@akanass/nestjsx-crypto/documentation/AesService.md

NestJS crypto module provides some functions for security features like AES key, Key pair, RSA key, PKCS12, Certificate, PEM and more

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# AesService

After imported `CryptoModule` in your module, you can access to `AesService` anywhere with **dependency injection**.

```typescript
import { CryptoModule, AesService } from '@akanass/nestjsx-crypto';
import { Injectable, Module } from '@nestjs/common';

@Injectable()
class NestJSServiceWithCrypto {
    constructor(private readonly _aesService: AesService) {}
}

@Module({
    imports: [
        CryptoModule
    ],
    providers: [
        NestJSServiceWithCrypto
    ]
})
export class NestJSModuleNeedsCryptoModule {}
```

## Table of contents

* [API in Detail](#api-in-detail)
    * [.createKey(password, salt)](#createkeypassword-salt)
    * [.encryptWithAesKey(data)](#encryptwithaeskeydata)
    * [.decryptWithAesKey(data)](#decryptwithaeskeydata)
* [Change History](#change-history)

## API in Detail

### `.createKey(password, salt)`

Creates `RSA-SHA256` `AES key` for given `password` and `salt`

**Parameters:**
> - ***{string | Buffer} password*** *(required): password for `AES key`.*
> - ***{string | Buffer} salt*** *(required): salt for `AES key` should also be as unique as possible. It is recommended that the salts are random and their lengths are greater than 16 bytes.*

**Response:**
> *{[RxJS.Observable](https://github.com/ReactiveX/rxjs/blob/master/src/internal/Observable.ts)} The successfully generated `AES key` will be passed as a `{key, iv}` object and used to encrypt and decrypt data.*

**Example:**
```javascript
this._aesService.createKey('P3HQdR35PUQLZ5ioOrsPlxx7QWra7WQl', 'Kt9V3wgxrhpf8GN3')
    .subscribe(
        (aesKeyCreationResult: AesKeyCreationResult) => console.log(aesKeyCreationResult), // Show `{key: '61cac683ff27580e4c68778df5208c745b0e4731727786586938c794a37f4419', iv: '31cef43b785870e993cbc94aee0354cf'}` in the console
        e => console.error(e.message) // Show error message in the console
    );
```
[Back to top](#table-of-contents)

### `.encryptWithAesKey(data)`

Encrypting `data` method with `AES key`. This method is an `Observable's` `operator`.

**Parameters:**
> - ***{Buffer} data*** *(required): data for encrypting.*

**Response:**
> *{[RxJS.Observable](https://github.com/ReactiveX/rxjs/blob/master/src/internal/Observable.ts)} The successfully `encrypted` data will be passed as a `Buffer`.*

**Example:**
```javascript
import { encryptWithAesKey } from '@akanass/nestjsx-crypto/operators/aes';

...

this._aesService.createKey('P3HQdR35PUQLZ5ioOrsPlxx7QWra7WQl', 'Kt9V3wgxrhpf8GN3')
    .pipe(
        encryptWithAesKey(Buffer.from('data'))
    )
    .subscribe(
        (buffer: Buffer) => console.log(buffer.toString('hex')), // Show `a3d4bb8fcb8ec0e24a86cef07a28e3af` in the console
        e => console.error(e.message) // Show error message in the console
    );
```

[Back to top](#table-of-contents)

### `.decryptWithAesKey(data)`

Decrypting `data` method with `AES key`. This method is an `Observable's` `operator`.

**Parameters:**
> - ***{Buffer} data*** *(required): data for decrypting.*

**Response:**
> *{[RxJS.Observable](https://github.com/ReactiveX/rxjs/blob/master/src/internal/Observable.ts)} The successfully `decrypted` data will be passed as a `Buffer`.*

**Example:**
```javascript
import { decryptWithAesKey } from '@akanass/nestjsx-crypto/operators/aes';

...

this._aesService.createKey('P3HQdR35PUQLZ5ioOrsPlxx7QWra7WQl', 'Kt9V3wgxrhpf8GN3')
    .pipe(
        decryptWithAesKey(Buffer.from('a3d4bb8fcb8ec0e24a86cef07a28e3af', 'hex'))
    )
    .subscribe(
        (buffer: Buffer) => console.log(buffer.toString()), // Show `data` in the console
        e => console.error(e.message) // Show error message in the console
    );
```

[Back to top](#table-of-contents)

## Change History

* Implementation of all methods (2019-09-12)
    * [.createKey(password, salt)](#createkeypassword-salt)
    * [.encryptWithAesKey(data)](#encryptwithaeskeydata)
    * [.decryptWithAesKey(data)](#decryptwithaeskeydata)
    
[Back to top](#table-of-contents)