clawhdf5-remote, h5rs: URLs' credentials are never shown

Every RemoteError message and HttpStorage's Debug output held the URL as
given, with any user:password@ and the query string — for a presigned
S3/GCS/Azure URL, its signature or token. An application logging the
error leaked the credential.

- New clawhdf5_remote::redact_url: no userinfo, no fragment, query values
  replaced by REDACTED (plain key names kept).
- HttpStorage formats every message with the redacted URL, and scrubs the
  URL's secret parts from errors of the HTTP client (whose texts can echo
  the URI); Debug shows the redacted URL. storage_for_url's and the object
  store URL errors are redacted too. HttpStorage::url() still returns the
  URL as given, documented as not for logging.
- h5rs prints FILE arguments that are URLs redacted: in errors and in
  dump/stat/check/diff output.
- The test server can force a status and send a wrong Content-Range.

Tests: 404, 403 (at open and on a read), wrong Content-Range (at open and
on a read), no range support, encoded body, ETag change, timeout,
connection closed and bad scheme errors, Display and Debug, contain none
of the secrets; h5rs likewise for every subcommand.

Co-Authored-By: Claude Opus 5.5 (1M context) <[email protected]>

crates/clawhdf5-remote/tests/http.rs

@@ -604,3 +604,121 @@ fn download_is_bounded_by_its_limit_not_the_claimed_length() {
     );
     assert_eq!(server.requests(), 0, "refused before reading");
 }
+
+/// A URL's credentials — userinfo, and the query string of a presigned
+/// URL — never appear in an error message or a `Debug` output, whatever
+/// failed.
+#[test]
+fn credentials_never_appear_in_errors_or_debug() {
+    const SECRETS: [&str; 4] = ["hunter2", "SECRETSIG", "AKIDSECRET", "user:"];
+    fn clean(what: &str, text: &str) {
+        for s in SECRETS {
+            assert!(!text.contains(s), "{what}: {s} leaked in {text}");
+        }
+    }
+    fn check_err<T>(what: &str, r: Result<T, Error>) {
+        let Err(e) = r else {
+            panic!("{what}: expected an error")
+        };
+        clean(what, &format!("{e}"));
+        clean(what, &format!("{e:?}"));
+    }
+    let bytes = multi_block_file();
+    let server = Server::start(vec![("/m.h5".into(), bytes.clone())]);
+    let secret_url = |path: &str| {
+        format!(
+            "http://user:hunter2@{}{path}?X-Amz-Credential=AKIDSECRET&X-Amz-Signature=SECRETSIG",
+            server.addr
+        )
+    };
+    let url = secret_url("/m.h5");
+    let mut opts = quick();
+    opts.http.retries = 0;
+
+    // Opening works through such a URL, and Debug shows it redacted.
+    let (http, _) = HttpStorage::open(&url, opts.http.clone()).unwrap();
+    let debug = format!("{http:?}");
+    clean("Debug", &debug);
+    assert!(debug.contains("X-Amz-Signature=REDACTED"), "{debug}");
+    assert_eq!(http.url(), url, "the URL itself is kept for requests");
+
+    check_err("404", open_url_with(&secret_url("/missing.h5"), &opts));
+    server.shared.force_status.store(403, Ordering::SeqCst);
+    check_err("403", open_url_with(&url, &opts));
+    server.shared.force_status.store(0, Ordering::SeqCst);
+    server.shared.wrong_range.store(true, Ordering::SeqCst);
+    check_err("bad range at open", open_url_with(&url, &opts));
+    server.shared.wrong_range.store(false, Ordering::SeqCst);
+    server.shared.ignore_range.store(true, Ordering::SeqCst);
+    check_err("no range support", open_url_with(&url, &opts));
+    server.shared.ignore_range.store(false, Ordering::SeqCst);
+    server.shared.gzip_label.store(true, Ordering::SeqCst);
+    check_err("encoded body", open_url_with(&url, &opts));
+    server.shared.gzip_label.store(false, Ordering::SeqCst);
+
+    // Errors of reads after the open, through a File.
+    let f = open_url_with(&url, &opts).unwrap();
+    server.shared.wrong_range.store(true, Ordering::SeqCst);
+    check_err(
+        "bad range",
+        f.dataset("big")
+            .map(|d| d.read_f64())
+            .and_then(|r| r)
+            .map_err(Error::Hdf5),
+    );
+    server.shared.wrong_range.store(false, Ordering::SeqCst);
+    let f = open_url_with(&url, &opts).unwrap();
+    server.shared.force_status.store(403, Ordering::SeqCst);
+    check_err(
+        "403 on a read",
+        f.dataset("big")
+            .map(|d| d.read_f64())
+            .and_then(|r| r)
+            .map_err(Error::Hdf5),
+    );
+    server.shared.force_status.store(0, Ordering::SeqCst);
+    let f = open_url_with(&url, &opts).unwrap();
+    let mut other = bytes.clone();
+    let n = other.len();
+    other[n / 2] ^= 0xff;
+    server.shared.put("/m.h5", other);
+    check_err(
+        "ETag change",
+        f.dataset("big")
+            .map(|d| d.read_f64())
+            .and_then(|r| r)
+            .map_err(Error::Hdf5),
+    );
+    // A timeout.
+    let mut slow = opts.clone();
+    slow.http.timeout = Duration::from_millis(100);
+    server.shared.delay_ms.store(1000, Ordering::SeqCst);
+    check_err("timeout", open_url_with(&url, &slow));
+    server.shared.delay_ms.store(0, Ordering::SeqCst);
+    // A connection closed unanswered, a bad scheme.
+    let port = {
+        let l = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
+        let port = l.local_addr().unwrap().port();
+        std::thread::spawn(move || {
+            for c in l.incoming() {
+                drop(c);
+            }
+        });
+        port
+    };
+    check_err(
+        "connection closed",
+        open_url_with(
+            &format!("http://user:[email protected]:{port}/a.h5?X-Amz-Signature=SECRETSIG"),
+            &opts,
+        ),
+    );
+    check_err(
+        "scheme",
+        open_url("ftp://user:[email protected]/a.h5?X-Amz-Signature=SECRETSIG"),
+    );
+    assert_eq!(
+        clawhdf5_remote::redact_url("https://me:pw@host:8/d/f.h5?X-Amz-Signature=abc&a=1#frag"),
+        "https://host:8/d/f.h5?X-Amz-Signature=REDACTED&a=REDACTED"
+    );
+}