#include <elgamal.h>

Inheritance diagram for Botan::ElGamal_PublicKey:

Public Member Functions
std::string	algo_name () const override

AlgorithmIdentifier	algorithm_identifier () const override

bool	check_key (RandomNumberGenerator &rng, bool) const override

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

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

virtual Signature_Format	default_x509_signature_format () const

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

	ElGamal_PublicKey (const DL_Group &group, const BigInt &y)

size_t	estimated_strength () const override

std::string	fingerprint_public (const std::string &alg="SHA-256") const

const DL_Group &	get_domain () const

const DL_Group &	get_group () const

virtual OID	get_oid () const

const BigInt &	get_y () const

DL_Group_Format	group_format () const override

const BigInt &	group_g () const

const BigInt &	group_p () const

const BigInt &	group_q () 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

std::vector< uint8_t >	subject_public_key () const

Protected Member Functions
	ElGamal_PublicKey ()=default

Protected Attributes
DL_Group	m_group

BigInt	m_y

Detailed Description

ElGamal Public Key

Definition at line 18 of file elgamal.h.

Constructor & Destructor Documentation

◆ ElGamal_PublicKey() [1/3]

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

inline

Load a public key.

Parameters

alg_id	the X.509 algorithm identifier
key_bits	DER encoded public key bits

Definition at line 29 of file elgamal.h.

                                                            :
         DL_Scheme_PublicKey(alg_id, key_bits, DL_Group_Format::ANSI_X9_42)
         {}

References Botan::ANSI_X9_42.

◆ ElGamal_PublicKey() [2/3]

Botan::ElGamal_PublicKey::ElGamal_PublicKey	(	const DL_Group &	group,
		const BigInt &	y
	)

Create a public key.

Parameters

group	the underlying DL group
y	the public value y = g^x mod p

Definition at line 19 of file elgamal.cpp.

                                                                           :
   DL_Scheme_PublicKey(group, y)
   {
   }

◆ ElGamal_PublicKey() [3/3]

Botan::ElGamal_PublicKey::ElGamal_PublicKey ( )

protecteddefault

Member Function Documentation

◆ algo_name()

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

inlineoverridevirtual

Get the name of the underlying public key scheme.

Returns: name of the public key scheme

Implements Botan::Public_Key.

Definition at line 21 of file elgamal.h.

21{ return "ElGamal"; }

Referenced by Botan::ElGamal_PrivateKey::create_decryption_op(), and create_encryption_op().

◆ algorithm_identifier()

AlgorithmIdentifier Botan::DL_Scheme_PublicKey::algorithm_identifier ( ) const

overridevirtualinherited

Returns: X.509 AlgorithmIdentifier for this key

Implements Botan::Public_Key.

Definition at line 25 of file dl_algo.cpp.

   {
   return AlgorithmIdentifier(get_oid(),
                              m_group.DER_encode(group_format()));
   }

References Botan::DL_Group::DER_encode(), Botan::Public_Key::get_oid(), Botan::DL_Scheme_PublicKey::group_format(), and Botan::DL_Scheme_PublicKey::m_group.

◆ check_key()

bool Botan::DL_Scheme_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::DSA_PrivateKey, Botan::DL_Scheme_PrivateKey, and Botan::ElGamal_PrivateKey.

Definition at line 69 of file dl_algo.cpp.

   {
   return m_group.verify_group(rng, strong) && m_group.verify_public_element(m_y);
   }

References Botan::DL_Scheme_PublicKey::m_group, Botan::DL_Scheme_PublicKey::m_y, Botan::DL_Group::verify_group(), and Botan::DL_Group::verify_public_element().

◆ create_encryption_op()

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

overridevirtual

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 from Botan::Public_Key.

Definition at line 201 of file elgamal.cpp.

   {
   if(provider == "base" || provider.empty())
      return std::make_unique<ElGamal_Encryption_Operation>(*this, params);
   throw Provider_Not_Found(algo_name(), provider);
   }

References algo_name().

