Everywhere: Initial commit

This patch adds an initial implementation of a tool to
download and (if encrypted) decrypt matrix media based
on the decrypted event content.
This commit is contained in:
networkException 2024-08-21 21:29:04 +02:00
commit af2baa5089
Signed by: networkException
GPG key ID: E3877443AE684391
7 changed files with 3850 additions and 0 deletions

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/target

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{
"cSpell.words": [
"homeserver"
]
}

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[package]
name = "matrix-media-event-decrypt"
description = "Decrypt matrix media events"
version = "0.1.0"
edition = "2021"
authors = ["networkException <git@nwex.de>"]
license = "BSD-2-Clause"
repository = "https://git.nwex.de/networkException/matrix-media-event-decrypt"
[dependencies]
anyhow = "1.0.86"
clap = { version = "4.5.16", features = ["derive", "env"] }
env_logger = "0.11.5"
log = "0.4.22"
# NOTE: We need newer apis for resolving the homeserver's base url
matrix-sdk = { git = "https://github.com/matrix-org/matrix-rust-sdk", rev = "40d447dc69a29f0d805984157565e5c5eeca265e", default-features = false, features = ["native-tls", "e2e-encryption"] }
rpassword = "7.3.1"
rustyline-async = "0.4.3"
serde = { version = "1.0.208", features = ["derive"] }
serde_json = "1.0.125"
tokio = { version = "1.39.3", features = ["full"] }

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BSD 2-Clause License
Copyright (c) 2024, networkException <git@nwex.de>
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this
list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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{ pkgs ? import <nixpkgs> {} }: pkgs.mkShell {
nativeBuildInputs = with pkgs; [
# building
cargo
pkg-config
openssl
];
}

