Botan::X942_PRF Class Reference

#include <prf_x942.h>

Inheritance diagram for Botan::X942_PRF:

Public Member Functions
void	clear ()
KDF *	clone () const
SecureVector< byte >	derive (size_t, const byte[], size_t, const byte[], size_t) const
SecureVector< byte >	derive_key (size_t key_len, const byte secret[], size_t secret_len, const byte salt[], size_t salt_len) const
SecureVector< byte >	derive_key (size_t key_len, const byte secret[], size_t secret_len, const std::string &salt="") const
SecureVector< byte >	derive_key (size_t key_len, const MemoryRegion< byte > &secret, const byte salt[], size_t salt_len) const
SecureVector< byte >	derive_key (size_t key_len, const MemoryRegion< byte > &secret, const MemoryRegion< byte > &salt) const
SecureVector< byte >	derive_key (size_t key_len, const MemoryRegion< byte > &secret, const std::string &salt="") const
std::string	name () const
	X942_PRF (const std::string &oid)

Detailed Description

PRF from ANSI X9.42

Definition at line 18 of file prf_x942.h.

Constructor & Destructor Documentation

X942_PRF()

Botan::X942_PRF::X942_PRF

(

const std::string &

oid

)

Definition at line 84 of file prf_x942.cpp.

   {
   if(OIDS::have_oid(oid))
      key_wrap_oid = OIDS::lookup(oid).as_string();
   else
      key_wrap_oid = oid;
   }

References Botan::OIDS::have_oid(), and Botan::OIDS::lookup().

Referenced by clone(), and Botan::get_kdf().

Member Function Documentation

clear()

void Botan::KDF::clear ( )

inlinevirtualinherited

Zeroize internal state

Implements Botan::Algorithm.

Definition at line 81 of file kdf.h.

{}

clone()

KDF * Botan::X942_PRF::clone ( ) const

inlinevirtual

Implements Botan::KDF.

Definition at line 25 of file prf_x942.h.

{ return new X942_PRF(key_wrap_oid); }

References X942_PRF().

derive()

SecureVector< byte > Botan::X942_PRF::derive ( size_t key_len, const byte secret[], size_t secret_len, const byte salt[], size_t salt_len ) const

virtual

Implements Botan::KDF.

Definition at line 35 of file prf_x942.cpp.

   {
   SHA_160 hash;
   const OID kek_algo(key_wrap_oid);
 
   SecureVector<byte> key;
   u32bit counter = 1;
 
   while(key.size() != key_len && counter)
      {
      hash.update(secret, secret_len);
 
      hash.update(
         DER_Encoder().start_cons(SEQUENCE)
 
            .start_cons(SEQUENCE)
               .encode(kek_algo)
               .raw_bytes(encode_x942_int(counter))
            .end_cons()
 
            .encode_if(salt_len != 0,
               DER_Encoder()
                  .start_explicit(0)
                     .encode(salt, salt_len, OCTET_STRING)
                  .end_explicit()
               )
 
            .start_explicit(2)
               .raw_bytes(encode_x942_int(static_cast<u32bit>(8 * key_len)))
            .end_explicit()
 
         .end_cons().get_contents()
         );
 
      SecureVector<byte> digest = hash.final();
      const size_t needed = std::min(digest.size(), key_len - key.size());
      key += std::make_pair(&digest[0], needed);
 
      ++counter;
      }
 
   return key;
   }

References Botan::Buffered_Computation::final(), Botan::OCTET_STRING, Botan::SEQUENCE, Botan::MemoryRegion< T >::size(), and Botan::Buffered_Computation::update().

derive_key() [1/5]

SecureVector< byte > Botan::KDF::derive_key ( size_t key_len, const byte secret[], size_t secret_len, const byte salt[], size_t salt_len ) const

inherited

Derive a key

Parameters

key_len	the desired output length in bytes
secret	the secret input
secret_len	size of secret in bytes
salt	a diversifier
salt_len	size of salt in bytes

Definition at line 61 of file kdf.cpp.

   {
   return derive(key_len, secret, secret_len, salt, salt_len);
   }

derive_key() [2/5]

SecureVector< byte > Botan::KDF::derive_key ( size_t key_len, const byte secret[], size_t secret_len, const std::string & salt = "" ) const

inherited

Derive a key

Parameters

key_len	the desired output length in bytes
secret	the secret input
secret_len	size of secret in bytes
salt	a diversifier

Definition at line 49 of file kdf.cpp.

   {
   return derive_key(key_len, secret, secret_len,
                     reinterpret_cast<const byte*>(salt.data()),
                     salt.length());
   }

References derive_key().

derive_key() [3/5]

SecureVector< byte > Botan::KDF::derive_key ( size_t key_len, const MemoryRegion< byte > & secret, const byte salt[], size_t salt_len ) const

inherited

Derive a key

Parameters

key_len	the desired output length in bytes
secret	the secret input
salt	a diversifier
salt_len	size of salt in bytes

Definition at line 27 of file kdf.cpp.

   {
   return derive_key(key_len, &secret[0], secret.size(),
                     salt, salt_len);
   }

References derive_key(), and Botan::MemoryRegion< T >::size().

derive_key() [4/5]

SecureVector< byte > Botan::KDF::derive_key ( size_t key_len, const MemoryRegion< byte > & secret, const MemoryRegion< byte > & salt ) const

inherited

Derive a key

Parameters

key_len	the desired output length in bytes
secret	the secret input
salt	a diversifier

Definition at line 38 of file kdf.cpp.

   {
   return derive_key(key_len, &secret[0], secret.size(),
                     &salt[0], salt.size());
   }

References derive_key(), and Botan::MemoryRegion< T >::size().

derive_key() [5/5]

SecureVector< byte > Botan::KDF::derive_key ( size_t key_len, const MemoryRegion< byte > & secret, const std::string & salt = "" ) const

inherited

Derive a key

Parameters

key_len	the desired output length in bytes
secret	the secret input
salt	a diversifier

Definition at line 15 of file kdf.cpp.

   {
   return derive_key(key_len, &secret[0], secret.size(),
                     reinterpret_cast<const byte*>(salt.data()),
                     salt.length());
   }

References derive_key(), and Botan::MemoryRegion< T >::size().

Referenced by derive_key(), derive_key(), derive_key(), and derive_key().

name()

std::string Botan::X942_PRF::name ( ) const

inlinevirtual

Returns

name of this algorithm

Implements Botan::Algorithm.

Definition at line 24 of file prf_x942.h.

{ return "X942_PRF(" + key_wrap_oid + ")"; }

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

• src/kdf/prf_x942/prf_x942.h
• src/kdf/prf_x942/prf_x942.cpp