Botan  1.10.9
Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
Botan::ElGamal_PrivateKey Class Reference

#include <elgamal.h>

Inheritance diagram for Botan::ElGamal_PrivateKey:
Botan::ElGamal_PublicKey Botan::DL_Scheme_PrivateKey Botan::DL_Scheme_PublicKey Botan::DL_Scheme_PublicKey Botan::Private_Key Botan::Public_Key Botan::Public_Key Botan::Public_Key

Public Member Functions

std::string algo_name () const
 
AlgorithmIdentifier algorithm_identifier () const
 
bool check_key (RandomNumberGenerator &rng, bool) const
 
 ElGamal_PrivateKey (const AlgorithmIdentifier &alg_id, const MemoryRegion< byte > &key_bits, RandomNumberGenerator &rng)
 
 ElGamal_PrivateKey (RandomNumberGenerator &rng, const DL_Group &group, const BigInt &priv_key=0)
 
const DL_Groupget_domain () const
 
virtual OID get_oid () const
 
const BigIntget_x () const
 
const BigIntget_y () const
 
DL_Group::Format group_format () const
 
const BigIntgroup_g () const
 
const BigIntgroup_p () const
 
const BigIntgroup_q () const
 
size_t max_input_bits () const
 
virtual size_t message_part_size () const
 
virtual size_t message_parts () const
 
virtual AlgorithmIdentifier pkcs8_algorithm_identifier () const
 
MemoryVector< bytepkcs8_private_key () const
 
MemoryVector< bytex509_subject_public_key () const
 

Protected Member Functions

void gen_check (RandomNumberGenerator &rng) const
 
virtual void load_check (RandomNumberGenerator &rng) const
 
void load_check (RandomNumberGenerator &rng) const
 

Protected Attributes

DL_Group group
 
BigInt x
 
BigInt y
 

Detailed Description

ElGamal Private Key

Definition at line 43 of file elgamal.h.

Constructor & Destructor Documentation

Botan::ElGamal_PrivateKey::ElGamal_PrivateKey ( const AlgorithmIdentifier alg_id,
const MemoryRegion< byte > &  key_bits,
RandomNumberGenerator rng 
)

Definition at line 46 of file elgamal.cpp.

References Botan::DL_Scheme_PublicKey::group_g(), Botan::DL_Scheme_PublicKey::group_p(), Botan::Private_Key::load_check(), Botan::power_mod(), Botan::DL_Scheme_PrivateKey::x, and Botan::DL_Scheme_PublicKey::y.

48  :
50  {
51  y = power_mod(group_g(), x, group_p());
52  load_check(rng);
53  }
void load_check(RandomNumberGenerator &rng) const
Definition: pk_keys.cpp:40
const BigInt & group_p() const
Definition: dl_algo.h:44
RandomNumberGenerator * rng
Definition: global_rng.cpp:165
BigInt power_mod(const BigInt &base, const BigInt &exp, const BigInt &mod)
Definition: numthry.cpp:251
const BigInt & group_g() const
Definition: dl_algo.h:56
Botan::ElGamal_PrivateKey::ElGamal_PrivateKey ( RandomNumberGenerator rng,
const DL_Group group,
const BigInt priv_key = 0 
)

Definition at line 28 of file elgamal.cpp.

References Botan::dl_work_factor(), Botan::Private_Key::gen_check(), Botan::DL_Scheme_PublicKey::group, Botan::DL_Scheme_PublicKey::group_g(), Botan::DL_Scheme_PublicKey::group_p(), Botan::Private_Key::load_check(), Botan::power_mod(), Botan::BigInt::randomize(), Botan::DL_Scheme_PrivateKey::x, and Botan::DL_Scheme_PublicKey::y.

31  {
32  group = grp;
33  x = x_arg;
34 
35  if(x == 0)
36  x.randomize(rng, 2 * dl_work_factor(group_p().bits()));
37 
38  y = power_mod(group_g(), x, group_p());
39 
40  if(x_arg == 0)
41  gen_check(rng);
42  else
43  load_check(rng);
44  }
void load_check(RandomNumberGenerator &rng) const
Definition: pk_keys.cpp:40
const BigInt & group_p() const
Definition: dl_algo.h:44
RandomNumberGenerator * rng
Definition: global_rng.cpp:165
void randomize(RandomNumberGenerator &rng, size_t bitsize=0)
Definition: big_rand.cpp:29
BigInt power_mod(const BigInt &base, const BigInt &exp, const BigInt &mod)
Definition: numthry.cpp:251
const BigInt & group_g() const
Definition: dl_algo.h:56
size_t dl_work_factor(size_t bits)
Definition: workfactor.cpp:14
void gen_check(RandomNumberGenerator &rng) const
Definition: pk_keys.cpp:49

Member Function Documentation

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

Get the name of the underlying public key scheme.

