Class: Cryptorecord::Sshfp

Inherits:
Object
  • Object
show all
Defined in:
lib/cryptorecord/sshfp.rb

Overview

Cryptorecord::Sshfp-class generates sshfp-dns-records. The ssh-host-keys are read from files

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(args = {}) ⇒ Sshfp

This constructor initializes cipher, key, digest, host and keyfile If keyfile was provided, the key will automatically read from file

Parameters:

  • args (Hash) (defaults to: {}) —

    the options to initialize the object with

Options Hash (args):

  • digest (Integer) —

    sha1 = 1, sha256 = 2

  • host (String) —

    fqdn of the host

  • keyfile (String) —

    path to the keyfile



49
50
51
52
53
54
55
56
57
 
# File 'lib/cryptorecord/sshfp.rb', line 49

def initialize(args = {})
  @cipher = nil
  @key = nil
  self.digest = args.fetch(:digest, 2)
  @host = args.fetch(:host, 'localhost')
  keyfile = args.fetch(:keyfile, nil)

  read_file(keyfile) unless keyfile.nil?
end

Instance Attribute Details

#cipher ⇒ Integer

Returns the cipher. ssh-rsa = 1, ssh-dss = 2, ecdsa = 3 and ed25519 = 4.

Returns:

  • (Integer) —

    the cipher. ssh-rsa = 1, ssh-dss = 2, ecdsa = 3 and ed25519 = 4



38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
 
# File 'lib/cryptorecord/sshfp.rb', line 38

class Sshfp
  attr_reader :cipher, :digest, :key
  attr_accessor :host

  # This constructor initializes cipher, key, digest, host and keyfile
  # If keyfile was provided, the key will automatically read from file
  #
  # @param [Hash] args the options to initialize the object with
  # @option args [Integer] digest sha1 = 1, sha256 = 2
  # @option args [String] host fqdn of the host
  # @option args [String] keyfile path to the keyfile
  def initialize(args = {})
    @cipher = nil
    @key = nil
    self.digest = args.fetch(:digest, 2)
    @host = args.fetch(:host, 'localhost')
    keyfile = args.fetch(:keyfile, nil)

    read_file(keyfile) unless keyfile.nil?
  end

  # This setter initializes cipher
  #
  # @param [Integer] val the key-cipher.
  # ssh-rsa = 1, ssh-dss = 2, ecdsa = 3 and ed25519 = 4
  # @raise Cryptorecord::ArgumentError
  def cipher=(val)
    if val.to_i < 1 || val.to_i > 4
      raise ArgumentError, 'Invalid cipher. Has to be 0,1,2,3 or 4'
    end

    @cipher = val
  end

  # This setter initializes the hash-algo
  #
  # @param [Integer] val digest. sha1 = 1, sha256 = 2
  # @raise Cryptorecord::ArgumentError
  def digest=(val)
    unless val.to_i == 1 || val.to_i == 2
      raise ArgumentError, 'Invalid digest. Has to be 1 or 2'
    end
    @digest = val
  end

  # This function reads in the key from file and
  # initializes the cipher- and key-variable
  # @param [String] keyfile path to the ssh-hostkey-file
  # @raise Cryptorecord::ArgumentError
  def read_file(keyfile)
    raise ArgumentError, 'No hostkey-file defined' if keyfile.nil?

    data = File.read(keyfile)
    (type, @key) = data.split(' ')
    cipher_by_type(type)
  end

  # this function creates a Hash-String
  #
  # @return [String] Hash-string of the key
  # @raise Cryptorecord::KeyError
  def fingerprint
    raise Cryptorecord::KeyError, 'No certificate defined' if @key.nil?

    case @digest.to_i
    when 1
      return OpenSSL::Digest::SHA1.new(Base64.strict_decode64(@key)).to_s
    when 2
      return OpenSSL::Digest::SHA256.new(Base64.strict_decode64(@key)).to_s
    end
  end

  # This method concats the sshfp-record
  #
  # @return [String] sshfp dns-record as defined in rfc4255
  # @raise Cryptorecord::KeyError
  def to_s
    raise Cryptorecord::KeyError, 'No certificate defined' if @key.nil?
    "#{@host}. IN SSHFP #{@cipher} #{@digest} #{fingerprint}"
  end

  private

  # This helper-function selects the cipher using the given
  # type
  #
  # @param [String] type ssh-rsa = 1, ssh-dss = 2,
  # ecdsa-sha2-nistp256 = 3, ssh-ed25519 = 4
  # @raise Cryptorecord::CipherError
  # @return [Integer] integer value of the cipher
  def cipher_by_type(type)
    case type
    when 'ssh-rsa'
      self.cipher = 1
    when 'ssh-dss'
      self.cipher = 2
    when 'ecdsa-sha2-nistp256'
      self.cipher = 3
    when 'ssh-ed25519'
      self.cipher = 4
    else
      raise Cryptorecord::CipherError, 'Unsupported cipher'
    end
  end
end

#digest ⇒ Integer

Returns sha1 = 1, sha256 = 2.

