Improve security

src/auth/extractor.rs

@@ -0,0 +1,23 @@
+use std::future::{ready, Ready};
+
+use actix_web::dev::Payload;
+use actix_web::{error::ErrorUnauthorized, Error, FromRequest, HttpMessage, HttpRequest};
+
+/// The user id of the caller, as established by the auth middleware after
+/// verifying the `user-token` header. Extracting this (instead of trusting a
+/// client-supplied `user_id` in the path/body) is the source of truth for
+/// "who is making this request".
+#[derive(Clone, Copy)]
+pub struct AuthUser(pub i32);
+
+impl FromRequest for AuthUser {
+    type Error = Error;
+    type Future = Ready<Result<Self, Self::Error>>;
+
+    fn from_request(req: &HttpRequest, _payload: &mut Payload) -> Self::Future {
+        match req.extensions().get::<AuthUser>() {
+            Some(auth_user) => ready(Ok(*auth_user)),
+            None => ready(Err(ErrorUnauthorized("missing authenticated user"))),
+        }
+    }
+}

src/auth/jwt.rs

@@ -2,17 +2,32 @@ extern crate hmac;
 extern crate jwt;
 extern crate sha2;
 
-use std::collections::BTreeMap;
 use std::env;
 
 use actix_web::HttpRequest;
+use chrono::{Duration, Utc};
 use dotenv::dotenv;
 use hmac::{Hmac, Mac};
 use jwt::{Header, SignWithKey, Token, VerifyWithKey};
+use serde::{Deserialize, Serialize};
 use sha2::Sha256;
 
+/// How long a freshly issued token remains valid for.
+const TOKEN_LIFETIME_HOURS: i64 = 24;
+
 pub struct JwtToken {
     pub user_id: i32,
+    pub token_version: i32,
+}
+
+#[derive(Serialize, Deserialize)]
+struct Claims {
+    user_id: i32,
+    /// Must match `users.token_version` for the token to be accepted; bumping
+    /// the column (e.g. on logout) revokes every token issued before that point.
+    tv: i32,
+    /// Unix timestamp after which the token is rejected, independent of signature validity.
+    exp: i64,
 }
 
 type HmacSha256 = Hmac<Sha256>;
@@ -25,11 +40,14 @@ fn signing_key() -> HmacSha256 {
 }
 
 impl JwtToken {
-    pub fn encode(user_id: i32) -> String {
+    pub fn encode(user_id: i32, token_version: i32) -> String {
         let key: HmacSha256 = signing_key();
-        let mut claims = BTreeMap::new();
-        claims.insert("user_id", user_id);
-        // Signing a simple map of claims with a valid HMAC key cannot fail.
+        let claims = Claims {
+            user_id,
+            tv: token_version,
+            exp: (Utc::now() + Duration::hours(TOKEN_LIFETIME_HOURS)).timestamp(),
+        };
+        // Signing claims with a valid HMAC key cannot fail.
         claims
             .sign_with_key(&key)
             .expect("signing claims with a valid HMAC key cannot fail")
@@ -38,15 +56,18 @@ impl JwtToken {
     pub fn decode(encoded_token: String) -> Result<JwtToken, &'static str> {
         let key: HmacSha256 = signing_key();
         let token_str: &str = encoded_token.as_str();
-        let token: Result<Token<Header, BTreeMap<String, i32>, jwt::Verified>, jwt::Error> =
+        let token: Result<Token<Header, Claims, jwt::Verified>, jwt::Error> =
             VerifyWithKey::verify_with_key(token_str, &key);
 
         match token {
             Ok(token) => {
-                let _header = token.header();
                 let claims = token.claims();
+                if claims.exp < Utc::now().timestamp() {
+                    return Err("token has expired");
+                }
                 Ok(JwtToken {
-                    user_id: claims["user_id"],
+                    user_id: claims.user_id,
+                    token_version: claims.tv,
                 })
             }
             Err(_err) => Err("could not decode token"),
@@ -68,14 +89,19 @@ impl JwtToken {
 #[cfg(test)]
 mod jwt_test {
     use actix_web::{http::header, test};
+    use chrono::{Duration, Utc};
+    use hmac::Hmac;
+    use jwt::SignWithKey;
+    use sha2::Sha256;
 
-    use super::JwtToken;
+    use super::{Claims, JwtToken};
 
     #[test]
     async fn encode_decode() {
-        let encoded_token: String = JwtToken::encode(32);
+        let encoded_token: String = JwtToken::encode(32, 0);
         let decoded_token: JwtToken = JwtToken::decode(encoded_token).unwrap();
         assert_eq!(32, decoded_token.user_id);
+        assert_eq!(0, decoded_token.token_version);
     }
 
     #[test]
@@ -88,9 +114,25 @@ mod jwt_test {
         }
     }
 
+    #[test]
+    async fn decode_expired_token() {
+        let key: Hmac<Sha256> = super::signing_key();
+        let claims = Claims {
+            user_id: 32,
+            tv: 0,
+            exp: (Utc::now() - Duration::hours(1)).timestamp(),
+        };
+        let expired_token: String = claims.sign_with_key(&key).unwrap();
+
+        match JwtToken::decode(expired_token) {
+            Err(message) => assert_eq!(message, "token has expired"),
+            _ => panic!("Expired token should not be accepted."),
+        }
+    }
+
     #[actix_web::test]
     async fn decode_from_request_with_correct_token() {
-        let encoded_token: String = JwtToken::encode(32);
+        let encoded_token: String = JwtToken::encode(32, 0);
         let request = test::TestRequest::default()
             .insert_header(header::ContentType::json())
             .insert_header(("user-token", encoded_token))

src/auth/mod.rs

@@ -1,12 +1,13 @@
 use actix_web::dev::ServiceRequest;
+pub mod extractor;
 pub mod jwt;
 pub mod processes;
-use crate::auth::processes::check_password;
+use crate::auth::processes::check_token;
 use crate::auth::processes::extract_header_token;
 
 pub fn process_token(request: &ServiceRequest) -> Result<i32, &'static str> {
     match extract_header_token(request) {
-        Ok(token) => check_password(token),
+        Ok(token) => check_token(token),
         Err(message) => Err(message),
     }
 }
@@ -16,19 +17,24 @@ mod mod_test {
 
     use actix_web::test::TestRequest;
 
