feature #754: Missing ssh library for auth drivers

src/authm_mad/remotes/ssh/ssh_auth.rb

@@ -0,0 +1,114 @@
+# -------------------------------------------------------------------------- #
+# Copyright 2002-2011, OpenNebula Project Leads (OpenNebula.org)             #
+#                                                                            #
+# Licensed under the Apache License, Version 2.0 (the "License"); you may    #
+# not use this file except in compliance with the License. You may obtain    #
+# a copy of the License at                                                   #
+#                                                                            #
+# http://www.apache.org/licenses/LICENSE-2.0                                 #
+#                                                                            #
+# Unless required by applicable law or agreed to in writing, software        #
+# distributed under the License is distributed on an "AS IS" BASIS,          #
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   #
+# See the License for the specific language governing permissions and        #
+# limitations under the License.                                             #
+#--------------------------------------------------------------------------- #
+
+
+require 'pp'
+require 'openssl'
+require 'base64'
+require 'fileutils'
+
+# SSH key authentication class. It can be used as a driver for auth_mad
+# as auth method is defined. It also holds some helper methods to be used
+# by oneauth command
+class SshAuth
+    attr_reader :public_key
+                 
+    def initialize(pub_key = nil)
+        # Init proxy file path and creates ~/.one directory if needed
+        proxy_dir=ENV['HOME']+'/.one'
+        
+        begin
+            FileUtils.mkdir_p(proxy_dir)
+        rescue Errno::EEXIST
+        end
+       
+        @proxy_path  = proxy_dir + '/one_ssh'
+
+        # Init ssh keys using private key. public key is extracted in a 
+        # format compatible with openssl. The public key does not contain
+        # "---- BEGIN/END RSA PUBLIC KEY ----" and is in a single line
+        @private_key = File.read(ENV['HOME']+'/.ssh/id_rsa')
+
+        if pub_key == nil
+            key = OpenSSL::PKey::RSA.new(@private_key)
+
+            @public_key = key.public_key.to_pem.split("\n")
+            @public_key = @public_key.reject {|l| l.match(/RSA PUBLIC KEY/) }.join('')
+        else
+            @public_key = pub_key
+        end
+    end
+
+    # Creates the login file for ssh authentication at ~/.one/one_ssh.
+    # By default it is valid for 1 hour but it can be changed to any number
+    # of seconds with expire parameter (in seconds)
+    def login(user, expire=3600)
+        time = Time.now.to_i + expire
+
+        secret_plain   = "#{user}:#{time}"
+        secret_crypted = encrypt(secret_plain)
+
+        proxy = "#{user}:ssh:#{secret_crypted}"
+        
+        file = File.open(@proxy_path, "w")
+
+        file.write(proxy)
+
+        file.close
+        
+        # Help string
+        puts "export ONE_AUTH=#{ENV['HOME']}/.one/one_ssh"
+        
+        secret_crypted
+    end
+
+    # Checks the proxy created with the login method
+    def authenticate(user, token)
+        begin
+            token_plain = decrypt(token)
+            _user, time = token_plain.split(':')
+            
+            if user == _user
+                if Time.now.to_i >= time.to_i
+                    return "ssh proxy expired, login again to renew it"
+                else
+                    return true
+                end
+            else
+                return "invalid credentials"
+            end
+        rescue
+            return "error"
+        end
+    end
+
+private
+    ###########################################################################
+    #                       Methods to handle ssh keys
+    ###########################################################################
+    # Encrypts data with the private key of the user and returns
+    # base 64 encoded output in a single line 
+    def encrypt(data)
+        rsa=OpenSSL::PKey::RSA.new(@private_key)
+        Base64::encode64(rsa.private_encrypt(data)).gsub!(/\n/, '').strip
+    end
+
+    # Decrypts base 64 encoded data with pub_key (public key)
+    def decrypt(data)
+        rsa=OpenSSL::PKey::RSA.new(Base64::decode64(@public_key))
+        rsa.public_decrypt(Base64::decode64(data))
+    end
+end