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, std::string_view params, std::string_view provider) const
virtual std::unique_ptr< PK_Ops::KEM_Encryption >	create_kem_encryption_op (std::string_view params, std::string_view provider) const
virtual std::unique_ptr< PK_Ops::Verification >	create_verification_op (std::string_view params, std::string_view provider) const
virtual std::unique_ptr< PK_Ops::Verification >	create_x509_verification_op (const AlgorithmIdentifier &signature_algorithm, std::string_view provider) const
virtual Signature_Format	default_x509_signature_format () 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, std::span< const uint8_t > key_bits)
	ECDH_PublicKey (const EC_Group &dom_par, const EC_Point &public_point)
size_t	estimated_strength () const override
std::string	fingerprint_public (std::string_view alg="SHA-256") const
const BigInt &	get_int_field (std::string_view field) const override
OID	get_oid () const
size_t	key_length () const override
virtual size_t	message_part_size () const
virtual size_t	message_parts () const
virtual OID	object_identifier () const
EC_Point_Format	point_encoding () const
std::vector< uint8_t >	public_key_bits () const override
const EC_Point &	public_point () const
std::vector< uint8_t >	public_value () const
std::vector< uint8_t >	public_value (EC_Point_Format format) const
void	set_parameter_encoding (EC_Group_Encoding enc)
void	set_point_encoding (EC_Point_Format enc)
std::vector< uint8_t >	subject_public_key () const
bool	supports_operation (PublicKeyOperation op) const override

Protected Member Functions
	ECDH_PublicKey ()=default

Protected Attributes
EC_Group_Encoding	m_domain_encoding
EC_Group	m_domain_params
EC_Point_Format	m_point_encoding = EC_Point_Format::Uncompressed
EC_Point	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, std::span< const 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 EC_Point &  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::Asymmetric_Key.

Definition at line 45 of file ecdh.h.

{ return "ECDH"; }

Referenced by Botan::ECDH_PrivateKey::create_key_agreement_op().

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 66 of file ecc_key.cpp.

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

References Botan::EC_PublicKey::DER_domain(), and Botan::Asymmetric_Key::object_identifier().

check_key()

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

overridevirtualinherited

Implements Botan::Public_Key.

Reimplemented in Botan::ECDSA_PrivateKey, Botan::ECGDSA_PrivateKey, Botan::ECKCDSA_PrivateKey, and Botan::SM2_PrivateKey.

Definition at line 58 of file ecc_key.cpp.

   {
   return m_domain_params.verify_group(rng) &&
          m_domain_params.verify_public_element(public_point());
   }

References Botan::EC_PublicKey::m_domain_params, Botan::EC_PublicKey::public_point(), Botan::EC_Group::verify_group(), and Botan::EC_Group::verify_public_element().

create_encryption_op()

std::unique_ptr< PK_Ops::Encryption > Botan::Public_Key::create_encryption_op ( RandomNumberGenerator &  rng, std::string_view  params, std::string_view  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::ElGamal_PublicKey, Botan::RSA_PublicKey, and Botan::SM2_PublicKey.

Definition at line 102 of file pk_keys.cpp.

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

References Botan::Asymmetric_Key::algo_name(), and Botan::fmt().

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

create_kem_encryption_op()

std::unique_ptr< PK_Ops::KEM_Encryption > Botan::Public_Key::create_kem_encryption_op ( std::string_view  params, std::string_view  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

params	additional parameters
provider	the provider to use

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

Definition at line 110 of file pk_keys.cpp.

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

References Botan::Asymmetric_Key::algo_name(), and Botan::fmt().

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

create_verification_op()

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

virtualinherited

This is an internal library function exposed on key types. In 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::Dilithium_PublicKey, Botan::DSA_PublicKey, Botan::ECDSA_PublicKey, Botan::ECGDSA_PublicKey, Botan::ECKCDSA_PublicKey, Botan::Ed25519_PublicKey, Botan::GOST_3410_PublicKey, Botan::RSA_PublicKey, Botan::SM2_PublicKey, and Botan::XMSS_PublicKey.

Definition at line 117 of file pk_keys.cpp.

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

References Botan::Asymmetric_Key::algo_name(), and Botan::fmt().

