simple-digest-md5
=================
This module implements DIGEST-MD5 in pure javascript. I didn't see any other implementations in pure JS here on npm, so when I wrote one I thought that I would put it up here - hopefully this helps somebody.
[](https://nodei.co/npm/simple-digest-md5/)
[](https://nodei.co/npm/simple-digest-md5/)
Installation
------------
```bash
npm install simple-digest-md5
```
Usage
-----
This module will calculate the response to a given DIGEST-MD5 challenge, but it won't send it down the wire for you.
To use it do something like this:
```javascript
var md5_digest = require("simple-md5-digest");
// Initialise socket here & send initial packets
socket.on("data", function(data) {
// Process incoming message here
// ...
// We have get a challenge from the server!
var ch_response = md5_digest.get_response(challenge, "username", "password", "resource");
// Package the response up to send it down the wire here
socket.write(message);
});
```
**Warning: Some server's don't actually support an `authzid` when using DIGEST_MD5! (e.g. prosody). If this the case, omit the `resource` parameter:**
```javascript
var ch_response = md5_digest.get_response(challenge, "username", "password");
```
This will cause `simple-digest-md5` to omit the `authzid` from the response it calculates. Note that the `authzid` is the part that adds support for the resource string.
Note that when calculating the response to a given DIGEST_MD5 challenge, you have to provide the name of the service that you are authenticating with. This module is set up for `xmpp` by default, but you can change it like so:
```javascript
digest_md5.set_service("service_name_here");
```
If you have got a challenge encoded as base64, simply use `md5_digest.get_response_b64` instead and it will decode the response first.
Using this with XMPP
--------------------
If you are using this with XMPP, I recommend you read [this page](http://web.archive.org/web/20050224191820/http://cataclysm.cx/wip/digest-md5-crash.html), which walks you through the proecss and gives you a sample exchange. For convenience, I will include the sample exchange here:
```
1 >>>
1 <<< cmVhbG09ImNhdGFjbHlzbS5jeCIsbm9uY2U9Ik9BNk1HOXRFUUdtMmhoIixxb3A9ImF1dGgiLGNoYXJzZXQ9dXRmLTgsYWxnb3JpdGhtPW1kNS1zZXNz
2 >>> dXNlcm5hbWU9InJvYiIscmVhbG09ImNhdGFjbHlzbS5jeCIsbm9uY2U9Ik9BNk1HOXRFUUdtMmhoIixjbm9uY2U9Ik9BNk1IWGg2VnFUclJrIixuYz0wMDAwMDAwMSxxb3A9YXV0aCxkaWdlc3QtdXJpPSJ4bXBwL2NhdGFjbHlzbS5jeCIscmVzcG9uc2U9ZDM4OGRhZDkwZDRiYmQ3NjBhMTUyMzIxZjIxNDNhZjcsY2hhcnNldD11dGYtOCxhdXRoemlkPSJyb2JAY2F0YWNseXNtLmN4L215UmVzb3VyY2Ui
2 <<< cnNwYXV0aD1lYTQwZjYwMzM1YzQyN2I1NTI3Yjg0ZGJhYmNkZmZmZA==
3 >>>
3 <<<
```
The 2nd message that you send is the base64 encoded result from `digest_md5.get_response()`.
Advanced Usage
--------------
The following functions are also available for use if you need finer control over how this module operates:
- `digest_md5.base64_encode(thing)` - Encodes something to base_64. This is probably useful when sending your response to the server - XMPP at least requires the response encoded at base64.
- `digest_md5.base64_decode(thing)` - Decodes something encoded with base64.
- `digest_md5.parse_challenge(challenge)` - Parses a given challenge string into it's component parts.
- `digest_md5.set_service(service_name)` - Sets the serivce that you are authenticating with.
- `digest_md5.parse_challenge(challange_str)` - Parses a given challange string into its component parts.
- `digest_md5.get_response_raw(parsed_challenge, user, pass, resource)` - Calculates a response to a challenge string parsed with the above function.
- `md5(thing, encoding)` - Calculates the md5 hash of something. Usually that something will be a string. Encoding is set to "hex" by default, but you can change it to "binary" or anything else you like that `crypto`'s `createHash("md5").digest()` supports.
If the above explanations don't make sense, simply read the source code located in `index.js` - the functions are extensively documented there. If that still doesn't help, contact me and I will try and help you :)
Bugs & Support
----
You can report bugs and / or get help on the [GitHub Issue Tracker](https://github.com/sbrl/simple-md5-digest/issues). I can also be contacted by email.
Credits
-------
- This webpage was used to implement this module: [A crash course in SASL and DIGEST-MD5 for XMPP](http://web.archive.org/web/20050224191820/http://cataclysm.cx/wip/digest-md5-crash.html) by Robert Norris