Add support for cedar entities validation.

Signed-off-by: Mohamed Amine Ouali <mdamine@amazon.com>

CedarJava/src/main/java/com/cedarpolicy/AuthorizationEngine.java

@@ -80,6 +80,17 @@ PartialAuthorizationResponse isAuthorizedPartial(PartialAuthorizationRequest req
      */
     ValidationResponse validate(ValidationRequest request) throws AuthException;
 
+    /**
+     * Asks whether the entities in the given {@link EntityValidationRequest} <code>q</code> are correct
+     * when validated against the schema it describes.
+     *
+     * @param request The request containing the entities to validate and the schema to validate them
+     *    against.
+     * @throws BadRequestException if any errors were found in the syntax of the entities.
+     * @throws AuthException if any internal errors occurred while validating the entities.
+     */
+    void validateEntities(EntityValidationRequest request) throws AuthException;
+
     /**
      * Get the Cedar language major version (e.g., "1.2") used by this CedarJava library.
      *

CedarJava/src/main/java/com/cedarpolicy/BasicAuthorizationEngine.java

@@ -24,15 +24,20 @@
 import com.cedarpolicy.loader.LibraryLoader;
 import com.cedarpolicy.model.*;
 import com.cedarpolicy.model.exception.AuthException;
+import com.cedarpolicy.model.exception.BadRequestException;
 import com.cedarpolicy.model.exception.InternalException;
 import com.cedarpolicy.model.exception.MissingExperimentalFeatureException;
 import com.cedarpolicy.model.entity.Entity;
 import com.cedarpolicy.model.policy.PolicySet;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.JsonNode;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 
+import java.util.List;
 import java.util.Set;
 
 /** An authorization engine that is compiled in process. Communicated with via JNI. */
@@ -73,6 +78,18 @@ public ValidationResponse validate(ValidationRequest q) throws AuthException {
         return call("ValidateOperation", ValidationResponse.class, q);
     }
 
+    @Override
+    public void validateEntities(EntityValidationRequest q) throws AuthException {
+        EntityValidationResponse entityValidationResponse = call("ValidateEntities", EntityValidationResponse.class, q);
+        if (!entityValidationResponse.success) {
+            if (entityValidationResponse.isInternal) {
+                throw new InternalException(entityValidationResponse.errors.toArray(new String[0]));
+            } else {
+                throw new BadRequestException(entityValidationResponse.errors.toArray(new String[0]));
+            }
+        }
+    }
+
     private static <REQ, RESP> RESP call(String operation, Class<RESP> responseClass, REQ request)
             throws AuthException {
         try {
@@ -100,6 +117,40 @@ private static <REQ, RESP> RESP call(String operation, Class<RESP> responseClass
         }
     }
 
+    /**
+     * The result of processing an EntityValidationRequest.
+     */
+    @JsonIgnoreProperties({"result"})  // Ignore only the 'result' field
+    private static final class EntityValidationResponse {
+
+        /** A string that indicates if the operation was successful.*/
+        private final boolean success;
+
+        /** A boolean flag that indicates whether the error is internal.*/
+        private final boolean isInternal;
+
+        /** A list of error messages encountered during the operation.*/
+        private final List<String> errors;
+
+        /**
+         * Parameterized constructor for initializing all fields of EntityValidationResponse.
+         *
+         * @param success    A boolean indicating success status.
+         * @param isInternal A boolean indicating if the error is internal.
+         * @param errors     A list of error messages.
+         */
+        @JsonCreator
+        @SuppressFBWarnings
+        EntityValidationResponse(
+                @JsonProperty("success") boolean success,
+                @JsonProperty("isInternal") boolean isInternal,
+                @JsonProperty("errors") List<String> errors) {
+            this.success = success;
+            this.isInternal = isInternal;
+            this.errors = errors;
+        }
+    }
+
     private static class AuthorizationRequest extends com.cedarpolicy.model.AuthorizationRequest {
         @JsonProperty private final PolicySet policies;
         @JsonProperty private final Set<Entity> entities;

