Corrected the length of the salt for private key encryption #346
This would corrupt the private key file whenever the DES cipher would get selected.
For me, executing these two lines results in an error and deletes the private key:
The error is the following:
In the example, the filename is a path to the ssh private key file, generated with ssh-keygen, encrypted with AES-128-CBC. The oldpassword contains the old key for the ssh key, newpassword the new one.