Returns:

  • (Integer) —

    sha1 = 1, sha256 = 2



38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
 
# File 'lib/cryptorecord/sshfp.rb', line 38

class Sshfp
  attr_reader :cipher, :digest, :key
  attr_accessor :host

  # This constructor initializes cipher, key, digest, host and keyfile
  # If keyfile was provided, the key will automatically read from file
  #
  # @param [Hash] args the options to initialize the object with
  # @option args [Integer] digest sha1 = 1, sha256 = 2
  # @option args [String] host fqdn of the host
  # @option args [String] keyfile path to the keyfile
  def initialize(args = {})
    @cipher = nil
    @key = nil
    self.digest = args.fetch(:digest, 2)
    @host = args.fetch(:host, 'localhost')
    keyfile = args.fetch(:keyfile, nil)

    read_file(keyfile) unless keyfile.nil?
  end

  # This setter initializes cipher
  #
  # @param [Integer] val the key-cipher.
  # ssh-rsa = 1, ssh-dss = 2, ecdsa = 3 and ed25519 = 4
  # @raise Cryptorecord::ArgumentError
  def cipher=(val)
    if val.to_i < 1 || val.to_i > 4
      raise ArgumentError, 'Invalid cipher. Has to be 0,1,2,3 or 4'
    end

    @cipher = val
  end

  # This setter initializes the hash-algo
  #
  # @param [Integer] val digest. sha1 = 1, sha256 = 2
  # @raise Cryptorecord::ArgumentError
  def digest=(val)
    unless val.to_i == 1 || val.to_i == 2
      raise ArgumentError, 'Invalid digest. Has to be 1 or 2'
    end
    @digest = val
  end

  # This function reads in the key from file and
  # initializes the cipher- and key-variable
  # @param [String] keyfile path to the ssh-hostkey-file
  # @raise Cryptorecord::ArgumentError
  def read_file(keyfile)
    raise ArgumentError, 'No hostkey-file defined' if keyfile.nil?

    data = File.read(keyfile)
    (type, @key) = data.split(' ')
    cipher_by_type(type)
  end

  # this function creates a Hash-String
  #
  # @return [String] Hash-string of the key
  # @raise Cryptorecord::KeyError
  def fingerprint
    raise Cryptorecord::KeyError, 'No certificate defined' if @key.nil?

    case @digest.to_i
    when 1
      return OpenSSL::Digest::SHA1.new(Base64.strict_decode64(@key)).to_s
    when 2
      return OpenSSL::Digest::SHA256.new(Base64.strict_decode64(@key)).to_s
    end
  end

  # This method concats the sshfp-record
  #
  # @return [String] sshfp dns-record as defined in rfc4255
  # @raise Cryptorecord::KeyError
  def to_s
    raise Cryptorecord::KeyError, 'No certificate defined' if @key.nil?
    "#{@host}. IN SSHFP #{@cipher} #{@digest} #{fingerprint}"
  end

  private

  # This helper-function selects the cipher using the given
  # type
  #
  # @param [String] type ssh-rsa = 1, ssh-dss = 2,
  # ecdsa-sha2-nistp256 = 3, ssh-ed25519 = 4
  # @raise Cryptorecord::CipherError
  # @return [Integer] integer value of the cipher
  def cipher_by_type(type)
    case type
    when 'ssh-rsa'
      self.cipher = 1
    when 'ssh-dss'
      self.cipher = 2
    when 'ecdsa-sha2-nistp256'
      self.cipher = 3
    when 'ssh-ed25519'
      self.cipher = 4
    else
      raise Cryptorecord::CipherError, 'Unsupported cipher'
    end
  end
end

#host ⇒ String

Returns the fqdn-host.

