# class MCollective::SSL

A class that assists in encrypting and decrypting data using a combination of RSA and AES

Data will be AES encrypted for speed, the Key used in # the AES stage will be encrypted using RSA

    ssl = SSL.new(public_key, private_key, passphrase)

    data = File.read("largefile.dat")

    crypted_data = ssl.encrypt_with_private(data)

    pp crypted_data

This will result in a hash of data like:

    crypted = {:key  => "crd4NHvG....=",
               :data => "XWXlqN+i...=="}

The key and data will all be base 64 encoded already by default you can pass a 2nd parameter as false to #encrypt_with_private and counterparts that will prevent the base 64 encoding

You can pass the data hash into ssl.decrypt_with_public which should return your original data

There are matching methods for using a public key to encrypt data to be decrypted using a private key

### Attributes

private_key_file[R]
public_key_file[R]
ssl_cipher[R]

### Public Class Methods

base64_decode(string) click to toggle source

    # File lib/mcollective/ssl.rb, line 195
    def self.base64_decode(string)
      Base64.decode64(string)
    end

base64_encode(string) click to toggle source

    # File lib/mcollective/ssl.rb, line 186
    def self.base64_encode(string)
      Base64.encode64(string)
    end

md5(string) click to toggle source

    # File lib/mcollective/ssl.rb, line 203
    def self.md5(string)
      Digest::MD5.hexdigest(string)
    end

new(pubkey=nil, privkey=nil, passphrase=nil, cipher=nil) click to toggle source

    # File lib/mcollective/ssl.rb, line 37
    def initialize(pubkey=nil, privkey=nil, passphrase=nil, cipher=nil)
      @public_key_file = pubkey
      @private_key_file = privkey

      @public_key  = read_key(:public, pubkey)
      @private_key = read_key(:private, privkey, passphrase)

      @ssl_cipher = "aes-256-cbc"
      @ssl_cipher = Config.instance.ssl_cipher if Config.instance.ssl_cipher
      @ssl_cipher = cipher if cipher

      raise "The supplied cipher '#{@ssl_cipher}' is not supported" unless OpenSSL::Cipher.ciphers.include?(@ssl_cipher)
    end

uuid(string=nil) click to toggle source

Creates a RFC 4122 version 5 UUID. If string is supplied it will produce repeatable UUIDs for that string else a random 128bit string will be used from OpenSSL::BN

Code used with permission from:

    https://github.com/kwilczynski/puppet-functions/blob/master/lib/puppet/parser/functions/uuid.rb

    # File lib/mcollective/ssl.rb, line 213
    def self.uuid(string=nil)
      string ||= OpenSSL::Random.random_bytes(16).unpack('H*').shift

      uuid_name_space_dns = "\x6b\xa7\xb8\x10\x9d\xad\x11\xd1\x80\xb4\x00\xc0\x4f\xd4\x30\xc8"

      sha1 = Digest::SHA1.new
      sha1.update(uuid_name_space_dns)
      sha1.update(string)

      # first 16 bytes..
      bytes = sha1.digest[0, 16].bytes.to_a

      # version 5 adjustments
      bytes[6] &= 0x0f
      bytes[6] |= 0x50

      # variant is DCE 1.1
      bytes[8] &= 0x3f
      bytes[8] |= 0x80

      bytes = [4, 2, 2, 2, 6].collect do |i|
        bytes.slice!(0, i).pack('C*').unpack('H*')
      end

      bytes.join('-')
    end

### Public Instance Methods

aes_decrypt(key, crypt_string) click to toggle source

decrypts a string given key, iv and data

    # File lib/mcollective/ssl.rb, line 158
    def aes_decrypt(key, crypt_string)
      cipher = OpenSSL::Cipher::Cipher.new(ssl_cipher)

      cipher.decrypt
      cipher.key = key
      cipher.pkcs5_keyivgen(key)
      decrypted_data = cipher.update(crypt_string) + cipher.final
    end

aes_encrypt(plain_string) click to toggle source

encrypts a string, returns a hash of key, iv and data

    # File lib/mcollective/ssl.rb, line 144
    def aes_encrypt(plain_string)
      cipher = OpenSSL::Cipher::Cipher.new(ssl_cipher)
      cipher.encrypt

      key = cipher.random_key

      cipher.key = key
      cipher.pkcs5_keyivgen(key)
      encrypted_data = cipher.update(plain_string) + cipher.final

      {:key => key, :data => encrypted_data}
    end

base64_decode(string) click to toggle source

base 64 decode a string

    # File lib/mcollective/ssl.rb, line 191
    def base64_decode(string)
      SSL.base64_decode(string)
    end

base64_encode(string) click to toggle source

base 64 encode a string

    # File lib/mcollective/ssl.rb, line 182
    def base64_encode(string)
      SSL.base64_encode(string)
    end

decrypt_with_private(crypted, base64=true) click to toggle source

Decrypts data, expects a hash as create with crypt_with_public

    # File lib/mcollective/ssl.rb, line 88
    def decrypt_with_private(crypted, base64=true)
      raise "Crypted data should include a key" unless crypted.include?(:key)
      raise "Crypted data should include data" unless crypted.include?(:data)

      if base64
        key = rsa_decrypt_with_private(base64_decode(crypted[:key]))
        aes_decrypt(key, base64_decode(crypted[:data]))
      else
        key = rsa_decrypt_with_private(crypted[:key])
        aes_decrypt(key, crypted[:data])
      end
    end

