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/*
* HKDF
* (C) 2013,2015 Jack Lloyd
* (C) 2016 René Korthaus, Rohde & Schwarz Cybersecurity
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#ifndef BOTAN_HKDF_H_
#define BOTAN_HKDF_H_
#include <botan/mac.h>
#include <botan/kdf.h>
/*
* The definitions of HKDF, HKDF_Extract, HKDF_Expand will be made internal
* in the future. However the function hkdf_expand_label will still be defined.
*/
//BOTAN_FUTURE_INTERNAL_HEADER(hkdf.h)
namespace Botan {
/**
* HKDF from RFC 5869.
*/
class BOTAN_PUBLIC_API(2,0) HKDF final : public KDF
{
public:
/**
* @param prf MAC algorithm to use
*/
explicit HKDF(MessageAuthenticationCode* prf) : m_prf(prf) {}
KDF* clone() const override { return new HKDF(m_prf->clone()); }
std::string name() const override { return "HKDF(" + m_prf->name() + ")"; }
size_t kdf(uint8_t key[], size_t key_len,
const uint8_t secret[], size_t secret_len,
const uint8_t salt[], size_t salt_len,
const uint8_t label[], size_t label_len) const override;
private:
std::unique_ptr<MessageAuthenticationCode> m_prf;
};
/**
* HKDF Extraction Step from RFC 5869.
*/
class BOTAN_PUBLIC_API(2,0) HKDF_Extract final : public KDF
{
public:
/**
* @param prf MAC algorithm to use
*/
explicit HKDF_Extract(MessageAuthenticationCode* prf) : m_prf(prf) {}
KDF* clone() const override { return new HKDF_Extract(m_prf->clone()); }
std::string name() const override { return "HKDF-Extract(" + m_prf->name() + ")"; }
size_t kdf(uint8_t key[], size_t key_len,
const uint8_t secret[], size_t secret_len,
const uint8_t salt[], size_t salt_len,
const uint8_t label[], size_t label_len) const override;
private:
std::unique_ptr<MessageAuthenticationCode> m_prf;
};
/**
* HKDF Expansion Step from RFC 5869.
*/
class BOTAN_PUBLIC_API(2,0) HKDF_Expand final : public KDF
{
public:
/**
* @param prf MAC algorithm to use
*/
explicit HKDF_Expand(MessageAuthenticationCode* prf) : m_prf(prf) {}
KDF* clone() const override { return new HKDF_Expand(m_prf->clone()); }
std::string name() const override { return "HKDF-Expand(" + m_prf->name() + ")"; }
size_t kdf(uint8_t key[], size_t key_len,
const uint8_t secret[], size_t secret_len,
const uint8_t salt[], size_t salt_len,
const uint8_t label[], size_t label_len) const override;
private:
std::unique_ptr<MessageAuthenticationCode> m_prf;
};
/**
* HKDF-Expand-Label from TLS 1.3/QUIC
* @param hash_fn the hash to use
* @param secret the secret bits
* @param secret_len the length of secret
* @param label the full label (no "TLS 1.3, " or "tls13 " prefix
* is applied)
* @param hash_val the previous hash value (used for chaining, may be empty)
* @param hash_val_len the length of hash_val
* @param length the desired output length
*/
secure_vector<uint8_t>
BOTAN_PUBLIC_API(2,3) hkdf_expand_label(
const std::string& hash_fn,
const uint8_t secret[], size_t secret_len,
const std::string& label,
const uint8_t hash_val[], size_t hash_val_len,
size_t length);
}
#endif