Here’s how to do it.

1. Find a Windows PC.
2. Install iTunes.
3. Download purplera1n.
4. Run purplera1n.
5. Wait.
6. Run Freeze.
7. Reboot.

Now you’re jailbroken. To run OpenSSH simply install the OpenSSH package in Cydia and ssh to your iPhone with root/alpine login/pass combination.