Returns
name of the public key scheme

Implements Botan::Public_Key.

Definition at line 25 of file elgamal.h.

25 { return "ElGamal"; }
AlgorithmIdentifier Botan::DL_Scheme_PublicKey::algorithm_identifier ( ) const
virtualinherited
Returns
X.509 AlgorithmIdentifier for this key

Implements Botan::Public_Key.

Definition at line 15 of file dl_algo.cpp.

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

16  {
17  return AlgorithmIdentifier(get_oid(),
19  }
virtual OID get_oid() const
Definition: pk_keys.cpp:17
SecureVector< byte > DER_encode(Format format) const
Definition: dl_group.cpp:205
virtual DL_Group::Format group_format() const =0
bool Botan::ElGamal_PrivateKey::check_key ( RandomNumberGenerator rng,
bool  strong 
) const
virtual

Test the key values for consistency.

Parameters
rngrng to use
strongwhether to perform strong and lengthy version of the test
Returns
true if the test is passed

Reimplemented from Botan::DL_Scheme_PrivateKey.

Definition at line 58 of file elgamal.cpp.

References Botan::DL_Scheme_PrivateKey::check_key(), and Botan::KeyPair::encryption_consistency_check().

60  {
62  return false;
63 
64  if(!strong)
65  return true;
66 
67  return KeyPair::encryption_consistency_check(rng, *this, "EME1(SHA-1)");
68  }
bool check_key(RandomNumberGenerator &rng, bool) const
Definition: dl_algo.cpp:67
RandomNumberGenerator * rng
Definition: global_rng.cpp:165
bool encryption_consistency_check(RandomNumberGenerator &rng, const Private_Key &key, const std::string &padding)
Definition: keypair.cpp:18
void Botan::Private_Key::gen_check ( RandomNumberGenerator rng) const
protectedinherited

Self-test after generating a key

Parameters
rnga random number generator

Definition at line 49 of file pk_keys.cpp.

References Botan::Public_Key::algo_name(), and Botan::Public_Key::check_key().

Referenced by Botan::DH_PrivateKey::DH_PrivateKey(), Botan::DSA_PrivateKey::DSA_PrivateKey(), ElGamal_PrivateKey(), Botan::NR_PrivateKey::NR_PrivateKey(), Botan::RSA_PrivateKey::RSA_PrivateKey(), and Botan::RW_PrivateKey::RW_PrivateKey().

50  {
51  if(!check_key(rng, BOTAN_PRIVATE_KEY_STRONG_CHECKS_ON_GENERATE))
52  throw Self_Test_Failure(algo_name() + " private key generation failed");
53  }
virtual bool check_key(RandomNumberGenerator &rng, bool strong) const =0
virtual std::string algo_name() const =0
RandomNumberGenerator * rng
Definition: global_rng.cpp:165
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 33 of file dl_algo.h.

Referenced by Botan::Server_Key_Exchange::Server_Key_Exchange().

33 { return group; }
OID Botan::Public_Key::get_oid ( ) const
virtualinherited

Get the OID of the underlying public key scheme.

Returns
OID of the public key scheme

Definition at line 17 of file pk_keys.cpp.

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

Referenced by Botan::DL_Scheme_PublicKey::algorithm_identifier(), Botan::IF_Scheme_PublicKey::algorithm_identifier(), Botan::GOST_3410_PublicKey::algorithm_identifier(), and Botan::EC_PublicKey::algorithm_identifier().

18  {
19  try {
20  return OIDS::lookup(algo_name());
21  }
22  catch(Lookup_Error)
23  {
24  throw Lookup_Error("PK algo " + algo_name() + " has no defined OIDs");
25  }
26  }
virtual std::string algo_name() const =0
std::string lookup(const OID &oid)
Definition: oids.cpp:31
const BigInt& Botan::DL_Scheme_PrivateKey::get_x ( ) const
inlineinherited

Get the secret key x.

Returns
secret key

Definition at line 95 of file dl_algo.h.

Referenced by Botan::ElGamal_Decryption_Operation::ElGamal_Decryption_Operation().

95 { return x; }
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 38 of file dl_algo.h.

Referenced by Botan::ElGamal_Encryption_Operation::ElGamal_Encryption_Operation().

38 { return y; }
DL_Group::Format Botan::ElGamal_PublicKey::group_format ( ) const
inlinevirtualinherited

Get the underlying groups encoding format.

Returns
encoding format

Implements Botan::DL_Scheme_PublicKey.

Definition at line 26 of file elgamal.h.

