Hey community,
I’ve written a little certificate checker.
Maybe someone will find it useful, or maybe you have ideas for improvements or additions.
AUR makes it so easy to install this in seconds. Thanks for sharing.
1 Like
Sure thing. I still need to tweak the PKGBUILD script for the AUR. The binary is pretty large, and I want to compress it, just like the version on GitHub.
2 Likes
Despite of availability of bulky all-in-one tools, say, openssl for the case, it is often convenient to have laconic single-purpose tool nicely tailored to one’s needs and purposes. 
I can speculate that cert-checker could benefit from the following options:
- print certificate’s ‘meta’ in human-readable form w/o keys;
- save original
.pemcertificate; - print and/or save info in structured format (json/xml) to simplify using
cert-checkerwithinbashscripts; - reflect certificate validity through return codes (+silent mode?);
- allow for offline operation on saved certificate files.
3 Likes
sounds good!
I’ll try to put some of these ideas into practice. Thanks.
4 Likes
Unfortunately, I didn’t have much time today. Still, here are two additional pieces of information as requested.
What do you think of a simple version and a version with more information?
Github and AUR are updated
2 Likes
Looks very nice to me!
BTW, do you think that ‘chains of trust’ may be a problem that’s worth consideration? E.g.
3 Likes
Thanks!
I think Go already provides everything you need. Go is well-suited for things like this without needing extra libraries.
But I’ll look into it; I like the idea.
2 Likes
5 Likes
Excellent! Very well done, @toadie !
4 Likes
Thank you. Today I want to code a bit more before tomorrow business starts again 
4 Likes
Now it’s possible to save the output as a JSON file:
{
"generated_at": "2026-04-19T22:06:17+02:00",
"total_count": 4,
"results": [
{
"URL": "archlinux.org",
"Issuer": "CN=E7,O=Let's Encrypt,C=US",
"Subject": "archlinux.org",
"SerialNumber": "501723845572470313389773169616896755109263",
"NotBefore": "2026-04-13T11:59:12Z",
"NotAfter": "2026-07-12T11:59:11Z",
"DaysRemaining": 83,
"Status": "OK",
"Error": null,
"KeyAlgorithm": "ECDSA",
"KeySize": 256,
"SignatureAlgorithm": "ECDSA-SHA384",
"SANs": [
"archlinux.org"
],
"ThumbprintSHA1": "b36e7e96c849673e16903dd2a17c684a2ac0be02",
"ThumbprintSHA256": "7b76334e7e52028a90f09baa408f1a2a71a714369902f146d8a2a742150db3a1",
"ChainLength": 2,
"IsChainComplete": true,
"ChainError": "",
"IsSelfSigned": false,
"RootIssuer": "ISRG Root X1"
},
{
"URL": "github.com",
"Issuer": "CN=Sectigo Public Server Authentication CA DV E36,O=Sectigo Limited,C=GB",
"Subject": "github.com",
"SerialNumber": "39557711522153605937503944820825465427",
"NotBefore": "2026-03-06T00:00:00Z",
"NotAfter": "2026-06-03T23:59:59Z",
"DaysRemaining": 45,
"Status": "SOON",
"Error": null,
"KeyAlgorithm": "ECDSA",
"KeySize": 256,
"SignatureAlgorithm": "ECDSA-SHA256",
"SANs": [
"github.com",
"www.github.com"
],
"ThumbprintSHA1": "ab58ea128ba92ca69a31b36b4e545653eed2a6cf",
"ThumbprintSHA256": "9716d39441ca651c51be78e969ca385ec213ec17715b8c91f01ee652f90fc62c",
"ChainLength": 3,
"IsChainComplete": true,
"ChainError": "",
"IsSelfSigned": false,
"RootIssuer": "USERTrust ECC Certification Authority"
},
{
"URL": "ubuntu.com",
"Issuer": "CN=R12,O=Let's Encrypt,C=US",
"Subject": "ubuntu.com",
"SerialNumber": "588183328622646244879507649310188122479749",
"NotBefore": "2026-04-17T04:13:36Z",
"NotAfter": "2026-07-16T04:13:35Z",
"DaysRemaining": 87,
"Status": "OK",
"Error": null,
"KeyAlgorithm": "RSA",
"KeySize": 2048,
"SignatureAlgorithm": "SHA256-RSA",
"SANs": [
"ubuntu.com",
"www.ubuntu.com"
],
"ThumbprintSHA1": "f39b552a2183a34263e8566cc02eece120cc3996",
"ThumbprintSHA256": "f3a90c7328568d1e032c0202b5ed49c9a5327e6650e0335ce182a81a0896ff0e",
"ChainLength": 2,
"IsChainComplete": true,
"ChainError": "",
"IsSelfSigned": false,
"RootIssuer": "ISRG Root X1"
},
{
"URL": "linuxcommunity.io",
"Issuer": "CN=WE1,O=Google Trust Services,C=US",
"Subject": "linuxcommunity.io",
"SerialNumber": "289311228209441141257262774674593578366",
"NotBefore": "2026-02-23T07:36:54Z",
"NotAfter": "2026-05-24T08:36:47Z",
"DaysRemaining": 34,
"Status": "SOON",
"Error": null,
"KeyAlgorithm": "ECDSA",
"KeySize": 256,
"SignatureAlgorithm": "ECDSA-SHA256",
"SANs": [
"linuxcommunity.io",
"*.linuxcommunity.io"
],
"ThumbprintSHA1": "5a2ca02b7195d0e978779dae6b07fe6954673e48",
"ThumbprintSHA256": "aa8534a227cf12c73c0fadbc37530d9d172c5ad21c7477815e80a9eca4cc86d5",
"ChainLength": 3,
"IsChainComplete": true,
"ChainError": "",
"IsSelfSigned": false,
"RootIssuer": "GlobalSign Root CA"
}
]
}
5 Likes
A new version is available.