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

create_x509_verification_op()

std::unique_ptr< PK_Ops::Verification > Botan::Public_Key::create_x509_verification_op ( const AlgorithmIdentifier &  signature_algorithm, std::string_view  provider  ) const

virtualinherited

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

Return a verification operation for this combination of key and signature algorithm or throw.

Parameters

signature_algorithm	is the X.509 algorithm identifier encoding the padding scheme and hash hash function used in the signature if applicable.
provider	the provider to use

Reimplemented in Botan::RSA_PublicKey, Botan::XMSS_PublicKey, Botan::Dilithium_PublicKey, Botan::DSA_PublicKey, Botan::ECDSA_PublicKey, Botan::ECGDSA_PublicKey, Botan::ECKCDSA_PublicKey, Botan::Ed25519_PublicKey, and Botan::GOST_3410_PublicKey.

Definition at line 124 of file pk_keys.cpp.

   {
   throw Lookup_Error(fmt("{} does not support X.509 verification", algo_name()));
   }

References Botan::Asymmetric_Key::algo_name(), and Botan::fmt().

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

default_x509_signature_format()

virtual Signature_Format Botan::Public_Key::default_x509_signature_format ( ) const

inlinevirtualinherited

Reimplemented in Botan::GOST_3410_PublicKey.

Definition at line 184 of file pk_keys.h.

         {
         return (this->message_parts() >= 2) ? Signature_Format::DerSequence : Signature_Format::Standard;
         }

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

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 74 of file ecc_key.h.

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

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

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 56 of file ecc_key.h.

{ return m_domain_params; }

Referenced by Botan::GOST_3410_PublicKey::algo_name(), Botan::GOST_3410_PublicKey::algorithm_identifier(), botan_pubkey_sm2_compute_za(), Botan::EC_PrivateKey::EC_PrivateKey(), Botan::EC_PublicKey::get_int_field(), Botan::GOST_3410_PublicKey::GOST_3410_PublicKey(), Botan::EC_PublicKey::key_length(), Botan::ECDH_PrivateKey::public_key(), Botan::ECDSA_PrivateKey::public_key(), Botan::ECGDSA_PrivateKey::public_key(), Botan::ECKCDSA_PrivateKey::public_key(), Botan::GOST_3410_PrivateKey::public_key(), Botan::SM2_PrivateKey::public_key(), Botan::ECDSA_PublicKey::recovery_param(), and Botan::SM2_PrivateKey::SM2_PrivateKey().

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 81 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::Asymmetric_Key.

Definition at line 25 of file ecc_key.cpp.

   {
   return ecp_work_factor(key_length());
   }

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

fingerprint_public()

std::string Botan::Public_Key::fingerprint_public ( std::string_view  alg = "SHA-256" ) const

inherited

Returns

Hash of the subject public key

Definition at line 88 of file pk_keys.cpp.

   {
   return create_hex_fingerprint(subject_public_key(), hash_algo);
   }

References Botan::create_hex_fingerprint(), and Botan::Public_Key::subject_public_key().

get_int_field()

const BigInt & Botan::EC_PublicKey::get_int_field ( std::string_view  field ) const

overridevirtualinherited

Access an algorithm specific field

If the field is not known for this algorithm, an Invalid_Argument is thrown. The interpretation of the result requires knowledge of which algorithm is involved. For instance for RSA "p" represents one of the secret primes, while for DSA "p" is the public prime.

Some algorithms may not implement this method at all.

This is primarily used to implement the FFI botan_pubkey_get_field and botan_privkey_get_field functions.

Reimplemented from Botan::Asymmetric_Key.

Reimplemented in Botan::EC_PrivateKey.

Definition at line 197 of file ecc_key.cpp.