Returns:

  • (String) —

    the fqdn-host



38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
 
# File 'lib/cryptorecord/sshfp.rb', line 38

class Sshfp
  attr_reader :cipher, :digest, :key
  attr_accessor :host

  # This constructor initializes cipher, key, digest, host and keyfile
  # If keyfile was provided, the key will automatically read from file
  #
  # @param [Hash] args the options to initialize the object with
  # @option args [Integer] digest sha1 = 1, sha256 = 2
  # @option args [String] host fqdn of the host
  # @option args [String] keyfile path to the keyfile
  def initialize(args = {})
    @cipher = nil
    @key = nil
    self.digest = args.fetch(:digest, 2)
    @host = args.fetch(:host, 'localhost')
    keyfile = args.fetch(:keyfile, nil)

    read_file(keyfile) unless keyfile.nil?
  end

  # This setter initializes cipher
  #
  # @param [Integer] val the key-cipher.
  # ssh-rsa = 1, ssh-dss = 2, ecdsa = 3 and ed25519 = 4
  # @raise Cryptorecord::ArgumentError
  def cipher=(val)
    if val.to_i < 1 || val.to_i > 4
      raise ArgumentError, 'Invalid cipher. Has to be 0,1,2,3 or 4'
    end

    @cipher = val
  end

  # This setter initializes the hash-algo
  #
  # @param [Integer] val digest. sha1 = 1, sha256 = 2
  # @raise Cryptorecord::ArgumentError
  def digest=(val)
    unless val.to_i == 1 || val.to_i == 2
      raise ArgumentError, 'Invalid digest. Has to be 1 or 2'
    end
    @digest = val
  end

  # This function reads in the key from file and
  # initializes the cipher- and key-variable
  # @param [String] keyfile path to the ssh-hostkey-file
  # @raise Cryptorecord::ArgumentError
  def read_file(keyfile)
    raise ArgumentError, 'No hostkey-file defined' if keyfile.nil?

    data = File.read(keyfile)
    (type, @key) = data.split(' ')
    cipher_by_type(type)
  end

  # this function creates a Hash-String
  #
  # @return [String] Hash-string of the key
  # @raise Cryptorecord::KeyError
  def fingerprint
    raise Cryptorecord::KeyError, 'No certificate defined' if @key.nil?

    case @digest.to_i
    when 1
      return OpenSSL::Digest::SHA1.new(Base64.strict_decode64(@key)).to_s
    when 2
      return OpenSSL::Digest::SHA256.new(Base64.strict_decode64(@key)).to_s
    end
  end

  # This method concats the sshfp-record
  #
  # @return [String] sshfp dns-record as defined in rfc4255
  # @raise Cryptorecord::KeyError
  def to_s
    raise Cryptorecord::KeyError, 'No certificate defined' if @key.nil?
    "#{@host}. IN SSHFP #{@cipher} #{@digest} #{fingerprint}"
  end

  private

  # This helper-function selects the cipher using the given
  # type
  #
  # @param [String] type ssh-rsa = 1, ssh-dss = 2,
  # ecdsa-sha2-nistp256 = 3, ssh-ed25519 = 4
  # @raise Cryptorecord::CipherError
  # @return [Integer] integer value of the cipher
  def cipher_by_type(type)
    case type
    when 'ssh-rsa'
      self.cipher = 1
    when 'ssh-dss'
      self.cipher = 2
    when 'ecdsa-sha2-nistp256'
      self.cipher = 3
    when 'ssh-ed25519'
      self.cipher = 4
    else
      raise Cryptorecord::CipherError, 'Unsupported cipher'
    end
  end
end

#key ⇒ String (readonly)

Returns the ssh-host-key, without the type and comment.

Returns:

  • (String) —

    the ssh-host-key, without the type and comment



38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
 
# File 'lib/cryptorecord/sshfp.rb', line 38

class Sshfp
  attr_reader :cipher, :digest, :key
  attr_accessor :host

  # This constructor initializes cipher, key, digest, host and keyfile
  # If keyfile was provided, the key will automatically read from file
  #
  # @param [Hash] args the options to initialize the object with
  # @option args [Integer] digest sha1 = 1, sha256 = 2
  # @option args [String] host fqdn of the host
  # @option args [String] keyfile path to the keyfile
  def initialize(args = {})
    @cipher = nil
    @key = nil
    self.digest = args.fetch(:digest, 2)
    @host = args.fetch(:host, 'localhost')
    keyfile = args.fetch(:keyfile, nil)

    read_file(keyfile) unless keyfile.nil?
  end

  # This setter initializes cipher
  #
  # @param [Integer] val the key-cipher.
  # ssh-rsa = 1, ssh-dss = 2, ecdsa = 3 and ed25519 = 4
  # @raise Cryptorecord::ArgumentError
  def cipher=(val)
    if val.to_i < 1 || val.to_i > 4
      raise ArgumentError, 'Invalid cipher. Has to be 0,1,2,3 or 4'
    end

