(refactor) represent signatures as bytes

[japaric]

rather than as base64-encoded text.

this would make it easier to modify / recompute signature as it would avoid the need to manually use the base64 crate to do the decoding and re-encoding.

fields that would change

• signature in RRSIG would become Vec<u8>
  

  dnssec-tests/packages/dns-test/src/record.rs

  Line 563 in d25cc92

  pub signature: String,

the base64 encoding would happen in the fmt::Display implementation where the RRSIG is transformed into text. whereas the base64 decoding would happen in the FromStr implementation, which parses the text representation of an RRSIG

example of code that would be simplified

dnssec-tests/packages/conformance-tests/src/resolver/dnssec/scenarios/bogus.rs

Lines 33 to 37 in d25cc92

	let mut signature = BASE64_STANDARD.decode(&rrsig.signature)?;
	let last = signature.last_mut().expect("empty signature");
	*last = !*last;
	rrsig.signature = BASE64_STANDARD.encode(&signature);