Botan::EAX_Base Class Reference

#include <eax.h>

Inheritance diagram for Botan::EAX_Base:

Public Member Functions
virtual bool	attachable ()
virtual void	end_msg ()
std::string	name () const
void	set_header (const byte header[], size_t header_len)
void	set_iv (const InitializationVector &iv)
void	set_key (const SymmetricKey &key)
bool	valid_iv_length (size_t) const
bool	valid_keylength (size_t key_len) const
virtual void	write (const byte input[], size_t length)=0
	~EAX_Base ()

Protected Member Functions
	EAX_Base (BlockCipher *cipher, size_t tag_size)
void	send (byte in)
void	send (const byte in[], size_t length)
void	send (const MemoryRegion< byte > &in)
void	send (const MemoryRegion< byte > &in, size_t length)
void	start_msg ()

Protected Attributes
const size_t	BLOCK_SIZE
std::string	cipher_name
MessageAuthenticationCode *	cmac
StreamCipher *	ctr
SecureVector< byte >	ctr_buf
SecureVector< byte >	header_mac
SecureVector< byte >	nonce_mac
const size_t	TAG_SIZE

Detailed Description

EAX Base Class

Definition at line 21 of file eax.h.

Constructor & Destructor Documentation

~EAX_Base()

Botan::EAX_Base::~EAX_Base ( )

inline

Definition at line 47 of file eax.h.

{ delete ctr; delete cmac; }

References cmac, and ctr.

EAX_Base()

Botan::EAX_Base::EAX_Base ( BlockCipher * cipher, size_t tag_size )

protected

Parameters

cipher	the cipher to use
tag_size	is how big the auth tag will be

Definition at line 38 of file eax.cpp.

                                                       :
   BLOCK_SIZE(cipher->block_size()),
   TAG_SIZE(tag_size ? tag_size / 8 : BLOCK_SIZE),
   cipher_name(cipher->name()),
   ctr_buf(DEFAULT_BUFFERSIZE)
   {
   cmac = new CMAC(cipher->clone());
   ctr = new CTR_BE(cipher); // takes ownership
 
   if(tag_size % 8 != 0 || TAG_SIZE == 0 || TAG_SIZE > cmac->output_length())
      throw Invalid_Argument(name() + ": Bad tag size " + to_string(tag_size));
   }

References BLOCK_SIZE, cipher_name, Botan::BlockCipher::clone(), Botan::CMAC::CMAC(), cmac, ctr, Botan::CTR_BE::CTR_BE(), ctr_buf, name(), Botan::Buffered_Computation::output_length(), TAG_SIZE, and Botan::to_string().

Referenced by Botan::EAX_Decryption::EAX_Decryption(), Botan::EAX_Decryption::EAX_Decryption(), Botan::EAX_Encryption::EAX_Encryption(), and Botan::EAX_Encryption::EAX_Encryption().

Member Function Documentation

attachable()

virtual bool Botan::Filter::attachable ( )

inlinevirtualinherited

Check whether this filter is an attachable filter.

Returns

true if this filter is attachable, false otherwise

Reimplemented in Botan::DataSink, and Botan::SecureQueue.

Definition at line 50 of file filter.h.

{ return true; }

end_msg()

virtual void Botan::Filter::end_msg ( )

inlinevirtualinherited

Notify that the current message is finished; flush buffers and do end-of-message processing (if any).

Reimplemented in Botan::Base64_Decoder, Botan::Base64_Encoder, Botan::Bzip_Compression, Botan::Bzip_Decompression, Botan::Hash_Filter, Botan::Hex_Decoder, Botan::Hex_Encoder, Botan::MAC_Filter, Botan::PBE_PKCS5v15, Botan::PBE_PKCS5v20, Botan::PK_Decryptor_Filter, Botan::PK_Encryptor_Filter, Botan::PK_Signer_Filter, Botan::PK_Verifier_Filter, Botan::Zlib_Compression, and Botan::Zlib_Decompression.

Definition at line 44 of file filter.h.

{}

name()

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

virtual

Returns

name of this mode

Implements Botan::Filter.

Definition at line 106 of file eax.cpp.

   {
   return (cipher_name + "/EAX");
   }

References cipher_name.

Referenced by EAX_Base().

send() [1/4]

void Botan::Filter::send ( byte in )

inlineprotectedinherited

Parameters

in	some input for the filter

Definition at line 63 of file filter.h.

