libcryfs/crypto/kdf/Scrypt.h

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#pragma once
#ifndef MESSMER_CPPUTILS_CRYPTO_KDF_SCRYPT_H
#define MESSMER_CPPUTILS_CRYPTO_KDF_SCRYPT_H
#include "../../macros.h"
#include "../../random/Random.h"
extern "C" {
#include <messmer/scrypt/lib/crypto/crypto_scrypt.h>
}
#include <stdexcept>
#include "DerivedKey.h"
namespace cpputils {
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struct SCryptSettings {
size_t SALT_LEN;
uint64_t N;
uint32_t r;
uint32_t p;
};
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class SCrypt final {
public:
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static constexpr SCryptSettings ParanoidSettings = SCryptSettings {32, 1048576, 8, 16};
static constexpr SCryptSettings DefaultSettings = SCryptSettings {32, 524288, 1, 1};
static constexpr SCryptSettings TestSettings = SCryptSettings {32, 1024, 1, 1};
SCrypt() {}
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template<size_t KEYSIZE>
DerivedKey<KEYSIZE> generateKey(const std::string &password, const SCryptSettings &settings) {
auto salt = Random::PseudoRandom().get(settings.SALT_LEN);
auto config = DerivedKeyConfig(std::move(salt), settings.N, settings.r, settings.p);
auto key = generateKeyFromConfig<KEYSIZE>(password, config);
return DerivedKey<KEYSIZE>(std::move(config), key);
}
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template<size_t KEYSIZE>
FixedSizeData<KEYSIZE> generateKeyFromConfig(const std::string &password, const DerivedKeyConfig &config) {
auto key = FixedSizeData<KEYSIZE>::Null();
int errorcode = crypto_scrypt(reinterpret_cast<const uint8_t*>(password.c_str()), password.size(),
reinterpret_cast<const uint8_t*>(config.salt().data()), config.salt().size(),
config.N(), config.r(), config.p(),
static_cast<uint8_t*>(key.data()), KEYSIZE);
if (errorcode != 0) {
throw std::runtime_error("Error running scrypt key derivation.");
}
return key;
}
private:
DISALLOW_COPY_AND_ASSIGN(SCrypt);
};
}
#endif