockSize()) {
        return {};
    }
 
    IceKey ice;
    ice.set(reinterpret_cast<const unsigned char*>(code.data()));
 
    const auto* in = reinterpret_cast<const unsigned char*>(data.data());
 
    std::vector<std::byte> outVec(data.size());
    auto* out = reinterpret_cast<unsigned char*>(outVec.data());
 
    auto bytesLeft = data.size();
    while (bytesLeft >= IceKey::blockSize()) {
        if (encrypt) {
            ice.encrypt(in, out);
        } else {
            ice.decrypt(in, out);
        }
        bytesLeft -= IceKey::blockSize();
        in += IceKey::blockSize();
        out += IceKey::blockSize();
    }
    if (bytesLeft) {
        std::memcpy(out, in, bytesLeft);
    }
 
    return outVec;
}
 
} // namespace
 
std::vector<std::byte> VICE::encrypt(std::span<const std::byte> data, std::string_view code) {
    return ::applyIce(data, code, true);
}
 
std::vector<std::byte> VICE::decrypt(std::span<const std::byte> data, std::string_view code) {
    return ::applyIce(data, code, false);
}