Botan::ECDH_PublicKey Class Reference

#include <ecdh.h>

Inheritance diagram for Botan::ECDH_PublicKey:

Public Member Functions
std::string	algo_name () const override
AlgorithmIdentifier	algorithm_identifier () const override
bool	check_key (RandomNumberGenerator &rng, bool strong) const override
virtual std::unique_ptr< PK_Ops::Encryption >	create_encryption_op (RandomNumberGenerator &rng, const std::string &params, const std::string &provider) const
virtual std::unique_ptr< PK_Ops::KEM_Encryption >	create_kem_encryption_op (RandomNumberGenerator &rng, const std::string &params, const std::string &provider) const
virtual std::unique_ptr< PK_Ops::Verification >	create_verification_op (const std::string &params, const std::string &provider) const
std::vector< uint8_t >	DER_domain () const
const EC_Group &	domain () const
EC_Group_Encoding	domain_format () const
	ECDH_PublicKey (const AlgorithmIdentifier &alg_id, const std::vector< uint8_t > &key_bits)
	ECDH_PublicKey (const EC_Group &dom_par, const PointGFp &public_point)
size_t	estimated_strength () const override
virtual OID	get_oid () const
size_t	key_length () const override
virtual size_t	message_part_size () const
virtual size_t	message_parts () const
std::vector< uint8_t >	public_key_bits () const override
const PointGFp &	public_point () const
std::vector< uint8_t >	public_value () const
std::vector< uint8_t >	public_value (PointGFp::Compression_Type type) const
void	set_parameter_encoding (EC_Group_Encoding enc)
std::vector< uint8_t >	subject_public_key () const

Protected Member Functions
	ECDH_PublicKey ()=default

Protected Attributes
EC_Group_Encoding	m_domain_encoding
EC_Group	m_domain_params
PointGFp	m_public_key

Detailed Description

This class represents ECDH Public Keys.

Definition at line 20 of file ecdh.h.

Constructor & Destructor Documentation

ECDH_PublicKey() [1/3]

Botan::ECDH_PublicKey::ECDH_PublicKey ( const AlgorithmIdentifier &  alg_id, const std::vector< uint8_t > &  key_bits  )

inline

Create an ECDH public key.

Parameters

alg_id	algorithm identifier
key_bits	DER encoded public key bits

Definition at line 28 of file ecdh.h.

                                                         :
         EC_PublicKey(alg_id, key_bits) {}

ECDH_PublicKey() [2/3]

Botan::ECDH_PublicKey::ECDH_PublicKey ( const EC_Group &  dom_par, const PointGFp &  public_point  )

inline

Construct a public key from a given public point.

Parameters

dom_par	the domain parameters associated with this key
public_point	the public point defining this key

Definition at line 37 of file ecdh.h.

                                                   :
         EC_PublicKey(dom_par, public_point) {}

ECDH_PublicKey() [3/3]

Botan::ECDH_PublicKey::ECDH_PublicKey ( )

protecteddefault

Member Function Documentation

algo_name()

std::string Botan::ECDH_PublicKey::algo_name ( ) const

inlineoverridevirtual

Get this keys algorithm name.

Returns

this keys algorithm name

Implements Botan::Public_Key.

Definition at line 45 of file ecdh.h.

{ return "ECDH"; }

algorithm_identifier()

AlgorithmIdentifier Botan::EC_PublicKey::algorithm_identifier ( ) const

overridevirtualinherited

Returns

X.509 AlgorithmIdentifier for this key

Implements Botan::Public_Key.

Reimplemented in Botan::GOST_3410_PublicKey.

Definition at line 81 of file ecc_key.cpp.

References Botan::EC_PublicKey::DER_domain(), and Botan::Public_Key::get_oid().

Referenced by Botan::GOST_3410_PrivateKey::pkcs8_algorithm_identifier().

   {
   return AlgorithmIdentifier(get_oid(), DER_domain());
   }

check_key()

bool Botan::EC_PublicKey::check_key ( RandomNumberGenerator &  rng, bool  strong  ) const

overridevirtualinherited

Test the key values for consistency.

Parameters

rng	rng to use
strong	whether to perform strong and lengthy version of the test

Returns

true if the test is passed

Implements Botan::Public_Key.

Reimplemented in Botan::ECDSA_PrivateKey, Botan::ECGDSA_PrivateKey, and Botan::ECKCDSA_PrivateKey.

Definition at line 47 of file ecc_key.cpp.

References Botan::EC_Group::get_cofactor(), Botan::EC_Group::get_order(), Botan::CT::is_zero(), Botan::PointGFp::is_zero(), Botan::EC_PublicKey::m_domain_params, Botan::PointGFp::on_the_curve(), Botan::EC_PublicKey::public_point(), and Botan::EC_Group::verify_group().

