Initializing public ECC key and checking signature

[Robert Zillner]

Hello everyone,

may someone help me with checking a signature using crypto++.

My situation:

1. A mesage is signed externally using an ATECC108 chip (K283 curve).

2. The public key is available as 2 byte atrrays (36 byte X and 36 byte Y component).

3. Initializing a public key in crypto++ throws an error on validating the public key "CryptoMaterial: this object contains invalid values"

i´m using this code to check a signature

PolynomialMod2 X(pubKey, 36);

PolynomialMod2 Y(&pubKey[36], 36);

EC2N::Point D(X, Y);

ECDSA<EC2N, SHA256>::PublicKey pKey;

pKey.Initialize(oid, D);

result = pKey.Validate( prng, 3);

if( !result )

{

      cout << "Validation of public key failed !!!" << endl;

}

StringSource sss(signature+message, true,

 new SignatureVerificationFilter(

     ECDSA<EC2N,SHA256>::Verifier(pKey),

     new ArraySink( (byte*)&result, sizeof(result) )

 ) // SignatureVerificationFilter

);

if( !result )

{

  cout << "Signature check failed !!!" << endl;

}

else

{

  cout << "Signature check succeed !!!" << endl;

}

Using the crypto++ library to sign and to check works fine, but initializing and using a public key goes wrong.

Can anyone help?

BR

Robert

[Robert Zillner]

Update:

The external public key is now accepted.

The only thing not working is the signature test itself.

StringSource verify(message+signature, true,

 new SignatureVerificationFilter(

     ECDSA<EC2N,SHA256>::Verifier(pKey),

     new ArraySink( (byte*)&result, sizeof(result) )

 ) // SignatureVerificationFilter

);

// Verification failure?

if(!result)

{

     cout << "Signature check failed !!!\r" << endl;

}

else

{

     cout << "Signature check succeed !!!\r" << endl;

}