openssh-2.1.0p2 (and previous): reading incorrect options causes 'ssh' to crash

[kromJx]

'ssh' will crash if the 'Cipher' option is given with no arguments
Eg. a line like
	Cipher
or
	Ciphers
in $HOME/.ssh/config, or (equivalently)
	ssh -o 'Cipher' some_host
will cause the command to crash with a
	Segmentation fault
error.

If some other option like 'Hostname' is used similarly
	ssh -o 'Hostname' some_host
the program correctly returns
	command-line line 0: Missing argument.


So there must be a problem with the 'cipher' keyword parsing code.

This was all tested on a i386 linux box with both openssh-2.1.0 and
openssh-2.1.0p2.

- J