.. _eccpvalidatekeypair:

ECCPValidateKeyPair
===================


Validates private and public keys of the elliptic cryptosystem over
GF(p).


Syntax
------


IppStatus ippsECCPValidateKeyPair(const IppsBigNumState\* pPrivate,
const IppsECCPPointState\* pPublic, IppECResult\* pResult,
IppsECCPState\* pECC);


Include Files
-------------


``ippcp.h``


Parameters
----------


.. list-table:: 
   :header-rows: 0

   * - pPrivate   
     - Pointer to the private key ``privKey``.
   * - pPublic   
     - Pointer to the public key ``pubKey``.
   * - pResult   
     - Pointer to the validation result.
   * - pECC   
     - Pointer to the context of the elliptic cryptosystem.




Description
-----------


The function validates the private key ``privKey`` and public key
``pubKey`` of the elliptic cryptosystem over a finite field GF(*p*) and
allocates the result of the validation in accordance with the pointer
pResult.


The private key ``privKey`` is a number that lies in the range of [1,
*n*-1] where *n* is the order of the elliptic curve base point. The
public key ``pubKey`` is an elliptic curve point such that
``pubKey = privKey``\ · ``G``, where ``G`` is the base point of the
elliptic curve.


The elliptic curve domain parameters must be hitherto defined by one of
the functions:
`ECCPSet <eccpset.html>`__
or
`ECCPSetStd <eccpsetstd.html>`__.


The result of the cryptosystem keys validation for correctness can take
one of the following values:


.. list-table:: 
   :header-rows: 0

   * - ippECValid   
     - Keys are valid.
   * - ippECInvalidKeyPair   
     - Keys are not valid because ``privKey``\ · ``G`` ≠ ``pubKey``
   * - ippECInvalidPrivateKey   
     - Key *privKey* falls outside the range of [1, *n*-1].
   * - ippECPointIsAtInfinite   
     - Key *pubKey* is the point at infinity.
   * - ippECInvalidPublicKey   
     - Key *pubKey* is not valid because *n* · ``pubKey`` ≠ *O* , where *O* is the point at infinity.




Return Values
-------------


.. list-table:: 
   :header-rows: 0

   * - ippStsNoErr    
     - Indicates no error. Any other value indicates an error or warning.
   * - ippStsNullPtrErr   
     - Indicates an error condition if any of the specified pointers is NULL.
   * - ippStsContextMatchErr   
     - Indicates an error condition if one of the contexts pointed by pPrivate, pPublic, or pECC is not valid.