Module: Toybox.Cryptography

Overview

The Cryptography Module will allow the application to create a Cipher object that can encrypt and decrypt ByteArray objects.

Since:

API Level 3.0.0

Supported Devices:

Classes Under Namespace

Classes: Cipher, CipherBasedMessageAuthenticationCode, Hash, HashBasedMessageAuthenticationCode, InvalidBlockSizeException, Key, KeyAgreement, KeyPair

Constant Summary

HashAlgorithm

Since:

API Level 3.0.0

Name Value Since Description See Also
HASH_SHA1 0

API Level 3.0.0

SHA-1 implementation for Hash objects

  • https://en.wikipedia.org/wiki/SHA-1
    • HASH_SHA256 1

    API Level 3.0.0

    SHA-256 implementation for Hash objects

  • https://en.wikipedia.org/wiki/SHA-2
    • HASH_MD5 2

    API Level 3.0.0

    MD5 implementation for Hash objects

  • https://en.wikipedia.org/wiki/MD5

    • CipherAlgorithm

    Since:

    API Level 3.0.0

    Name Value Since Description See Also
    CIPHER_AES128 0

    API Level 3.0.0

    AES128 implementation for Cipher objects

  • https://en.wikipedia.org/wiki/Advanced_Encryption_Standard
    • CIPHER_AES256 1

    API Level 3.0.0

    AES256 implementation for Cipher objects

  • https://en.wikipedia.org/wiki/Advanced_Encryption_Standard

    • EncryptionMode

    Since:

    API Level 3.0.0

    Name Value Since Description See Also
    MODE_ECB 0

    API Level 3.0.0

    Electronic Code Book (ECB)

    This is the simplest encryption mode. Each plaintext block is directly encrypted into a ciphertext block, independent of any other block. This mode exposes frequency of symbols in your plaintext. Other modes (e.g. CBC) are recommended.

  • https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Electronic_Codebook_(ECB)
    • MODE_CBC 1

    API Level 3.0.0

    Cipher-Block Chaining

    Each ciphertext block depends on the current and all previous plaintext blocks. An Initialization Vector (IV) is required. The IV is a data block to be transmitted to the receiver. The IV can be made public, but it must be authenticated by the receiver and it should be picked randomly.

  • https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Cipher_Block_Chaining_(CBC)

    • KeyPairAlgorithm

    Since:

    API Level 3.0.0

    Name Value Since Description See Also
    KEY_PAIR_ELLIPTIC_CURVE_SECP224R1 0

    API Level 3.0.0

    224-bit secp224r1 Elliptic Curve

    Based on the algebraic structure of elliptic curves over finite fields. ECC requires smaller keys compared to non-ECC cryptography to provide equivalent security.

  • https://en.wikipedia.org/wiki/Elliptic-curve_cryptography
    • KEY_PAIR_ELLIPTIC_CURVE_SECP256R1 1

    API Level 3.0.0

    256-bit secp256r1 Elliptic Curve

    Based on the algebraic structure of elliptic curves over finite fields. ECC requires smaller keys compared to non-ECC cryptography to provide equivalent security.

  • https://en.wikipedia.org/wiki/Elliptic-curve_cryptography

    • KeyAgreementProtocol

    Since:

    API Level 3.0.0

    Name Value Since Description See Also
    KEY_AGREEMENT_ECDH 0

    API Level 3.0.0

    Elliptic Curve Diffie-Hellman (ECDH)

  • https://en.wikipedia.org/wiki/Elliptic-curve_Diffie%E2%80%93Hellman

    • Instance Method Summary collapse

    Instance Method Details

    createPublicKey(algorithm as Cryptography.HashAlgorithm, bytes as Lang.ByteArray) as Cryptography.Key

    Create a public Key object from bytes to be added to a KeyAgreement.

    If a public key is received from another party, it can be converted to a Key object using this method.

    Note:

    bytes is expected to be in little-endian byte order.

    Parameters:

    Supported Devices:

    Returns:

    See Also:

    Since:

    API Level 3.0.0

    Throws:

    randomBytes(size as Lang.Number) as Lang.ByteArray

    Generates cryptographically random bytes.

    Parameters:

    • size — (Lang.Number) —

      The number of requested random bytes

    Returns:

    • Lang.ByteArray —

      A ByteArray of the requested size filled with cryptographically random bytes

    Since:

    API Level 3.0.0

    Generated May 15, 2025, 11:15:41 AM