◆ 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::Kyber_PublicKey, Botan::McEliece_PublicKey, and Botan::RSA_PublicKey.

Definition at line 99 of file pk_keys.cpp.

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

References Botan::Public_Key::algo_name().

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

◆ 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_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_WOTS_Addressed_PublicKey.

Definition at line 107 of file pk_keys.cpp.

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

References Botan::Public_Key::algo_name().

Referenced by Botan::XMSS_WOTS_Addressed_PublicKey::create_verification_op(), and 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 125 of file pk_keys.h.

         {
         return (this->message_parts() >= 2) ? DER_SEQUENCE : IEEE_1363;
         }

References Botan::DER_SEQUENCE, and Botan::IEEE_1363.

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

◆ estimated_strength()

size_t Botan::DL_Scheme_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 20 of file dl_algo.cpp.

   {
   return m_group.estimated_strength();
   }

References Botan::DL_Group::estimated_strength(), and Botan::DL_Scheme_PublicKey::m_group.

◆ fingerprint_public()

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

inherited

Returns: Hash of the subject public key

Definition at line 77 of file pk_keys.cpp.

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

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

◆ get_domain()

const DL_Group & Botan::DL_Scheme_PublicKey::get_domain ( ) const

inlineinherited

Get the DL domain parameters of this key.

Returns: DL domain parameters of this key

Definition at line 32 of file dl_algo.h.

32{ return m_group; }

◆ get_group()

const DL_Group & Botan::DL_Scheme_PublicKey::get_group ( ) const

inlineinherited

Get the DL domain parameters of this key.

Returns: DL domain parameters of this key

Definition at line 38 of file dl_algo.h.

38{ return m_group; }

Referenced by Botan::DH_PrivateKey::public_key(), Botan::DSA_PrivateKey::public_key(), and Botan::ElGamal_PrivateKey::public_key().

◆ 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 53 of file pk_keys.cpp.

   {
   OID o = OIDS::str2oid_or_empty(algo_name());
   if(o.empty())
      throw Lookup_Error("PK algo " + algo_name() + " has no defined OIDs");
   return o;
   }

References Botan::Public_Key::algo_name(), Botan::OID::empty(), and Botan::OIDS::str2oid_or_empty().

◆ get_y()

const BigInt & Botan::DL_Scheme_PublicKey::get_y ( ) const

inlineinherited

Get the public value y with y = g^x mod p where x is the secret key.

Definition at line 43 of file dl_algo.h.

43{ return m_y; }

Referenced by Botan::DH_PrivateKey::public_key(), Botan::DSA_PrivateKey::public_key(), and Botan::ElGamal_PrivateKey::public_key().

◆ group_format()

DL_Group_Format Botan::ElGamal_PublicKey::group_format ( ) const

inlineoverridevirtual

Get the underlying groups encoding format.

Returns: encoding format

Implements Botan::DL_Scheme_PublicKey.

Definition at line 22 of file elgamal.h.

22{ return DL_Group_Format::ANSI_X9_42; }

References Botan::ANSI_X9_42.

◆ group_g()

const BigInt & Botan::DL_Scheme_PublicKey::group_g ( ) const

inlineinherited

Get the generator g of the underlying DL group.

Returns: generator g

Definition at line 61 of file dl_algo.h.

61{ return m_group.get_g(); }

Botan::DL_Group::get_g

const BigInt & get_g() const

Definition: dl_group.cpp:469

◆ group_p()

const BigInt & Botan::DL_Scheme_PublicKey::group_p ( ) const

inlineinherited

Get the prime p of the underlying DL group.

Returns: prime p

Definition at line 49 of file dl_algo.h.

49{ return m_group.get_p(); }

Botan::DL_Group::get_p

const BigInt & get_p() const

Definition: dl_group.cpp:461

Referenced by Botan::DH_PublicKey::public_value().

◆ group_q()

const BigInt & Botan::DL_Scheme_PublicKey::group_q ( ) const

inlineinherited

Get the prime q of the underlying DL group.