-    use super::{jwt::JwtToken, process_token};
+    use super::process_token;
+    use crate::auth::jwt::JwtToken;
+    use crate::database::establish_connection;
+    use crate::test_helpers::{delete_user, insert_user};
 
     #[test]
     fn process_token_test() {
-        let token = JwtToken::encode(32);
+        let mut connection = establish_connection();
+        let user = insert_user(&mut connection, "secret");
+
+        let token = JwtToken::encode(user.id, user.token_version);
         let request = TestRequest::delete()
             .insert_header(("user-token", token))
             .to_srv_request();
 
-        match process_token(&request) {
-            Ok(user_id) => assert_eq!(32, user_id),
-            Err(_) => panic!("process token failed"),
-        }
+        assert_eq!(Ok(user.id), process_token(&request));
+
+        delete_user(&mut connection, user.id);
     }
 
     #[actix_web::test]

src/auth/processes.rs

@@ -1,22 +1,33 @@
 use super::jwt;
+use crate::database::establish_connection;
+use crate::models::user::rss_user::User;
+use crate::schema::users;
 use actix_web::dev::ServiceRequest;
+use diesel::prelude::*;
 
-pub fn check_password(password: String) -> Result<i32, &'static str> {
-    match jwt::JwtToken::decode(password) {
-        Ok(token) => Ok(token.user_id),
-        Err(message) => Err(message),
+/// Decodes the token and confirms it hasn't been revoked, i.e. its `token_version`
+/// still matches the one stored on the user (bumped on logout / password change).
+pub fn check_token(token: String) -> Result<i32, &'static str> {
+    let decoded = jwt::JwtToken::decode(token)?;
+
+    let mut connection = establish_connection();
+    let user: User = users::table
+        .find(decoded.user_id)
+        .first(&mut connection)
+        .map_err(|_| "could not decode token")?;
+
+    if user.token_version != decoded.token_version {
+        return Err("token has been revoked");
     }
+
+    Ok(decoded.user_id)
 }
 
 pub fn extract_header_token(request: &ServiceRequest) -> Result<String, &'static str> {
-    log::info!("Request: {:?}", request);
     match request.headers().get("user-token") {
         Some(token) => match token.to_str() {
-            Ok(processed_password) => {
-                log::info!("Token provided: {}", processed_password);
-                Ok(String::from(processed_password))
-            }
-            Err(_processed_password) => Err("there was an error processing token"),
+            Ok(processed_token) => Ok(String::from(processed_token)),
+            Err(_) => Err("there was an error processing token"),
         },
         None => Err("there is no token"),
     }
@@ -25,31 +36,51 @@ pub fn extract_header_token(request: &ServiceRequest) -> Result<String, &'static
 #[cfg(test)]
 mod processes_test {
     use actix_web::test::TestRequest;
+    use diesel::prelude::*;
 
     use crate::auth::jwt::JwtToken;
+    use crate::database::establish_connection;
+    use crate::test_helpers::{delete_user, insert_user};
 
-    use super::check_password;
+    use super::check_token;
 
     #[test]
-    fn check_correct_password() {
-        let password_string: String = JwtToken::encode(32);
+    fn check_correct_token() {
+        let mut connection = establish_connection();
+        let user = insert_user(&mut connection, "secret");
 
-        let result = check_password(password_string);
+        let token: String = JwtToken::encode(user.id, user.token_version);
 
-        match result {
-            Ok(user_id) => assert_eq!(32, user_id),
-            _ => panic!("Check correct password failed."),
-        }
+        let result = check_token(token);
+
+        assert_eq!(Ok(user.id), result);
+
+        delete_user(&mut connection, user.id);
     }
 
     #[test]
-    fn incorrect_check_password() {
-        let password: String = String::from("test");
+    fn revoked_token_is_rejected() {
+        let mut connection = establish_connection();
+        let user = insert_user(&mut connection, "secret");
 
-        match check_password(password) {
-            Err(message) => assert_eq!("could not decode token", message),
-            _ => panic!("check password should not be able to be decoded"),
-        }
+        // Token signed with the user's current version, then the version is bumped
+        // (as logout would do), which must invalidate the previously issued token.
+        let token: String = JwtToken::encode(user.id, user.token_version);
+        diesel::update(crate::schema::users::table.find(user.id))
+            .set(crate::schema::users::token_version.eq(user.token_version + 1))
+            .execute(&mut connection)
+            .unwrap();
+
+        assert_eq!(Err("token has been revoked"), check_token(token));
+
+        delete_user(&mut connection, user.id);
+    }
+
+    #[test]
+    fn incorrect_check_token() {
+        let token: String = String::from("test");
+
+        assert_eq!(Err("could not decode token"), check_token(token));
     }
 
     #[test]