[**@sodot/sodot-react-native-sdk**](/rn/api-ref) • **Docs**

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[@sodot/sodot-react-native-sdk](/rn/api-ref) / MessageHash

# Class: MessageHash

A 32 byte message hash used for signing ECDSA messages.

## Example

```ts
// A SHA256 hash of the string 'Hello World'
const messageHash = MessageHash.sha256('Hello World');
// A Keccak256 hash of the string 'Hello World'
const messageHash = MessageHash.keccak256('Hello World');
// In case you already have a hashed value you can just call the constructor with it:
const messageHash = new MessageHash('aabbccddeeff00112233445566778899aabbccddeeff00112233445566778899');
```

## Constructors

### new MessageHash()

> **new MessageHash**(`bytes`): [`MessageHash`](/rn/api-ref/classes/MessageHash)

Creates a new MessageHash object from a 32 byte hash represented as Uint8Array or hex string of length 64

#### Parameters

• **bytes**: `string` | `Uint8Array`

The 32 bytes of the message hash. Can be a hex string or a Uint8Array

#### Returns

[`MessageHash`](/rn/api-ref/classes/MessageHash)

## Properties

### bytes

> `readonly` **bytes**: `Uint8Array`

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### LENGTH

> `readonly` `static` **LENGTH**: `32` = `32`

## Methods

### toHex()

> **toHex**(): `string`

#### Returns

`string`

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### keccak256()

> `static` **keccak256**(`message`): [`MessageHash`](/rn/api-ref/classes/MessageHash)

A helper function to create a MessageHash from a string or Uint8Array using keccak256.

#### Parameters

• **message**: `string` | `Uint8Array`

The message to hash. Can be a string or a Uint8Array.

#### Returns

[`MessageHash`](/rn/api-ref/classes/MessageHash)

A MessageHash object representing the keccak256 hash of the message.

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### sha256()

> `static` **sha256**(`message`): [`MessageHash`](/rn/api-ref/classes/MessageHash)

A helper function to create a MessageHash from a string or Uint8Array using SHA256.

#### Parameters

• **message**: `string` | `Uint8Array`

The message to hash. Can be a string or a Uint8Array.

#### Returns

[`MessageHash`](/rn/api-ref/classes/MessageHash)

A MessageHash object representing the SHA256 hash of the message.

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### sha256d()

> `static` **sha256d**(`message`): [`MessageHash`](/rn/api-ref/classes/MessageHash)

A helper function to create a MessageHash from a string or Uint8Array using Double SHA256 (Bitcoin's Sha256d)

#### Parameters

• **message**: `string` | `Uint8Array`

The message to hash. Can be a string or a Uint8Array.

#### Returns

[`MessageHash`](/rn/api-ref/classes/MessageHash)

A MessageHash object representing the Double-SHA256 hash of the message.