https://github.com/mrtoadie/go-check-cert
simple validity checker for website certificates with web dashboard
https://github.com/mrtoadie/go-check-cert
certificates go linux terminal-app
Last synced: about 1 month ago
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simple validity checker for website certificates with web dashboard
- Host: GitHub
- URL: https://github.com/mrtoadie/go-check-cert
- Owner: mrtoadie
- License: mit
- Created: 2026-04-07T19:13:45.000Z (3 months ago)
- Default Branch: main
- Last Pushed: 2026-05-26T19:41:56.000Z (about 1 month ago)
- Last Synced: 2026-05-26T21:21:19.421Z (about 1 month ago)
- Topics: certificates, go, linux, terminal-app
- Language: Go
- Homepage:
- Size: 38.5 MB
- Stars: 5
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
- Security: SECURITY.md
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README
# *Stay secure, stay informed*
    
**Cert-Checker** is a *privacy-focused* [Go](https://go.dev/) tool that monitors **SSL/TLS certificates** on domains and local files, analyzes expiration dates, and alerts users if any issues are detected.
It offers both a powerful **command-line** interface for automation and an interactive **web dashboard**.
## Latest Release
May 30, 2026 [Version 1.4.0](https://github.com/mrtoadie/go-check-cert/releases/tag/v1.4.0)
## Features
- **Certificate Verification**
- Hybrid Scanning: Supports remote domains (https://example.com) and local certificate files (.pem, .crt, .key).
- Chain Validation: Verifies certificate chains, detects self-signed certificates, and identifies missing intermediates.
- CI/CD Ready: Returns specific exit codes (0=OK, 1=Warning, 2=Error) for integration into pipelines.
- **Interactive Web Dashboard**
- Real-Time Visualization: Responsive UI with Dark Mode support.
- Filtering: Filter by status, search by domain/issuer, and sort by expiration date.
- Auto-Refresh: Configurable background updates (e.g., every 15 mins) to keep data fresh.
- **Security & Privacy**
- Local Storage: No external databases or cloud dependencies required.
- HTTPS Dashboard: Built-in support for self-signed or Let's Encrypt certificates to secure the dashboard connection.
- **Automation & Management**
- Cron Job Manager: Built-in interactive CLI to create, list, and remove scheduled scans.
- Reporting: Exports detailed JSON reports with timestamps for archival or external processing.
- Save Certificates: Download valid certificates (optional)
## Quick Start
### Build from source
```bash
git clone https://github.com/mrtoadie/go-check-cert.git
cd go-check-cert
go build -o cert-checker
```
### Run directly (without build)
```bash
go run .
```
### Arch Linux
Install from [AUR](https://aur.archlinux.org/packages/cert-checker)
```bash
yay -S cert-checker
```
### Launch with Dashboard
```bash
# Without HTTPS
./cert-checker -web
# With HTTPS and self-signed certificate
./cert-checker -web -cert ./certs/cert.pem -key ./certs/key.pem
```
Open http://localhost:8080 or https://localhost:8080 in your browser.
## Screenshots
## Command Line Options
| Flag | Alias | Description |
| --- | --- | --- |
| -a | -advanced | Show advanced certificate details |
| -f | -file | Path to a local .pem, .crt, .cer, or .key file |
| -c | -cron | Interactive Cron setup |
| -dl | -download | Download valid certificates to certs folder |
| -md | -markdown | Saves results in Markdown format |
| -ls | -list | List and manage Cron jobs |
| -l | -log | Show cron job log file |
| -ci | -ci-mode | CI/CD Mode (non-interactive, uses urls.txt) |
| -w | -web | Start web dashboard on localhost:8080 |
| -cert | | Path to SSL certificate file (.pem/.crt) |
| -key | | Path to SSL private key file (.pem) |
| -h | -help | Display help message |
## Examples
Check a single certificate:
```bash
./cert-checker -f ./server.crt
```
Set up cron job(s):
```bash
./cert-checker -c
```
List active Cron jobs:
```bash
./cert-checker -ls
```
## Configuration
The tool automatically creates a configuration file on the first run.
Location: `~/.config/cert-checker/urls.txt`
Format: One URL per line. Comments starting with # are supported.
## Output Examples
Text Output (Default)
```bash
=== RESULTS ===
1. forum.linuxguides.de
Days: 44 | Valid: 26.02.26 → 27.05.26
Issuer: R12
------------------------------------
2. github.com
Days: 52 | Valid: 06.03.26 → 03.06.26
Issuer: Sectigo Public Server Authentication CA DV E36
------------------------------------
=== SUMMARY ===
OK: 0 | Warn: 2 | Exp: 0 | Err: 0
```
JSON Output
```json
{
"generated_at": "2026-05-03T14:47:42Z",
"total_count": 1,
"results": [
{
"url": "https://github.com",
"status": "OK",
"days_remaining": 180,
"is_chain_complete": true,
"key_algorithm": "RSA",
"key_size": 2048
}
]
}
```
## Cron Job Management
Interactive Menu
```bash
./cert-checker -cron
```
Options:
1. Set up cron job – Create a new automated check
2. List & manage jobs – View/delete existing jobs
3. Exit – Quit the program
List Cron Jobs
```bash
./cert-checker -list
``
Output:
```bash
=== CERTIFICATE CHECK CRON JOBS ===
1. # cert-checker - 2026-05-03 14:47:42
0 8 * * * /home/user/cert-checker -ci >> /tmp/cert-check.log 2>&1
2. # cert-checker - 2026-05-03 15:00:00
0 */6 * * * /home/user/cert-checker -ci >> /tmp/cert-check.log 2>&1
Total: 2 job(s) found.
```
#### Delete Individual Jobs
- Run ./cert-checker -list
- Select "Delete individual jobs"
- Mark jobs with Spacebar
- Confirm with Enter
## Usage
The input is interactive and automatically detects the correct format.
- Press **Enter** to use the default list of URLs (~/.config/cert-checker/urls.txt)
- To check individual URLs: *github.com* or *github.com*, *ubuntu.com*, *example.org*
- Check local certificate file: '~/github.pem'
- Certificate files can also be checked using a flag: cert-checker --file ~/github.pem
Certificate files with the following extensions work: .pem, .cer, .crt, .key
## Tested on
:white_check_mark: [Arch Linux](https://archlinux.org/)
:white_check_mark: [Solus](https://getsol.us/)
:white_check_mark: WSL2 (Ubuntu)
## License
go-check-cert is licensed under the [MIT License](LICENSE).