JWT logging improvements (#5823)

* lower level on auth success from info to debug (fixes #5820)
* don't log stacktraces on auth errors (as requested on slack). we do this by introducing an `AuthError` type instead of using `anyhow` and `bail`.
* return errors that have been censored for improved security.

libs/utils/src/auth.rs

@@ -2,7 +2,7 @@
 
 use arc_swap::ArcSwap;
 use serde;
-use std::{fs, sync::Arc};
+use std::{borrow::Cow, fmt::Display, fs, sync::Arc};
 
 use anyhow::Result;
 use camino::Utf8Path;
@@ -11,7 +11,7 @@ use jsonwebtoken::{
 };
 use serde::{Deserialize, Serialize};
 
-use crate::id::TenantId;
+use crate::{http::error::ApiError, id::TenantId};
 
 /// Algorithm to use. We require EdDSA.
 const STORAGE_TOKEN_ALGORITHM: Algorithm = Algorithm::EdDSA;
@@ -54,7 +54,7 @@ impl SwappableJwtAuth {
     pub fn swap(&self, jwt_auth: JwtAuth) {
         self.0.swap(Arc::new(jwt_auth));
     }
-    pub fn decode(&self, token: &str) -> Result<TokenData<Claims>> {
+    pub fn decode(&self, token: &str) -> std::result::Result<TokenData<Claims>, AuthError> {
         self.0.load().decode(token)
     }
 }
@@ -65,6 +65,24 @@ impl std::fmt::Debug for SwappableJwtAuth {
     }
 }
 
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+pub struct AuthError(pub Cow<'static, str>);
+
+impl Display for AuthError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+impl From<AuthError> for ApiError {
+    fn from(_value: AuthError) -> Self {
+        // Don't pass on the value of the AuthError as a precautionary measure.
+        // Being intentionally vague in public error communication hurts debugability
+        // but it is more secure.
+        ApiError::Forbidden("JWT authentication error".to_string())
+    }
+}
+
 pub struct JwtAuth {
     decoding_keys: Vec<DecodingKey>,
     validation: Validation,
@@ -114,7 +132,7 @@ impl JwtAuth {
     /// The function tries the stored decoding keys in succession,
     /// and returns the first yielding a successful result.
     /// If there is no working decoding key, it returns the last error.
-    pub fn decode(&self, token: &str) -> Result<TokenData<Claims>> {
+    pub fn decode(&self, token: &str) -> std::result::Result<TokenData<Claims>, AuthError> {
         let mut res = None;
         for decoding_key in &self.decoding_keys {
             res = Some(decode(token, decoding_key, &self.validation));
@@ -123,9 +141,9 @@ impl JwtAuth {
             }
         }
         if let Some(res) = res {
-            res.map_err(anyhow::Error::new)
+            res.map_err(|e| AuthError(Cow::Owned(e.to_string())))
         } else {
-            anyhow::bail!("no JWT decoding keys configured")
+            Err(AuthError(Cow::Borrowed("no JWT decoding keys configured")))
         }
     }
 }
@@ -166,9 +184,9 @@ MC4CAQAwBQYDK2VwBCIEID/Drmc1AA6U/znNRWpF3zEGegOATQxfkdWxitcOMsIH
 "#;
 
     #[test]
-    fn test_decode() -> Result<(), anyhow::Error> {
+    fn test_decode() {
         let expected_claims = Claims {
-            tenant_id: Some(TenantId::from_str("3d1f7595b468230304e0b73cecbcb081")?),
+            tenant_id: Some(TenantId::from_str("3d1f7595b468230304e0b73cecbcb081").unwrap()),
             scope: Scope::Tenant,
         };
 
@@ -187,28 +205,24 @@ MC4CAQAwBQYDK2VwBCIEID/Drmc1AA6U/znNRWpF3zEGegOATQxfkdWxitcOMsIH
         let encoded_eddsa = "eyJhbGciOiJFZERTQSIsInR5cCI6IkpXVCJ9.eyJzY29wZSI6InRlbmFudCIsInRlbmFudF9pZCI6IjNkMWY3NTk1YjQ2ODIzMDMwNGUwYjczY2VjYmNiMDgxIiwiaXNzIjoibmVvbi5jb250cm9scGxhbmUiLCJleHAiOjE3MDkyMDA4NzksImlhdCI6MTY3ODQ0MjQ3OX0.U3eA8j-uU-JnhzeO3EDHRuXLwkAUFCPxtGHEgw6p7Ccc3YRbFs2tmCdbD9PZEXP-XsxSeBQi1FY0YPcT3NXADw";
 
