SSH config parser does not strip quotes from IdentityFile values

[andrewfung729]

Shuttle's SSH config parser (src/shuttle/core/ssh_config.py) leaves surrounding quotes on IdentityFile values. Because the quotes are not removed, SSHConfigEntry.resolve_key() tries to resolve a literal path that still contains the quote characters, and fails to find the key file.

Reproduction

With the following ~/.ssh/config:

Host myserver
    HostName 10.0.0.1
    IdentityFile "~/.ssh/id_rsa"

Run:

from pathlib import Path
from shuttle.core.ssh_config import parse_ssh_config

# Make sure the key file exists
key = Path.home() / ".ssh" / "id_rsa"
key.write_text("KEY")

entries = parse_ssh_config()
print(entries[0].identity_file)  # '"~/.ssh/id_rsa"'  (includes double quotes)
print(entries[0].resolve_key())   # None

Expected behavior

entry.identity_file should be ~/.ssh/id_rsa (without the surrounding double quotes), and entry.resolve_key() should return the actual key path.

Actual behavior

entry.identity_file is "~/.ssh/id_rsa" (the quotes are part of the string), and resolve_key() returns None.

Additional notes

• The same problem occurs with single quotes: IdentityFile '~/.ssh/id_rsa'.
• Paths containing spaces, e.g. IdentityFile "~/.ssh/my key", are also mishandled. The current parser uses str.split(None, 1), which splits at the first whitespace inside the quoted value and drops the rest of the path.

Environment

• macOS
• Python 3.12+
• Shuttle main branch

Proposed solution

Replace the ad-hoc split(None, 1) / split("=", 1) logic with a regex that captures the whole rest of the line, so quoted values containing spaces are preserved. Then strip a single pair of matching outer quotes (" or ') from every value.

In src/shuttle/core/ssh_config.py:

1. Add a line regex that treats whitespace or = as the key/value separator, allowing optional spaces around =:

   _LINE_RE = re.compile(r"^(\S+?)(?:\s*=\s*|\s+)(.*)$")

2. Add a small _unquote helper:

   def _unquote(value: str) -> str:
       value = value.strip()
       if len(value) >= 2 and value[0] == value[-1] and value[0] in ('"', "'"):
           return value[1:-1]
       return value

3. In the parse loop, match the line with _LINE_RE, then unquote the captured value and skip empty values:

   match = _LINE_RE.match(line)
   if not match:
       continue
   
   key, value = match.group(1).strip(), _unquote(match.group(2))
   if not value:
       continue

This handles:

• IdentityFile "~/.ssh/id_rsa" → ~/.ssh/id_rsa
• IdentityFile "~/.ssh/my key" → ~/.ssh/my key
• IdentityFile = "~/.ssh/id_rsa" → ~/.ssh/id_rsa

Tests to add

In tests/test_core/test_ssh_config.py, add cases that:

1. Parse IdentityFile "~/.ssh/quoted_key" and verify the quotes are stripped and resolve_key() finds the file.
2. Parse IdentityFile "~/.ssh/my key" (with spaces inside the quotes) and verify the full path is kept and resolve_key() finds the file.

Offer to contribute

If the maintainers accept this approach, I’m happy to open a PR with the proposed fix and the corresponding tests.

[enwaiax]

Thanks for such a thorough report — the reproduction, the root-cause analysis, and a concrete patch with the exact tests to add is about as good as a bug report gets. Confirmed and fixed in #8, which follows your proposed approach almost verbatim (_LINE_RE + _unquote, skip empty values).

Apologies for jumping on it before you had the chance to open the PR — you offered and I should have given you the window. Full credit for the diagnosis is yours, and it's noted in the changelog entry.

Two notes from working through it:

1. There was a second, more severe bug hiding behind the same split() logic. Your regex fixes it as a side effect, so it's worth calling out explicitly. A spaced = separator — valid ssh_config(5) syntax — leaked the = into the value:

Port = 2222   →   value '= 2222'   →   int('= 2222')   →   ValueError

That exception propagates out of parse_ssh_config(), so a single such line means no hosts parse at all, not just the one. The existing test_equals_separator only covered the unspaced Port=3022, which is why it went unnoticed. test_equals_separator_with_spaces now covers it.

2. One small correction to the report. Under "Additional notes" you mention that str.split(None, 1) "splits at the first whitespace inside the quoted value and drops the rest of the path". maxsplit=1 actually keeps the remainder, so IdentityFile "~/.ssh/my key" was already preserved in full — the only reason it failed was the unstripped quotes. Doesn't change the fix or the test you suggested, just flagging it so the reasoning in the thread stays accurate for anyone reading later.

The quoted-path-with-spaces case is covered by test_quoted_path_with_spaces_preserved and an end-to-end resolve_key() test, exactly as you proposed.