Botan  1.11.15
Public Types | Public Member Functions | Static Public Member Functions
Botan::RC4 Class Reference

#include <rc4.h>

Inheritance diagram for Botan::RC4:
Botan::StreamCipher Botan::SymmetricAlgorithm

List of all members.

Public Types

typedef SCAN_Name Spec

Public Member Functions

void cipher (const byte in[], byte out[], size_t length)
void cipher1 (byte buf[], size_t len)
void clear ()
StreamCipherclone () const
template<typename Alloc >
void decrypt (std::vector< byte, Alloc > &inout)
template<typename Alloc >
void encipher (std::vector< byte, Alloc > &inout)
template<typename Alloc >
void encrypt (std::vector< byte, Alloc > &inout)
Key_Length_Specification key_spec () const
size_t maximum_keylength () const
size_t minimum_keylength () const
std::string name () const
 RC4 (size_t skip=0)
virtual void set_iv (const byte[], size_t iv_len)
void set_key (const SymmetricKey &key)
template<typename Alloc >
void set_key (const std::vector< byte, Alloc > &key)
void set_key (const byte key[], size_t length)
virtual bool valid_iv_length (size_t iv_len) const
bool valid_keylength (size_t length) const
 ~RC4 ()

Static Public Member Functions

static RC4make (const Spec &spec)

Detailed Description

RC4 stream cipher

Definition at line 19 of file rc4.h.


Member Typedef Documentation

typedef SCAN_Name Botan::StreamCipher::Spec [inherited]

Definition at line 73 of file stream_cipher.h.


Constructor & Destructor Documentation

Botan::RC4::RC4 ( size_t  skip = 0)
Parameters:
skipskip this many initial bytes in the keystream

Definition at line 117 of file rc4.cpp.

Referenced by make().

: SKIP(s) {}
Botan::RC4::~RC4 ( ) [inline]

Definition at line 41 of file rc4.h.

{ clear(); }

Member Function Documentation

void Botan::RC4::cipher ( const byte  in[],
byte  out[],
size_t  len 
) [virtual]

Encrypt or decrypt a message

Parameters:
inthe plaintext
outthe byte array to hold the output, i.e. the ciphertext
lenthe length of both in and out in bytes

Implements Botan::StreamCipher.

Definition at line 27 of file rc4.cpp.

References Botan::xor_buf().

   {
   while(length >= buffer.size() - position)
      {
      xor_buf(out, in, &buffer[position], buffer.size() - position);
      length -= (buffer.size() - position);
      in += (buffer.size() - position);
      out += (buffer.size() - position);
      generate();
      }
   xor_buf(out, in, &buffer[position], length);
   position += length;
   }
void Botan::StreamCipher::cipher1 ( byte  buf[],
size_t  len 
) [inline, inherited]

Encrypt or decrypt a message

Parameters:
bufthe plaintext / ciphertext
lenthe length of buf in bytes

Definition at line 36 of file stream_cipher.h.

Referenced by Botan::SIV_Encryption::finish().

         { cipher(buf, buf, len); }
void Botan::RC4::clear ( ) [virtual]

Implements Botan::SymmetricAlgorithm.

Definition at line 107 of file rc4.cpp.

References Botan::zap().

   {
   zap(state);
   zap(buffer);
   position = X = Y = 0;
   }
StreamCipher* Botan::RC4::clone ( ) const [inline, virtual]

Get a new object representing the same algorithm as *this

Implements Botan::StreamCipher.

Definition at line 27 of file rc4.h.

{ return new RC4(SKIP); }
template<typename Alloc >
void Botan::StreamCipher::decrypt ( std::vector< byte, Alloc > &  inout) [inline, inherited]

Definition at line 48 of file stream_cipher.h.

         { cipher(&inout[0], &inout[0], inout.size()); }
template<typename Alloc >
void Botan::StreamCipher::encipher ( std::vector< byte, Alloc > &  inout) [inline, inherited]

Definition at line 40 of file stream_cipher.h.

         { cipher(&inout[0], &inout[0], inout.size()); }
template<typename Alloc >
void Botan::StreamCipher::encrypt ( std::vector< byte, Alloc > &  inout) [inline, inherited]

Definition at line 44 of file stream_cipher.h.

