Matrix Encrypt Attachment

Encrypt and decrypt attachments in accordance with the Matrix Client-Server API spec.

Supports browsers using WebCryptoAPI and Node.js via crypto.

This project builds on and deprecates browser-encrypt-attachment to add support for non-browser environments.

Protocol versions

Previous versions of the protocol are not currently documented in the spec, and are described here for reference:

| Protocol | Description | | --- | --- | | v0 | use all 128 bits of the counter | | v1 | use only 64 bits of the counter | | v2 (current) | use only 64 bits and also zero out the other half to maximise the space before it wraps |

Encryption

The library will encrypt to the following protocol versions:

| Protocol | Browser | Node.js | | --- | --- | --- | | Encrypt | v2 | v2 |

Decryption

The library supports decryption of the following protocol versions:

| Protocol | Browser | Node.js | | --- | --- | --- | | Decrypt v0 | ✅ | ❌ | | Decrypt v1 | ✅ | ❌ | | Decrypt v2 | ✅ | ✅ |