@iota/checksum

Add, remove and validate checksums.

Installation

Install using npm:

npm install @iota/checksum

or using yarn:

yarn add @iota/checksum

API Reference

• checksum

* [.addChecksum(input, [checksumLength], [isAddress])](#module_checksum.addChecksum)

* [.removeChecksum(input)](#module_checksum.removeChecksum)

* [.isValidChecksum(addressWithChecksum)](#module_checksum.isValidChecksum)

checksum.addChecksum(input, checksumLength, isAddress)

Summary: Generates a checksum and appends it to the given trytes.
Throws:

• errors.INVALID\_ADDRESS : Make sure that the given address is 90 trytes long.
• errors.INVALID\_TRYTES : Make sure that the input argument contains only trytes
• errors.INVALID\_CHECKSUM\_LENGTH : Make sure that the checksumLength argument is a number greater than or equal to 3. If the isAddress argument is set to true, make sure that the checksumLength argument is 9.

| Param | Type | Default | Description | | --- | --- | --- | --- | | input | string | | 81 trytes to which to append the checksum | | checksumLength | number | 9 | Length of the checksum to generate | | isAddress | boolean | true | Whether the input is an address |
This method takes 81 trytes, which could be an address or a seed, generates the checksum and appends it to the trytes.
To generate a checksum that is less than 9 trytes long, make sure to set the isAddress argument to false.

Related methods

To generate an address, use the getNewAddress() method.
Returns: string - The original trytes with an appended checksum.
Example

let addressWithChecksum = Checksum.addChecksum('ADDRESS...');

checksum.removeChecksum(input)

Summary: Removes the checksum from the given address.
Throws:

• errors.INVALID\_ADDRESS : Make sure that the given address is 90 trytes long.

| Param | Type | Description | | --- | --- | --- | | input | string | Address from which to remove the checksum |
This method takes an address of 90 trytes, and removes the last 9 trytes to return the address without a checksum.

Related methods

To generate an address, use the getNewAddress() method. To add a checksum to an address, use the addChecksum() method.
Returns: string - The original address without the appended checksum.
Example

let addressWithoutChecksum = Checksum.removeChecksum('ADDRESS...');

checksum.isValidChecksum(addressWithChecksum)

Summary: Validates the checksum of an address.
Throws:

• errors.INVALID\_ADDRESS : Make sure that the given address is 90 trytes long.

| Param | Type | Description | | --- | --- | --- | | addressWithChecksum | string | Address with a checksum |
This method takes an address of 90 trytes, and checks if the checksum is valid.

Related methods

To generate an address, use the getNewAddress() method. To add a checksum to an address, use the addChecksum() method.
Returns: boolean - Whether the checksum is valid.
Example

let valid = Checksum.isValidChecksum('ADDRESS...');