Class: EasyCrypto::Crypto

Inherits:
Object
  • Object
show all
Defined in:
lib/easycrypto/crypto.rb

Constant Summary collapse

KEY_BITS = 
256
AES_MODE = 
:GCM
IV_LEN = 
12
AUTH_TAG_LEN = 
16

Instance Method Summary collapse

Constructor Details

#initialize(salt_length = DEFAULT_SALT_LENGTH) ⇒ Crypto

Returns a new instance of Crypto.



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# File 'lib/easycrypto/crypto.rb', line 12

def initialize(salt_length = DEFAULT_SALT_LENGTH)
  @salt_length = salt_length
end

Instance Method Details

#decrypt(password, ciphertext) ⇒ Object 



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# File 'lib/easycrypto/crypto.rb', line 34

def decrypt(password, ciphertext)
  salt = get_salt_from_ciphertext(ciphertext)
  key = EasyCrypto::Key.generate_with_salt(password, salt)

  decrypt_with_key(key, ciphertext)
end

#decrypt_with_key(key, ciphertext) ⇒ Object 



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# File 'lib/easycrypto/crypto.rb', line 41

def decrypt_with_key(key, ciphertext)
  validate_key_type(key)

  raw_ciphertext = Base64.strict_decode64(ciphertext)

  iv = raw_ciphertext[key.salt.length, IV_LEN]
  encrypted = raw_ciphertext[(key.salt.length + IV_LEN)..-(AUTH_TAG_LEN + 1)]
  auth_tag = raw_ciphertext[-AUTH_TAG_LEN..-1]

  decipher = create_decipher(key, iv, auth_tag)

  decipher.update(encrypted) + decipher.final
end

#encrypt(password, plaintext) ⇒ Object 



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# File 'lib/easycrypto/crypto.rb', line 16

def encrypt(password, plaintext)
  key = EasyCrypto::Key.generate(password, @salt_length)

  encrypt_with_key(key, plaintext)
end

#encrypt_with_key(key, plaintext) ⇒ Object 



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# File 'lib/easycrypto/crypto.rb', line 22

def encrypt_with_key(key, plaintext)
  validate_key_type(key)
  validate_plaintext(plaintext)

  iv = OpenSSL::Random.random_bytes(Crypto::IV_LEN)
  cipher = create_cipher(key, iv)

  encrypted = cipher.update(plaintext) + cipher.final

  Base64.strict_encode64(key.salt + iv + encrypted + cipher.auth_tag)
end