v5.1.x API Reference

Methods

await seal(object, password, options)

Seriealizes, encrypts, and signs objects into an iron protocol string where:

  • object - the data being sealed. Can be any JavaScript value that is serializable via JSON.stringify().

  • password - one of:

    • a password string used to generate a key using the pbkdf2 algorithm.

    • a key buffer used as-is (after validating sufficient length based on the algorithm used).

    • an object with:

      • id - a password identifier (must consist of only letters, numbers, and _).
      • secret - a password string or key buffer used for both encryption and integrity.
    • an object with:

      • id - a password identifier (must consist of only letters, numbers, and _).
      • encryption - a password string or key buffer used for encryption.
      • integrity - a password string or key buffer used for integrity.
  • options - see Options.

Return value: iron sealed string.

Note: assigning the password used an id allows for password rotation to improve the security of your deployment. Passwords should be rotated over time to reduce the risk of compromised security. When providing a password id, the id is included with the iron protocol string and it must match the id used to unseal.

It is recommended to combine password id with the ttl option to generate iron protocol strings of limited time validity which also allow for rotating passwords without the need to keep all previous passwords around (only the number of passwords used within the ttl window).

await unseal(sealed, password, options)

Verifies, decrypts, and reconstruct an iron protocol string into an object where:

  • sealed - the iron protocol string generated with seal().

  • password - must match the password value passed to seal() and be one of:

    • a password string used to generate a key using the pbkdf2 algorithm.

    • a key buffer used as-is (after validating sufficient length based on the algorithm used).

    • an object with id as the key and value is one of:

      • a password string or key buffer used for both encryption and integrity.
      • an object with:
        • encryption - a password string or key buffer used for encryption.
        • integrity - a password string or key buffer used for integrity.
  • options - see Options. Must match the options value passed to seal()

Return value: the verified, decripted object.

Note: In order to enable password rotation, the password argument can accept an object with more than one password, each keyed by its id. Together with the ttl option, the password object only needs to include the passwords used within the ttl window.

await generateKey(password, options)

Generates an key from the password where:

  • password - a password string or buffer key.
  • options - see Options.

Return value: an object with the following keys:

  • key
  • salt
  • iv

await encrypt(password, options, data)

Encrypts data where:

  • password - a password string or buffer key.
  • options - see Options.
  • 'data' - the string to encrypt.

Return value: an object with the following keys:

  • encrypted
  • key:
    • key
    • salt
    • iv

await decrypt(password, options, data)

Decrypts data where:

  • password - a password string or buffer key.
  • options - see Options.
  • 'data' - the string to decrypt.

Return value: the decrypted string.

await hmacWithPassword(password, options, data)

Calculates an HMAC digest where:

  • password - a password string or buffer key.
  • options - see Options.
  • 'data' - the string to calculate the HMAC over.

Return value: an object with the following keys:

  • digest
  • salt

Options

iron provides options for customizing the key deriviation algorithm used to generate encryption and integrity verification keys, as well as the algorithms and salt sizes used.iron methods take an options object with the following keys:

  • encryption - (required) defines the options used by the encryption process.
  • integrity - (required) defines the options used by the HMAC integrity verification process.

Each of these option objects support the following keys:

  • algorithm - (required) the algorithm name ('aes-256-cbc' and 'aes-128-ctr' for encryption and 'sha256' for integrity are the only two supported at this time).
  • iv - (optional) an initialization vector buffer. If no iv is provided, one is generated based on the algorithm ivBits configuration.

When the password argument passed is a string (used for key generation), the following options are used:

  • salt - (optional) a pre-generated salt string (a random buffer used to ensure that two identical objects will generate a different encrypted result).
  • saltBits - (required if salt is not provided, otherwise ignored) the size of the salt.
  • iterations - (required) the number of iterations used to derive a key from the password. Defaults to 1 iteration. The number of ideal iterations to use is dependent on your application's performance requirements. More iterations means it takes longer to generate the key.
  • minPasswordlength - (required) the minimum password string length required for key generation. Defaults to 32 characters.

The 'seal()' and 'unseal()' methods also support the following options:

  • ttl - sealed object lifetime in milliseconds where 0 means forever. Defaults to 0.
  • timestampSkewSec - number of seconds of permitted clock skew for incoming expirations. Defaults to 60 seconds.
  • localtimeOffsetMsec - local clock time offset, expressed in number of milliseconds (positive or negative). Defaults to 0.

Defaults

iron includes a default options object which can be passed to the methods as shown above in the example. The default settings are:

var options = {
    encryption: {
        saltBits: 256,
        algorithm: 'aes-256-cbc',
        iterations: 1
    },
    integrity: {
        saltBits: 256,
        algorithm: 'sha256',
        iterations: 1
    },
    ttl: 0,
    timestampSkewSec: 60,
    localtimeOffsetMsec: 0
};