Extra validation for w3c credentials and presentations (#325)

Signed-off-by: Andrew Whitehead <cywolf@gmail.com>

src/data_types/w3c/credential.rs

@@ -20,6 +20,7 @@ use crate::Result;
 /// Note, that this definition is tied to AnonCreds W3C form
 #[derive(Debug, Clone, PartialEq, Eq, Deserialize, Serialize)]
 #[serde(rename_all = "camelCase")]
+#[serde(deny_unknown_fields)]
 pub struct W3CCredential {
     #[serde(rename = "@context")]
     pub context: Contexts,
@@ -162,4 +163,16 @@ mod tests {
             serde_json::from_str(&out_json).expect("Error deserializing w3c credential");
         assert_eq!(cred1, cred2);
     }
+
+    #[test]
+    fn serde_w3c_credential_deny_unknown() {
+        let cred_json = include_str!("sample_credential.json");
+        let mut cred: serde_json::Value =
+            serde_json::from_str(cred_json).expect("Error deserializing w3c credential");
+        cred.as_object_mut()
+            .unwrap()
+            .insert("prop".into(), "val".into());
+        let res = serde_json::from_value::<W3CCredential>(cred);
+        assert!(res.is_err());
+    }
 }

src/data_types/w3c/presentation.rs

@@ -11,6 +11,7 @@ use crate::Result;
 /// Note, that this definition is tied to AnonCreds W3C form
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
+#[serde(deny_unknown_fields)]
 pub struct W3CPresentation {
     #[serde(rename = "@context")]
     pub context: Contexts,
@@ -69,4 +70,16 @@ mod tests {
             serde_json::from_str(&out_json).expect("Error deserializing w3c presentation");
         assert_eq!(pres1, pres2);
     }
+
+    #[test]
+    fn serde_w3c_presentation_deny_unknown() {
+        let pres_json = include_str!("sample_presentation.json");
+        let mut pres: serde_json::Value =
+            serde_json::from_str(pres_json).expect("Error deserializing w3c presentation");
+        pres.as_object_mut()
+            .unwrap()
+            .insert("prop".into(), "val".into());
+        let res = serde_json::from_value::<W3CPresentation>(pres);
+        assert!(res.is_err());
+    }
 }

src/services/w3c/verifier.rs

@@ -370,6 +370,24 @@ fn check_request_data(
         )?;
     }
 
+    for (cred, proof) in presentation
+        .verifiable_credential
+        .as_slice()
+        .iter()
+        .zip(credential_proofs)
+    {
+        let Some(cred_def_issuer) = cred_defs.get(&proof.cred_def_id).map(|cd| &cd.issuer_id) else {
+            return Err(err_msg!("Missing credential definition"));
+        };
+        if cred_def_issuer != &cred.issuer {
+            return Err(err_msg!("Inconsistent issuer ID"));
+        }
+        let di_proof = cred.get_data_integrity_proof()?;
+        if di_proof.verification_method != proof.cred_def_id.0 {
+            return Err(err_msg!("Inconsistent credential definition ID"));
+        }
+    }
+
     Ok(())
 }
 
@@ -892,4 +910,50 @@ pub(crate) mod tests {
         .unwrap_err();
         assert_eq!(ErrorKind::Input, err.kind());
     }
+
+    #[rstest]
+    #[case(_presentation_request_with_single_attribute())]
+    fn test_check_cred_def_id_mismatch_fails(
+        schemas: HashMap<SchemaId, Schema>,
+        cred_defs: HashMap<CredentialDefinitionId, CredentialDefinition>,
+        presentation: W3CPresentation,
+        #[case] presentation_request: PresentationRequestPayload,
+    ) {
+        let mut cred_proofs = presentation.credential_proofs();
+        cred_proofs[0].cred_def_id = "other:id".try_into().unwrap();
+
+        let err = check_request_data(
+            &presentation_request,
+            &presentation,
+            &schemas,
+            &cred_defs,
+            None,
+            &cred_proofs,
+        )
+        .unwrap_err();
+        assert_eq!(ErrorKind::Input, err.kind());
+    }
+
+    #[rstest]
+    #[case(_presentation_request_with_single_attribute())]
+    fn test_check_issuer_id_mismatch_fails(
+        schemas: HashMap<SchemaId, Schema>,
+        mut cred_defs: HashMap<CredentialDefinitionId, CredentialDefinition>,
+        presentation: W3CPresentation,
+        #[case] presentation_request: PresentationRequestPayload,
+    ) {
+        let cred_def = cred_defs.iter_mut().next().unwrap().1;
+        cred_def.issuer_id = "other:id".try_into().unwrap();
+
+        let err = check_request_data(
+            &presentation_request,
+            &presentation,
+            &schemas,
+            &cred_defs,
+            None,
+            &presentation.credential_proofs(),
+        )
+        .unwrap_err();
+        assert_eq!(ErrorKind::Input, err.kind());
+    }
 }