apt-get update: Err https://mirror.umd.edu -> server certificate verification failed

Question

Today I tried executed the command: apt-get update. But there seems to be a problem, because I get error-messages like these:

Err https://mirror.umd.edu trusty/main Sources
  server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none

Err https://mirror.umd.edu trusty/restricted Sources
  server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none

etc. And then:

W: Failed to fetch https://mirror.umd.edu/ubuntu/dists/trusty/main/source/Sources  server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none

W: Failed to fetch https://mirror.umd.edu/ubuntu/dists/trusty/restricted/source/Sources  server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none

etc.

I guess this problem is because I don't have a file called 'ca-certificates.crt' in that folder. I looked also on another server with Ubuntu 14.04 on it, but this certicate file doesn't excist there either. So, where can I find/download this crt-file?

I hope someone can help me.

Thanks, Kevin

Answer 1

Their certificate is invalid as of the other day - they forgot to renew their SSL Certificate

Simply visiting the URL with Firefox and checking the certificate warning shows you this.

mirror.umd.edu uses an invalid security certificate.

The certificate expired on 19/04/17 13:00.

The current time is 21/04/17 14:31.

You can either

• wait a bit
• Change repository
• Change the URLs in your apt sources to http:// (safe enough fi GPG signing is performed)
• Set Verify-Peer in your apt.conf settings to false (not recommended as a set-and-forget solution)