{ send(&in, 1); }

References send().

Referenced by send().

send() [2/4]

void Botan::Filter::send ( const byte in[], size_t length )

protectedinherited

Parameters

in	some input for the filter
length	the length of in

Definition at line 28 of file filter.cpp.

   {
   bool nothing_attached = true;
   for(size_t j = 0; j != total_ports(); ++j)
      if(next[j])
         {
         if(write_queue.size())
            next[j]->write(&write_queue[0], write_queue.size());
         next[j]->write(input, length);
         nothing_attached = false;
         }
 
   if(nothing_attached)
      write_queue += std::make_pair(input, length);
   else
      write_queue.clear();
   }

Referenced by Botan::Base64_Decoder::end_msg(), Botan::Base64_Encoder::end_msg(), Botan::Bzip_Compression::end_msg(), Botan::Bzip_Decompression::end_msg(), Botan::Hash_Filter::end_msg(), Botan::Hex_Decoder::end_msg(), Botan::Hex_Encoder::end_msg(), Botan::MAC_Filter::end_msg(), Botan::PK_Decryptor_Filter::end_msg(), Botan::PK_Encryptor_Filter::end_msg(), Botan::PK_Signer_Filter::end_msg(), Botan::PK_Verifier_Filter::end_msg(), Botan::Zlib_Compression::end_msg(), Botan::Zlib_Decompression::end_msg(), Botan::Bzip_Compression::flush(), Botan::Zlib_Compression::flush(), send(), Botan::Base64_Decoder::write(), Botan::Bzip_Compression::write(), Botan::Bzip_Decompression::write(), Botan::Chain::write(), Botan::Fork::write(), Botan::Hex_Decoder::write(), Botan::StreamCipher_Filter::write(), Botan::Zlib_Compression::write(), and Botan::Zlib_Decompression::write().

send() [3/4]

void Botan::Filter::send ( const MemoryRegion< byte > & in )

inlineprotectedinherited

Parameters

in	some input for the filter

Definition at line 68 of file filter.h.

{ send(&in[0], in.size()); }

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

Referenced by send().

send() [4/4]

void Botan::Filter::send ( const MemoryRegion< byte > & in, size_t length )

inlineprotectedinherited

Parameters

in	some input for the filter
length	the number of bytes of in to send

Definition at line 74 of file filter.h.

         {
         send(&in[0], length);
         }

References send().

set_header()

void Botan::EAX_Base::set_header	(	const byte	header[],
		size_t	header_len )

Set some additional data that is not included in the ciphertext but that will be authenticated.

Parameters

header	the header contents
header_len	length of header in bytes

Definition at line 98 of file eax.cpp.

   {
   header_mac = eax_prf(1, BLOCK_SIZE, cmac, header, length);
   }

References BLOCK_SIZE, cmac, and header_mac.

set_iv()

void Botan::EAX_Base::set_iv ( const InitializationVector & iv )

virtual

Set the initialization vector of this filter. Note: you should call set_iv() only after you have called set_key()

Parameters

iv	the initialization vector to use

Reimplemented from Botan::Keyed_Filter.

Definition at line 89 of file eax.cpp.

   {
   nonce_mac = eax_prf(0, BLOCK_SIZE, cmac, iv.begin(), iv.length());
   ctr->set_iv(&nonce_mac[0], nonce_mac.size());
   }

References Botan::OctetString::begin(), BLOCK_SIZE, cmac, ctr, Botan::OctetString::length(), nonce_mac, Botan::StreamCipher::set_iv(), and Botan::MemoryRegion< T >::size().

Referenced by Botan::EAX_Decryption::EAX_Decryption(), and Botan::EAX_Encryption::EAX_Encryption().

set_key()

void Botan::EAX_Base::set_key ( const SymmetricKey & key )

virtual

Set the key of this filter

Parameters

key	the key to use

Implements Botan::Keyed_Filter.

Definition at line 64 of file eax.cpp.

   {
   /*
   * These could share the key schedule, which is one nice part of EAX,
   * but it's much easier to ignore that here...
   */
   ctr->set_key(key);
   cmac->set_key(key);
 
   header_mac = eax_prf(1, BLOCK_SIZE, cmac, 0, 0);
   }

References BLOCK_SIZE, cmac, ctr, header_mac, and Botan::SymmetricAlgorithm::set_key().

