Class: Dnsruby::RR::DS

Inherits:
Dnsruby::RR show all
Defined in:
lib/dnsruby/resource/DS.rb

Overview

RFC4034, section 4 The DS Resource Record refers to a DNSKEY RR and is used in the DNS DNSKEY authentication process. A DS RR refers to a DNSKEY RR by storing the key tag, algorithm number, and a digest of the DNSKEY RR. Note that while the digest should be sufficient to identify the public key, storing the key tag and key algorithm helps make the identification process more efficient. By authenticating the DS record, a resolver can authenticate the DNSKEY RR to which the DS record points. The key authentication process is described in [RFC4035].

Direct Known Subclasses

CDS, DLV

Defined Under Namespace

Classes: DigestTypes

Constant Summary collapse

ClassValue =

:nodoc: all

nil
TypeValue =

:nodoc: all

Types::DS

Constants inherited from Dnsruby::RR

ClassInsensitiveTypes

Instance Attribute Summary collapse

Attributes inherited from Dnsruby::RR

#klass, #name, #rdata, #ttl, #type

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Dnsruby::RR

#<=>, #==, #clone, create, #eql?, find_class, #from_hash, get_class, get_num, #hash, implemented_rrs, #init_defaults, new_from_data, new_from_hash, new_from_string, #rdlength, #sameRRset, #to_s

Instance Attribute Details

#algorithm ⇒ Object

The algorithm used for this key See Dnsruby::Algorithms for permitted values



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# File 'lib/dnsruby/resource/DS.rb', line 62

def algorithm
  @algorithm
end

#digest ⇒ Object

The DS record refers to a DNSKEY RR by including a digest of that DNSKEY RR.



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# File 'lib/dnsruby/resource/DS.rb', line 69

def digest
  @digest
end

#digest_type ⇒ Object

The DS RR refers to a DNSKEY RR by including a digest of that DNSKEY RR. The Digest Type field identifies the algorithm used to construct the digest.



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# File 'lib/dnsruby/resource/DS.rb', line 66

def digest_type
  @digest_type
end

#digestbin ⇒ Object

Returns the value of attribute digestbin.



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# File 'lib/dnsruby/resource/DS.rb', line 70

def digestbin
  @digestbin
end

#key_tag ⇒ Object

The Key Tag field lists the key tag of the DNSKEY RR referred to by the DS record, in network byte order.



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# File 'lib/dnsruby/resource/DS.rb', line 59

def key_tag
  @key_tag
end

Class Method Details

.decode_rdata(msg) ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/DS.rb', line 245

def self.decode_rdata(msg) #:nodoc: all
  key_tag, algorithm, digest_type = msg.get_unpack("ncc")
  digest = msg.get_bytes
  return self.new(
    [key_tag, algorithm, digest_type, digest])
end

.from_key(key, digest_type) ⇒ Object 



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# File 'lib/dnsruby/resource/DS.rb', line 150

def DS.from_key(key, digest_type)
# # The key must not be a NULL key.
#    if ((key.flags & 0xc000 ) == 0xc000 )
# 	puts "\nCreating a DS record for a NULL key is illegal"
#        return
#    end
# 
#    # Bit 0 must not be set.
#    if (key.flags & 0x8000)
# 	puts "\nCreating a DS record for a key with flag bit 0 set " +
# 	    "to 0 is illegal"
#          return
#    end
# 
    #  Bit 6 must be set to 0 bit 7 must be set to 1
    if (( key.flags & 0x300) != 0x100)
	puts "\nCreating a DS record for a key with flags 6 and 7 not set "+
	    "0  and 1 respectively is illegal"
   return
    end
# 
# 
#    if (key.protocol  != 3 )
# 	puts "\nCreating a DS record for a non DNSSEC (protocol=3) " +
# 	    "key is illegal"
#          return
#    end
# 
  digest_type = get_digest_type(digest_type)
  #  Create a new DS record from the specified key
  ds = RR.create(:name => key.name, :type => "DS", :ttl => key.ttl,
                :key_tag => key.key_tag,
               :digest_type => digest_type, :algorithm => key.algorithm)

  ds.digestbin = ds.digest_key(key, digest_type)
  ds.digest = ds.digestbin.unpack("H*")[0]
  return ds
end

