@web4/bitsign

Utility methods related to public key cryptography to be used with distributed mutable storage.

npm install @web4/bitsign

API

const { keypair, salt, sign, signable } = bitsign()

Call the exported function to get bitsign instance.

There is also a class bitsign.Bitsign which can be extended.

keypair()

Use this method to generate an assymetric keypair. Returns an object with {publicKey, secretKey}. publicKey holds a public key buffer, secretKey holds a private key buffer.

salt([str, ]size = 32)

Utility method for creating a random or hashed salt value.

If called with a string the string will be hashed, to a generic hash of size length.

If called without any inputs, or with a number, random butes of size length will be

sign(value, options)

Utility method which can be used to create a sig.

Options:

• keypair – REQUIRED, use keypair to generate this.
• salt - OPTIONAL - default undefined, a buffer >= 16 and <= 64 bytes. If supplied it will salt the signature used to verify mutable values.
• seq - OPTIONAL - default 0. The sequence number of the value.

signable(value, options)

Utility method which returns the exact buffer that would be signed in by sign. This is only needed when using a salt, otherwise it will return the same value passed in. This method is to facilitate out-of-band signing (e.g. hardware signing), do not pass the returned signable value into sign, it already uses signable. If you need to sign a value that has already been passed through signable, use cryptoSign.

Options:

• salt - OPTIONAL - default undefined, a buffer >= 16 and <= 64 bytes. If supplied it will salt the signature used to verify mutable values.
• seq - OPTIONAL - default 0. The sequence number of the value.

cryptoSign(msg, keypair)

Utility method which can be used to create a signature using the crypto_sign_detached Sodium method. This only needs to be used when you do not need to apply encoding to value, salt and seq(e.g. if value and options have already been passed to signable).

Options:

• keypair – REQUIRED, use keypair to generate this.
• salt - OPTIONAL - default undefined, a buffer >= 16 and <= 64 bytes. If supplied it will salt the signature used to verify mutable values.
• seq - OPTIONAL - default 0. The sequence number of the value.

License

MIT