Referenced by Botan::EAX_Decryption::EAX_Decryption(), and Botan::EAX_Encryption::EAX_Encryption().

start_msg()

void Botan::EAX_Base::start_msg ( )

protectedvirtual

Start a new message. Must be closed by end_msg() before another message can be started.

Reimplemented from Botan::Filter.

Definition at line 79 of file eax.cpp.

   {
   for(size_t i = 0; i != BLOCK_SIZE - 1; ++i)
      cmac->update(0);
   cmac->update(2);
   }

References BLOCK_SIZE, cmac, and Botan::Buffered_Computation::update().

valid_iv_length()

bool Botan::EAX_Base::valid_iv_length ( size_t ) const

inlinevirtual

EAX supports arbitrary IV lengths

Reimplemented from Botan::Keyed_Filter.

Definition at line 45 of file eax.h.

{ return true; }

valid_keylength()

bool Botan::EAX_Base::valid_keylength ( size_t length ) const

virtual

Check whether a key length is valid for this filter

Parameters

length

the key length to be checked for validity

Returns

true if the key length is valid, false otherwise

Implements Botan::Keyed_Filter.

Definition at line 54 of file eax.cpp.

   {
   if(!ctr->valid_keylength(n))
      return false;
   return true;
   }

References ctr, and Botan::SymmetricAlgorithm::valid_keylength().

write()

virtual void Botan::Filter::write ( const byte input[], size_t length )

pure virtualinherited

Write a portion of a message to this filter.

Parameters

input	the input as a byte array
length	the length of the byte array input

Implemented in Botan::Base64_Decoder, Botan::Base64_Encoder, Botan::BitBucket, Botan::Bzip_Compression, Botan::Bzip_Decompression, Botan::Chain, Botan::DataSink_Stream, Botan::Fork, Botan::Hash_Filter, Botan::Hex_Decoder, Botan::Hex_Encoder, Botan::MAC_Filter, Botan::PBE_PKCS5v15, Botan::PBE_PKCS5v20, Botan::PK_Decryptor_Filter, Botan::PK_Encryptor_Filter, Botan::PK_Signer_Filter, Botan::PK_Verifier_Filter, Botan::SecureQueue, Botan::StreamCipher_Filter, Botan::Zlib_Compression, and Botan::Zlib_Decompression.

Member Data Documentation

BLOCK_SIZE

const size_t Botan::EAX_Base::BLOCK_SIZE

protected

The block size of the underlying cipher

Definition at line 59 of file eax.h.

Referenced by EAX_Base(), set_header(), set_iv(), set_key(), and start_msg().

cipher_name

std::string Botan::EAX_Base::cipher_name

protected

The name of the cipher

Definition at line 69 of file eax.h.

Referenced by EAX_Base(), and name().

cmac

MessageAuthenticationCode* Botan::EAX_Base::cmac

protected

The MAC (CMAC)

Definition at line 79 of file eax.h.

Referenced by EAX_Base(), set_header(), set_iv(), set_key(), start_msg(), and ~EAX_Base().

ctr

StreamCipher* Botan::EAX_Base::ctr

protected

The stream cipher (CTR mode)

Definition at line 74 of file eax.h.

Referenced by EAX_Base(), set_iv(), set_key(), valid_keylength(), and ~EAX_Base().

ctr_buf

SecureVector<byte> Botan::EAX_Base::ctr_buf

protected

A buffer for CTR mode encryption

Definition at line 94 of file eax.h.

Referenced by EAX_Base().

header_mac

SecureVector<byte> Botan::EAX_Base::header_mac

protected

The MAC of the header

Definition at line 89 of file eax.h.

Referenced by set_header(), and set_key().

nonce_mac

SecureVector<byte> Botan::EAX_Base::nonce_mac

protected

The MAC of the nonce

Definition at line 84 of file eax.h.

Referenced by set_iv().

TAG_SIZE

const size_t Botan::EAX_Base::TAG_SIZE

protected

The requested tag name

Definition at line 64 of file eax.h.

Referenced by EAX_Base(), Botan::EAX_Decryption::EAX_Decryption(), and Botan::EAX_Decryption::EAX_Decryption().

---

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

• src/filters/modes/eax/eax.h
• src/filters/modes/eax/eax.cpp