Class: VNCRec::RFB::Authentication::Abstract

Inherits:
Object
  • Object
show all
Defined in:
lib/vncrec/rfb/authentication.rb

Direct Known Subclasses

None, VncAuthentication

Instance Method Summary collapse

Constructor Details

#initialize(io, *args) ⇒ Abstract

Returns a new instance of Abstract.



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# File 'lib/vncrec/rfb/authentication.rb', line 5

def initialize(io, *args)
  @io = io
end

Instance Method Details

#get_security_types ⇒ Object

Once the protocol version has been decided, the server and client must agree on the type of security to be used on the connection. The server lists the security types that it supports:

--------------------------————--------------------------- | No. of bytes | Type | Description | | | [Value] | | --------------------------————--------------------------- | 1 | U8 | number-of-security-types | | number-of-security-types | U8 array | security-types | --------------------------————--------------------------- If the server listed at least one valid security type supported by the client, the client sends back a single byte indicating which security type is to be used on the connection:

+--------------+--------------+---------------+
| No. of bytes | Type [Value] | Description   |
+--------------+--------------+---------------+
| 1            | U8           | security-type |
+--------------+--------------+---------------+

If number-of-security-types is zero, then for some reason the connection failed (e.g., the server cannot support the desired protocol version). This is followed by a string describing the reason (where a string is specified as a length followed by that many ASCII characters):

    +---------------+--------------+---------------+
    | No. of bytes  | Type [Value] | Description   |
    +---------------+--------------+---------------+
    | 4             | U32          | reason-length |
    | reason-length | U8 array     | reason-string |
    +---------------+--------------+---------------+

The server closes the connection after sending the reason-string.
@return [Integer] types



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# File 'lib/vncrec/rfb/authentication.rb', line 57

def get_security_types
  num_of_st = @io.readbyte
  if num_of_st == 0 # failed
    reason_len = @io.readpartial(4).unpack('L>')[0]
    reason = @io.readpartial(reason_len)
    raise reason
  else
    result = []
    num_of_st.times do
      result << @io.readbyte
    end
    result
  end
end

#handle_types(types) ⇒ Object 



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# File 'lib/vncrec/rfb/authentication.rb', line 72

def handle_types(types)
  raise 'The server does not support requested auth method' unless types.include? @code
end

#handshake ⇒ Object 



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# File 'lib/vncrec/rfb/authentication.rb', line 13

def handshake
  types = get_security_types
  handle_types(types)
  send_type
  perform_authentication
  security_result
end

#perform_authentication ⇒ Object 



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# File 'lib/vncrec/rfb/authentication.rb', line 113

def perform_authentication
  raise 'NI'
end

#security_result ⇒ Object

The server sends a word to inform the client whether the security handshaking was successful.

+--------------+--------------+-------------+
| No. of bytes | Type [Value] | Description |
+--------------+--------------+-------------+
| 4            | U32          | status:     |
|              | 0            | OK          |
|              | 1            | failed      |
+--------------+--------------+-------------+

If unsuccessful, the server sends a string describing the reason for the failure, and then closes the connection:

+---------------+--------------+---------------+
| No. of bytes  | Type [Value] | Description   |
+---------------+--------------+---------------+
| 4             | U32          | reason-length |
| reason-length | U8 array     | reason-string |
+---------------+--------------+---------------+



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# File 'lib/vncrec/rfb/authentication.rb', line 104

def security_result
  word = (@io.readpartial 4).unpack('L>').first
  if word != 0
    reason_len = (@io.readpartial 4).unpack('L>').first
    reason = @io.readpartial(reason_len)
    raise reason
  end
end

#send_type ⇒ Object

If the server listed at least one valid security type supported by the client, the client sends back a single byte indicating which security type is to be used on the connection.



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# File 'lib/vncrec/rfb/authentication.rb', line 79

def send_type
  @io.syswrite to_msg
end

#to_msg ⇒ Object 



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# File 'lib/vncrec/rfb/authentication.rb', line 9

def to_msg
  [@code].pack('C')
end