SSH Config Editor

Introduction:

Secure Shell (SSH) clients read a plain-text config file that maps memorable host aliases to connection details such as hostname, port, and identity file. This indirection shortens command lines, enforces consistent options, and supports complex jump-host routing without repeating parameters across terminals.

The editor loads your existing configuration into a client-side reactive engine, parses every Host block, and lets you rename patterns, tweak options, or add new entries. A download button then regenerates a syntactically correct file you can overwrite on any device.

Use it when migrating keys, adding bastion routing, or decluttering wildcards; *always back up your original file before replacing production settings.*

Technical Details:

An SSH configuration is parsed line-by-line: each Host pattern header starts a stanza whose indented key–value pairs override client defaults for matching connections. Patterns may be exact names, wildcard globs, or negations, and later entries win on ties. Correct spacing, case-insensitive keys, and terminal newlines are essential for predictable behaviour.

1. Segment text at newline boundaries.
2. Detect lines that begin with Host ; start a new record.
3. Split subsequent non-blank lines into key value.
4. Normalise recognised keys; tag unknown ones as “Custom”.
5. Group records by wildcard, domain, or leave ungrouped for display.
6. On export, serialise every record and append a trailing newline.

Grouping only affects on-screen organisation; the downloaded file preserves the edited order exactly.

• Host Pattern – alias or glob matched by the SSH client.
• Key – recognised option or custom directive.
• Value – parameter string supplied to the key.
• Grouping Type – UI filter; none, wildcard, or domain.

Host web-*          ➜  Host web-*
    HostName 10.0.0.*       HostName app.internal
    User ubuntu             User deploy

• Whitespace outside keys is ignored.
• Duplicate keys keep the last edited occurrence.
• Comments are discarded on re-export.
• Negative patterns (!host) are treated as literals.

• Empty patterns are skipped during export.
• Custom keys without values generate an empty placeholder.
• Tabs convert to single spaces on load.
• Very large files may exhaust browser memory.

Behaviour mirrors the specification in RFC 4254 and the OpenSSH ssh_config manual, which define precedence, quoting, and wildcard rules.

This client-side process handles only local text and is unaffected by GDPR or HIPAA scopes.

Step-by-Step Guide:

Follow these steps to refactor your SSH settings safely.

1. Click Select SSH Config File and choose your existing file.
2. Review parsed hosts; pick a Group Hosts By option to reorder visually.
3. Edit patterns, keys, or values directly inside each accordion panel.
4. Use Add Line or Remove for individual directives.
5. Add entirely new hosts with Add Host.
6. Download the regenerated file, then replace ~/.ssh/config manually.

FAQ:

Glossary:

Host Pattern

Alias or wildcard targeting one or more servers.

Directive

Key controlling SSH behaviour for the matched host.

Wildcard

* or ? characters matching multiple names.

Jump Host

Intermediate server forwarding connections to the target.

Identity File

Path to the public/private key pair used for authentication.