CedarJava/src/main/java/com/cedarpolicy/model/EntityValidationRequest.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright Cedar Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+ package com.cedarpolicy.model;
+
+ import java.util.List;
+ import java.util.Objects;
+
+ import com.cedarpolicy.model.entity.Entity;
+ import com.cedarpolicy.model.schema.Schema;
+ import com.fasterxml.jackson.annotation.JsonProperty;
+ import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+
+ /**
+  * Information passed to Cedar for entities validation.
+  */
+ public final class EntityValidationRequest {
+     @JsonProperty("schema")
+     private final Schema schema;
+     @JsonProperty("entities")
+     private final List<Entity> entities;
+
+     /**
+      * Construct a validation request.
+      *
+      * @param schema   Schema for the request
+      * @param entities Map.
+      */
+     @SuppressFBWarnings
+     public EntityValidationRequest(Schema schema, List<Entity> entities) {
+         if (schema == null) {
+             throw new NullPointerException("schema");
+         }
+
+         if (entities == null) {
+             throw new NullPointerException("entities");
+         }
+
+         this.schema = schema;
+         this.entities = entities;
+     }
+
+     /**
+      * Test equality.
+      */
+     @Override
+     public boolean equals(final Object o) {
+         if (!(o instanceof EntityValidationRequest)) {
+             return false;
+         }
+
+         final EntityValidationRequest other = (EntityValidationRequest) o;
+         return schema.equals(other.schema) && entities.equals(other.entities);
+     }
+
+     /**
+      * Hash.
+      */
+     @Override
+     public int hashCode() {
+         return Objects.hash(schema, entities);
+     }
+
+     /**
+      * Get readable string representation.
+      */
+     public String toString() {
+         return "EntityValidationRequest(schema=" + schema + ", entities=" + entities + ")";
+     }
+ }

CedarJava/src/test/java/com/cedarpolicy/EntityValidationTests.java

@@ -0,0 +1,109 @@
+/*
+ * Copyright Cedar Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.cedarpolicy;
+
+import static com.cedarpolicy.TestUtil.loadSchemaResource;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.BeforeAll;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+
+import com.cedarpolicy.model.EntityValidationRequest;
+import com.cedarpolicy.model.entity.Entity;
+import com.cedarpolicy.model.exception.AuthException;
+import com.cedarpolicy.model.exception.BadRequestException;
+import com.cedarpolicy.model.schema.Schema;
+import com.cedarpolicy.pbt.EntityGen;
+import com.cedarpolicy.value.EntityTypeName;
+import com.cedarpolicy.value.PrimBool;
+
+
+/**
+ * Tests for entity validator
+ */
+public class EntityValidationTests {
+    private static EntityGen entityGen;
+    private static AuthorizationEngine engine;
+
+    /**
+     * Test that a valid entity is accepted.
+     */
+    @Test
+    public void testValidEntity() throws AuthException {
+        Entity entity = EntityValidationTests.entityGen.arbitraryEntity();
+
+        EntityValidationRequest r = new EntityValidationRequest(
+                ROLE_SCHEMA, List.of(entity));
+
+        engine.validateEntities(r);
+    }
+
+    /**
+     * Test that an entity with an attribute not specified in the schema throws an exception.
+     */
+    @Test
+    public void testEntityWithUnknownAttribute() throws AuthException {
+        Entity entity = EntityValidationTests.entityGen.arbitraryEntity();
+        entity.attrs.put("test", new PrimBool(true));
+
+        EntityValidationRequest request = new EntityValidationRequest(ROLE_SCHEMA, List.of(entity));
+
+        BadRequestException exception = assertThrows(BadRequestException.class, () -> engine.validateEntities(request));
+
+        String errMsg = exception.getErrors().get(0);
+        assertTrue(errMsg.matches("attribute `test` on `Role::\".*\"` should not exist according to the schema"),
+                "Expected to match regex but was: '%s'".formatted(errMsg));
+    }
+
+    /**
+     * Test that entities with a cyclic parent relationship throw an exception.
+     */
+    @Test
+    public void testEntitiesWithCyclicParentRelationship() throws AuthException {
+        // Arrange
+        Entity childEntity = EntityValidationTests.entityGen.arbitraryEntity();
+        Entity parentEntity = EntityValidationTests.entityGen.arbitraryEntity();
+
+        // Create a cyclic parent relationship between the entities
+        childEntity.parentsEUIDs.add(parentEntity.getEUID());
+        parentEntity.parentsEUIDs.add(childEntity.getEUID());
+
+        EntityValidationRequest request = new EntityValidationRequest(ROLE_SCHEMA, List.of(parentEntity, childEntity));
+
+        BadRequestException exception = assertThrows(BadRequestException.class, () -> engine.validateEntities(request));
+
+        String errMsg = exception.getErrors().get(0);
+        assertTrue(errMsg.matches("input graph has a cycle containing vertex `Role::\".*\"`"),
+                "Expected to match regex but was: '%s'".formatted(errMsg));
+    }
+
+    @BeforeAll
+    public static void setUp() {
+
+        engine = new BasicAuthorizationEngine();
+        EntityTypeName user = EntityTypeName.parse("Role").get();
+
+        EntityValidationTests.entityGen = new EntityGen(user);
+    }
+
+    private static final Schema ROLE_SCHEMA = loadSchemaResource("/role_schema.json");
+}

