# Function: openEnvelope()

```ts
function openEnvelope(
   key, 
   label, 
   bound, 
   sealed
): Promise<Uint8Array<ArrayBuffer> | null>;
```

Defined in: [packages/core/src/identity/envelope.ts:64](https://github.com/leifriksheim/minca/blob/main/core/src/identity/envelope.ts#L64)

Opens what `sealEnvelope` sealed.

## Parameters

| Parameter | Type |
| ------ | ------ |
| `key` | `CryptoKey` |
| `label` | `string` |
| `bound` | [`Bound`](https://minca.dev/api/core/type-aliases/Bound.md) |
| `sealed` | `Uint8Array` |

## Returns

`Promise`\<`Uint8Array`\<`ArrayBuffer`\> \| `null`\>

The plaintext, or null for an unknown version, too few bytes, the
  wrong key, label or bound, or anything changed