## lc4
* [lc4](#module_lc4)
* [.encrypt(settings)](#module_lc4.encrypt) ⇒ String
* [.decrypt(settings)](#module_lc4.decrypt) ⇒ String
* [.generateKey([mode])](#module_lc4.generateKey) ⇒ String
* [.generateNonce([mode], [length])](#module_lc4.generateNonce) ⇒ String
* [.escapeToLC4(string)](#module_lc4.escapeToLC4) ⇒ String
* [.escapeToLS47(string)](#module_lc4.escapeToLS47) ⇒ String
* [.escapeString(string, [mode])](#module_lc4.escapeString) ⇒ String
### lc4.encrypt(settings) ⇒ String
Encrypt a message with LC4 or LS47
**Kind**: static method of [lc4](#module_lc4)
**Returns**: String - the encrypted (and signed) message
**Throws**:
- TypeError Will throw a type error if settings are invalid or
missing
| Param | Type | Default | Description |
| --- | --- | --- | --- |
| settings | Object | | encryption settings |
| [settings.mode] | String | "lc4" | encryption algorithm. Can be either "lc4" or "ls47" |
| settings.message | String \| Array | | message or array of messages to encrypt. Invalid LC4 or LS47 strings are escaped with the `escapeString` method |
| settings.key | String | | valid LC4 or LS47 key or password; If a password is passed, the key/state will be expanded from the password |
| [settings.nonce] | String | String | String | Boolean | false | boolean indicating whether verbose mode should be used (will print intermediate steps to console) |
**Example** *(Encrypt a message with a random key)*
```js
const { encrypt, generateKey } = require("lc4");
encrypt({
message: "hello_world",
key: generateKey(),
nonce: "lorem_ipsum"
});
```
**Example** *(Encrypt a multiline message with a random key and LS47)*
```js
const { encrypt, generateKey } = require("lc4");
encrypt({
message: [ "hello", "ls47" ],
key: generateKey("ls47"),
nonce: "lorem_ipsum",
mode: "ls47"
})
```
**Example** *(Encrypt and sign a message)*
```js
const { encrypt, generateKey, generateNonce } = require("lc4");
encrypt({
message: "Lorem Ipsum", // will be escaped to lorem_ipsum
key: "my_super_secret_password",
nonce: generateNonce(),
signature: "#secret_signature",
verbose: true
});
```
### lc4.decrypt(settings) ⇒ String
Decrypt a message with LC4 or LS47
**Kind**: static method of [lc4](#module_lc4)
**Returns**: String - the encrypted (and signed) message
**Throws**:
- Error Will throw error "Invalid Signature" if message doesn't end
with specified signature
- TypeError Will throw a type error if settings are invalid or
missing
| Param | Type | Default | Description |
| --- | --- | --- | --- |
| settings | Object | | decryption settings |
| [settings.mode] | String | "lc4" | decryption algorithm. Can be either "lc4" or "ls47" |
| settings.message | String \| Array | | message or array of multiline message to decrypt; When decrypting a multiline message with a signature the signature must be the last element of the array |
| settings.key | String | | valid LC4 or LS47 key or password; If a password is passed, the key/state will be expanded from the password |
| [settings.nonce] | String | String | String | Boolean | false | boolean indicating whether verbose mode should be used (will print intermediate steps to console) |
**Example** *(Decrypt a message with a given key)*
```js
const { decrypt } = require("lc4");
decrypt({
message: "v74hxj5pxmo",
key: "igqehmd48pvxrl7k36y95j2sfnbo#wc_ztau",
nonce: "lorem_ipsum"
});
//=> "hello_world"
```
**Example** *(Decrypt a message with a given key and LS47)*
```js
const { decrypt } = require("lc4");
decrypt({
message: "8.bc-'suz+6l",
key: "4un)pj0c6(h!ms+_-5q*vkt,zi?9xoglw:18e'.dy/rba73f2",
mode: "ls47"
})
//=> "hello_world!"
