First page Back Continue Last page Overview Graphics
SSH.com’s SSH1, originally completely free with source code, then license changed with version 1.2.13
SSH.com’s SSH2, originally only commercial, but now free for some uses.
OpenSSH team took the last free SSH1 release, refixed bugs, added features, and added support for the SSH2 protocol.
The licensing issue is rather complex; depending on which release of the ssh1 and ssh2 applications you choose:
Source code may or may not be available
Use may be free or for cost for educational institutions
Use may be free or for cost for companies
The O’Reilly SSH book covers this in good detail.
The SSH1 protocol has some shortcomings that aren’t easily fixed except by using the newer, but incompatible SSH2 protocol. If possible, you should use SSH clients and servers that support SSH2 and prefer it over SSH1 protocol connections.