# password-encrypted-overlay

> Password encrypted overlay to Random Access modules

Latest version **3.0.0** (published 2020-05-29) · ISC license · 0 weekly downloads

## Install

```sh
npm install password-encrypted-overlay
pnpm add password-encrypted-overlay
yarn add password-encrypted-overlay
bun add password-encrypted-overlay
```

## Health

**Score 15/100 (F)** — status: abandoned.

Positive: no vulnerabilities.

Warnings: low downloads; no types; no esm support.

Negative: abandoned; low maintenance score.

## Facts

| | |
|---|---|
| Version | 3.0.0 |
| Published | 2020-05-29 |
| First published | 2018-11-30 |
| Weekly downloads | 0 |
| License | ISC |
| TypeScript types | none |
| Module format | CommonJS |
| Dependencies | 4 |
| Unpacked size | 19.2 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 16 |
| Author | Emil Bay |
| Maintainers | emilbayes |
| Keywords | passphrase, encrypted, password, file |

## Links

- npm: https://www.npmjs.com/package/password-encrypted-overlay
- Repository: https://github.com/emilbayes/password-encrypted-overlay
- Homepage: https://github.com/emilbayes/password-encrypted-overlay#readme
- Issues: https://github.com/emilbayes/password-encrypted-overlay/issues
- npm.io page: https://npm.io/package/password-encrypted-overlay

## Dependencies (4)

- [thunky](https://npm.io/package/thunky.md) ^1.0.3
- [mutexify](https://npm.io/package/mutexify.md) ^1.2.0
- [nanoassert](https://npm.io/package/nanoassert.md) ^1.1.0
- [sodium-native](https://npm.io/package/sodium-native.md) ^3.1.1

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## Recent versions

- 3.0.0 (latest) — 2020-05-29
- 2.1.0 — 2019-11-28
- 2.0.0 — 2019-01-10
- 1.0.0 — 2018-12-10
- 0.0.0 — 2018-11-30

## README

# `password-encrypted-overlay`

> Password encrypted overlay to Random Access modules

## Usage

### Create and write

```js
var PasswordEncryptedOverlay = require('password-encrypted-overlay')
var raf = require('random-access-file') // or random-access-memory or ...

var passwordBuffer = // ... (preferably sodium SecureBuffer)
// Note that the passwordBuffer is "consumed" by the constructor, ie. it will
// be cleared when a key has been derived from the password. If you need to keep
// the password, you should copy it and pass in the copy
PasswordEncryptedOverlay.create(
  raf('./secret.enc'),
  passwordBuffer,
  PasswordEncryptedOverlay.MODERATE,
  onready
)

function onready (err, storage) {
  if (err) throw err

  storage.write(Buffer.from('My encrypted file'), function (err) {
    if (err) throw err

    storage.destroy()
    storage = null
  })
}
```

### Read

```js
var PasswordEncryptedOverlay = require('password-encrypted-overlay')
var raf = require('random-access-file')

var passwordBuffer = // ... (preferably sodium SecureBuffer)
PasswordEncryptedOverlay.open(raf('./secret.enc'), passwordBuffer, function(err, storage) {
  if (err) throw err

  storage.read(function (err, buf) {
    if (err) throw err

    console.log(buf) // buf is sodium SecureBuffer, contains 'My encrypted file'
  })
})
```

## API

### `PasswordEncryptedOverlay.create(raf, password, {memlimit, opslimit}, cb(err, peo))`
Create a new raf with the given hardness settings. Password must be a `Buffer`,
optimally a `SecureBuffer`. `password` will be zero'ed out after it has been
derived into a key. Please copy this if you want to manage the password after
key derivation. Hardness settings determine the resources spent turning password
into a encryption key. See the constants below for some predefined settings.
`memlimit` is the number of bytes of memory used, rounded down to the nearest
kilobyte. `opslimit` is the number of passes over the memory.
Both must be `Numbers` and fit in a 32-bit unsigned integer.

### `PasswordEncryptedOverlay.open(raf, password, cb(err, peo))`
Open a existing raf with encrypted with `password`. Password must be a `Buffer`,
optimally a `SecureBuffer`. `password` will be zero'ed out after it has been
derived into a key. Please copy this if you want to manage the password after
key derivation.

### `peo.read(cb(err, secureBuf))`
Read and decrypt into a `SecureBuffer` from the raf. If an `err` is given in the
callback, the `peo` will have been destroyed before.

### `peo.write(buf, cb(err))`
Encrypt and write a `Buffer` to the raf. This updates the settings and rotates
the nonce. If an `err` is given in the callback, the `peo` will have been
destroyed before.

### `peo.destroy()`
Destroy the internal state, including zero'ing all internal data.
Makes all other methods unusable hereafter

### `PasswordEncryptedOverlay.deriveKey(password, {memlimit, opslimit, nonce?}, cb(err, key, nonce))`
Derive a key manually with an optional nonce. Useful if you want to compare passwords without
storing the password itself.

### `const equal = PasswordEncryptedOverlay.compareKeys(k1, k2)`
Compare two keys safely, in constant-time.

### Constants

* `PasswordEncryptedOverlay.INTERACTIVE`
  - `PasswordEncryptedOverlay.MEMLIMIT_INTERACTIVE`
  - `PasswordEncryptedOverlay.OPSLIMIT_INTERACTIVE`
* `PasswordEncryptedOverlay.MODERATE`
  - `PasswordEncryptedOverlay.MEMLIMIT_MODERATE`
  - `PasswordEncryptedOverlay.OPSLIMIT_MODERATE`
* `PasswordEncryptedOverlay.SENSITIVE`
  - `PasswordEncryptedOverlay.MEMLIMIT_SENSITIVE`
  - `PasswordEncryptedOverlay.OPSLIMIT_SENSITIVE`

## Install

```sh
npm install password-encrypted-overlay
```

## License

[ISC](LICENSE)

---
_Source: https://npm.io/package/password-encrypted-overlay · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._