Botan::OAEP Class Reference

#include <oaep.h>

Inheritance diagram for Botan::OAEP:

Public Member Functions
secure_vector< uint8_t >	encode (const secure_vector< uint8_t > &in, size_t key_length, RandomNumberGenerator &rng) const
secure_vector< uint8_t >	encode (const uint8_t in[], size_t in_length, size_t key_length, RandomNumberGenerator &rng) const
size_t	maximum_input_size (size_t) const override
	OAEP (std::unique_ptr< HashFunction > hash, std::string_view P="")
	OAEP (std::unique_ptr< HashFunction > hash, std::unique_ptr< HashFunction > mgf1_hash, std::string_view P="")

Static Public Member Functions
static std::unique_ptr< EME >	create (std::string_view algo_spec)

Detailed Description

OAEP (called EME1 in IEEE 1363 and in earlier versions of the library) as specified in PKCS#1 v2.0 (RFC 2437) or PKCS#1 v2.1 (RFC 3447)

Definition at line 20 of file oaep.h.

Constructor & Destructor Documentation

OAEP() [1/2]

Botan::OAEP::OAEP	(	std::unique_ptr< HashFunction >	hash,
		std::string_view	P = ""
	)

Parameters

hash	function to use for hashing (takes ownership)
P	an optional label. Normally empty.

Definition at line 152 of file oaep.cpp.

                             :
   m_mgf1_hash(std::move(hash))
   {
   m_Phash = m_mgf1_hash->process(P);
   }

OAEP() [2/2]

Botan::OAEP::OAEP	(	std::unique_ptr< HashFunction >	hash,
		std::unique_ptr< HashFunction >	mgf1_hash,
		std::string_view	P = ""
	)

Parameters

hash	function to use for hashing (takes ownership)
mgf1_hash	function to use for MGF1 (takes ownership)
P	an optional label. Normally empty.

Definition at line 159 of file oaep.cpp.

                             :
   m_mgf1_hash(std::move(mgf1_hash))
   {
   auto phash = std::move(hash);
   m_Phash = phash->process(P);
   }

Member Function Documentation

create()

std::unique_ptr< EME > Botan::EME::create ( std::string_view  algo_spec )

staticinherited

Factory method for EME (message-encoding methods for encryption) objects

Parameters

algo_spec

the name of the EME to create

Returns

pointer to newly allocated object of that type

Definition at line 27 of file eme.cpp.

   {
#if defined(BOTAN_HAS_EME_RAW)
   if(algo_spec == "Raw")
      return std::make_unique<EME_Raw>();
#endif
 
#if defined(BOTAN_HAS_EME_PKCS1)
   if(algo_spec == "PKCS1v15" || algo_spec == "EME-PKCS1-v1_5")
      return std::make_unique<EME_PKCS1v15>();
#endif
 
#if defined(BOTAN_HAS_EME_OAEP)
   SCAN_Name req(algo_spec);
 
   if(req.algo_name() == "OAEP" ||
      req.algo_name() == "EME-OAEP" ||
      req.algo_name() == "EME1")
      {
      if(req.arg_count() == 1 ||
         ((req.arg_count() == 2 || req.arg_count() == 3) && req.arg(1) == "MGF1"))
         {
         if(auto hash = HashFunction::create(req.arg(0)))
            return std::make_unique<OAEP>(std::move(hash), req.arg(2, ""));
         }
      else if(req.arg_count() == 2 || req.arg_count() == 3)
         {
         auto mgf_params = parse_algorithm_name(req.arg(1));
 
         if(mgf_params.size() == 2 && mgf_params[0] == "MGF1")
            {
            auto hash = HashFunction::create(req.arg(0));
            auto mgf1_hash = HashFunction::create(mgf_params[1]);
 
            if(hash && mgf1_hash)
               {
               return std::make_unique<OAEP>(std::move(hash),
                                             std::move(mgf1_hash),
                                             req.arg(2, ""));
               }
            }
         }
      }
#endif
 
   throw Algorithm_Not_Found(algo_spec);
   }

References Botan::SCAN_Name::algo_name(), Botan::SCAN_Name::arg(), Botan::SCAN_Name::arg_count(), Botan::HashFunction::create(), and Botan::parse_algorithm_name().

encode() [1/2]

secure_vector< uint8_t > Botan::EME::encode ( const secure_vector< uint8_t > &  in, size_t  key_length, RandomNumberGenerator &  rng  ) const

inherited

Encode an input

Parameters

in	the plaintext
key_length	length of the key in bits
rng	a random number generator

Returns

encoded plaintext

Definition at line 88 of file eme.cpp.

   {
   return pad(msg.data(), msg.size(), key_bits, rng);
   }

References Botan::EME::pad().

encode() [2/2]

secure_vector< uint8_t > Botan::EME::encode ( const uint8_t  in[], size_t  in_length, size_t  key_length, RandomNumberGenerator &  rng  ) const

inherited

Encode an input

Parameters

in	the plaintext
in_length	length of plaintext in bytes
key_length	length of the key in bits
rng	a random number generator

Returns

encoded plaintext

Definition at line 78 of file eme.cpp.

   {
   return pad(msg, msg_len, key_bits, rng);
   }

References Botan::EME::pad().

maximum_input_size()

size_t Botan::OAEP::maximum_input_size ( size_t  keybits ) const

overridevirtual

Return the maximum input size in bytes we can support

Parameters

keybits

the size of the key in bits

Returns

upper bound of input in bytes

Implements Botan::EME.

Definition at line 144 of file oaep.cpp.

   {
   if(keybits / 8 > 2*m_Phash.size() + 1)
      return ((keybits / 8) - 2*m_Phash.size() - 1);
   else
      return 0;
   }

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

• src/lib/pk_pad/eme_oaep/oaep.h
• src/lib/pk_pad/eme_oaep/oaep.cpp