Detailed documentation will follow in the coming days.
In short, you can do the following:
- Check a list of URLs
- Check individual URLs (comma-separated)
- Check local certificate files
- Save information as JSON
flag mode
or interactive
5 Likes
Hi everyone,
I received the following email today. What do you think of it? Has anyone else seen this?
PitchHut
Hi Toadie,
I hope this message finds you well! I’m Anar from PitchHut. We came across your project go-check-cert and would love to invite you to showcase it on our platform. To make the process seamless, we have created a temporary preview page for you. You can access it using the link below. Rest assured, we do not publicly share this page anywhere.
Here is what we have highlighted about go-check-cert:
Preview page link: https://pitchhut.com/project/go-check-cert-validator
Tagline: Effortlessly check website certificate validity with a simple tool.
Pitch: Go-check-cert is a straightforward tool designed to verify the validity of website certificates. Whether checking a single URL or processing a batch from a file, this utility simplifies the process, offering clarity on certificate status with easy installation and usage. Enjoy peace of mind about your website’s security.
We would love to have go-check-cert in our growing collection of exceptional projects, and I believe we could help amplify its visibility and reach.
Your project, your control
You have full control over your project’s presence on PitchHut. If you prefer not to have go-check-cert on PitchHut, simply reply ‘Delete’ to this email and we’ll remove the preview page immediately. If we do not hear from you within 30 days, we will permanently delete the preview page. The preview page features only publicly available information about go-check-cert. We respect your preferences and want to ensure you’re comfortable with how your project is shared with our community.
What’s next?
If you’re interested in giving it a try, you can create an account to:
- use our token system to increase your project’s visibility
- customize how your project is presented
- get insights on who’s viewing your project
If you sign up with this email address, you’ll automatically get access to manage your project. Using a different email? Just reply to this email, and we’ll help you claim ownership.
How it works
PitchHut is a gamified project discovery platform where makers showcase their work and connect with potential users and contributors. PitchHut uses a simple token system - you earn contribution tokens by viewing projects from other users, then use those tokens to boost your own project’s visibility. It’s a fair way to help projects find their early users and contributors.
We’d love for you to check out the platform, take control of your project, and start growing your user base with us. Looking forward to having you on board!
Best regards,
Anar
3 Likes
A very quick check revealed that
- PitchHut’s site homepage mentiones “Nano Leaps” LTD.
- “Nano Leaps” LTD has “nanoleaps.com” site which is in its early babyhood.
- Some more information can be found at NANO LEAPS LTD. overview - Find and update company information - GOV.UK and https://open.endole.co.uk/insight/company/16090277-nano-leaps-ltd
Provided that “Nano Leaps” is a registered entity, which claims to be software publisher and developer, and that its information and “Pitch Hut” refers to the same personalities, I’d conclude that they are probably harmless. (No pro- or contra- warranties, though)
The rest is at your disposition.
3 Likes
Agreed. Looks like a similar idea to producthunt.com.
You probably accepted because I’m able to access the page they linked to in email.
Looks like a legit new project to me also.
3 Likes
I am a bit worried about this sentence:
Ownership will be transferred to the creator upon claiming.
What does that even imply ?
3 Likes
Thank you @tkn - I build the tool just for fun and primary for my own needs but I don’t want to give it away
3 Likes
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