I am trying to generate a self-signed certificate using the instructions that Heroku suggests here: http://www.akadia.com/services/ssh_test_certificate.html
This cre
Just in case others are getting this error - I was getting the same error setting up a test hostname SSL certificate for my app.
The answer was that I had not added the domain name the certificate was for first - it does not explicity say this in the Heroku SSL docs. So before adding the cert do:
heroku domains:add secure.mydomain.com
and then you can add the certificate:
heroku ssl:add ssl.crt ssl.key
Have you added the SSL addon on your heroku app setting?
Also, you shouldn't be posting your private key online since it's supposed to be... well... private.
I suggest you generate a new key pair for your app.
EDIT:
You mentioned that you enabled the piggyback SSL, in which case, you don't need to generate your own keys. See this:
An app specific SSL certificate is not required for Piggyback SSL. The *.heroku.com wildcard SSL certificate is used for all apps. You can view information about this certificate by visiting https://heroku.com/ and clicking the lock icon in your browser.