Can't open .pem file in keychain access

Question

So I'm trying to set up an EC2 instance on AWS and I've created a key pair and downloaded the .pem file. However, when I try to open it I get the error message:

I've also read about entering the following in the terminal to work around the issue:

security import pub_key.pem -k ~/Library/Keychains/login.keychain

but this doesn't work either (I get the following error message:

security: Error reading infile pub_key.pem: No such file or directory).

I've also tried just creating new key pairs but the problem persists.

Answer 1

The keychain extension changed with Sierra. Now it is login.keychain-db. You should navigate to where the pem key file is and use

security import pub_key.pem -k ~/Library/Keychains/login.keychain-db