Self-Signed Certificate in Certificate Chain

Situation

A backup plan via firewall returns the following errror: SSL certificate problem: self-signed certificate in certificate chain"

Cause

A certificate is self-signed, so it is non-trusted by default.

Solution

Add Certificate Contents to .cacerts.pem File Manually

To add contents of your certificate that produced such error, proceed as follows:

  1. Convert your .cer certificate file to .pem certificate. For example, use this command in terminal emulator: openssl x509 -in certname.cer -inform DER -out certname.pem -outform PEM
  2. Open the new file (certname.pem) in any text editor.
  3. Copy the contents of the file.
  4. Navigate to /Applications/backupname.app/Contents/Resources/share.
  5. Find the .cacerts.pem and edit it in text editor.
  6. Scroll to the end of the .cacerts.pem file, then and paste the certificate contents of the certname.pem file.
  7. Save the .cacerts.pem file.