feat: improved http signatures code

README.md

@@ -3,7 +3,7 @@
 
 μpub aims to be a fast, lightweight and secure [ActivityPub](https://www.w3.org/TR/activitypub/) server
 
-μpub is currently being developed and can do some basic things, like posting notes, follows and likes
+μpub is currently being developed and can do most basic things, like posting notes, liking things, following others, deliveries.
 
 all interactions must happen with ActivityPub's client-server methods (basically POST your activities to your outbox)
 

src/routes/activitypub/user/mod.rs

@@ -4,7 +4,7 @@ pub mod outbox;
 
 pub mod following;
 
-use axum::{extract::{Path, State}, http::StatusCode};
+use axum::extract::{Path, State};
 use sea_orm::{ColumnTrait, Condition, EntityTrait, QueryFilter};
 
 use apb::{PublicKeyMut, ActorMut, DocumentMut, DocumentType, ObjectMut, BaseMut, Node};

src/server/auth.rs

@@ -1,3 +1,5 @@
+use std::collections::BTreeMap;
+
 use axum::{extract::{FromRef, FromRequestParts}, http::{header, request::Parts}};
 use base64::Engine;
 use openssl::{hash::MessageDigest, pkey::PKey, sign::Verifier};
@@ -64,18 +66,19 @@ where
 			.get("Signature")
 			.map(|v| v.to_str().unwrap_or(""))
 		{
-			let http_signature = HttpSignature::parse(sig);
+			let mut http_signature = HttpSignature::parse(sig);
 
-			let user_id = http_signature.key_id.replace("#main-key", "");
-			match ctx.fetch().user(&user_id).await {
-				Ok(user) => {
-					let to_sign = http_signature.build_string(parts);
 			// TODO assert payload's digest is equal to signature's
-					match verify_control_text(&to_sign, &user.public_key, &http_signature.signature) {
+			let user_id = http_signature.key_id.replace("#main-key", "");
+
+			match ctx.fetch().user(&user_id).await {
+				Ok(user) => match http_signature
+						.build_from_parts(parts)
+						.verify(&user.public_key)
+					{
 						Ok(true) => identity = Identity::Remote(Context::server(&user_id)),
 						Ok(false) => tracing::warn!("invalid signature"),
 						Err(e) => tracing::error!("error verifying signature: {e}"),
-					}
 					},
 				Err(e) => tracing::warn!("could not fetch user (won't verify): {e}"),
 			}
@@ -86,33 +89,25 @@ where
 }
 
 
-
-fn verify_control_text(txt: &str, key: &str, control: &str) -> crate::Result<bool> {
-	let pubkey = PKey::public_key_from_pem(key.as_bytes())?;
-	let mut verifier = Verifier::new(MessageDigest::sha256(), &pubkey)?;
-	let signature = base64::prelude::BASE64_STANDARD.decode(control)?;
-	Ok(verifier.verify_oneshot(&signature, txt.as_bytes())?)
-}
-
-
-
-
-
-
-
-
-
-
-
 #[derive(Debug, Clone, Default)]
 pub struct HttpSignature {
-	key_id: String,
-	algorithm: String,
-	headers: Vec<String>,
-	signature: String,
+	pub key_id: String,
+	pub algorithm: String,
+	pub headers: Vec<String>,
+	pub signature: String,
+	pub control: String,
 }
 
 impl HttpSignature {
+	pub fn new(key_id: String, algorithm: String, headers: &[&str]) -> Self {
+		HttpSignature {
+			key_id, algorithm,
+			headers: headers.iter().map(|x| x.to_string()).collect(),
+			signature: String::new(),
+			control: String::new(),
+		}
+	}
+
 	pub fn parse(header: &str) -> Self {
 		let mut sig = HttpSignature::default();
 		header.split(',')
@@ -128,7 +123,24 @@ impl HttpSignature {
 		sig
 	}
 
