SSL verification error when installing cocoapods

Question

What I did sudo gem install cocoapods

This is the full message from terminal

ERROR:  You must add /C=BE/O=GlobalSign nv-sa/CN=AlphaSSL CA - SHA256 - G2 to your local trusted store
ERROR:  Could not find a valid gem 'cocoapods' (>= 0), here is why:
          Unable to download data from https://rubygems.org/ - hostname "rubygems.org" does not match the server certificate (https://rubygems.org/specs.4.8.gz)
ERROR:  SSL verification error at depth 0: unable to get local issuer certificate (20)

I have no experience with SSL but I followed a couple of question similar to mine but no luck

What I've tried:

• Download and install the new SHA256 intermediate certificate
• Change hostname from https to http
• Follow this guide but couldn't copy GlobalSignRootCA.pem to ruby folder
• Use HomeBrew but got another error while installing it

Answer 1

MichaelHuelsen has the correct answer. Here I will give my step-by-step instructions that worked for me but overwrites the pem file with a large one, so beware if this has sensitive info you might want to not destroy.

1. ID the cert file.

$ ruby -ropenssl -e 'p OpenSSL::X509::DEFAULT_CERT_FILE'
"/etc/pki/tls/cert.pem"

Tells me where my cert file is.

1. Backup the cert file

cp /etc/pki/tls/cert.pem /tmp/cert.pem.bak

1. Copy down a full cert file via curl

See: https://curl.se/docs/caextract.html

curl --remote-name --time-cond cacert.pem https://curl.se/ca/cacert.pem

1. Move the new cacert.pem file to replace the old one

mv cacert.pem /etc/pki/tls/cert.pem

I then ran gem update --system to update things, but you may just be ok running your original gem command.