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During the configuration of your instance you should have created a security group allowing at the minimum SSH access to the instance. If this has been done correctly, you can, for example, use SSH from the command-line or from a tool such as PuTTY to access the command-line of the user sshuser (for Charon-SSP prepackaged marketplace images) or your custom user (for RPM installations) on the Charon-SSP instance.
Please note: PuTTY uses a different key file format. It comes with tools to convert between its own .ppk format and the format of OpenSSH used by the default Linux tools.
If you select your instance in the instance list and then click on Connect, you will see the instructions for connecting via SSH.
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