Returns: prime q

Definition at line 55 of file dl_algo.h.

55{ return m_group.get_q(); }

Botan::DL_Group::get_q

const BigInt & get_q() const

Definition: dl_group.cpp:477

Referenced by Botan::DSA_PrivateKey::check_key(), Botan::DSA_PrivateKey::DSA_PrivateKey(), and Botan::DSA_PublicKey::DSA_PublicKey().

◆ key_length()

size_t Botan::DL_Scheme_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 15 of file dl_algo.cpp.

   {
   return m_group.p_bits();
   }

References Botan::DL_Scheme_PublicKey::m_group, and Botan::DL_Group::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::DSA_PublicKey, Botan::ECDSA_PublicKey, Botan::ECGDSA_PublicKey, Botan::ECKCDSA_PublicKey, Botan::GOST_3410_PublicKey, and Botan::SM2_PublicKey.

Definition at line 123 of file pk_keys.h.

123{ 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 112 of file pk_keys.h.

112{ return 1; }

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

◆ public_key_bits()

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

overridevirtualinherited

Returns: BER encoded public key bits

Implements Botan::Public_Key.

Definition at line 31 of file dl_algo.cpp.

   {
   std::vector<uint8_t> output;
   DER_Encoder(output).encode(m_y);
   return output;
   }

References Botan::DER_Encoder::encode(), and Botan::DL_Scheme_PublicKey::m_y.

◆ 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 38 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().

Member Data Documentation

◆ m_group

DL_Group Botan::DL_Scheme_PublicKey::m_group

protectedinherited

The DL group

Definition at line 97 of file dl_algo.h.

Referenced by Botan::DL_Scheme_PublicKey::algorithm_identifier(), Botan::DL_Scheme_PublicKey::check_key(), Botan::DL_Scheme_PrivateKey::check_key(), Botan::DH_PrivateKey::DH_PrivateKey(), Botan::DH_PublicKey::DH_PublicKey(), Botan::DL_Scheme_PrivateKey::DL_Scheme_PrivateKey(), Botan::DSA_PrivateKey::DSA_PrivateKey(), Botan::DSA_PublicKey::DSA_PublicKey(), Botan::ElGamal_PrivateKey::ElGamal_PrivateKey(), Botan::DL_Scheme_PublicKey::estimated_strength(), and Botan::DL_Scheme_PublicKey::key_length().

◆ m_y

BigInt Botan::DL_Scheme_PublicKey::m_y

protectedinherited

The DL public key

Definition at line 92 of file dl_algo.h.

Referenced by Botan::DL_Scheme_PublicKey::check_key(), Botan::DL_Scheme_PrivateKey::check_key(), Botan::DH_PrivateKey::DH_PrivateKey(), Botan::DH_PublicKey::DH_PublicKey(), Botan::DSA_PrivateKey::DSA_PrivateKey(), Botan::DSA_PublicKey::DSA_PublicKey(), Botan::ElGamal_PrivateKey::ElGamal_PrivateKey(), Botan::DL_Scheme_PublicKey::public_key_bits(), and Botan::DH_PublicKey::public_value().

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

src/lib/pubkey/elgamal/elgamal.h
src/lib/pubkey/elgamal/elgamal.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ElGamal_PublicKey() [1/3]

◆ ElGamal_PublicKey() [2/3]

◆ ElGamal_PublicKey() [3/3]

Member Function Documentation

◆ algo_name()

◆ algorithm_identifier()

◆ check_key()

◆ create_encryption_op()

◆ create_kem_encryption_op()

◆ create_verification_op()

◆ default_x509_signature_format()

◆ estimated_strength()

◆ fingerprint_public()

◆ get_domain()

◆ get_group()

◆ get_oid()

◆ get_y()

◆ group_format()

◆ group_g()

◆ group_p()

◆ group_q()

◆ key_length()

◆ message_part_size()

◆ message_parts()

◆ public_key_bits()

◆ subject_public_key()

Member Data Documentation

◆ m_group

◆ m_y