:globe_with_meridians: Let’s Encrypt + KTOR When connecting to a server with a `Let's Encrypt` SSL ...

# ktor

[Max]

🌐 Let’s Encrypt + KTOR

When connecting to a server with a Let's Encrypt SSL certificate, I’m getting:
java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.

Can somebody tell me if this is a problem with the server configuration OR with my ktor-setup?

[Aleksei Tirman [JB]]

That means that the validity of the server CA cannot be verified. Can you share the URL to the HTTP server?

[Ludovic]

Do you get this error on a specific (range of) version of Android?
asking because this might be related to : https://letsencrypt.org/docs/certificate-compatibility/

[Max]

@Aleksei Tirman [JB] I’ll talk with my client if i can DM you the url, but need to ask first for permission.

@Ludovic Tested till now on Android 13 and Android 14, both times same error. Thx for the link! Is there a way to know if my certificate is ISRG Root X1 or ISRG Root X2?

In Chrome on Android 13 I can open the https link and no issues are reported (see screenshot 1).
I also ran an online test for the url and got screenshot 2.

[Ludovic]

@Max we can see the url in the first screenshot, you might want to delete it while waiting for your client's permission

[Max]

@Ludovic i checked 2 times i don’t have the url anywhere 👀 thx man!

[Ludovic]

Regarding the "is it ISRG Root X1 or ISRG Root X2 ?"

In Chrome desktop, you can see the certificate details through :
• icon next to the url
• Connexion is secured – with the padlock icon
• Valid certificate – with the check in a box icon
• Details tab in the dialog
sorry for the french screenshot :(

[Max]

@Ludovic Thx! I followed your steps and it actually is neither X1 nor X2, but it says USERTrust RSA Certification Authority. Some Googleing suggests this might be an older root certificate than X1 or X2?