Botan  2.4.0
Crypto and TLS for C++11
Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
Botan::RSA_PublicKey Class Reference

#include <rsa.h>

Inheritance diagram for Botan::RSA_PublicKey:
Botan::Public_Key Botan::RSA_PrivateKey

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::Encryptioncreate_encryption_op (RandomNumberGenerator &rng, const std::string &params, const std::string &provider) const override
 
std::unique_ptr< PK_Ops::KEM_Encryptioncreate_kem_encryption_op (RandomNumberGenerator &rng, const std::string &params, const std::string &provider) const override
 
std::unique_ptr< PK_Ops::Verificationcreate_verification_op (const std::string &params, const std::string &provider) const override
 
size_t estimated_strength () const override
 
std::string fingerprint_public (const std::string &alg="SHA-256") const
 
const BigIntget_e () const
 
const BigIntget_n () const
 
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
 
 RSA_PublicKey (const AlgorithmIdentifier &alg_id, const std::vector< uint8_t > &key_bits)
 
 RSA_PublicKey (const BigInt &n, const BigInt &e)
 
std::vector< uint8_t > subject_public_key () const
 

Protected Member Functions

 RSA_PublicKey ()=default
 

Protected Attributes

BigInt m_e
 
BigInt m_n
 

Detailed Description

RSA Public Key

Definition at line 19 of file rsa.h.

Constructor & Destructor Documentation

◆ RSA_PublicKey() [1/3]

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

Load a public key.

Parameters
alg_idthe X.509 algorithm identifier
key_bitsDER encoded public key bits

Definition at line 54 of file rsa.cpp.

References Botan::BER_Decoder::decode(), Botan::BER_Decoder::end_cons(), m_e, m_n, Botan::SEQUENCE, and Botan::BER_Decoder::start_cons().

56  {
57  BER_Decoder(key_bits)
58  .start_cons(SEQUENCE)
59  .decode(m_n)
60  .decode(m_e)
61  .end_cons();
62  }
BigInt m_e
Definition: rsa.h:76
BigInt m_n
Definition: rsa.h:76

◆ RSA_PublicKey() [2/3]

Botan::RSA_PublicKey::RSA_PublicKey ( const BigInt n,
const BigInt e 
)
inline

Create a public key.

  • n the modulus
  • e the exponent

Definition at line 35 of file rsa.h.

35  :
36  m_n(n), m_e(e) {}
BigInt m_e
Definition: rsa.h:76
BigInt m_n
Definition: rsa.h:76

◆ RSA_PublicKey() [3/3]

Botan::RSA_PublicKey::RSA_PublicKey ( )
protecteddefault

Member Function Documentation

◆ algo_name()

std::string Botan::RSA_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 38 of file rsa.h.

Referenced by Botan::RSA_PrivateKey::create_decryption_op(), create_encryption_op(), Botan::RSA_PrivateKey::create_kem_decryption_op(), create_kem_encryption_op(), Botan::RSA_PrivateKey::create_signature_op(), create_verification_op(), and Botan::RSA_PrivateKey::RSA_PrivateKey().

38 { return "RSA"; }

◆ algorithm_identifier()

AlgorithmIdentifier Botan::RSA_PublicKey::algorithm_identifier ( ) const
overridevirtual
Returns
X.509 AlgorithmIdentifier for this key

Implements Botan::Public_Key.

Definition at line 38 of file rsa.cpp.

References Botan::Public_Key::get_oid(), and Botan::AlgorithmIdentifier::USE_NULL_PARAM.

39  {
40  return AlgorithmIdentifier(get_oid(),
42  }
virtual OID get_oid() const
Definition: pk_keys.cpp:51

◆ check_key()

bool Botan::RSA_PublicKey::check_key ( RandomNumberGenerator rng,
bool  strong 
) const
overridevirtual

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

Implements Botan::Public_Key.

