Obtain Information about hash algorithm from ECDSA public key
For the public key there is no hash defined. The hash is a configuration option for the signature generation algorithm but it would work for any EC key.

And your information about the key is, for that reason, also incorrect. SHA-1 is maybe mentioned by a tool, but the OID you gave can be written out in long-form (ASN.1 notation) as:

{iso(1) member-body(2) us(840) ansi-x962(10045) fieldType(1) prime-field(1)}


... there is no SHA-1 in there.

So basically the signature generation is dependent on the application you used to produce the signature.

If it is configurable then the hash algorithm should be included with the signature - not with the key. It would of course be advisable to validate that the signature and hash algorithm are within a pre-configured range if they are configurable: you do not want to verify MD-5 / SHA-1 based signatures anymore.

Note that ECDSA directly use the hash without padding (possibly even using fewer bits than is in the hash). No hash algorithm indication is (or can be) used within the signature format itself. The padding of RSA signatures generally contain a hash identifier that can be viewed modular exponentiation with the RSA public key.