         // Check it can be validated with the public key
-        let auth = JwtAuth::new(vec![DecodingKey::from_ed_pem(TEST_PUB_KEY_ED25519)?]);
-        let claims_from_token = auth.decode(encoded_eddsa)?.claims;
+        let auth = JwtAuth::new(vec![DecodingKey::from_ed_pem(TEST_PUB_KEY_ED25519).unwrap()]);
+        let claims_from_token = auth.decode(encoded_eddsa).unwrap().claims;
         assert_eq!(claims_from_token, expected_claims);
-
-        Ok(())
     }
 
     #[test]
-    fn test_encode() -> Result<(), anyhow::Error> {
+    fn test_encode() {
         let claims = Claims {
-            tenant_id: Some(TenantId::from_str("3d1f7595b468230304e0b73cecbcb081")?),
+            tenant_id: Some(TenantId::from_str("3d1f7595b468230304e0b73cecbcb081").unwrap()),
             scope: Scope::Tenant,
         };
 
-        let encoded = encode_from_key_file(&claims, TEST_PRIV_KEY_ED25519)?;
+        let encoded = encode_from_key_file(&claims, TEST_PRIV_KEY_ED25519).unwrap();
 
         // decode it back
-        let auth = JwtAuth::new(vec![DecodingKey::from_ed_pem(TEST_PUB_KEY_ED25519)?]);
-        let decoded = auth.decode(&encoded)?;
+        let auth = JwtAuth::new(vec![DecodingKey::from_ed_pem(TEST_PUB_KEY_ED25519).unwrap()]);
+        let decoded = auth.decode(&encoded).unwrap();
 
         assert_eq!(decoded.claims, claims);
-
-        Ok(())
     }
 }

libs/utils/src/http/endpoint.rs

@@ -1,4 +1,4 @@
-use crate::auth::{Claims, SwappableJwtAuth};
+use crate::auth::{AuthError, Claims, SwappableJwtAuth};
 use crate::http::error::{api_error_handler, route_error_handler, ApiError};
 use anyhow::Context;
 use hyper::header::{HeaderName, AUTHORIZATION};
@@ -400,9 +400,11 @@ pub fn auth_middleware<B: hyper::body::HttpBody + Send + Sync + 'static>(
                     })?;
                     let token = parse_token(header_value)?;
 
-                    let data = auth
-                        .decode(token)
-                        .map_err(|_| ApiError::Unauthorized("malformed jwt token".to_string()))?;
+                    let data = auth.decode(token).map_err(|err| {
+                        warn!("Authentication error: {err}");
+                        // Rely on From<AuthError> for ApiError impl
+                        err
+                    })?;
                     req.set_context(data.claims);
                 }
                 None => {
@@ -450,12 +452,11 @@ where
 
 pub fn check_permission_with(
     req: &Request<Body>,
-    check_permission: impl Fn(&Claims) -> Result<(), anyhow::Error>,
+    check_permission: impl Fn(&Claims) -> Result<(), AuthError>,
 ) -> Result<(), ApiError> {
     match req.context::<Claims>() {
-        Some(claims) => {
-            Ok(check_permission(&claims).map_err(|err| ApiError::Forbidden(err.to_string()))?)
-        }
+        Some(claims) => Ok(check_permission(&claims)
+            .map_err(|_err| ApiError::Forbidden("JWT authentication error".to_string()))?),
         None => Ok(()), // claims is None because auth is disabled
     }
 }

libs/utils/src/http/error.rs

@@ -3,7 +3,7 @@ use serde::{Deserialize, Serialize};
 use std::borrow::Cow;
 use std::error::Error as StdError;
 use thiserror::Error;
-use tracing::{error, info};
+use tracing::{error, info, warn};
 
 #[derive(Debug, Error)]
 pub enum ApiError {
@@ -118,6 +118,9 @@ pub fn api_error_handler(api_error: ApiError) -> Response<Body> {
     // Print a stack trace for Internal Server errors
 
     match api_error {
+        ApiError::Forbidden(_) | ApiError::Unauthorized(_) => {
+            warn!("Error processing HTTP request: {api_error:#}")
+        }
         ApiError::ResourceUnavailable(_) => info!("Error processing HTTP request: {api_error:#}"),
         ApiError::NotFound(_) => info!("Error processing HTTP request: {api_error:#}"),
         ApiError::InternalServerError(_) => error!("Error processing HTTP request: {api_error:?}"),