   {
   //verify domain parameters
   if(!m_domain_params.verify_group(rng))
      {
      return false;
      }
   //check that public point is not at infinity
   if(public_point().is_zero())
      {
      return false;
      }
   //check that public point is on the curve
   if(!public_point().on_the_curve())
      {
      return false;
      }
   if(m_domain_params.get_cofactor() > 1)
      {
      if((public_point() * m_domain_params.get_cofactor()).is_zero())
         {
         return false;
         }
      //check that public point has order q
      if(!(public_point() * m_domain_params.get_order()).is_zero())
         {
         return false;
         }
      }
   return true;
   }

create_encryption_op()

std::unique_ptr< PK_Ops::Encryption > Botan::Public_Key::create_encryption_op ( RandomNumberGenerator &  rng, const std::string &  params, const std::string &  provider  ) const

virtualinherited

This is an internal library function exposed on key types. In almost all cases applications should use wrappers in pubkey.h

Return an encryption operation for this key/params or throw

Parameters

rng	a random number generator. The PK_Op may maintain a reference to the RNG and use it many times. The rng must outlive any operations which reference it.
params	additional parameters
provider	the provider to use

Reimplemented in Botan::RSA_PublicKey, and Botan::ElGamal_PublicKey.

Definition at line 79 of file pk_keys.cpp.

References Botan::Public_Key::algo_name().

Referenced by Botan::PK_Encryptor_EME::PK_Encryptor_EME().

   {
   throw Lookup_Error(algo_name() + " does not support encryption");
   }

create_kem_encryption_op()

std::unique_ptr< PK_Ops::KEM_Encryption > Botan::Public_Key::create_kem_encryption_op ( RandomNumberGenerator &  rng, const std::string &  params, const std::string &  provider  ) const

virtualinherited

This is an internal library function exposed on key types. In almost all cases applications should use wrappers in pubkey.h

Return a KEM encryption operation for this key/params or throw

Parameters

rng	a random number generator. The PK_Op may maintain a reference to the RNG and use it many times. The rng must outlive any operations which reference it.
params	additional parameters
provider	the provider to use

Reimplemented in Botan::RSA_PublicKey, and Botan::McEliece_PublicKey.

Definition at line 87 of file pk_keys.cpp.

References Botan::Public_Key::algo_name().

Referenced by Botan::PK_KEM_Encryptor::PK_KEM_Encryptor().

   {
   throw Lookup_Error(algo_name() + " does not support KEM encryption");
   }

create_verification_op()

std::unique_ptr< PK_Ops::Verification > Botan::Public_Key::create_verification_op ( const std::string &  params, const std::string &  provider  ) const

virtualinherited

This is an internal library function exposed on key types. In almost all cases applications should use wrappers in pubkey.h

Return a verification operation for this key/params or throw

Parameters

params	additional parameters
provider	the provider to use

Reimplemented in Botan::XMSS_WOTS_PublicKey, Botan::XMSS_PublicKey, Botan::RSA_PublicKey, Botan::XMSS_WOTS_Addressed_PublicKey, Botan::GOST_3410_PublicKey, Botan::ECDSA_PublicKey, Botan::ECGDSA_PublicKey, Botan::ECKCDSA_PublicKey, and Botan::DSA_PublicKey.

Definition at line 95 of file pk_keys.cpp.

References Botan::Public_Key::algo_name().

Referenced by Botan::PK_Verifier::PK_Verifier().

   {
   throw Lookup_Error(algo_name() + " does not support verification");
   }

DER_domain()

std::vector<uint8_t> Botan::EC_PublicKey::DER_domain ( ) const

inlineinherited

Return the DER encoding of this keys domain in whatever format is preset for this particular key

Definition at line 85 of file ecc_key.h.

Referenced by Botan::EC_PublicKey::algorithm_identifier().

         { return domain().DER_encode(domain_format()); }

domain()

const EC_Group& Botan::EC_PublicKey::domain ( ) const

inlineinherited

Get the domain parameters of this key.

Exceptions

Invalid_State

is thrown if the domain parameters of this point are not set

Returns

the domain parameters of this key

Definition at line 73 of file ecc_key.h.

Referenced by Botan::GOST_3410_PublicKey::algorithm_identifier(), Botan::EC_PrivateKey::EC_PrivateKey(), Botan::EC_PublicKey::EC_PublicKey(), Botan::GOST_3410_PublicKey::GOST_3410_PublicKey(), and Botan::EC_PublicKey::key_length().

{ return m_domain_params; }

domain_format()

EC_Group_Encoding Botan::EC_PublicKey::domain_format ( ) const

inlineinherited

Get the domain parameter encoding to be used when encoding this key.

Returns

the encoding to use

Definition at line 92 of file ecc_key.h.