-	pub fn build_string(&self, parts: &Parts) -> String {
+	pub fn header(&self) -> String {
+		format!(
+			"keyId=\"{}\",algorithm=\"{}\",headers=\"{}\",signature=\"{}\"",
+			self.key_id, self.algorithm, self.headers.join(" "), self.signature,
+		)
+	}
+
+	pub fn build_manually(&mut self, method: &str, target: &str, mut headers: BTreeMap<String, String>) -> &mut Self {
+		let mut out = Vec::new();
+		out.push(format!("(request-target): {method} {target}"));
+		for header in &self.headers {
+			out.push(format!("{header}: {}", headers.remove(header).unwrap_or_default()));
+		}
+		self.control = out.join("\n");
+		self
+	}
+
+	pub fn build_from_parts(&mut self, parts: &Parts) -> &mut Self {
 		let mut out = Vec::new();
 		for header in self.headers.iter() {
 			match header.as_str() {
@@ -146,19 +158,53 @@ impl HttpSignature {
 				)),
 			}
 		}
-		out.join("\n")
+		self.control = out.join("\n");
+		self
 	}
 
-	pub fn digest(&self) -> MessageDigest {
-		match self.algorithm.as_str() {
-			"rsa-sha512" => MessageDigest::sha512(),
-			"rsa-sha384" => MessageDigest::sha384(),
-			"rsa-sha256" => MessageDigest::sha256(),
-			"rsa-sha1" => MessageDigest::sha1(),
-			_ => {
-				tracing::error!("unknown digest algorithm, trying with rsa-sha256");
-				MessageDigest::sha256()
-			}
+	pub fn verify(&self, key: &str) -> crate::Result<bool> {
+		let pubkey = PKey::public_key_from_pem(key.as_bytes())?;
+		let mut verifier = Verifier::new(MessageDigest::sha256(), &pubkey)?;
+		let signature = base64::prelude::BASE64_STANDARD.decode(&self.signature)?;
+		Ok(verifier.verify_oneshot(&signature, self.control.as_bytes())?)
 	}
+
+	pub fn sign(&mut self, key: &str) -> crate::Result<&str> {
+		let privkey = PKey::private_key_from_pem(key.as_bytes())?;
+		let mut signer = openssl::sign::Signer::new(MessageDigest::sha256(), &privkey)?;
+		signer.update(self.control.as_bytes())?;
+		self.signature = base64::prelude::BASE64_STANDARD.encode(signer.sign_to_vec()?);
+		Ok(&self.signature)
+	}
+}
+
+#[cfg(test)]
+mod test {
+	#[test]
+	fn http_signature_signs_and_verifies() {
+		let key = openssl::rsa::Rsa::generate(2048).unwrap();
+		let private_key = std::str::from_utf8(&key.private_key_to_pem().unwrap()).unwrap().to_string();
+		let public_key = std::str::from_utf8(&key.public_key_to_pem().unwrap()).unwrap().to_string();
+		let mut signer = super::HttpSignature {
+			key_id: "test".to_string(),
+			algorithm: "rsa-sha256".to_string(),
+			headers: vec![
+				"(request-target)".to_string(),
+				"host".to_string(),
+				"date".to_string(),
+			],
+			signature: String::new(),
+			control: String::new(),
+		};
+
+		signer
+			.build_manually("get", "/actor/inbox", [("host".into(), "example.net".into()), ("date".into(), "Sat, 13 Apr 2024 13:36:23 GMT".into())].into())
+			.sign(&private_key)
+			.unwrap();
+
+		let mut verifier = super::HttpSignature::parse(&signer.header());
+		verifier.build_manually("get", "/actor/inbox", [("host".into(), "example.net".into()), ("date".into(), "Sat, 13 Apr 2024 13:36:23 GMT".into())].into());
+
+		assert!(verifier.verify(&public_key).unwrap());
 	}
 }

src/server/dispatcher.rs

@@ -1,4 +1,3 @@
-use openssl::pkey::PKey;
 use reqwest::Method;
 use sea_orm::{ColumnTrait, Condition, DatabaseConnection, EntityTrait, Order, QueryFilter, QueryOrder};
 use tokio::{sync::broadcast, task::JoinHandle};
@@ -92,12 +91,6 @@ async fn worker(db: DatabaseConnection, domain: String, poll_interval: u64, mut
 			continue;
 		};
 
