Preliminary support for RSA user authentication in SSH2! Most of the

error messages are currently wrong, and Pageant doesn't yet support
the new key type, and I haven't thoroughly tested that falling back
to password authentication and trying invalid keys etc all work. But
what I have here has successfully performed a public key
authentication, so it's working to at least some extent.

[originally from svn r973]

sshdh.c

@@ -1,10 +1,10 @@
 #include "ssh.h"
 
-struct ssh_kex ssh_diffiehellman = {
+const struct ssh_kex ssh_diffiehellman = {
     "diffie-hellman-group1-sha1"
 };
 
-struct ssh_kex ssh_diffiehellman_gex = {
+const struct ssh_kex ssh_diffiehellman_gex = {
     "diffie-hellman-group-exchange-sha1"
 };