Nicer error for unsupported SSH key type [GH-805]

CHANGELOG.md

@@ -2,6 +2,7 @@
 
   - Provisioners will still mount folders and such if `--no-provision` is
     used, so that `vagrant provision` works. [GH-803]
+  - Nicer error message if an unsupported SSH key type is used. [GH-805]
 
 ## 1.0.1 (March 11, 2012)
 

lib/vagrant/communication/ssh.rb

@@ -129,10 +129,24 @@ module Vagrant
         @vm.ssh.check_key_permissions(ssh_info[:private_key_path])
 
         # Connect to SSH, giving it a few tries
-        @logger.info("Connecting to SSH: #{ssh_info[:host]}:#{ssh_info[:port]}")
-        exceptions = [Errno::ECONNREFUSED, Net::SSH::Disconnect]
-        connection = retryable(:tries => @vm.config.ssh.max_tries, :on => exceptions) do
-          Net::SSH.start(ssh_info[:host], ssh_info[:username], opts)
+        connection = nil
+        begin
+          @logger.info("Connecting to SSH: #{ssh_info[:host]}:#{ssh_info[:port]}")
+          exceptions = [Errno::ECONNREFUSED, Net::SSH::Disconnect]
+          connection = retryable(:tries => @vm.config.ssh.max_tries, :on => exceptions) do
+            Net::SSH.start(ssh_info[:host], ssh_info[:username], opts)
+          end
+        rescue Net::SSH::AuthenticationFailed
+          # This happens if authentication failed. We wrap the error in our
+          # own exception.
+          raise Errors::SSHAuthenticationFailed
+        rescue Errno::ECONNREFUSED
+          # This is raised if we failed to connect the max amount of times
+          raise Errors::SSHConnectionRefused
+        rescue NotImplementedError
+          # This is raised if a private key type that Net-SSH doesn't support
+          # is used. Show a nicer error.
+          raise Errors::SSHKeyTypeNotSupported
         end
 
         @connection = connection
@@ -145,14 +159,7 @@ module Vagrant
         # Yield the connection that is ready to be used and
         # return the value of the block
         return yield connection if block_given?
-      rescue Net::SSH::AuthenticationFailed
-        # This happens if authentication failed. We wrap the error in our
-        # own exception.
-        raise Errors::SSHAuthenticationFailed
-      rescue Errno::ECONNREFUSED
-        # This is raised if we failed to connect the max amount of times
-        raise Errors::SSHConnectionRefused
-      end
+     end
 
       # Executes the command on an SSH connection within a login shell.
       def shell_execute(connection, command, sudo=false)

lib/vagrant/errors.rb

@@ -318,6 +318,11 @@ module Vagrant
       error_key(:ssh_key_bad_permissions)
     end
 
+    class SSHKeyTypeNotSupported < VagrantError
+      status_code(76)
+      error_key(:ssh_key_type_not_supported)
+    end
+
     class SSHPortNotDetected < VagrantError
       status_code(50)
       error_key(:ssh_port_not_detected)

templates/locales/en.yml

@@ -124,6 +124,10 @@ en:
         permissions on the following file to 0600 and then try running this command again:
 
         %{key_path}
+      ssh_key_type_not_supported: |-
+        The private key you're attempting to use with this Vagrant box uses
+        an unsupported encryption type. The SSH library Vagrant uses does not support
+        this key type. Please use `ssh-rsa` or `ssh-dss` instead.
       ssh_port_not_detected: |-
         Vagrant couldn't determine the SSH port for your VM! Vagrant attempts to
         automatically find a forwarded port that matches your `config.ssh.guest_port`