How do I fix “Server SSL certificate verification failed: issuer is not trusted” when using SVN?

GIT is often the version control of choice these days for developers, but for anyone managing WordPress plugins or themes, you’ll be used to SVN.

However, if you get the following error, then you may also find that you can’t access your repos either:

svn: E230001: Server SSL certificate verification failed: issuer is not trusted

What’s causing the “Server SSL certificate verification failed” error?

Whether this is with WordPress repos or any other code on SVN, this indicates an issue with the SSL certificate. What’s important here is that last part: “issue is not trusted”. The certificate couldn’t be confirmed so you should tread with caution.

When this last happened to me with my WordPress repos, I highlighted it to the WordPress Core development team so that they could investigate the root cause (which was with the general plugins repo). Once you know the cause and are happy that the certificate can be trusted, then proceed with the following.

How to work around the error

Assuming you have SVN installed on your computer locally, kick open a command prompt and run the following command:

svn list [repository URL]

Replace [repository URL] with the appropriate URL of your repository. It will then prompt you to reject or accept the certificate (either permanently or temporarily). Once that’s done, you can then access the repo again.

Here’s what it looks like when I did it for one of my plugin repositories:

svn list https://plugins.svn.wordpress.org/no-self-ping
Error validating server certificate for 'https://plugins.svn.wordpress.org:443':
 - The certificate is not issued by a trusted authority. Use the
   fingerprint to validate the certificate manually!
Certificate information:
 - Hostname: *.svn.wordpress.org
 - Valid: from Jun 20 19:25:08 2018 GMT until Jul 15 19:04:26 2020 GMT
 - Issuer: Go Daddy Secure Certificate Authority - G2, http://certs.godaddy.com/repository/, GoDaddy.com, Inc., Scottsdale, Arizona, US
 - Fingerprint: [redacted]
(R)eject, accept (t)emporarily or accept (p)ermanently? p

Because the certificate covers all of the wp.org repo in this instance, just running this once is sufficient to correct all the repositories that you may have there.

How to Install SVN

If you’re using some kind of SVN management software (e.g. svnX, TortoiseSVN or Versions) then you may not have SVN installed for command line access. Follow the guides here to install it:

macOS

This is quite simple and can be done by running the following in Terminal:

brew install svn

Brew is a package manager for macOS so if you don’t have it installed then you can simply install it.

Windows

Windows is easier still. Download and install the latest version of Subversion here (whichever is titled “Includes all Subversion command-line binaries”).