Botan::HMAC Class Reference

#include <hmac.h>

Inheritance diagram for Botan::HMAC:

Public Member Functions
void	clear ()
MessageAuthenticationCode *	clone () const
SecureVector< byte >	final ()
void	final (byte out[])
	HMAC (HashFunction *hash)
Key_Length_Specification	key_spec () const
size_t	maximum_keylength () const
size_t	minimum_keylength () const
std::string	name () const
size_t	output_length () const
SecureVector< byte >	process (const byte in[], size_t length)
SecureVector< byte >	process (const MemoryRegion< byte > &in)
SecureVector< byte >	process (const std::string &in)
void	set_key (const byte key[], size_t length)
void	set_key (const SymmetricKey &key)
void	update (byte in)
void	update (const byte in[], size_t length)
void	update (const MemoryRegion< byte > &in)
void	update (const std::string &str)
template<typename T>
void	update_be (const T in)
bool	valid_keylength (size_t length) const
virtual bool	verify_mac (const byte in[], size_t length)
	~HMAC ()

Detailed Description

HMAC

Definition at line 19 of file hmac.h.

Constructor & Destructor Documentation

HMAC()

Botan::HMAC::HMAC

(

HashFunction *

hash

)

Parameters

hash	the hash to use for HMACing

Definition at line 87 of file hmac.cpp.

                                : hash(hash_in)
   {
   if(hash->hash_block_size() == 0)
      throw Invalid_Argument("HMAC cannot be used with " + hash->name());
 
   i_key.resize(hash->hash_block_size());
   o_key.resize(hash->hash_block_size());
   }

Referenced by clone(), Botan::CryptoBox::decrypt(), Botan::CryptoBox::encrypt(), Botan::Core_Engine::find_mac(), and Botan::TLS_PRF::TLS_PRF().

~HMAC()

Botan::HMAC::~HMAC ( )

inline

Definition at line 38 of file hmac.h.

{ delete hash; }

Member Function Documentation

clear()

void Botan::HMAC::clear ( )

virtual

Zeroize internal state

Implements Botan::Algorithm.

Definition at line 61 of file hmac.cpp.

   {
   hash->clear();
   zeroise(i_key);
   zeroise(o_key);
   }

References Botan::zeroise().

clone()

MessageAuthenticationCode * Botan::HMAC::clone ( ) const

virtual

Get a new object representing the same algorithm as *this

Implements Botan::MessageAuthenticationCode.

Definition at line 79 of file hmac.cpp.

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

References HMAC().

final() [1/2]

SecureVector< byte > Botan::Buffered_Computation::final ( )

inlineinherited

Complete the computation and retrieve the final result.

Returns

SecureVector holding the result

Definition at line 87 of file buf_comp.h.

         {
         SecureVector<byte> output(output_length());
         final_result(&output[0]);
         return output;
         }

References output_length().

final() [2/2]

void Botan::Buffered_Computation::final ( byte out[] )

inlineinherited

Complete the computation and retrieve the final result.

Parameters

out	The byte array to be filled with the result. Must be of length output_length()

Definition at line 80 of file buf_comp.h.

{ final_result(out); }

Referenced by Botan::X942_PRF::derive(), Botan::HandshakeHash::final(), and Botan::HandshakeHash::final_ssl3().

key_spec()

Key_Length_Specification Botan::HMAC::key_spec ( ) const

inlinevirtual

Returns

object describing limits on key size

Implements Botan::SymmetricAlgorithm.

Definition at line 28 of file hmac.h.

         {
         // Absurd max length here is to support PBKDF2
         return Key_Length_Specification(0, 512);
         }

maximum_keylength()

size_t Botan::SymmetricAlgorithm::maximum_keylength ( ) const

inlineinherited

Returns

minimum allowed key length

Definition at line 33 of file sym_algo.h.

         {
         return key_spec().maximum_keylength();
         }

References key_spec().

minimum_keylength()

size_t Botan::SymmetricAlgorithm::minimum_keylength ( ) const

inlineinherited

Returns

maxmium allowed key length

Definition at line 41 of file sym_algo.h.

         {
         return key_spec().minimum_keylength();
         }

References key_spec().

name()

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

virtual

Get the name of this algorithm.

Returns

name of this algorithm

Implements Botan::MessageAuthenticationCode.

Definition at line 71 of file hmac.cpp.

   {
   return "HMAC(" + hash->name() + ")";
   }

output_length()

size_t Botan::HMAC::output_length ( ) const

inlinevirtual

Returns

length of the output of this function in bytes

Implements Botan::Buffered_Computation.

Definition at line 26 of file hmac.h.

{ return hash->output_length(); }

process() [1/3]

SecureVector< byte > Botan::Buffered_Computation::process ( const byte in[], size_t length )

inlineinherited

Update and finalize computation. Does the same as calling update() and final() consecutively.

