test(e2e): add negative header-SigV4 rejection suite (backlog#1151 sec-1)
RustFS delegates SigV4 verification to the s3s dependency, so nothing in
this repo pins OUR end-to-end wiring of it. Add negative_sigv4_test.rs
sending REJECTED header-SigV4 requests against a live RustFSTestEnvironment
and asserting the HTTP status plus the S3 error code XML:
- valid_header_sigv4_request_succeeds (positive control so the negatives
cannot pass for the wrong reason)
- tampered_signature_returns_signature_does_not_match -> 403 SignatureDoesNotMatch
- wrong_secret_key_returns_signature_does_not_match -> 403 SignatureDoesNotMatch
- tampered_payload_is_rejected (body != signed x-amz-content-sha256) -> not 200
- skewed_date_returns_request_time_too_skewed (>15min) -> 403 RequestTimeTooSkewed
- malformed_authorization_header_returns_clean_4xx (present-not-missing) -> 4xx, never 5xx
Signatures are hand-built via rustfs_signer::request_signature_v4 primitives
(get_signing_key/get_signature/get_scope) so the test controls the timestamp,
secret, signed payload hash, and final signature bytes. Missing-credential
negatives are intentionally not duplicated (covered by multipart_auth_test /
anonymous_access_test).
Refs backlog#1151 (sec-1), master plan backlog#1155.