Awesome

hardbin.

The world's most secure encrypted pastebin, guaranteed *

Hardbin is an encrypted pastebin, with the decryption key passed in the URL fragment, and the code and data served securely with IPFS. (IPFS is a distributed content-addressable storage system that is web-compatible; it's basically bittorrent for the web).

The IPFS gateway you use has the same capabilities as an ordinary web server (i.e. it can modify content at will), so you should make sure to use a gateway you trust. Running a local gateway is the best option. Start with the IPFS Getting Started guide.

Compared to a traditional encrypted pastebin (e.g. ZeroBin), when used over a trusted gateway, neither the code nor the data can be modified as the content hashes are cryptographically verified by IPFS. This means there is no possibility for a server operator to insert malicious code to exfiltrate the plaintext or decryption key. It's the perfect encrypted pastebin.

(* this is not a guarantee)

Usage

Note that the security benefits of hardbin only apply when accessing it over a local (or otherwise trusted) gateway. If you access it over a gateway that you do not control, then the security model degrades to be equivalent to that of traditional encrypted pastebins.

The github repo should also link directly to the latest IPFS hash.

It doesn't matter which IPFS gateway is used to access hardbin, but you won't be able to publish anything unless you use a writable gateway (i.e. ipfs daemon --writable). But remember that using a public gateway means you are trusting the public gateway not to ship malicious code to (for example) exfiltrate the plaintext.

In general it should either work out-of-the-box or give good instructions on how to make it work.

The content will need to be pinned to make sure it stays around for long term (the same as any content stored in IPFS). Pinata is a service offering to pin content for a very, very small fee. Failing that, content will stay around as long as it is cached on any node (e.g. a public gateway).

If you want to share a link to hardbin which will automatically load this README, append #about as the fragment.

Local gateway

A local gateway that you run yourself is the safest way to use hardbin.

Follow the IPFS Getting Started guide, but make sure to run the gateway with ipfs daemon --writable, else you won't be able to publish anything.

You can then install a browser extension such as <a href="https://chrome.google.com/webstore/detail/ipfs-companion/nibjojkomfdiaoajekhjakgkdhaomnch">IPFS Companion</a> for Chrome to automatically redirect IPFS paths to your local gateway.

Public gateway

Any public gateway will work fine for viewing content, but you won't be able to publish anything on a non-writable gateway. Using a public gateway also trusts the public gateway not to insert malicious code to exfiltrate content (or do anything else it shouldn't).

Writable public gateway

A writable public gateway will work fine for viewing and publishing, but you're still trusting the public gateway not to insert malicious code.

How it works

The hardbin code is served out of IPFS. The user then inputs the content. When the content is published, a key is generated using the crypto.getRandomValues() API and the content is encrypted in javascript in the browser using AES-256 via Crypto-JS. The new content is then pushed to the IPFS gateway.

The decryption key is passed in the URL fragment, and the URL can be shared with anybody.

As long as the IPFS gateway is not compromised, and the user visits a known-good hash in the first place, there is no possibility for anybody to modify either the code or the data, because to do so would change the IPFS hash.

Since nobody can modify the code, and nobody can view the key unless you show it to them, nobody without the key can either read the plaintext or ship a malicious viewer which would exfiltrate the plaintext (or key).

Self-hosting

You can "self-host" hardbin as follows:

git clone https://github.com/jes/hardbin
ipfs add -r hardbin/

Custom modifications

If you want to use any custom modifications, you can simply make them, publish your new code on IPFS with ipfs add, and then it's available and ready to use. It's just as much a first-class citizen as the version in this git repo, and you're equally welcome to access it via a public writable gateway.

Of course, pull requests are always welcome for improvements that might be useful to others.

Security considerations

You still need to share the paste URL securely, otherwise a third-party can read it as easily as anybody else can.

You need to make very sure to use a known-good version of the code when creating pastes, as it would be trivial to create a malicious version that looks identical. The best thing to do is write down the hash the first time you use it, and always use the same hash. If you want to upgrade to a new version of the software, you'll need to update your hash.

If you don't use a local (or otherwise trusted) IPFS gateway, then the gateway server operator can perform all the same attacks that a traditional encrypted pastebin operator could perform.

I don't recommend using hardbin for highly critical stuff as the code has not been thoroughly audited by anyone but me. If you want to audit it please contact me.

Contact me

Hardbin was created by James Stanley. You can email me on james@incoherency.co.uk, or read my blog at incoherency.co.uk.