#include <hkdf.h>

Inheritance diagram for Botan::HKDF_Extract:

Public Member Functions
KDF *	clone () const

secure_vector< uint8_t >	derive_key (size_t key_len, const secure_vector< uint8_t > &secret, const std::string &salt="", const std::string &label="") const

secure_vector< uint8_t >	derive_key (size_t key_len, const secure_vector< uint8_t > &secret, const uint8_t salt[], size_t salt_len, const std::string &label="") const

template<typename Alloc , typename Alloc2 , typename Alloc3 >
secure_vector< uint8_t >	derive_key (size_t key_len, const std::vector< uint8_t, Alloc > &secret, const std::vector< uint8_t, Alloc2 > &salt, const std::vector< uint8_t, Alloc3 > &label) const

secure_vector< uint8_t >	derive_key (size_t key_len, const uint8_t secret[], size_t secret_len, const std::string &salt="", const std::string &label="") const

secure_vector< uint8_t >	derive_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[]=nullptr, size_t label_len=0) const

	HKDF_Extract (std::unique_ptr< MessageAuthenticationCode > prf)

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

std::string	name () const override

std::unique_ptr< KDF >	new_object () const override

Static Public Member Functions
static std::unique_ptr< KDF >	create (const std::string &algo_spec, const std::string &provider="")

static std::unique_ptr< KDF >	create_or_throw (const std::string &algo_spec, const std::string &provider="")

static std::vector< std::string >	providers (const std::string &algo_spec)

Detailed Description

HKDF Extraction Step from RFC 5869.

Definition at line 48 of file hkdf.h.

Constructor & Destructor Documentation

◆ HKDF_Extract()

Botan::HKDF_Extract::HKDF_Extract ( std::unique_ptr< MessageAuthenticationCode > prf )

inlineexplicit

Parameters

prf	MAC algorithm to use

Definition at line 54 of file hkdf.h.

54 :

55 m_prf(std::move(prf)) {}

Member Function Documentation

◆ clone()

KDF * Botan::KDF::clone ( ) const

inlineinherited

Returns: new object representing the same algorithm as *this

Definition at line 188 of file kdf.h.

         {
         return this->new_object().release();
         }

◆ create()

std::unique_ptr< KDF > Botan::KDF::create	(	const std::string &	algo_spec,
		const std::string &	provider = `""`
	)

staticinherited

Create an instance based on a name If provider is empty then best available is chosen.

Parameters

algo_spec	algorithm name
provider	provider implementation to choose

Returns: a null pointer if the algo/provider combination cannot be found

Definition at line 69 of file kdf.cpp.

   {
   const SCAN_Name req(algo_spec);
 
#if defined(BOTAN_HAS_HKDF)
   if(req.algo_name() == "HKDF" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         return kdf_create_mac_or_hash<HKDF>(req.arg(0));
         }
      }
 
   if(req.algo_name() == "HKDF-Extract" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         return kdf_create_mac_or_hash<HKDF_Extract>(req.arg(0));
         }
      }
 
   if(req.algo_name() == "HKDF-Expand" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         return kdf_create_mac_or_hash<HKDF_Expand>(req.arg(0));
         }
      }
#endif
 
#if defined(BOTAN_HAS_KDF2)
   if(req.algo_name() == "KDF2" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         if(auto hash = HashFunction::create(req.arg(0)))
            return std::make_unique<KDF2>(std::move(hash));
         }
      }
#endif
 
#if defined(BOTAN_HAS_KDF1_18033)
   if(req.algo_name() == "KDF1-18033" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         if(auto hash = HashFunction::create(req.arg(0)))
            return std::make_unique<KDF1_18033>(std::move(hash));
         }
      }
#endif
 
#if defined(BOTAN_HAS_KDF1)
   if(req.algo_name() == "KDF1" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         if(auto hash = HashFunction::create(req.arg(0)))
            return std::make_unique<KDF1>(std::move(hash));
         }
      }
#endif
 
#if defined(BOTAN_HAS_TLS_V12_PRF)
   if(req.algo_name() == "TLS-12-PRF" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         return kdf_create_mac_or_hash<TLS_12_PRF>(req.arg(0));
         }
      }
#endif
 
#if defined(BOTAN_HAS_X942_PRF)
   if(req.algo_name() == "X9.42-PRF" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         return std::make_unique<X942_PRF>(req.arg(0));
         }
      }
#endif
 
#if defined(BOTAN_HAS_SP800_108)
   if(req.algo_name() == "SP800-108-Counter" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         return kdf_create_mac_or_hash<SP800_108_Counter>(req.arg(0));
         }
      }
 
   if(req.algo_name() == "SP800-108-Feedback" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         return kdf_create_mac_or_hash<SP800_108_Feedback>(req.arg(0));
         }
      }
 
   if(req.algo_name() == "SP800-108-Pipeline" && req.arg_count() == 1)
      {
      if(provider.empty() || provider == "base")
         {
         return kdf_create_mac_or_hash<SP800_108_Pipeline>(req.arg(0));
         }
      }
#endif
 