         { cipher(&inout[0], &inout[0], inout.size()); }
Key_Length_Specification Botan::RC4::key_spec ( ) const [inline, virtual]
Returns:
object describing limits on key size

Implements Botan::SymmetricAlgorithm.

Definition at line 29 of file rc4.h.

         {
         return Key_Length_Specification(1, 256);
         }
RC4 * Botan::RC4::make ( const Spec spec) [static]

Definition at line 15 of file rc4.cpp.

References Botan::SCAN_Name::algo_name(), Botan::SCAN_Name::arg_as_integer(), and RC4().

   {
   if(spec.algo_name() == "RC4")
      return new RC4(spec.arg_as_integer(0, 0));
   if(spec.algo_name() == "RC4_drop")
      return new RC4(768);
   return nullptr;
   }
size_t Botan::SymmetricAlgorithm::maximum_keylength ( ) const [inline, inherited]
Returns:
minimum allowed key length

Definition at line 36 of file sym_algo.h.

References Botan::Key_Length_Specification::maximum_keylength().

         {
         return key_spec().maximum_keylength();
         }
size_t Botan::SymmetricAlgorithm::minimum_keylength ( ) const [inline, inherited]
Returns:
maxmium allowed key length

Definition at line 44 of file sym_algo.h.

         {
         return key_spec().minimum_keylength();
         }
std::string Botan::RC4::name ( ) const [virtual]

Implements Botan::SymmetricAlgorithm.

Definition at line 97 of file rc4.cpp.

References Botan::ASN1::to_string().

   {
   if(SKIP == 0)   return "RC4";
   if(SKIP == 256) return "MARK-4";
   else            return "RC4_skip(" + std::to_string(SKIP) + ")";
   }
virtual void Botan::StreamCipher::set_iv ( const byte  [],
size_t  iv_len 
) [inline, virtual, inherited]

Resync the cipher using the IV

Parameters:
ivthe initialization vector
iv_lenthe length of the IV in bytes

Reimplemented in Botan::CTR_BE, Botan::OFB, Botan::ChaCha, and Botan::Salsa20.

Definition at line 56 of file stream_cipher.h.

Referenced by Botan::SIV_Mode::set_ctr_iv().

         {
         if(iv_len)
            throw Invalid_IV_Length(name(), iv_len);
         }
void Botan::SymmetricAlgorithm::set_key ( const SymmetricKey key) [inline, inherited]

Set the symmetric key of this object.

Parameters:
keythe SymmetricKey to be set.

Definition at line 63 of file sym_algo.h.

References Botan::OctetString::begin(), and Botan::OctetString::length().

Referenced by Botan::aont_package(), Botan::aont_unpackage(), botan_mac_set_key(), Botan::TLS::Session::decrypt(), Botan::TLS::Session::encrypt(), and Botan::pbkdf2().

         {
         set_key(key.begin(), key.length());
         }
template<typename Alloc >
void Botan::SymmetricAlgorithm::set_key ( const std::vector< byte, Alloc > &  key) [inline, inherited]

Definition at line 69 of file sym_algo.h.

         {
         set_key(&key[0], key.size());
         }
void Botan::SymmetricAlgorithm::set_key ( const byte  key[],
size_t  length 
) [inline, inherited]

Set the symmetric key of this object.

Parameters:
keythe to be set as a byte array.
lengthin bytes of key param

Definition at line 79 of file sym_algo.h.

         {
         if(!valid_keylength(length))
            throw Invalid_Key_Length(name(), length);
         key_schedule(key, length);
         }
virtual bool Botan::StreamCipher::valid_iv_length ( size_t  iv_len) const [inline, virtual, inherited]
Parameters:
iv_lenthe length of the IV in bytes
Returns:
if the length is valid for this algorithm

Reimplemented in Botan::CTR_BE, Botan::OFB, Botan::ChaCha, and Botan::Salsa20.

Definition at line 66 of file stream_cipher.h.

{ return (iv_len == 0); }
bool Botan::SymmetricAlgorithm::valid_keylength ( size_t  length) const [inline, inherited]

Check whether a given key length is valid for this algorithm.

Parameters:
lengththe key length to be checked.
Returns:
true if the key length is valid.

Definition at line 54 of file sym_algo.h.

Referenced by Botan::aont_package(), and Botan::aont_unpackage().

         {
         return key_spec().valid_keylength(length);
         }

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