#include <pgp_s2k.h>

Inheritance diagram for Botan::OpenPGP_S2K:

Public Member Functions
void	clear ()
PBKDF *	clone () const
OctetString	derive_key (size_t output_len, const std::string &passphrase, const byte salt[], size_t salt_len, size_t iterations) const
std::string	name () const
	OpenPGP_S2K (HashFunction *hash_in)
	~OpenPGP_S2K ()

Detailed Description

OpenPGP's S2K

Definition at line 19 of file pgp_s2k.h.

Constructor & Destructor Documentation

◆ OpenPGP_S2K()

Botan::OpenPGP_S2K::OpenPGP_S2K ( HashFunction * hash_in )

inline

Parameters

hash_in the hash function to use

Definition at line 25 of file pgp_s2k.h.

25: hash(hash_in) {}

Referenced by clone(), and Botan::Core_Engine::find_pbkdf().

◆ ~OpenPGP_S2K()

Botan::OpenPGP_S2K::~OpenPGP_S2K ( )

inline

Definition at line 27 of file pgp_s2k.h.

27{ delete hash; }

Member Function Documentation

◆ clear()

void Botan::PBKDF::clear ( )

inlinevirtualinherited

Zeroize internal state

Implements Botan::Algorithm.

Definition at line 30 of file pbkdf.h.

30{}

◆ clone()

PBKDF * Botan::OpenPGP_S2K::clone ( ) const

inlinevirtual

Returns: new instance of this same algorithm

Implements Botan::PBKDF.

Definition at line 34 of file pgp_s2k.h.

         {
         return new OpenPGP_S2K(hash->clone());
         }

References OpenPGP_S2K().

◆ derive_key()

OctetString Botan::OpenPGP_S2K::derive_key	(	size_t	output_len,
		const std::string &	passphrase,
		const byte	salt[],
		size_t	salt_len,
		size_t	iterations ) const

virtual

Derive a key from a passphrase

Parameters

output_len	the desired length of the key to produce
passphrase	the password to derive the key from
salt	a randomly chosen salt
salt_len	length of salt in bytes
iterations	the number of iterations to use (use 10K or more)

Implements Botan::PBKDF.

Definition at line 15 of file pgp_s2k.cpp.

   {
   SecureVector<byte> key(key_len), hash_buf;
 
   size_t pass = 0, generated = 0,
          total_size = passphrase.size() + salt_size;
   size_t to_hash = std::max(iterations, total_size);
 
   hash->clear();
   while(key_len > generated)
      {
      for(size_t j = 0; j != pass; ++j)
         hash->update(0);
 
      size_t left = to_hash;
      while(left >= total_size)
         {
         hash->update(salt_buf, salt_size);
         hash->update(passphrase);
         left -= total_size;
         }
      if(left <= salt_size)
         hash->update(salt_buf, left);
      else
         {
         hash->update(salt_buf, salt_size);
         left -= salt_size;
         hash->update(reinterpret_cast<const byte*>(passphrase.data()), left);
         }
 
      hash_buf = hash->final();
      key.copy(generated, &hash_buf[0], hash->output_length());
      generated += hash->output_length();
      ++pass;
      }
 
   return key;
   }

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

◆ name()

std::string Botan::OpenPGP_S2K::name ( ) const