#if defined(BOTAN_HAS_SP800_56A)
   if(req.algo_name() == "SP800-56A" && req.arg_count() == 1)
      {
      if(auto hash = HashFunction::create(req.arg(0)))
         return std::make_unique<SP800_56A_Hash>(std::move(hash));
      if(auto mac = MessageAuthenticationCode::create(req.arg(0)))
         return std::make_unique<SP800_56A_HMAC>(std::move(mac));
      }
#endif
 
#if defined(BOTAN_HAS_SP800_56C)
   if(req.algo_name() == "SP800-56C" && req.arg_count() == 1)
      {
      std::unique_ptr<KDF> exp(kdf_create_mac_or_hash<SP800_108_Feedback>(req.arg(0)));
      if(exp)
         {
         if(auto mac = MessageAuthenticationCode::create(req.arg(0)))
            return std::make_unique<SP800_56C>(std::move(mac), std::move(exp));
 
         if(auto mac = MessageAuthenticationCode::create("HMAC(" + req.arg(0) + ")"))
            return std::make_unique<SP800_56C>(std::move(mac), std::move(exp));
         }
      }
#endif
 
   BOTAN_UNUSED(req);
   BOTAN_UNUSED(provider);
 
   return nullptr;
   }

References Botan::SCAN_Name::algo_name(), Botan::SCAN_Name::arg(), Botan::SCAN_Name::arg_count(), BOTAN_UNUSED, Botan::HashFunction::create(), Botan::MessageAuthenticationCode::create(), and hash.

Referenced by Botan::KDF::create_or_throw(), and Botan::get_kdf().

◆ create_or_throw()

std::unique_ptr< KDF > Botan::KDF::create_or_throw	(	const std::string &	algo_spec,
		const std::string &	provider = `""`
	)

staticinherited

Create an instance based on a name, or throw if the algo/provider combination cannot be found. If provider is empty then best available is chosen.

Definition at line 212 of file kdf.cpp.

   {
   if(auto kdf = KDF::create(algo, provider))
      {
      return kdf;
      }
   throw Lookup_Error("KDF", algo, provider);
   }

References Botan::KDF::create(), and Botan::KDF::kdf().

Referenced by botan_kdf(), Botan::ECIES_KA_Operation::derive_secret(), Botan::PK_Ops::KEM_Decryption_with_KDF::KEM_Decryption_with_KDF(), Botan::PK_Ops::KEM_Encryption_with_KDF::KEM_Encryption_with_KDF(), Botan::PK_Ops::Key_Agreement_with_KDF::Key_Agreement_with_KDF(), and Botan::TLS::Handshake_State::protocol_specific_prf().

◆ derive_key() [1/5]

secure_vector< uint8_t > Botan::KDF::derive_key	(	size_t	key_len,
		const secure_vector< uint8_t > &	secret,
		const std::string &	salt = `""`,
		const std::string &	label = `""`
	)		const

inlineinherited

Derive a key

Parameters

key_len	the desired output length in bytes
secret	the secret input
salt	a diversifier
label	purpose for the derived keying material

Returns: the derived key

Definition at line 103 of file kdf.h.

         {
         return derive_key(key_len, secret.data(), secret.size(),
                           cast_char_ptr_to_uint8(salt.data()),
                           salt.length(),
                           cast_char_ptr_to_uint8(label.data()),
                           label.length());
 
         }

References Botan::cast_char_ptr_to_uint8().

◆ derive_key() [2/5]

secure_vector< uint8_t > Botan::KDF::derive_key	(	size_t	key_len,
		const secure_vector< uint8_t > &	secret,
		const uint8_t	salt[],
		size_t	salt_len,
		const std::string &	label = `""`
	)		const

inlineinherited

Derive a key

Parameters

key_len	the desired output length in bytes
secret	the secret input
salt	a diversifier
salt_len	size of salt in bytes
label	purpose for the derived keying material

Returns: the derived key

Definition at line 145 of file kdf.h.

         {
         return derive_key(key_len,
                           secret.data(), secret.size(),
                           salt, salt_len,
                           cast_char_ptr_to_uint8(label.data()),
                           label.size());
         }

References Botan::cast_char_ptr_to_uint8(), and salt_len.