    @cipher = val
  end

  # This setter initializes the hash-algo
  #
  # @param [Integer] val digest. sha1 = 1, sha256 = 2
  # @raise Cryptorecord::ArgumentError
  def digest=(val)
    unless val.to_i == 1 || val.to_i == 2
      raise ArgumentError, 'Invalid digest. Has to be 1 or 2'
    end
    @digest = val
  end

  # This function reads in the key from file and
  # initializes the cipher- and key-variable
  # @param [String] keyfile path to the ssh-hostkey-file
  # @raise Cryptorecord::ArgumentError
  def read_file(keyfile)
    raise ArgumentError, 'No hostkey-file defined' if keyfile.nil?

    data = File.read(keyfile)
    (type, @key) = data.split(' ')
    cipher_by_type(type)
  end

  # this function creates a Hash-String
  #
  # @return [String] Hash-string of the key
  # @raise Cryptorecord::KeyError
  def fingerprint
    raise Cryptorecord::KeyError, 'No certificate defined' if @key.nil?

    case @digest.to_i
    when 1
      return OpenSSL::Digest::SHA1.new(Base64.strict_decode64(@key)).to_s
    when 2
      return OpenSSL::Digest::SHA256.new(Base64.strict_decode64(@key)).to_s
    end
  end

  # This method concats the sshfp-record
  #
  # @return [String] sshfp dns-record as defined in rfc4255
  # @raise Cryptorecord::KeyError
  def to_s
    raise Cryptorecord::KeyError, 'No certificate defined' if @key.nil?
    "#{@host}. IN SSHFP #{@cipher} #{@digest} #{fingerprint}"
  end

  private

  # This helper-function selects the cipher using the given
  # type
  #
  # @param [String] type ssh-rsa = 1, ssh-dss = 2,
  # ecdsa-sha2-nistp256 = 3, ssh-ed25519 = 4
  # @raise Cryptorecord::CipherError
  # @return [Integer] integer value of the cipher
  def cipher_by_type(type)
    case type
    when 'ssh-rsa'
      self.cipher = 1
    when 'ssh-dss'
      self.cipher = 2
    when 'ecdsa-sha2-nistp256'
      self.cipher = 3
    when 'ssh-ed25519'
      self.cipher = 4
    else
      raise Cryptorecord::CipherError, 'Unsupported cipher'
    end
  end
end

Instance Method Details

#fingerprint ⇒ String

this function creates a Hash-String

Returns:

  • (String) —

    Hash-string of the key

Raises:

  • Cryptorecord::KeyError



99
100
101
102
103
104
105
106
107
108
 
# File 'lib/cryptorecord/sshfp.rb', line 99

def fingerprint
  raise Cryptorecord::KeyError, 'No certificate defined' if @key.nil?

  case @digest.to_i
  when 1
    return OpenSSL::Digest::SHA1.new(Base64.strict_decode64(@key)).to_s
  when 2
    return OpenSSL::Digest::SHA256.new(Base64.strict_decode64(@key)).to_s
  end
end

#read_file(keyfile) ⇒ Object

This function reads in the key from file and initializes the cipher- and key-variable

Parameters:

  • keyfile (String) —

    path to the ssh-hostkey-file

Raises:

  • Cryptorecord::ArgumentError



87
88
89
90
91
92
93
 
# File 'lib/cryptorecord/sshfp.rb', line 87

def read_file(keyfile)
  raise ArgumentError, 'No hostkey-file defined' if keyfile.nil?

  data = File.read(keyfile)
  (type, @key) = data.split(' ')
  cipher_by_type(type)
end

#to_s ⇒ String

This method concats the sshfp-record

Returns:

  • (String) —

    sshfp dns-record as defined in rfc4255

Raises:

  • Cryptorecord::KeyError



114
115
116
117
 
# File 'lib/cryptorecord/sshfp.rb', line 114

def to_s
  raise Cryptorecord::KeyError, 'No certificate defined' if @key.nil?
  "#{@host}. IN SSHFP #{@cipher} #{@digest} #{fingerprint}"
end