decrypt_with_public(crypted, base64=true) click to toggle source

Decrypts data, expects a hash as create with crypt_with_private

    # File lib/mcollective/ssl.rb, line 102
    def decrypt_with_public(crypted, base64=true)
      raise "Crypted data should include a key" unless crypted.include?(:key)
      raise "Crypted data should include data" unless crypted.include?(:data)

      if base64
        key = rsa_decrypt_with_public(base64_decode(crypted[:key]))
        aes_decrypt(key, base64_decode(crypted[:data]))
      else
        key = rsa_decrypt_with_public(crypted[:key])
        aes_decrypt(key, crypted[:data])
      end
    end

encrypt_with_private(plain_text, base64=true) click to toggle source

Encrypts supplied data using AES and then encrypts using RSA the key and IV

Return a hash with everything optionally base 64 encoded

    # File lib/mcollective/ssl.rb, line 73
    def encrypt_with_private(plain_text, base64=true)
      crypted = aes_encrypt(plain_text)

      if base64
        key = base64_encode(rsa_encrypt_with_private(crypted[:key]))
        data = base64_encode(crypted[:data])
      else
        key = rsa_encrypt_with_private(crypted[:key])
        data = crypted[:data]
      end

      {:key => key, :data => data}
    end

encrypt_with_public(plain_text, base64=true) click to toggle source

Encrypts supplied data using AES and then encrypts using RSA the key and IV

Return a hash with everything optionally base 64 encoded

    # File lib/mcollective/ssl.rb, line 55
    def encrypt_with_public(plain_text, base64=true)
      crypted = aes_encrypt(plain_text)

      if base64
        key = base64_encode(rsa_encrypt_with_public(crypted[:key]))
        data = base64_encode(crypted[:data])
      else
        key = rsa_encrypt_with_public(crypted[:key])
        data = crypted[:data]
      end

      {:key => key, :data => data}
    end

md5(string) click to toggle source

    # File lib/mcollective/ssl.rb, line 199
    def md5(string)
      SSL.md5(string)
    end

read_key(type, key=nil, passphrase=nil) click to toggle source

Reads either a :public or :private key from disk, uses an optional passphrase to read the private key

    # File lib/mcollective/ssl.rb, line 242
    def read_key(type, key=nil, passphrase=nil)
      return key if key.nil?

      raise "Could not find key #{key}" unless File.exist?(key)
      raise "#{type} key file '#{key}' is empty" if File.zero?(key)

      if type == :public
        begin
          key = OpenSSL::PKey::RSA.new(File.read(key))
        rescue OpenSSL::PKey::RSAError
          key = OpenSSL::X509::Certificate.new(File.read(key)).public_key
        end

        # Ruby < 1.9.3 had a bug where it does not correctly clear the
        # queue of errors while reading a key.  It tries various ways
        # to read the key and each failing attempt pushes an error onto
        # the queue.  With pubkeys only the 3rd attempt pass leaving 2
        # stale errors on the error queue.
        #
        # In 1.9.3 they fixed this by simply discarding the errors after
        # every attempt.  So we simulate this fix here for older rubies
        # as without it we get SSL_read errors from the Stomp+TLS sessions
        #
        # We do this only on 1.8 relying on 1.9.3 to do the right thing
        # and we do not support 1.9 less than 1.9.3
        #
        # See  http://bugs.ruby-lang.org/issues/4550
        OpenSSL.errors if Util.ruby_version =~ /^1.8/

        return key
      elsif type == :private
        return OpenSSL::PKey::RSA.new(File.read(key), passphrase)
      else
        raise "Can only load :public or :private keys"
      end
    end

rsa_decrypt_with_private(crypt_string) click to toggle source

Use the private key to RSA decrypt data

    # File lib/mcollective/ssl.rb, line 123
    def rsa_decrypt_with_private(crypt_string)
      raise "No private key set" unless @private_key

      @private_key.private_decrypt(crypt_string)
    end

rsa_decrypt_with_public(crypt_string) click to toggle source

Use the public key to RSA decrypt data

    # File lib/mcollective/ssl.rb, line 137
    def rsa_decrypt_with_public(crypt_string)
      raise "No public key set" unless @public_key

      @public_key.public_decrypt(crypt_string)
    end

rsa_encrypt_with_private(plain_string) click to toggle source

Use the private key to RSA encrypt data

    # File lib/mcollective/ssl.rb, line 130
    def rsa_encrypt_with_private(plain_string)
      raise "No private key set" unless @private_key

      @private_key.private_encrypt(plain_string)
    end

rsa_encrypt_with_public(plain_string) click to toggle source

Use the public key to RSA encrypt data

    # File lib/mcollective/ssl.rb, line 116
    def rsa_encrypt_with_public(plain_string)
      raise "No public key set" unless @public_key

      @public_key.public_encrypt(plain_string)
    end

sign(string, base64=false) click to toggle source

Signs a string using the private key

    # File lib/mcollective/ssl.rb, line 168
    def sign(string, base64=false)
      sig = @private_key.sign(OpenSSL::Digest::SHA1.new, string)

      base64 ? base64_encode(sig) : sig
    end

verify_signature(signature, string, base64=false) click to toggle source

Using the public key verifies that a string was signed using the private key

    # File lib/mcollective/ssl.rb, line 175
    def verify_signature(signature, string, base64=false)
      signature = base64_decode(signature) if base64

      @public_key.verify(OpenSSL::Digest::SHA1.new, signature, string)
    end