   {
   if(field == "public_x")
      {
      BOTAN_ASSERT_NOMSG(this->public_point().is_affine());
      return this->public_point().get_x();
      }
   else if(field == "public_y")
      {
      BOTAN_ASSERT_NOMSG(this->public_point().is_affine());
      return this->public_point().get_y();
      }
   else if(field == "base_x")
      return this->domain().get_g_x();
   else if(field == "base_y")
      return this->domain().get_g_y();
   else if(field == "p")
      return this->domain().get_p();
   else if(field == "a")
      return this->domain().get_a();
   else if(field == "b")
      return this->domain().get_b();
   else if(field == "cofactor")
      return this->domain().get_cofactor();
   else if(field == "order")
      return this->domain().get_order();
   else
      return Public_Key::get_int_field(field);
   }

References BOTAN_ASSERT_NOMSG, Botan::EC_PublicKey::domain(), Botan::EC_Group::get_a(), Botan::EC_Group::get_b(), Botan::EC_Group::get_cofactor(), Botan::EC_Group::get_g_x(), Botan::EC_Group::get_g_y(), Botan::Asymmetric_Key::get_int_field(), Botan::EC_Group::get_order(), Botan::EC_Group::get_p(), Botan::EC_Point::get_x(), Botan::EC_Point::get_y(), and Botan::EC_PublicKey::public_point().

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

get_oid()

OID Botan::Public_Key::get_oid ( ) const

inlineinherited

Deprecated version of object_identifier

Definition at line 122 of file pk_keys.h.

         {
         return this->object_identifier();
         }

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 20 of file ecc_key.cpp.

   {
   return domain().get_p_bits();
   }

References Botan::EC_PublicKey::domain(), and Botan::EC_Group::get_p_bits().

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

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::DSA_PublicKey, Botan::ECDSA_PublicKey, Botan::ECGDSA_PublicKey, Botan::ECKCDSA_PublicKey, Botan::GOST_3410_PublicKey, and Botan::SM2_PublicKey.

Definition at line 182 of file pk_keys.h.

{ return 0; }

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

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::DSA_PublicKey, Botan::ECDSA_PublicKey, Botan::ECGDSA_PublicKey, Botan::ECKCDSA_PublicKey, Botan::GOST_3410_PublicKey, and Botan::SM2_PublicKey.

Definition at line 171 of file pk_keys.h.

{ return 1; }

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

object_identifier()

OID Botan::Asymmetric_Key::object_identifier ( ) const

virtualinherited

Get the OID of the underlying public key scheme.

Returns

OID of the public key scheme

Reimplemented in Botan::Dilithium_PublicKey, and Botan::Kyber_PublicKey.

Definition at line 22 of file pk_keys.cpp.

   {
   try
      {
      return OID::from_string(algo_name());
      }
   catch(Lookup_Error&)
      {
      throw Lookup_Error(fmt("Public key algorithm {} has no defined OIDs", algo_name()));
      }
   }

References Botan::Asymmetric_Key::algo_name(), Botan::fmt(), and Botan::OID::from_string().

Referenced by Botan::TPM_PrivateKey::algorithm_identifier(), Botan::Curve25519_PublicKey::algorithm_identifier(), Botan::DH_PublicKey::algorithm_identifier(), Botan::DSA_PublicKey::algorithm_identifier(), Botan::EC_PublicKey::algorithm_identifier(), Botan::Ed25519_PublicKey::algorithm_identifier(), Botan::ElGamal_PublicKey::algorithm_identifier(), Botan::GOST_3410_PublicKey::algorithm_identifier(), Botan::McEliece_PublicKey::algorithm_identifier(), and Botan::RSA_PublicKey::algorithm_identifier().

point_encoding()

EC_Point_Format Botan::EC_PublicKey::point_encoding ( ) const

inlineinherited

Get the point encoding method to be used when encoding this key.

Returns

the encoding to use

Definition at line 88 of file ecc_key.h.

         { return m_point_encoding; }

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

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 71 of file ecc_key.cpp.

   {
   return public_point().encode(point_encoding());
   }

References Botan::EC_Point::encode(), Botan::EC_PublicKey::point_encoding(), and Botan::EC_PublicKey::public_point().

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

public_point()

const EC_Point & 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 41 of file ecc_key.h.

