Source code
Revision control
Copy as Markdown
Other Tools
/*
* Two-Step KDF defined in NIST SP 800-56Cr2 (Section 5)
* (C) 2016 Kai Michaelis
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_SP800_56C_H_
#define BOTAN_SP800_56C_H_
#include <botan/kdf.h>
#include <botan/mac.h>
namespace Botan {
/**
* NIST SP 800-56C Two-Step KDF (Section 5)
*/
class SP800_56C_Two_Step final : public KDF {
public:
std::string name() const override;
std::unique_ptr<KDF> new_object() const override;
/**
* @param mac MAC algorithm used for randomness extraction
* @param exp KDF used for key expansion
*/
SP800_56C_Two_Step(std::unique_ptr<MessageAuthenticationCode> mac, std::unique_ptr<KDF> exp) :
m_prf(std::move(mac)), m_exp(std::move(exp)) {}
private:
/**
* Derive a key using the SP800-56C Two-Step KDF.
*
* The implementation hard codes the context value for the
* expansion step to the empty string.
*
* @param key derived keying material K_M
* @param secret shared secret Z
* @param salt salt s of the extraction step
* @param label label for the expansion step
*/
void perform_kdf(std::span<uint8_t> key,
std::span<const uint8_t> secret,
std::span<const uint8_t> salt,
std::span<const uint8_t> label) const override;
private:
std::unique_ptr<MessageAuthenticationCode> m_prf;
std::unique_ptr<KDF> m_exp;
};
} // namespace Botan
#endif