-		let Ok(key) = PKey::private_key_from_pem(key.as_bytes())
-		else {
-			tracing::error!("failed parsing private key for user {}", delivery.actor);
-			continue;
-		};
-
 		if let Err(e) = Fetcher::request(
 			Method::POST, &delivery.target,
 			Some(&serde_json::to_string(&payload).unwrap()),

src/server/fetcher.rs

@@ -1,22 +1,23 @@
+use std::collections::BTreeMap;
+
 use base64::Engine;
-use openssl::{hash::MessageDigest, pkey::{PKey, Private}, sign::Signer};
 use reqwest::{header::{ACCEPT, CONTENT_TYPE, USER_AGENT}, Method, Response};
 use sea_orm::{DatabaseConnection, EntityTrait, IntoActiveModel};
 
 use crate::{model, VERSION};
 
-use super::Context;
+use super::{auth::HttpSignature, Context};
 
 
 pub struct Fetcher {
 	db: DatabaseConnection,
-	key: PKey<Private>, // TODO store pre-parsed
+	key: String, // TODO store pre-parsed
 	domain: String, // TODO merge directly with Context so we don't need to copy this
 }
 
 impl Fetcher {
 	pub fn new(db: DatabaseConnection, domain: String, key: String) -> Self {
-		Fetcher { db, domain, key: PKey::private_key_from_pem(key.as_bytes()).unwrap() }
+		Fetcher { db, domain, key }
 	}
 
 	pub async fn request(
@@ -24,16 +25,18 @@ impl Fetcher {
 		url: &str,
 		payload: Option<&str>,
 		from: &str,
-		key: &PKey<Private>,
+		key: &str,
 		domain: &str,
-	) -> reqwest::Result<Response> {
+	) -> crate::Result<Response> {
 		let host = Context::server(url);
 		let date = chrono::Utc::now().format("%a, %d %b %Y %H:%M:%S GMT").to_string(); // lmao @ "GMT"
 		let path = url.replace("https://", "").replace("http://", "").replace(&host, "");
-		// let mut headers : BTreeMap<String, String> = [
-		// 	("Host".to_string(), host.clone()),
-		// 	("Date".to_string(), date.clone()),
-		// ].into();
+
+		let mut headers = vec!["(request-target)", "host", "date"];
+		let mut headers_map : BTreeMap<String, String> = [
+			("host".to_string(), host.clone()),
+			("date".to_string(), date.clone()),
+		].into();
 
 		let mut client = reqwest::Client::new()
 			.request(method.clone(), url)
@@ -43,30 +46,32 @@ impl Fetcher {
 			.header("Host", host.clone())
 			.header("Date", date.clone());
 
-		let mut to_sign_raw = format!("(request-target): {} {path}\nhost: {host}\ndate: {date}", method.to_string().to_lowercase());
-		let mut headers_to_inspect = "(request-target) host date";
 
 		if let Some(payload) = payload {
 			let digest = format!("sha-256={}", base64::prelude::BASE64_STANDARD.encode(openssl::sha::sha256(payload.as_bytes())));
-			to_sign_raw = format!("(request-target): {} {path}\nhost: {host}\ndate: {date}\ndigest: {digest}", method.to_string().to_lowercase());
-			headers_to_inspect = "(request-target) host date digest";
+			headers_map.insert("digest".to_string(), digest.clone());
+			headers.push("digest");
 			client = client
 				.header("Digest", digest)
 				.body(payload.to_string());
 		}
 
-		let signature_header = {
-			let mut signer = Signer::new(MessageDigest::sha256(), key).unwrap();
-			signer.update(to_sign_raw.as_bytes()).unwrap();
-			let signature = base64::prelude::BASE64_STANDARD.encode(signer.sign_to_vec().unwrap());
-			format!("keyId=\"{from}#main-key\",algorithm=\"rsa-sha256\",headers=\"{headers_to_inspect}\",signature=\"{signature}\"")
-		};
+		let mut signer = HttpSignature::new(
+			format!("{from}#main-key"), // TODO don't hardcode #main-key
+			"rsa-sha256".to_string(),
+			&headers,
+		);
 		
-		client
-			.header("Signature", signature_header)
+		signer
+			.build_manually(&method.to_string().to_lowercase(), &path, headers_map)
+			.sign(key)?;
+
+		let res = client
+				.header("Signature", signer.header())
 				.send()
-			.await?
-			.error_for_status()
+				.await?;
+
+		Ok(res.error_for_status()?)
 	}
 
 	pub async fn user(&self, id: &str) -> crate::Result<model::user::Model> {