Botan::PK_Verifier Class Reference

#include <pubkey.h>

Public Member Functions
bool	check_signature (const byte sig[], size_t length)
bool	check_signature (const MemoryRegion< byte > &sig)
	PK_Verifier (const Public_Key &pub_key, const std::string &emsa, Signature_Format format=IEEE_1363)
void	set_input_format (Signature_Format format)
void	update (byte in)
void	update (const byte msg_part[], size_t length)
void	update (const MemoryRegion< byte > &in)
bool	verify_message (const byte msg[], size_t msg_length, const byte sig[], size_t sig_length)
bool	verify_message (const MemoryRegion< byte > &msg, const MemoryRegion< byte > &sig)
	~PK_Verifier ()

Detailed Description

Public Key Verifier. Use the verify_message() functions for small messages. Use multiple calls update() to process large messages and verify the signature by finally calling check_signature().

Definition at line 211 of file pubkey.h.

Constructor & Destructor Documentation

PK_Verifier()

Botan::PK_Verifier::PK_Verifier	(	const Public_Key &	pub_key,
		const std::string &	emsa,
		Signature_Format	format = IEEE_1363 )

Construct a PK Verifier.

Parameters

pub_key	the public key to verify against
emsa	the EMSA to use (eg "EMSA3(SHA-1)")
format	the signature format to use

Definition at line 248 of file pubkey.cpp.

   {
   Algorithm_Factory::Engine_Iterator i(global_state().algorithm_factory());
 
   op = 0;
 
   while(const Engine* engine = i.next())
      {
      op = engine->get_verify_op(key);
      if(op)
         break;
      }
 
   if(!op)
      throw Lookup_Error("Verification with " + key.algo_name() + " not supported");
 
   emsa = get_emsa(emsa_name);
   sig_format = format;
   }

References Botan::Public_Key::algo_name(), Botan::get_emsa(), Botan::global_state(), Botan::Lookup_Error::Lookup_Error(), and Botan::Algorithm_Factory::Engine_Iterator::next().

Referenced by Botan::get_pk_verifier().

~PK_Verifier()

Botan::PK_Verifier::~PK_Verifier ( )

inline

Definition at line 296 of file pubkey.h.

{ delete op; delete emsa; }

Member Function Documentation

check_signature() [1/2]

bool Botan::PK_Verifier::check_signature	(	const byte	sig[],
		size_t	length )

Check the signature of the buffered message, i.e. the one build by successive calls to update.

Parameters

sig	the signature to be verified as a byte array
length	the length of the above byte array

Returns

true if the signature is valid, false otherwise

Definition at line 301 of file pubkey.cpp.

   {
   try {
      if(sig_format == IEEE_1363)
         return validate_signature(emsa->raw_data(), sig, length);
      else if(sig_format == DER_SEQUENCE)
         {
         BER_Decoder decoder(sig, length);
         BER_Decoder ber_sig = decoder.start_cons(SEQUENCE);
 
         size_t count = 0;
         SecureVector<byte> real_sig;
         while(ber_sig.more_items())
            {
            BigInt sig_part;
            ber_sig.decode(sig_part);
            real_sig += BigInt::encode_1363(sig_part, op->message_part_size());
            ++count;
            }
 
         if(count != op->message_parts())
            throw Decoding_Error("PK_Verifier: signature size invalid");
 
         return validate_signature(emsa->raw_data(),
                                   &real_sig[0], real_sig.size());
         }
      else
         throw Decoding_Error("PK_Verifier: Unknown signature format " +
                              to_string(sig_format));
      }
   catch(Invalid_Argument) { return false; }
   }

References Botan::BER_Decoder::decode(), Botan::Decoding_Error::Decoding_Error(), Botan::DER_SEQUENCE, Botan::BigInt::encode_1363(), Botan::IEEE_1363, Botan::BER_Decoder::more_items(), Botan::SEQUENCE, Botan::MemoryRegion< T >::size(), Botan::BER_Decoder::start_cons(), and Botan::to_string().

Referenced by check_signature(), Botan::Server_Key_Exchange::verify(), and verify_message().

check_signature() [2/2]

bool Botan::PK_Verifier::check_signature ( const MemoryRegion< byte > & sig )

inline

Check the signature of the buffered message, i.e. the one build by successive calls to update.

Parameters

sig	the signature to be verified

Returns

true if the signature is valid, false otherwise

Definition at line 275 of file pubkey.h.

         {
         return check_signature(&sig[0], sig.size());
         }

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

set_input_format()

void Botan::PK_Verifier::set_input_format

(

Signature_Format

format

)

Set the format of the signatures fed to this verifier.

Parameters

format

the signature format to use

Definition at line 273 of file pubkey.cpp.

   {
   if(op->message_parts() == 1 && format != IEEE_1363)
      throw Invalid_State("PK_Verifier: This algorithm always uses IEEE 1363");
   sig_format = format;
   }

References Botan::IEEE_1363, and Botan::Invalid_State::Invalid_State().

update() [1/3]

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

inline

Add a message part (single byte) of the message corresponding to the signature to be verified.

Parameters

in	the byte to add

Definition at line 242 of file pubkey.h.

{ update(&in, 1); }

References update().

Referenced by update(), update(), Botan::Server_Key_Exchange::verify(), and verify_message().

update() [2/3]

void Botan::PK_Verifier::update	(	const byte	msg_part[],
		size_t	length )

Add a message part of the message corresponding to the signature to be verified.

Parameters

msg_part	the new message part as a byte array
length	the length of the above byte array

Definition at line 293 of file pubkey.cpp.

   {
   emsa->update(in, length);
   }

update() [3/3]

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

inline

Add a message part of the message corresponding to the signature to be verified.

Parameters

in	the new message part

Definition at line 257 of file pubkey.h.

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

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

verify_message() [1/2]

bool Botan::PK_Verifier::verify_message	(	const byte	msg[],
		size_t	msg_length,
		const byte	sig[],
		size_t	sig_length )

Verify a signature.

Parameters

msg	the message that the signature belongs to, as a byte array
msg_length	the length of the above byte array msg
sig	the signature as a byte array
sig_length	the length of the above byte array sig

Returns

true if the signature is valid

Definition at line 283 of file pubkey.cpp.

   {
   update(msg, msg_length);
   return check_signature(sig, sig_length);
   }

References check_signature(), and update().

Referenced by Botan::X509_Object::check_signature(), Botan::KeyPair::signature_consistency_check(), Botan::Certificate_Verify::verify(), and verify_message().

verify_message() [2/2]

bool Botan::PK_Verifier::verify_message ( const MemoryRegion< byte > & msg, const MemoryRegion< byte > & sig )

inline

Verify a signature.

Parameters

msg	the message that the signature belongs to
sig	the signature

Returns

true if the signature is valid

Definition at line 230 of file pubkey.h.

         {
         return verify_message(&msg[0], msg.size(),
                               &sig[0], sig.size());
         }

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

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

• src/pubkey/pubkey.h
• src/pubkey/pubkey.cpp