Reading
[...} 16 or 32 byte AES key [...]
(http://bosh.io/jobs/atc?source=github.com/concourse/concourse#p=encryption_key) I was expecting
$ openssl enc -aes-256-cbc -k my_super_secret -P -md sha1
salt=7DE7F5AAA98A1E52
key=3C2293866568D49DFF5A8D85611E3A717AF09F08E7DE85B145E17547CB14B0DC
iv =7399712748AB8A677DC1056FD8888FC6
encryption_key: 3C2293866568D49DFF5A8D85611E3A717AF09F08E7DE85B145E17547CB14B0DC
to work in bosh configuration. But after configuration, atc doesn't come up again. Any suggestions?
Your key is too long. Try
openssl enc -aes-128-cbc -k my_super_secret -P -md sha1