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use std::fs;
use std::process::exit;
use std::io::Read;
use anyhow::Result;
use clap::Parser;
use log::{info, debug, error};
use serde::Deserialize;
use rustyline_async::{Readline, ReadlineEvent};
use matrix_sdk::{matrix_auth::{MatrixSession, MatrixSessionTokens}, ruma::{api::client::{authenticated_media, media}, device_id, user_id}, Client, SessionMeta};
use matrix_sdk::ruma::events::room::{MediaSource, message::{MessageType, RoomMessageEventContent}};
// NOTE: This has been stolen from the matrix-rust-sdk to patch out checks for authenticated media
async fn get_media_content(
client: &Client,
source: &MediaSource,
use_auth: bool
) -> matrix_sdk::Result<Vec<u8>> {
let content: Vec<u8> = match &source {
MediaSource::Encrypted(file) => {
let content = if use_auth {
let request = authenticated_media::get_content::v1::Request::from_uri(&file.url)?;
client.send(request, None).await?.file
} else {
#[allow(deprecated)]
let request = media::get_content::v3::Request::from_url(&file.url)?;
client.send(request, None).await?.file
};
let content = {
debug!("Decrypting file");
let content_len = content.len();
let mut cursor = std::io::Cursor::new(content);
let mut reader = match matrix_sdk::crypto::AttachmentDecryptor::new(
&mut cursor,
file.as_ref().clone().into(),
) {
Ok(reader) => reader,
Err(error) => {
error!("Unable to decrypt: {}", error);
exit(1);
}
};
// Encrypted size should be the same as the decrypted size,
// rounded up to a cipher block.
let mut decrypted = Vec::with_capacity(content_len);
reader.read_to_end(&mut decrypted)?;
decrypted
};
content
}
MediaSource::Plain(uri) => {
debug!("File doesn't appear to be encrypted");
if use_auth {
let request = authenticated_media::get_content::v1::Request::from_uri(uri)?;
client.send(request, None).await?.file
} else {
#[allow(deprecated)]
let request = media::get_content::v3::Request::from_url(uri)?;
client.send(request, None).await?.file
}
}
};
Ok(content)
}
async fn process_media(source: MediaSource, body: Option<String>, server: Option<String>) -> Result<()> {
let uri = match source.clone() {
MediaSource::Plain(uri) => uri,
MediaSource::Encrypted(encrypted) => encrypted.url,
};
let server_name = uri.server_name()?;
let media_id = uri.media_id()?;
let client = match server {
Some(ref url) => Client::builder().server_name_or_homeserver_url(url),
None => Client::builder().server_name(server_name),
}.build().await?;
debug!("Downloading {} from {}", uri, client.homeserver());
let content = match get_media_content(&client, &source, false).await {
Ok(content) => content,
Err(error) => {
let error_is_needs_authentication = match &error {
matrix_sdk::Error::Http(http) => match http {
matrix_sdk::HttpError::IntoHttp(into_http) => {
match into_http {
matrix_sdk::ruma::api::error::IntoHttpError::NeedsAuthentication => true,
_ => false,
}
},
_ => false
},
_ => false,
};
if error_is_needs_authentication {
info!("The server did not allow downloading without authentication, please enter an access token:");
let token = rpassword::prompt_password("> ")?;
client.restore_session(MatrixSession {
meta: SessionMeta {
user_id: user_id!("@unused:example.com").to_owned(),
device_id: device_id!("UNUSED").to_owned(),
},
tokens: MatrixSessionTokens {
access_token: token,
refresh_token: None,
},
}).await?;
get_media_content(&client, &source, false).await
.map_err(|error| anyhow::Error::msg(error.to_string()))?
} else {
return Err(anyhow::Error::msg(error.to_string()));
}
}
};
let file_name = match body {
Some(body) => format!("{server_name}-{media_id}-{}", body),
None => format!("{server_name}-{media_id}")
};
info!("Saving to {file_name}");
fs::write(file_name, content)?;
Ok(())
}
#[derive(Deserialize, Debug)]
struct DecryptedEventSource {
content: RoomMessageEventContent,
}
#[derive(clap::Parser)]
#[command(author, version, about, long_about = None)]
struct Arguments {
/// Homeserver URL or Name
#[clap(long, env)]
server: Option<String>,
}
#[tokio::main]
async fn main() -> Result<()> {
env_logger::init_from_env(env_logger::Env::default().filter_or(env_logger::DEFAULT_FILTER_ENV, "matrix_media_event_decrypt=debug"));
let Arguments {
server
} = Arguments::parse();
info!("Enter decrypted event source, confirm with Ctrl+D");
let (mut readline, mut _stdout) = Readline::new("> ".to_owned()).unwrap();
let mut lines = Vec::new();
loop {
match readline.readline().await {
Ok(ReadlineEvent::Line(line)) => {
let line = line.trim();
if line.is_empty() {
break;
}
// readline.add_history_entry(line.to_owned());
lines.push(line.to_owned());
},
Ok(ReadlineEvent::Eof) => {
break
},
Ok(ReadlineEvent::Interrupted) => {
println!("^C");
exit(1);
},
Err(error) => {
error!("Unable to read in decrypted event source: {}", error.to_string());
exit(1);
},
}
}
drop(_stdout);
drop(readline);
let event = match serde_json::from_str::<DecryptedEventSource>(lines.join("\n").as_str()) {
Ok(event) => event,
Err(error) => {
error!("Unable to parse event: {}", error);
exit(1);
}
};
println!();
debug!("Parsed event with {} content", event.content.msgtype.msgtype());
if let Err(error) = match event.content.msgtype {
MessageType::Audio(content) => process_media(content.source, Some(content.body), server).await,
MessageType::File(content) => process_media(content.source, Some(content.body), server).await,
MessageType::Image(content) => process_media(content.source, Some(content.body), server).await,
MessageType::Video(content) => process_media(content.source, Some(content.body), server).await,
_ => {
error!("Event content is not known to contain media, exiting");
exit(1);
},
} {
error!("Unable to process media: {}", error);
}
Ok(())
}