Trusting Self-Signed Certificates from Ruby

I use Ruby as my primary general-purpose scripting language, and prefer to use it to automate repetitive / awkward tasks.

But working in a corporate environment, I don't always have the right certs trusted by my Operating System.

Let's say that we have the following code to reach out to an endpoint that knowingly uses a self-signed certificate:

uri = URI.parse('')
http =, uri.port)
http.use_ssl = true
data = http.get(uri.request_uri)
p data.to_hash

If the cert is not trusted, we'll receive the following exception:

/usr/lib/ruby/2.6.0/net/protocol.rb:44:in `connect_nonblock': SSL_connect returned=1 errno=0 state=error: certificate verify failed (self signed certificate in certificate chain) (OpenSSL::SSL::SSLError)
	from /usr/lib/ruby/2.6.0/net/protocol.rb:44:in `ssl_socket_connect'
	from /usr/lib/ruby/2.6.0/net/http.rb:996:in `connect'
	from /usr/lib/ruby/2.6.0/net/http.rb:930:in `do_start'
	from /usr/lib/ruby/2.6.0/net/http.rb:919:in `start'
	from /usr/lib/ruby/2.6.0/net/http.rb:1470:in `request'
	from /usr/lib/ruby/2.6.0/net/http.rb:1228:in `get'
	from http.rb:8:in `<main>'

This doesn't help us do our work, so we have some options to get around the issue.

The most effective solution is following your Operating System's guidelines for installing a certificate globally.

Alternatively, we can use one of the two OpenSSL environment variables to get around it:

env SSL_CERT_DIR=/path/to/certs/folder ruby http.rb
env SSL_CERT_FILE=/path/to/cert.crt ruby http.rb

I've had some difficulty getting SSL_CERT_DIR working, so maybe expect a follow-up post on that.

Update 2019-12-04: I've written up how to get SSL_CERT_DIR working in my blog post Setting up a directory for OpenSSL's `SSL_CERT_DIR.

Written by Jamie Tanna's profile image Jamie Tanna on , and last updated on .

Content for this article is shared under the terms of the Creative Commons Attribution Non Commercial Share Alike 4.0 International, and code is shared under the Apache License 2.0.


This post was filed under articles.

This post is part of the series nablopomo-2019.

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