the operation is not supported by the public key algorithm.
Unlike other functions the return value 0 from EVP_DigestVerifyFinal() only
-indicates that the signature did not not verify successfully (that is tbs did
+indicates that the signature did not verify successfully (that is tbs did
not match the original data or the signature was of invalid form) it is not an
indication of a more serious error.
or the operation will fail.
The call to EVP_DigestVerifyFinal() internally finalizes a copy of the digest
-context. This means that calls to EVP_VerifyUpdate() and EVP_VerifyFinal() can
+context. This means that EVP_VerifyUpdate() and EVP_VerifyFinal() can
be called later to digest and verify additional data.
Since only a copy of the digest context is ever finalized the context must