{ return m_public_key; }

Referenced by botan_pubkey_sm2_compute_za(), Botan::EC_PublicKey::check_key(), Botan::ECDSA_PrivateKey::check_key(), Botan::ECGDSA_PrivateKey::check_key(), Botan::ECKCDSA_PrivateKey::check_key(), Botan::SM2_PrivateKey::check_key(), Botan::EC_PublicKey::get_int_field(), Botan::ECDH_PrivateKey::public_key(), Botan::ECDSA_PrivateKey::public_key(), Botan::ECGDSA_PrivateKey::public_key(), Botan::ECKCDSA_PrivateKey::public_key(), Botan::GOST_3410_PrivateKey::public_key(), Botan::SM2_PrivateKey::public_key(), Botan::EC_PublicKey::public_key_bits(), Botan::GOST_3410_PublicKey::public_key_bits(), and Botan::ECDSA_PublicKey::recovery_param().

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.

         { return public_point().encode(EC_Point_Format::Uncompressed); }

public_value() [2/2]

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

inline

Returns

public point value

Definition at line 56 of file ecdh.h.

         { return public_point().encode(format); }

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 86 of file ecc_key.cpp.

   {
   if(form == EC_Group_Encoding::NamedCurve && m_domain_params.get_curve_oid().empty())
      throw Invalid_Argument("Cannot used NamedCurve encoding for a curve without an OID");
 
   m_domain_encoding = form;
   }

References Botan::OID::empty(), Botan::EC_Group::get_curve_oid(), Botan::EC_PublicKey::m_domain_encoding, Botan::EC_PublicKey::m_domain_params, and Botan::NamedCurve.

set_point_encoding()

void Botan::EC_PublicKey::set_point_encoding ( EC_Point_Format  enc )

inherited

Set the point encoding method to be used when encoding this key.

Parameters

enc	the encoding to use

Definition at line 76 of file ecc_key.cpp.

   {
   if(enc != EC_Point_Format::Compressed &&
      enc != EC_Point_Format::Uncompressed &&
      enc != EC_Point_Format::Hybrid)
      throw Invalid_Argument("Invalid point encoding for EC_PublicKey");
 
   m_point_encoding = enc;
   }

References Botan::Compressed, Botan::Hybrid, Botan::EC_PublicKey::m_point_encoding, and Botan::Uncompressed.

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 55 of file pk_keys.cpp.

   {
   std::vector<uint8_t> output;
 
   DER_Encoder(output).start_sequence()
         .encode(algorithm_identifier())
         .encode(public_key_bits(), ASN1_Type::BitString)
      .end_cons();
 
   return output;
   }

References Botan::Public_Key::algorithm_identifier(), Botan::BitString, Botan::DER_Encoder::encode(), Botan::DER_Encoder::end_cons(), Botan::Public_Key::public_key_bits(), and Botan::DER_Encoder::start_sequence().

Referenced by Botan::X509::BER_encode(), Botan::PKCS10_Request::create(), Botan::Public_Key::fingerprint_public(), and Botan::X509::PEM_encode().

supports_operation()

bool Botan::ECDH_PublicKey::supports_operation ( PublicKeyOperation  op ) const

inlineoverridevirtual

Return true if this key could be used for the specified type of operation.

Implements Botan::Asymmetric_Key.

Definition at line 59 of file ecdh.h.

         {
         return (op == PublicKeyOperation::KeyAgreement);
         }

Member Data Documentation

m_domain_encoding

EC_Group_Encoding Botan::EC_PublicKey::m_domain_encoding

protectedinherited

Definition at line 118 of file ecc_key.h.

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

m_domain_params

EC_Group Botan::EC_PublicKey::m_domain_params

protectedinherited

Definition at line 116 of file ecc_key.h.

Referenced by Botan::EC_PublicKey::check_key(), Botan::EC_PrivateKey::EC_PrivateKey(), Botan::GOST_3410_PrivateKey::GOST_3410_PrivateKey(), Botan::GOST_3410_PublicKey::GOST_3410_PublicKey(), and Botan::EC_PublicKey::set_parameter_encoding().

m_point_encoding

EC_Point_Format Botan::EC_PublicKey::m_point_encoding = EC_Point_Format::Uncompressed

protectedinherited

Definition at line 119 of file ecc_key.h.

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

m_public_key

EC_Point Botan::EC_PublicKey::m_public_key

protectedinherited

Definition at line 117 of file ecc_key.h.

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

---

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

• src/lib/pubkey/ecdh/ecdh.h