```
**Example** *(Decrypt a multiline, signed message)*
```js
const { decrypt } = require("lc4");
decrypt({
message: [ '6q4ij', 'p9597', 'bc8p325u2jc_d9xfw' ],
key: "notds7u_i3exc2wlbyzpa4g85#v9fqjkrmh6",
nonce: "r#39_4kgpz",
signature: "#secret_signature",
verbose: true
});
//=> ["lorem", "ipsum", "#secret_signature"]
```
### lc4.generateKey([mode]) ⇒ String
Generate a valid random LC4 or LS47 key
**Kind**: static method of [lc4](#module_lc4)
**Returns**: String - a valid LC4 or LS47 key
| Param | Type | Default | Description |
| --- | --- | --- | --- |
| [mode] | String | "lc4" | encryption/decryption mode. Can be either "lc4" or "ls47" |
**Example** *(Generate a random key)*
```js
let { generateKey } = require("lc4");
generateKey();
```
**Example** *(Generate a random LS47 key)*
```js
let { generateKey } = require("lc4");
generateKey("ls47");
```
**Example** *(Encrypt a message with a random key)*
```js
const { encrypt, generateKey } = require("lc4");
encrypt({
message: "hello_world",
key: generateKey(),
});
```
### lc4.generateNonce([mode], [length]) ⇒ String
Generate a valid random LC4 or LS47 nonce
**Kind**: static method of [lc4](#module_lc4)
**Returns**: String - a valid LC4 or LS47 nonce
**Throws**:
- Error Will throw an error if length is smaller than 6
| Param | Type | Default | Description |
| --- | --- | --- | --- |
| [mode] | String | "lc4" | encryption/decryption mode. Can be either "lc4" or "ls47" |
| [length] | Number | 10 | length of nonce (at least 6) |
**Example** *(Generate a random nonce)*
```js
let { generateNonce } = require("lc4");
generateNonce();
```
**Example** *(Encrypt a message with LS47 and a random nonce)*
```js
const { encrypt, generateKey, generateNonce } = require("lc4");
encrypt({
message: "Lorem Ipsum!",
key: generateKey("ls47"),
nonce: generateNonce("ls47")
})
```
### lc4.escapeToLC4(string) ⇒ String
Escape string to valid LC4 string
**Kind**: static method of [lc4](#module_lc4)
**Returns**: String - valid LC4 string
| Param | Type | Description |
| --- | --- | --- |
| string | String | (invalid) LC4 string |
**Example**
```js
let { escapeToLC4 } = require("lc4");
escapeToLC4("Hello World! This is the 10th test!");
//=> "hello_world_this_is_the__#th_test"
```
### lc4.escapeToLS47(string) ⇒ String
Escape string to valid LS47 string
**Kind**: static method of [lc4](#module_lc4)
**Returns**: String - valid LS47 string
| Param | Type | Description |
| --- | --- | --- |
| string | String | (invalid) LS47 string |
**Example**
```js
let { escapeToLS47 } = require("lc4");
escapeToLS47("Hello World! This is the 10th test!");
//=> "hello_world!_this_is_the_10th_test!"
```
### lc4.escapeString(string, [mode]) ⇒ String
Escapes a string to a valid LC4 or LS47 string
**Kind**: static method of [lc4](#module_lc4)
**Returns**: String - valid LC4 or LS47 string
| Param | Type | Default | Description |
| --- | --- | --- | --- |
| string | String | | (invalid) LC4 or LS47 string |
| [mode] | String | "lc4" | encryption/decryption mode. Can be either "lc4" or "ls47" |
**Example**
```js
let { escapeString } = require("lc4");
escapeString("Hello World! This is the 10th test!", "ls47");
//=> "hello_world!_this_is_the_10th_test!"
```
**Example**
```js
let { escapeString } = require("lc4");
escapeString("Hello World! This is the 10th test!", "lc4");
//=> "hello_world_this_is_the__#th_test"
```