.get_digest_type(d) ⇒ Object 



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# File 'lib/dnsruby/resource/DS.rb', line 77

def DS.get_digest_type(d)
  if (d.instance_of?String)
    if (d.length == 1)
      d = d.to_i
    end
  end
  begin
    digest = DigestTypes.new(d)
    return digest
  rescue ArgumentError => e
    raise DecodeError.new(e)
  end
end

Instance Method Details

#check_key(key) ⇒ Object

Check if the key’s digest is the same as that stored in the DS record



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# File 'lib/dnsruby/resource/DS.rb', line 134

def check_key(key)
  if ((key.key_tag == @key_tag) && (key.algorithm == @algorithm))

    digestbin = digest_key(key)
    if (@digestbin == digestbin)
      if (!key.zone_key?)
      else
        return true
      end
    else
    end
  end
  return false
end

#digest_key(*args) ⇒ Object

Return the digest of the specified DNSKEY RR



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# File 'lib/dnsruby/resource/DS.rb', line 106

def digest_key(*args) # key, digest_type)
  digest_type = @digest_type
  key = args[0]
  if (args.length == 2)
      digest_type = args[1]
  end


  data = MessageEncoder.new {|msg|
     msg.put_name(key.name, true)
     key.encode_rdata(msg, true)
  }.to_s


  if (digest_type.code == 1)
      digestbin = OpenSSL::Digest::SHA1.digest(data)
      return digestbin
  elsif (digest_type.code == 2)
      digestbin = OpenSSL::Digest::SHA256.digest(data)
      return digestbin
  elsif (digest_type.code == 4)
      digestbin = OpenSSL::Digest::SHA384.digest(data)
      return digestbin
  end

end

#encode_rdata(msg, canonical = false) ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/DS.rb', line 240

def encode_rdata(msg, canonical=false) #:nodoc: all
  msg.put_pack("ncc", @key_tag, @algorithm.code, @digest_type.code)
  msg.put_bytes(@digestbin)
end

#from_data(data) ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/DS.rb', line 189

def from_data(data) #:nodoc: all
  key_tag, algorithm, digest_type, digest = data
  self.key_tag=(key_tag)
  self.algorithm=(algorithm)
  self.digest_type=(digest_type)
  self.digestbin=(digest)
  self.digest=@digestbin.unpack("H*")[0]
end

#from_string(input) ⇒ Object 



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# File 'lib/dnsruby/resource/DS.rb', line 198

def from_string(input)
  if (input.length > 0)
    data = input.split(" ")
    self.key_tag=(data[0].to_i)
    self.algorithm=(data[1])
    self.digest_type=(data[2])

    buf = ""
    index = 3
    end_index = data.length - 1
    if (data[index]=="(")
      end_index = data.length - 2
      index = 4
    end
    (index..end_index).each {|i|
      if (comment_index = data[i].index(";"))
        buf += data[i].slice(0, comment_index)
        #  @TODO@ We lose the comments here - we should really keep them for when we write back to string format?
        break
      else
        buf += data[i]
      end
    }
#          self.digest=Base64.decode64(buf)
    buf.gsub!(/\n/, "")
    buf.gsub!(/ /, "")
#          self.digest=buf.unpack("m*")[0]
    self.digest=buf
    self.digestbin = [buf].pack("H*")
  end
end

#rdata_to_string ⇒ Object

:nodoc: all



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# File 'lib/dnsruby/resource/DS.rb', line 230

def rdata_to_string #:nodoc: all
  if (@key_tag != nil)
#          return "#{@key_tag.to_i} #{@algorithm.string} #{@digest_type} ( #{Base64.encode64(@digest)} )"
#          return "#{@key_tag.to_i} #{@algorithm.string} #{@digest_type.code} ( #{[@digest].pack("m*").gsub("\n", "")} )"
    return "#{@key_tag.to_i} #{@algorithm.string} #{@digest_type.code} ( #{@digest.upcase} )"
  else
    return ""
  end
end