hkdf.h

Go to the documentation of this file.

/*
* 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/kdf.h>
#include <botan/mac.h>
 
namespace Botan {
 
/**
* HKDF from RFC 5869.
*/
class HKDF final : public KDF {
   public:
      /**
      * @param prf MAC algorithm to use
      */
      explicit HKDF(std::unique_ptr<MessageAuthenticationCode> prf) : m_prf(std::move(prf)) {}
 
      std::unique_ptr<KDF> new_object() const override;
 
      std::string name() const override;
 
      void 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 HKDF_Extract final : public KDF {
   public:
      /**
      * @param prf MAC algorithm to use
      */
      explicit HKDF_Extract(std::unique_ptr<MessageAuthenticationCode> prf) : m_prf(std::move(prf)) {}
 
      std::unique_ptr<KDF> new_object() const override;
 
      std::string name() const override;
 
      void 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 HKDF_Expand final : public KDF {
   public:
      /**
      * @param prf MAC algorithm to use
      */
      explicit HKDF_Expand(std::unique_ptr<MessageAuthenticationCode> prf) : m_prf(std::move(prf)) {}
 
      std::unique_ptr<KDF> new_object() const override;
 
      std::string name() const override;
 
      void 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_TEST_API hkdf_expand_label(std::string_view hash_fn,
                                                        const uint8_t secret[],
                                                        size_t secret_len,
                                                        std::string_view label,
                                                        const uint8_t hash_val[],
                                                        size_t hash_val_len,
                                                        size_t length);
 
}  // namespace Botan
 
#endif