References Botan::DL_Group::ANSI_X9_42.

const BigInt& Botan::DL_Scheme_PublicKey::group_g ( ) const
inlineinherited
const BigInt& Botan::DL_Scheme_PublicKey::group_p ( ) const
inlineinherited
const BigInt& Botan::DL_Scheme_PublicKey::group_q ( ) const
inlineinherited
void Botan::Public_Key::load_check ( RandomNumberGenerator rng) const
protectedvirtualinherited

Self-test after loading a key

Parameters
rnga random number generator

Reimplemented in Botan::Private_Key.

Definition at line 31 of file pk_keys.cpp.

References Botan::Public_Key::algo_name(), and Botan::Public_Key::check_key().

32  {
33  if(!check_key(rng, BOTAN_PUBLIC_KEY_STRONG_CHECKS_ON_LOAD))
34  throw Invalid_Argument(algo_name() + ": Invalid public key");
35  }
virtual bool check_key(RandomNumberGenerator &rng, bool strong) const =0
virtual std::string algo_name() const =0
std::invalid_argument Invalid_Argument
Definition: exceptn.h:20
RandomNumberGenerator * rng
Definition: global_rng.cpp:165
void Botan::Private_Key::load_check ( RandomNumberGenerator rng) const
protectedvirtualinherited

Self-test after loading a key

Parameters
rnga random number generator

Reimplemented from Botan::Public_Key.

Definition at line 40 of file pk_keys.cpp.

References Botan::Public_Key::algo_name(), and Botan::Public_Key::check_key().

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

41  {
42  if(!check_key(rng, BOTAN_PRIVATE_KEY_STRONG_CHECKS_ON_LOAD))
43  throw Invalid_Argument(algo_name() + ": Invalid private key");
44  }
virtual bool check_key(RandomNumberGenerator &rng, bool strong) const =0
virtual std::string algo_name() const =0
std::invalid_argument Invalid_Argument
Definition: exceptn.h:20
RandomNumberGenerator * rng
Definition: global_rng.cpp:165
size_t Botan::ElGamal_PublicKey::max_input_bits ( ) const
inlinevirtualinherited

Get the maximum message size in bits supported by this public key.

Returns
maximum message size in bits

Implements Botan::Public_Key.

Definition at line 28 of file elgamal.h.

28 { return (group_p().bits() - 1); }
const BigInt & group_p() const
Definition: dl_algo.h:44
virtual size_t Botan::Public_Key::message_part_size ( ) const
inlinevirtualinherited

Find out the message part size supported by this scheme/key.

Returns
size of the message parts in bits

Reimplemented in Botan::GOST_3410_PublicKey, Botan::ECDSA_PublicKey, Botan::NR_PublicKey, and Botan::DSA_PublicKey.

Definition at line 56 of file pk_keys.h.

56 { return 0; }
virtual size_t Botan::Public_Key::message_parts ( ) const
inlinevirtualinherited

Find out the number of message parts supported by this scheme.

Returns
number of message parts

Reimplemented in Botan::GOST_3410_PublicKey, Botan::ECDSA_PublicKey, Botan::NR_PublicKey, and Botan::DSA_PublicKey.

Definition at line 50 of file pk_keys.h.

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

50 { return 1; }
virtual AlgorithmIdentifier Botan::Private_Key::pkcs8_algorithm_identifier ( ) const
inlinevirtualinherited
Returns
PKCS #8 AlgorithmIdentifier for this key Might be different from the X.509 identifier, but normally is not

Reimplemented in Botan::GOST_3410_PrivateKey.

Definition at line 98 of file pk_keys.h.

Referenced by Botan::PKCS8::BER_encode().

99  { return algorithm_identifier(); }
virtual AlgorithmIdentifier algorithm_identifier() const =0
MemoryVector< byte > Botan::DL_Scheme_PrivateKey::pkcs8_private_key ( ) const
virtualinherited
Returns
PKCS #8 private key encoding for this key object

Implements Botan::Private_Key.

Definition at line 36 of file dl_algo.cpp.

References Botan::DER_Encoder::encode(), Botan::DER_Encoder::get_contents(), and Botan::DL_Scheme_PrivateKey::x.

37  {
38  return DER_Encoder().encode(x).get_contents();
39  }
MemoryVector< byte > Botan::DL_Scheme_PublicKey::x509_subject_public_key ( ) const
virtualinherited
Returns
X.509 subject key encoding for this key object

Implements Botan::Public_Key.

Definition at line 21 of file dl_algo.cpp.

References Botan::DER_Encoder::encode(), Botan::DER_Encoder::get_contents(), and Botan::DL_Scheme_PublicKey::y.

22  {
23  return DER_Encoder().encode(y).get_contents();
24  }

Member Data Documentation

DL_Group Botan::DL_Scheme_PublicKey::group
protectedinherited
BigInt Botan::DL_Scheme_PrivateKey::x
protectedinherited
BigInt Botan::DL_Scheme_PublicKey::y
protectedinherited

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