Parameters

in	the input to process as a byte array
length	the length of the byte array

Returns

the result of the call to final()

Definition at line 101 of file buf_comp.h.

         {
         add_data(in, length);
         return final();
         }

Referenced by Botan::EME1::EME1(), Botan::RTSS_Share::split(), and Botan::Cert_Extension::Subject_Key_ID::Subject_Key_ID().

process() [2/3]

SecureVector< byte > Botan::Buffered_Computation::process ( const MemoryRegion< byte > & in )

inlineinherited

Update and finalize computation. Does the same as calling update() and final() consecutively.

Parameters

in	the input to process

Returns

the result of the call to final()

Definition at line 113 of file buf_comp.h.

         {
         add_data(&in[0], in.size());
         return final();
         }

References Botan::MemoryRegion< T >::size().

process() [3/3]

SecureVector< byte > Botan::Buffered_Computation::process ( const std::string & in )

inlineinherited

Update and finalize computation. Does the same as calling update() and final() consecutively.

Parameters

in	the input to process as a string

Returns

the result of the call to final()

Definition at line 125 of file buf_comp.h.

         {
         update(in);
         return final();
         }

References update().

set_key() [1/2]

void Botan::SymmetricAlgorithm::set_key ( const byte key[], size_t length )

inlineinherited

Set the symmetric key of this object.

Parameters

key	the to be set as a byte array.
length	in bytes of key param

Definition at line 68 of file sym_algo.h.

         {
         if(!valid_keylength(length))
            throw Invalid_Key_Length(name(), length);
         key_schedule(key, length);
         }

References Botan::Algorithm::name(), and valid_keylength().

set_key() [2/2]

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

inlineinherited

Set the symmetric key of this object.

Parameters

key	the SymmetricKey to be set.

Definition at line 60 of file sym_algo.h.

         { set_key(key.begin(), key.length()); }

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

Referenced by Botan::aont_package(), Botan::aont_unpackage(), Botan::MAC_Filter::MAC_Filter(), Botan::MAC_Filter::MAC_Filter(), Botan::EAX_Base::set_key(), set_key(), Botan::Record_Reader::set_keys(), Botan::Record_Writer::set_keys(), Botan::StreamCipher_Filter::StreamCipher_Filter(), and Botan::StreamCipher_Filter::StreamCipher_Filter().

update() [1/4]

void Botan::Buffered_Computation::update ( byte in )

inlineinherited

Process a single byte.

Parameters

in	the byte to process

Definition at line 72 of file buf_comp.h.

{ add_data(&in, 1); }

update() [2/4]

void Botan::Buffered_Computation::update ( const byte in[], size_t length )

inlineinherited

Add new input to process.

Parameters

in	the input to process as a byte array
length	of param in in bytes

Definition at line 33 of file buf_comp.h.

{ add_data(in, length); }

Referenced by Botan::X942_PRF::derive(), Botan::HandshakeHash::final(), Botan::HandshakeHash::final_ssl3(), process(), and Botan::EAX_Base::start_msg().

update() [3/4]

void Botan::Buffered_Computation::update ( const MemoryRegion< byte > & in )

inlineinherited

Add new input to process.

Parameters

in	the input to process as a MemoryRegion

Definition at line 39 of file buf_comp.h.

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

References Botan::MemoryRegion< T >::size().

update() [4/4]

void Botan::Buffered_Computation::update ( const std::string & str )

inlineinherited

Add new input to process.

Parameters

str	the input to process as a std::string. Will be interpreted as a byte array based on the strings encoding.

Definition at line 63 of file buf_comp.h.

         {
         add_data(reinterpret_cast<const byte*>(str.data()), str.size());
         }

update_be()

template<typename T>

void Botan::Buffered_Computation::update_be ( const T in )

inlineinherited

Add an integer in big-endian order

Parameters

in

the value

Definition at line 48 of file buf_comp.h.

         {
         for(size_t i = 0; i != sizeof(T); ++i)
            {
            byte b = get_byte(i, in);
            add_data(&b, 1);
            }
         }

References Botan::get_byte().

valid_keylength()

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

inlineinherited

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

Parameters

length

the key length to be checked.

Returns

true if the key length is valid.

Definition at line 51 of file sym_algo.h.

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

References key_spec().

Referenced by Botan::aont_package(), Botan::aont_unpackage(), set_key(), and Botan::EAX_Base::valid_keylength().

verify_mac()

bool Botan::MessageAuthenticationCode::verify_mac ( const byte in[], size_t length )

virtualinherited

Verify a MAC.

Parameters

in	the MAC to verify as a byte array
length	the length of param in

Returns

true if the MAC is valid, false otherwise

Definition at line 16 of file mac.cpp.

   {
   SecureVector<byte> our_mac = final();
 
   if(our_mac.size() != length)
      return false;
 
   return same_mem(&our_mac[0], &mac[0], length);
   }

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

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

• src/mac/hmac/hmac.h
• src/mac/hmac/hmac.cpp