Handling encrypted SSH keys

Hi
If an SSH key is encrypted, you get a nasty error message:

```
panic: Can't run remote command: asn1: structure error: tags don't match (16 vs {class:3 tag:14 length:112 isCompound:false}) {optional:false explicit:false application:false defaultValue:<nil> tag:<nil> stringType:0 set:false omitEmpty:false} pkcs1PrivateKey @2
```

Have you ever got around this problem?
Thanks
Alex
