diff --git a/Cargo.toml b/Cargo.toml
index 999dee1..6d817f4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,20 +24,20 @@ clap = { version = "4.4", features = ["derive"] }
 csv = "1.3"
 email_address = "0.2"
 fs4 = "0.7"
-hyper = "1.0"
+hyper = "1.1"
 hyper-util = "0.1"
 lettre = { version = "0.11", default-features = false, features = ["builder", "smtp-transport", "rustls-tls"] }
-oauth2 = { version = "4.4", default-features = false, features = ["rustls-tls"] }
+oauth2 = { version = "4.4", default-features = false }
 rand = "0.8"
 reqwest = { version = "0.11", default-features = false, features = ["rustls-tls", "json"] }
 roxmltree = "0.19"
 rusqlite = { version = "0.30", features = ["bundled"], optional = true }
-rustls = "0.21"
-rustls-pemfile = "1.0"
+rustls = "0.22"
+rustls-pemfile = "2.0"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-tokio = { version = "1.35", features = ["full"] }
-tokio-rustls = "0.24"
+tokio = { version = "1.36", features =  ["fs", "sync", "time", "macros", "rt-multi-thread"]}
+tokio-rustls = "0.25"
 tower = { version = "0.4", features = ["util", "timeout"] }
 tower-http = { version = "0.5", features = ["fs", "trace", "compression-deflate"] }
 tower-service = "0.3"
diff --git a/src/error.rs b/src/error.rs
index ba0126c..e92acd0 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -1,3 +1,5 @@
+use std::fmt;
+
 use axum::response::IntoResponse;
 use axum::Json;
 use hyper::StatusCode;
@@ -48,6 +50,14 @@ pub enum Error {
     UnsupportedProjectVersion,
 }
 
+impl std::error::Error for Error {}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(self, f)
+    }
+}
+
 #[cfg(feature = "sqlite")]
 #[allow(deprecated)]
 impl From<rusqlite::Error> for Error {
diff --git a/src/server/auth.rs b/src/server/auth.rs
index fa13488..4ad89a4 100644
--- a/src/server/auth.rs
+++ b/src/server/auth.rs
@@ -15,10 +15,9 @@ use base64::engine::general_purpose::STANDARD as BASE64;
 use base64::Engine;
 use hyper::{HeaderMap, StatusCode};
 use oauth2::basic::BasicClient;
-use oauth2::reqwest::async_http_client;
 use oauth2::{
-    AuthUrl, AuthorizationCode, ClientId, ClientSecret, CsrfToken, RedirectUrl, Scope,
-    TokenResponse, TokenUrl,
+    AuthUrl, AuthorizationCode, ClientId, ClientSecret, CsrfToken, HttpRequest, HttpResponse,
+    RedirectUrl, Scope, TokenResponse, TokenUrl,
 };
 use rand::RngCore;
 use serde::{Deserialize, Serialize};
@@ -300,6 +299,28 @@ fn unix_secs() -> u64 {
         .as_secs()
 }
 
+/// Asynchronous HTTP client.
+async fn async_http_client(request: HttpRequest) -> Result<HttpResponse> {
+    let client = reqwest::Client::builder()
+        // Following redirects opens the client up to SSRF vulnerabilities.
+        .redirect(reqwest::redirect::Policy::none())
+        .build()?;
+
+    let request = client
+        .request(request.method, request.url)
+        .headers(request.headers)
+        .body(request.body)
+        .build()?;
+
+    let response = client.execute(request).await?;
+
+    Ok(HttpResponse {
+        status_code: response.status(),
+        headers: response.headers().to_owned(),
+        body: response.bytes().await?.to_vec(),
+    })
+}
+
 #[cfg(test)]
 mod test {
     use super::Session;
diff --git a/src/server/mod.rs b/src/server/mod.rs
index 8fb79a3..fcb4896 100644
--- a/src/server/mod.rs
+++ b/src/server/mod.rs
@@ -16,7 +16,6 @@ use axum::Router;
 use hyper::body::Incoming;
 use hyper::Request;
 use hyper_util::rt::{TokioExecutor, TokioIo};
-use rustls::{Certificate, PrivateKey};
 use tokio::net::TcpListener;
 use tokio_rustls::rustls::ServerConfig;
 use tokio_rustls::TlsAcceptor;
@@ -128,19 +127,13 @@ async fn serve(host: SocketAddr, tls: ServerConfig, app: Router) -> io::Result<(
 
 fn load_tls_config(cert: &std::path::Path, key: &std::path::Path) -> io::Result<ServerConfig> {
     let certs = rustls_pemfile::certs(&mut io::BufReader::new(File::open(cert)?))
-        .map_err(|_| io::Error::new(io::ErrorKind::InvalidInput, "invalid cert"))?
-        .into_iter()
-        .map(Certificate)
-        .collect();
+        .collect::<Result<_, io::Error>>()?;
     let key = rustls_pemfile::pkcs8_private_keys(&mut io::BufReader::new(File::open(key)?))
-        .map_err(|_| io::Error::new(io::ErrorKind::InvalidInput, "invalid key"))?
-        .into_iter()
         .next()
-        .ok_or(io::Error::new(io::ErrorKind::InvalidInput, "invalid key"))?;
+        .ok_or(io::Error::new(io::ErrorKind::InvalidInput, "invalid key"))??;
     rustls::ServerConfig::builder()
-        .with_safe_defaults()
         .with_no_client_auth()
-        .with_single_cert(certs, PrivateKey(key))
+        .with_single_cert(certs, key.into())
         .map_err(|err| io::Error::new(io::ErrorKind::InvalidInput, err))
 }