lemmy/crates/apub/src/extensions/signatures.rs
2021-03-10 17:33:55 -05:00

139 lines
4 KiB
Rust

use crate::ActorType;
use activitystreams::unparsed::UnparsedMutExt;
use activitystreams_ext::UnparsedExtension;
use actix_web::HttpRequest;
use anyhow::{anyhow, Context};
use http::{header::HeaderName, HeaderMap, HeaderValue};
use http_signature_normalization_actix::Config as ConfigActix;
use http_signature_normalization_reqwest::prelude::{Config, SignExt};
use lemmy_utils::{location_info, LemmyError};
use log::debug;
use openssl::{
hash::MessageDigest,
pkey::PKey,
sign::{Signer, Verifier},
};
use reqwest::{Client, Response};
use serde::{Deserialize, Serialize};
use sha2::{Digest, Sha256};
use std::{collections::BTreeMap, str::FromStr};
use url::Url;
lazy_static! {
static ref CONFIG2: ConfigActix = ConfigActix::new();
static ref HTTP_SIG_CONFIG: Config = Config::new();
}
/// Creates an HTTP post request to `inbox_url`, with the given `client` and `headers`, and
/// `activity` as request body. The request is signed with `private_key` and then sent.
pub async fn sign_and_send(
client: &Client,
headers: BTreeMap<String, String>,
inbox_url: &Url,
activity: String,
actor_id: &Url,
private_key: String,
) -> Result<Response, LemmyError> {
let signing_key_id = format!("{}#main-key", actor_id);
let mut header_map = HeaderMap::new();
for h in headers {
header_map.insert(
HeaderName::from_str(h.0.as_str())?,
HeaderValue::from_str(h.1.as_str())?,
);
}
let response = client
.post(&inbox_url.to_string())
.headers(header_map)
.signature_with_digest(
HTTP_SIG_CONFIG.clone(),
signing_key_id,
Sha256::new(),
activity,
move |signing_string| {
let private_key = PKey::private_key_from_pem(private_key.as_bytes())?;
let mut signer = Signer::new(MessageDigest::sha256(), &private_key)?;
signer.update(signing_string.as_bytes())?;
Ok(base64::encode(signer.sign_to_vec()?)) as Result<_, LemmyError>
},
)
.await?;
Ok(response)
}
/// Verifies the HTTP signature on an incoming inbox request.
pub(crate) fn verify_signature(
request: &HttpRequest,
actor: &dyn ActorType,
) -> Result<(), LemmyError> {
let public_key = actor.public_key().context(location_info!())?;
let verified = CONFIG2
.begin_verify(
request.method(),
request.uri().path_and_query(),
request.headers().clone(),
)?
.verify(|signature, signing_string| -> Result<bool, LemmyError> {
debug!(
"Verifying with key {}, message {}",
&public_key, &signing_string
);
let public_key = PKey::public_key_from_pem(public_key.as_bytes())?;
let mut verifier = Verifier::new(MessageDigest::sha256(), &public_key)?;
verifier.update(&signing_string.as_bytes())?;
Ok(verifier.verify(&base64::decode(signature)?)?)
})?;
if verified {
debug!("verified signature for {}", &request.uri());
Ok(())
} else {
Err(anyhow!("Invalid signature on request: {}", &request.uri()).into())
}
}
/// Extension for actor public key, which is needed on person and community for HTTP signatures.
///
/// Taken from: https://docs.rs/activitystreams/0.5.0-alpha.17/activitystreams/ext/index.html
#[derive(Clone, Debug, Deserialize, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct PublicKeyExtension {
pub public_key: PublicKey,
}
#[derive(Clone, Debug, Deserialize, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct PublicKey {
pub id: String,
pub owner: Url,
pub public_key_pem: String,
}
impl PublicKey {
pub fn to_ext(&self) -> PublicKeyExtension {
PublicKeyExtension {
public_key: self.to_owned(),
}
}
}
impl<U> UnparsedExtension<U> for PublicKeyExtension
where
U: UnparsedMutExt,
{
type Error = serde_json::Error;
fn try_from_unparsed(unparsed_mut: &mut U) -> Result<Self, Self::Error> {
Ok(PublicKeyExtension {
public_key: unparsed_mut.remove("publicKey")?,
})
}
fn try_into_unparsed(self, unparsed_mut: &mut U) -> Result<(), Self::Error> {
unparsed_mut.insert("publicKey", self.public_key)?;
Ok(())
}
}