Verifies that the given signature is valid ECDSA signature
of the supplied hash value using the specified public key.
\param type this parameter is ignored
\param dgst pointer to the hash value
\param dgstlen length of the hash value
\param sig pointer to the DER encoded signature
\param siglen length of the DER encoded signature
\param eckey EC_KEY object containing a public EC key
\return 1 if the signature is valid, 0 if the signature is invalid
and -1 on error
Verifies that the given signature is valid ECDSA signature of the supplied hash value using the specified public key. \param type this parameter is ignored \param dgst pointer to the hash value \param dgstlen length of the hash value \param sig pointer to the DER encoded signature \param siglen length of the DER encoded signature \param eckey EC_KEY object containing a public EC key \return 1 if the signature is valid, 0 if the signature is invalid and -1 on error