         { return m_domain_encoding; }

estimated_strength()

size_t Botan::EC_PublicKey::estimated_strength ( ) const

overridevirtualinherited

Return the estimated strength of the underlying key against the best currently known attack. Note that this ignores anything but pure attacks against the key itself and do not take into account padding schemes, usage mistakes, etc which might reduce the strength. However it does suffice to provide an upper bound.

Returns

estimated strength in bits

Implements Botan::Public_Key.

Definition at line 26 of file ecc_key.cpp.

References Botan::ecp_work_factor(), and Botan::EC_PublicKey::key_length().

   {
   return ecp_work_factor(key_length());
   }

get_oid()

OID Botan::Public_Key::get_oid ( ) const

virtualinherited

Get the OID of the underlying public key scheme.

Returns

OID of the public key scheme

Reimplemented in Botan::XMSS_WOTS_Addressed_PublicKey.

Definition at line 30 of file pk_keys.cpp.

References Botan::Public_Key::algo_name(), and Botan::OIDS::lookup().

Referenced by Botan::DL_Scheme_PublicKey::algorithm_identifier(), Botan::Curve25519_PublicKey::algorithm_identifier(), Botan::McEliece_PublicKey::algorithm_identifier(), Botan::RSA_PublicKey::algorithm_identifier(), Botan::GOST_3410_PublicKey::algorithm_identifier(), Botan::EC_PublicKey::algorithm_identifier(), Botan::TPM_PrivateKey::algorithm_identifier(), and Botan::XMSS_WOTS_Addressed_PublicKey::get_oid().

   {
   try {
      return OIDS::lookup(algo_name());
      }
   catch(Lookup_Error&)
      {
      throw Lookup_Error("PK algo " + algo_name() + " has no defined OIDs");
      }
   }

key_length()

size_t Botan::EC_PublicKey::key_length ( ) const

overridevirtualinherited

Return an integer value best approximating the length of the primary security parameter. For example for RSA this will be the size of the modulus, for ECDSA the size of the ECC group, and for McEliece the size of the code will be returned.

Implements Botan::Public_Key.

Definition at line 21 of file ecc_key.cpp.

References Botan::BigInt::bits(), Botan::EC_PublicKey::domain(), Botan::EC_Group::get_curve(), and Botan::CurveGFp::get_p().

Referenced by Botan::EC_PublicKey::estimated_strength().

   {
   return domain().get_curve().get_p().bits();
   }

message_part_size()

virtual size_t Botan::Public_Key::message_part_size ( ) const

inlinevirtualinherited

Returns how large each of the message parts refered to by message_parts() is

This function is public but applications should have few reasons to ever call this.

Returns

size of the message parts in bits

Reimplemented in Botan::GOST_3410_PublicKey, Botan::ECDSA_PublicKey, Botan::ECGDSA_PublicKey, Botan::ECKCDSA_PublicKey, and Botan::DSA_PublicKey.

Definition at line 114 of file pk_keys.h.

Referenced by Botan::PK_Signer::PK_Signer(), and Botan::PK_Verifier::PK_Verifier().

{ return 0; }

message_parts()

virtual size_t Botan::Public_Key::message_parts ( ) const

inlinevirtualinherited

Returns more than 1 if the output of this algorithm (ciphertext, signature) should be treated as more than one value. This is used for algorithms like DSA and ECDSA, where the (r,s) output pair can be encoded as either a plain binary list or a TLV tagged DER encoding depending on the protocol.

This function is public but applications should have few reasons to ever call this.

Returns

number of message parts

Reimplemented in Botan::GOST_3410_PublicKey, Botan::ECDSA_PublicKey, Botan::ECGDSA_PublicKey, Botan::ECKCDSA_PublicKey, and Botan::DSA_PublicKey.

Definition at line 103 of file pk_keys.h.

Referenced by Botan::X509_Object::check_signature(), Botan::choose_sig_format(), Botan::PK_Signer::PK_Signer(), and Botan::PK_Verifier::PK_Verifier().

{ return 1; }

public_key_bits()

std::vector< uint8_t > Botan::EC_PublicKey::public_key_bits ( ) const

overridevirtualinherited

Returns

BER encoded public key bits

Implements Botan::Public_Key.

Reimplemented in Botan::GOST_3410_PublicKey.

Definition at line 86 of file ecc_key.cpp.

References Botan::PointGFp::COMPRESSED, Botan::EC2OSP(), Botan::EC_PublicKey::public_point(), and Botan::unlock().

Referenced by Botan::EC_PrivateKey::EC_PrivateKey().

   {
   return unlock(EC2OSP(public_point(), PointGFp::COMPRESSED));
   }

public_point()

const PointGFp& Botan::EC_PublicKey::public_point ( ) const

inlineinherited

Get the public point of this key.