◆ derive_key() [3/5]

template<typename Alloc , typename Alloc2 , typename Alloc3 >

secure_vector< uint8_t > Botan::KDF::derive_key	(	size_t	key_len,
		const std::vector< uint8_t, Alloc > &	secret,
		const std::vector< uint8_t, Alloc2 > &	salt,
		const std::vector< uint8_t, Alloc3 > &	label
	)		const

inlineinherited

Derive a key

Parameters

key_len	the desired output length in bytes
secret	the secret input
salt	a diversifier
label	purpose for the derived keying material

Returns: the derived key

Definition at line 125 of file kdf.h.

         {
         return derive_key(key_len,
                           secret.data(), secret.size(),
                           salt.data(), salt.size(),
                           label.data(), label.size());
         }

◆ derive_key() [4/5]

secure_vector< uint8_t > Botan::KDF::derive_key	(	size_t	key_len,
		const uint8_t	secret[],
		size_t	secret_len,
		const std::string &	salt = `""`,
		const std::string &	label = `""`
	)		const

inlineinherited

Derive a key

Parameters

key_len	the desired output length in bytes
secret	the secret input
secret_len	size of secret in bytes
salt	a diversifier
label	purpose for the derived keying material

Returns: the derived key

Definition at line 167 of file kdf.h.

         {
         return derive_key(key_len, secret, secret_len,
                           cast_char_ptr_to_uint8(salt.data()),
                           salt.length(),
                           cast_char_ptr_to_uint8(label.data()),
                           label.length());
         }

References Botan::cast_char_ptr_to_uint8().

◆ derive_key() [5/5]

secure_vector< uint8_t > Botan::KDF::derive_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[] = `nullptr`,
		size_t	label_len = `0`
	)		const

inlineinherited

Derive a key

Parameters

key_len	the desired output length in bytes
secret	the secret input
secret_len	size of secret in bytes
salt	a diversifier
salt_len	size of salt in bytes
label	purpose for the derived keying material
label_len	size of label in bytes

Returns: the derived key

Definition at line 82 of file kdf.h.

         {
         secure_vector<uint8_t> key(key_len);
         kdf(key.data(), key.size(), secret, secret_len, salt, salt_len, label, label_len);
         return key;
         }

References salt_len.

◆ kdf()

void Botan::HKDF_Extract::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

overridevirtual

Derive a key

Parameters

key	buffer holding the derived key, must be of length key_len
key_len	the desired output length in bytes
secret	the secret input
secret_len	size of secret in bytes
salt	a diversifier
salt_len	size of salt in bytes
label	purpose for the derived keying material
label_len	size of label in bytes

Implements Botan::KDF.

Definition at line 28 of file hkdf.cpp.

   {
   if(key_len == 0)
      return;
 
   const size_t prf_output_len = m_prf->output_length();
 
   if(key_len > prf_output_len)
      throw Invalid_Argument("HKDF-Extract maximum output length exceeeded");
 
   if(label_len > 0)
      throw Invalid_Argument("HKDF-Extract does not support a label input");
 
   if(salt_len == 0)
      {
      m_prf->set_key(std::vector<uint8_t>(prf_output_len));
      }
   else
      {
      m_prf->set_key(salt, salt_len);
      }
 
   m_prf->update(secret, secret_len);
 
   if(key_len == prf_output_len)
      {
      m_prf->final(key);
      }
   else
      {
      secure_vector<uint8_t> prk;
      m_prf->final(prk);
      copy_mem(&key[0], prk.data(), key_len);
      }
   }

References Botan::copy_mem(), and salt_len.

Referenced by Botan::HKDF::kdf().

◆ name()

std::string Botan::HKDF_Extract::name ( ) const

inlineoverridevirtual

Returns: KDF name

Implements Botan::KDF.

Definition at line 62 of file hkdf.h.

62{ return "HKDF-Extract(" + m_prf->name() + ")"; }

◆ new_object()

std::unique_ptr< KDF > Botan::HKDF_Extract::new_object ( ) const

inlineoverridevirtual

Returns: new object representing the same algorithm as *this

Implements Botan::KDF.

Definition at line 57 of file hkdf.h.

         {
         return std::make_unique<HKDF_Extract>(m_prf->new_object());
         }

◆ providers()

std::vector< std::string > Botan::KDF::providers ( const std::string & algo_spec )

staticinherited

Returns: list of available providers for this algorithm, empty if not available

Definition at line 222 of file kdf.cpp.

   {
   return probe_providers_of<KDF>(algo_spec);
   }

The documentation for this class was generated from the following files:

src/lib/kdf/hkdf/hkdf.h
src/lib/kdf/hkdf/hkdf.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ HKDF_Extract()

Member Function Documentation

◆ clone()

◆ create()

◆ create_or_throw()

◆ derive_key() [1/5]

◆ derive_key() [2/5]

◆ derive_key() [3/5]

◆ derive_key() [4/5]

◆ derive_key() [5/5]

◆ kdf()

◆ name()

◆ new_object()

◆ providers()