Class: Heya::License::Encryptor

Inherits:
Object
  • Object
show all
Defined in:
lib/heya/license/encryptor.rb

Defined Under Namespace

Classes: DecryptionError, Error, KeyError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(key) ⇒ Encryptor

Returns a new instance of Encryptor.



34
35
36
37
38
39
40
 
# File 'lib/heya/license/encryptor.rb', line 34

def initialize(key)
  if key && !key.is_a?(OpenSSL::PKey::RSA)
    raise KeyError, "No RSA encryption key provided."
  end

  @key = key
end

Instance Attribute Details

#key ⇒ Object

Returns the value of attribute key.



32
33
34
 
# File 'lib/heya/license/encryptor.rb', line 32

def key
  @key
end

Instance Method Details

#decrypt(data) ⇒ Object 



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
 
# File 'lib/heya/license/encryptor.rb', line 68

def decrypt(data)
  unless key.public?
    raise KeyError, "Provided key is not a public key."
  end

  json_data = Base64.decode64(data.chomp)

  begin
    encryption_data = JSON.parse(json_data)
  rescue JSON::ParserError
    raise DecryptionError, "Encryption data is invalid JSON."
  end

  unless %w[data key iv].all? { |key| encryption_data[key] }
    raise DecryptionError, "Required field missing from encryption data."
  end

  encrypted_data = Base64.decode64(encryption_data["data"])
  encrypted_key = Base64.decode64(encryption_data["key"])
  aes_iv = Base64.decode64(encryption_data["iv"])

  begin
    # Decrypt the AES key using asymmetric RSA encryption.
    aes_key = self.key.public_decrypt(encrypted_key)
  rescue OpenSSL::PKey::RSAError
    raise DecryptionError, "AES encryption key could not be decrypted."
  end

  # Decrypt the data using symmetric AES encryption.
  cipher = OpenSSL::Cipher::AES128.new(:CBC)
  cipher.decrypt

  begin
    cipher.key = aes_key
  rescue OpenSSL::Cipher::CipherError
    raise DecryptionError, "AES encryption key is invalid."
  end

  begin
    cipher.iv = aes_iv
  rescue OpenSSL::Cipher::CipherError
    raise DecryptionError, "AES IV is invalid."
  end

  begin
    data = cipher.update(encrypted_data) + cipher.final
  rescue OpenSSL::Cipher::CipherError
    raise DecryptionError, "Data could not be decrypted."
  end

  data
end

#encrypt(data) ⇒ Object 



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
 
# File 'lib/heya/license/encryptor.rb', line 42

def encrypt(data)
  unless key.private?
    raise KeyError, "Provided key is not a private key."
  end

  # Encrypt the data using symmetric AES encryption.
  cipher = OpenSSL::Cipher::AES128.new(:CBC)
  cipher.encrypt
  aes_key = cipher.random_key
  aes_iv = cipher.random_iv

  encrypted_data = cipher.update(data) + cipher.final

  # Encrypt the AES key using asymmetric RSA encryption.
  encrypted_key = key.private_encrypt(aes_key)

  encryption_data = {
    "data" => Base64.encode64(encrypted_data),
    "key" => Base64.encode64(encrypted_key),
    "iv" => Base64.encode64(aes_iv)
  }

  json_data = JSON.dump(encryption_data)
  Base64.encode64(json_data)
end