Exceptions

Invalid_State

is thrown if the domain parameters of this point are not set

Returns

the public point of this key

Definition at line 58 of file ecc_key.h.

Referenced by Botan::EC_PublicKey::check_key(), Botan::ECGDSA_PrivateKey::check_key(), Botan::ECKCDSA_PrivateKey::check_key(), Botan::ECDSA_PrivateKey::check_key(), Botan::EC_PublicKey::EC_PublicKey(), Botan::GOST_3410_PublicKey::public_key_bits(), and Botan::EC_PublicKey::public_key_bits().

{ return m_public_key; }

public_value() [1/2]

std::vector<uint8_t> Botan::ECDH_PublicKey::public_value ( ) const

inline

Returns

public point value

Definition at line 50 of file ecdh.h.

References Botan::EC2OSP(), Botan::PointGFp::UNCOMPRESSED, and Botan::unlock().

Referenced by Botan::TLS::Client_Key_Exchange::Client_Key_Exchange(), and Botan::ECDH_PrivateKey::public_value().

         { return unlock(EC2OSP(public_point(), PointGFp::UNCOMPRESSED)); }

public_value() [2/2]

std::vector<uint8_t> Botan::ECDH_PublicKey::public_value ( PointGFp::Compression_Type  type ) const

inline

Returns

public point value

Definition at line 56 of file ecdh.h.

References Botan::EC2OSP(), and Botan::unlock().

         { return unlock(EC2OSP(public_point(), type)); }

set_parameter_encoding()

void Botan::EC_PublicKey::set_parameter_encoding ( EC_Group_Encoding  enc )

inherited

Set the domain parameter encoding to be used when encoding this key.

Parameters

enc	the encoding to use

Definition at line 91 of file ecc_key.cpp.

References Botan::EC_DOMPAR_ENC_EXPLICIT, Botan::EC_DOMPAR_ENC_IMPLICITCA, Botan::EC_DOMPAR_ENC_OID, Botan::EC_Group::get_oid(), Botan::EC_PublicKey::m_domain_encoding, and Botan::EC_PublicKey::m_domain_params.

   {
   if(form != EC_DOMPAR_ENC_EXPLICIT &&
      form != EC_DOMPAR_ENC_IMPLICITCA &&
      form != EC_DOMPAR_ENC_OID)
      throw Invalid_Argument("Invalid encoding form for EC-key object specified");

   if((form == EC_DOMPAR_ENC_OID) && (m_domain_params.get_oid() == ""))
      throw Invalid_Argument("Invalid encoding form OID specified for "
                             "EC-key object whose corresponding domain "
                             "parameters are without oid");

   m_domain_encoding = form;
   }

subject_public_key()

std::vector< uint8_t > Botan::Public_Key::subject_public_key ( ) const

inherited

Returns

X.509 subject key encoding for this key object

Definition at line 17 of file pk_keys.cpp.

References Botan::Public_Key::algorithm_identifier(), Botan::BIT_STRING, Botan::DER_Encoder::encode(), Botan::DER_Encoder::end_cons(), Botan::DER_Encoder::get_contents_unlocked(), Botan::Public_Key::public_key_bits(), Botan::SEQUENCE, and Botan::DER_Encoder::start_cons().

Referenced by Botan::X509::BER_encode(), and Botan::X509::PEM_encode().

   {
   return DER_Encoder()
         .start_cons(SEQUENCE)
            .encode(algorithm_identifier())
            .encode(public_key_bits(), BIT_STRING)
         .end_cons()
      .get_contents_unlocked();
   }

Member Data Documentation

m_domain_encoding

EC_Group_Encoding Botan::EC_PublicKey::m_domain_encoding

protectedinherited

Definition at line 104 of file ecc_key.h.

Referenced by Botan::EC_PrivateKey::EC_PrivateKey(), Botan::EC_PublicKey::EC_PublicKey(), and Botan::EC_PublicKey::set_parameter_encoding().

m_domain_params

EC_Group Botan::EC_PublicKey::m_domain_params

protectedinherited

Definition at line 102 of file ecc_key.h.

Referenced by Botan::EC_PublicKey::check_key(), Botan::EC_PrivateKey::EC_PrivateKey(), Botan::GOST_3410_PublicKey::GOST_3410_PublicKey(), and Botan::EC_PublicKey::set_parameter_encoding().

m_public_key

PointGFp Botan::EC_PublicKey::m_public_key

protectedinherited

Definition at line 103 of file ecc_key.h.

Referenced by Botan::EC_PrivateKey::EC_PrivateKey(), Botan::EC_PublicKey::EC_PublicKey(), and Botan::GOST_3410_PublicKey::GOST_3410_PublicKey().

---

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

• src/lib/pubkey/ecdh/ecdh.h