Problems with private key in the authentication test

When I test the authentication I keep getting authentication_key.role=PUBLIC and the problem is probably related to the private key since my php error log says "openssl_sign(): Supplied key param cannot be coerced into a private key".
I generated the key with PuTTYgen and converted it from .ppk to .pem format but it keeps failing when trying to use it.
In addition to this I get the following error:

error:0909006C:PEM routines:get_name:no start line.

The key has the following format:

-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,4B42097CFDAC1C83

iE3YbdgrfpHd1Oya44/lNgRN4AKUw4Ps96E+Np0TK7fztsZIhkq5zseExTqw4uzW
JAkVovXcTyufIJ0DzdYd0gRwL+76m33PUhln2QBuHp7Caz+kDwLRJtmvnPbLB20E
U5Bh/AcTfg6+bsxpxc5173hOTe0aNNgNeym7lCkr/naTj38bn6Lx. . . . . . .
-----END RSA PRIVATE KEY-----

What I'm doing is importing the .pem file as openssl_pkey_get_private("file:../lib/privateKey.pem", "passphrase");

What could be wrong with this?