Botan::NR_Verification_Operation Class Reference

#include <nr.h>

Inheritance diagram for Botan::NR_Verification_Operation:

Public Member Functions
size_t	max_input_bits () const
size_t	message_part_size () const
size_t	message_parts () const
	NR_Verification_Operation (const NR_PublicKey &nr)
virtual bool	verify (const byte[], size_t, const byte[], size_t)
SecureVector< byte >	verify_mr (const byte msg[], size_t msg_len)
bool	with_recovery () const

Detailed Description

Nyberg-Rueppel verification operation

Definition at line 82 of file nr.h.

Constructor & Destructor Documentation

NR_Verification_Operation()

Botan::NR_Verification_Operation::NR_Verification_Operation

(

const NR_PublicKey &

nr

)

Definition at line 112 of file nr.cpp.

                                                                           :
   q(nr.group_q()), y(nr.get_y())
   {
   powermod_g_p = Fixed_Base_Power_Mod(nr.group_g(), nr.group_p());
   powermod_y_p = Fixed_Base_Power_Mod(y, nr.group_p());
   mod_p = Modular_Reducer(nr.group_p());
   mod_q = Modular_Reducer(nr.group_q());
   }

References Botan::Fixed_Base_Power_Mod::Fixed_Base_Power_Mod(), Botan::DL_Scheme_PublicKey::group_g(), Botan::DL_Scheme_PublicKey::group_p(), Botan::DL_Scheme_PublicKey::group_q(), and Botan::Modular_Reducer::Modular_Reducer().

Referenced by Botan::Core_Engine::get_verify_op().

Member Function Documentation

max_input_bits()

size_t Botan::NR_Verification_Operation::max_input_bits ( ) const

inlinevirtual

Get the maximum message size in bits supported by this public key.

Returns

maximum message in bits

Implements Botan::PK_Ops::Verification.

Definition at line 89 of file nr.h.

{ return (q.bits() - 1); }

message_part_size()

size_t Botan::NR_Verification_Operation::message_part_size ( ) const

inlinevirtual

Find out the message part size supported by this scheme/key.

Returns

size of the message parts

Reimplemented from Botan::PK_Ops::Verification.

Definition at line 88 of file nr.h.

{ return q.bytes(); }

message_parts()

size_t Botan::NR_Verification_Operation::message_parts ( ) const

inlinevirtual

Find out the number of message parts supported by this scheme.

Returns

number of message parts

Reimplemented from Botan::PK_Ops::Verification.

Definition at line 87 of file nr.h.

{ return 2; }

verify()

virtual bool Botan::PK_Ops::Verification::verify ( const byte [], size_t , const byte [], size_t  )

inlinevirtualinherited

Reimplemented in Botan::DSA_Verification_Operation, and Botan::ECDSA_Verification_Operation.

Definition at line 120 of file pk_ops.h.

         {
         throw Invalid_State("Message recovery required");
         }

verify_mr()

SecureVector< byte > Botan::NR_Verification_Operation::verify_mr ( const byte msg[], size_t msg_len )

virtual

Reimplemented from Botan::PK_Ops::Verification.

Definition at line 122 of file nr.cpp.

   {
   const BigInt& q = mod_q.get_modulus();
 
   if(msg_len != 2*q.bytes())
      throw Invalid_Argument("NR verification: Invalid signature");
 
   BigInt c(msg, q.bytes());
   BigInt d(msg + q.bytes(), q.bytes());
 
   if(c.is_zero() || c >= q || d >= q)
      throw Invalid_Argument("NR verification: Invalid signature");
 
   BigInt i = mod_p.multiply(powermod_g_p(d), powermod_y_p(c));
   return BigInt::encode(mod_q.reduce(c - i));
   }

References Botan::BigInt::encode(), and Botan::BigInt::is_zero().

with_recovery()

bool Botan::NR_Verification_Operation::with_recovery ( ) const

inlinevirtual

Returns

boolean specifying if this key type supports message recovery and thus if you need to call verify() or verify_mr()

Implements Botan::PK_Ops::Verification.

Definition at line 91 of file nr.h.

{ return true; }

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

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