How to add Certificate Authority (CA) in Fedora to support chain certificate?

Step 1. Using chrome to extract certificates.

Only need to use extract CA’s certificate. Export it with file extension named .pem

Please take a note that, update-ca-trust determines certificate format using file header which locates in very first bytes in the binary file. Eventhough you save certificates with .crt , .cer, it’s still .pem.

To determine file format, you shoule use command file, for example $ file file_name.

To illustrate this point. I’ll give an example.

####### List all file, take a look at the file extension, .crt and .pem
$ ls -l
'Default Trust_DigiCert Global Root CA.crt'
'Default Trust_DigiCert Global Root CA.pem'


####### Determine file format with command named `file`
$ file *
Default Trust_DigiCert Global Root CA.crt: PEM certificate
Default Trust_DigiCert Global Root CA.pem: PEM certificate

Step 2. Copy certificate authority’s certificate to /etc/pki/ca-trust/source/anchors

Step 3. Update /etc/ssl/certs/ca-certificates.crt

$ sudo update-ca-trust extract

You can check this file /etc/ssl/certs/ca-certificates.crt to ensure that it is updated.

Step 4. Testing

This is an image before update-ca-trust

And, this is an image after update-ca-trust.

Good luck!