Reimplemented in Botan::RSA_PrivateKey.

Definition at line 67 of file rsa.cpp.

References Botan::BigInt::is_even(), m_e, and m_n.

68  {
69  if(m_n < 35 || m_n.is_even() || m_e < 2)
70  return false;
71  return true;
72  }
bool is_even() const
Definition: bigint.h:237
BigInt m_e
Definition: rsa.h:76
BigInt m_n
Definition: rsa.h:76

◆ create_encryption_op()

std::unique_ptr< PK_Ops::Encryption > Botan::RSA_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
rnga 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.
paramsadditional parameters
providerthe provider to use

Reimplemented from Botan::Public_Key.

Definition at line 407 of file rsa.cpp.

References algo_name(), and Botan::Exception::what().

410  {
411 #if defined(BOTAN_HAS_OPENSSL)
412  if(provider == "openssl" || provider.empty())
413  {
414  try
415  {
416  return make_openssl_rsa_enc_op(*this, params);
417  }
418  catch(Exception& e)
419  {
420  /*
421  * If OpenSSL for some reason could not handle this (eg due to OAEP params),
422  * throw if openssl was specifically requested but otherwise just fall back
423  * to the normal version.
424  */
425  if(provider == "openssl")
426  throw Exception("OpenSSL RSA provider rejected key:", e.what());
427  }
428  }
429 #endif
430 
431  if(provider == "base" || provider.empty())
432  return std::unique_ptr<PK_Ops::Encryption>(new RSA_Encryption_Operation(*this, params));
433  throw Provider_Not_Found(algo_name(), provider);
434  }
std::string algo_name() const override
Definition: rsa.h:38

◆ create_kem_encryption_op()

std::unique_ptr< PK_Ops::KEM_Encryption > Botan::RSA_PublicKey::create_kem_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 a KEM encryption operation for this key/params or throw

Parameters
rnga 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.
paramsadditional parameters
providerthe provider to use

Reimplemented from Botan::Public_Key.

Definition at line 437 of file rsa.cpp.

References algo_name().

440  {
441  if(provider == "base" || provider.empty())
442  return std::unique_ptr<PK_Ops::KEM_Encryption>(new RSA_KEM_Encryption_Operation(*this, params));
443  throw Provider_Not_Found(algo_name(), provider);
444  }
std::string algo_name() const override
Definition: rsa.h:38

◆ create_verification_op()

std::unique_ptr< PK_Ops::Verification > Botan::RSA_PublicKey::create_verification_op ( 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 a verification operation for this key/params or throw

Parameters
paramsadditional parameters
providerthe provider to use

Reimplemented from Botan::Public_Key.

Definition at line 447 of file rsa.cpp.

References algo_name().

449  {
450 #if defined(BOTAN_HAS_OPENSSL)
451  if(provider == "openssl" || provider.empty())
452  {
453  std::unique_ptr<PK_Ops::Verification> res = make_openssl_rsa_ver_op(*this, params);
454  if(res)
455  return res;
456  }
457 #endif
458 
459  if(provider == "base" || provider.empty())
460  return std::unique_ptr<PK_Ops::Verification>(new RSA_Verify_Operation(*this, params));
461 
462  throw Provider_Not_Found(algo_name(), provider);
463  }
std::string algo_name() const override
Definition: rsa.h:38

◆ estimated_strength()

size_t Botan::RSA_PublicKey::estimated_strength ( ) const
overridevirtual

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 33 of file rsa.cpp.

References Botan::if_work_factor(), and key_length().

34  {
35  return if_work_factor(key_length());
36  }
size_t if_work_factor(size_t bits)
Definition: workfactor.cpp:19
size_t key_length() const override
Definition: rsa.cpp:28

◆ 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 78 of file pk_keys.cpp.

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

79  {
81  }
AlgorithmIdentifier hash_algo
Definition: x509_obj.cpp:22
std::string create_hex_fingerprint(const uint8_t bits[], size_t bits_len, const std::string &hash_name)
Definition: pk_keys.cpp:17
std::vector< uint8_t > subject_public_key() const
Definition: pk_keys.cpp:38

◆ get_e()

const BigInt& Botan::RSA_PublicKey::get_e ( ) const
inline
Returns
public exponent

Definition at line 54 of file rsa.h.

Referenced by Botan::RSA_PrivateKey::check_key().

54 { return m_e; }
BigInt m_e
Definition: rsa.h:76

◆ get_n()

const BigInt& Botan::RSA_PublicKey::get_n ( ) const
inline
Returns
public modulus

Definition at line 49 of file rsa.h.

References m_n.

Referenced by Botan::RSA_PrivateKey::check_key().

49 { return m_n; }
BigInt m_n
Definition: rsa.h:76

◆ 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 51 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::Ed25519_PublicKey::algorithm_identifier(), Botan::McEliece_PublicKey::algorithm_identifier(), algorithm_identifier(), Botan::GOST_3410_PublicKey::algorithm_identifier(), Botan::EC_PublicKey::algorithm_identifier(), Botan::TPM_PrivateKey::algorithm_identifier(), Botan::EC_PublicKey::EC_PublicKey(), and Botan::XMSS_WOTS_Addressed_PublicKey::get_oid().

52  {
53  try {
54  return OIDS::lookup(algo_name());
55  }
56  catch(Lookup_Error&)
57  {
58  throw Lookup_Error("PK algo " + algo_name() + " has no defined OIDs");
59  }
60  }
virtual std::string algo_name() const =0
std::string lookup(const OID &oid)
Definition: oids.cpp:18

◆ key_length()

size_t Botan::RSA_PublicKey::key_length ( ) const
overridevirtual

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 28 of file rsa.cpp.

References Botan::BigInt::bits(), and m_n.

Referenced by estimated_strength().

29  {
30  return m_n.bits();
31  }
size_t bits() const
Definition: bigint.cpp:183
BigInt m_n
Definition: rsa.h:76

◆ 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, Botan::SM2_Signature_PublicKey, and Botan::DSA_PublicKey.

Definition at line 118 of file pk_keys.h.

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

118 { 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, Botan::SM2_Signature_PublicKey, and Botan::DSA_PublicKey.

Definition at line 107 of file pk_keys.h.

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

107 { return 1; }

◆ public_key_bits()

std::vector< uint8_t > Botan::RSA_PublicKey::public_key_bits ( ) const
overridevirtual
Returns
BER encoded public key bits

Implements Botan::Public_Key.

Definition at line 44 of file rsa.cpp.

References Botan::DER_Encoder::encode(), Botan::DER_Encoder::end_cons(), Botan::DER_Encoder::get_contents_unlocked(), m_e, m_n, Botan::SEQUENCE, and Botan::DER_Encoder::start_cons().

45  {
46  return DER_Encoder()
47  .start_cons(SEQUENCE)
48  .encode(m_n)
49  .encode(m_e)
50  .end_cons()
51  .get_contents_unlocked();
52  }
BigInt m_e
Definition: rsa.h:76
BigInt m_n
Definition: rsa.h:76

◆ 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.

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(), Botan::Public_Key::fingerprint_public(), and Botan::X509::PEM_encode().

39  {
40  return DER_Encoder()
41  .start_cons(SEQUENCE)
42  .encode(algorithm_identifier())
43  .encode(public_key_bits(), BIT_STRING)
44  .end_cons()
45  .get_contents_unlocked();
46  }
virtual std::vector< uint8_t > public_key_bits() const =0
virtual AlgorithmIdentifier algorithm_identifier() const =0

Member Data Documentation

◆ m_e

BigInt Botan::RSA_PublicKey::m_e
protected

◆ m_n

BigInt Botan::RSA_PublicKey::m_n
protected

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