CedarJava/src/test/resources/role_schema.json

@@ -0,0 +1,12 @@
+{
+  "": {
+    "entityTypes": {
+      "Role": {
+        "memberOfTypes": [
+          "Role"
+        ]
+      }
+    },
+    "actions": {}
+  }
+}

CedarJavaFFI/src/interface.rs

@@ -18,7 +18,7 @@
 use cedar_policy::ffi::is_authorized_partial_json_str;
 use cedar_policy::{
     ffi::{is_authorized_json_str, validate_json_str},
-    EntityUid, Policy, PolicySet, Schema, Template,
+    Entities, EntityUid, Policy, PolicySet, Schema, Template,
 };
 use cedar_policy_formatter::{policies_str_to_pretty, Config};
 use jni::{
@@ -29,6 +29,8 @@ use jni::{
 use jni_fn::jni_fn;
 use serde::{Deserialize, Serialize};
 use std::{error::Error, str::FromStr, thread};
+use cedar_policy::entities_errors::EntitiesError;
+use serde_json::{from_str, Value};
 
 use crate::{
     answer::Answer,
@@ -43,6 +45,7 @@ const V0_AUTH_OP: &str = "AuthorizationOperation";
 #[cfg(feature = "partial-eval")]
 const V0_AUTH_PARTIAL_OP: &str = "AuthorizationPartialOperation";
 const V0_VALIDATE_OP: &str = "ValidateOperation";
+const V0_VALIDATE_ENTITIES: &str = "ValidateEntities";
 
 fn build_err_obj(env: &JNIEnv<'_>, err: &str) -> jstring {
     env.new_string(
@@ -115,6 +118,7 @@ pub(crate) fn call_cedar(call: &str, input: &str) -> String {
         #[cfg(feature = "partial-eval")]
         V0_AUTH_PARTIAL_OP => is_authorized_partial_json_str(input),
         V0_VALIDATE_OP => validate_json_str(input),
+        V0_VALIDATE_ENTITIES => json_validate_entities(&input),
         _ => {
             let ires = Answer::fail_internally(format!("unsupported operation: {}", call));
             serde_json::to_string(&ires)
@@ -125,6 +129,43 @@ pub(crate) fn call_cedar(call: &str, input: &str) -> String {
     })
 }
 
+#[derive(Serialize, Deserialize)]
+struct ValidateEntityCall {
+    schema: Value,
+    entities: Value,
+}
+
+pub fn json_validate_entities(input: &str) -> serde_json::Result<String> {
+    let ans = validate_entities(input)?;
+    serde_json::to_string(&ans)
+}
+
+/// public string-based JSON interface to be invoked by FFIs. Takes in a `ValidateEntityCall` and (if successful)
+/// returns unit value () which is null value when serialized to json.
+pub fn validate_entities(input: &str) -> serde_json::Result<Answer> {
+    let validate_entity_call = from_str::<ValidateEntityCall>(&input)?;
+    match Schema::from_json_value(validate_entity_call.schema) {
+        Err(e) => Ok(Answer::fail_bad_request(vec![e.to_string()])),
+        Ok(schema) => {
+            match Entities::from_json_value(validate_entity_call.entities, Some(&schema)) {
+                Err(error) => {
+                    let err_message = match error {
+                        EntitiesError::Serialization(err) => err.to_string(),
+                        EntitiesError::Deserialization(err) => err.to_string(),
+                        EntitiesError::Duplicate(err) => err.to_string(),
+                        EntitiesError::TransitiveClosureError(err) => err.to_string(),
+                        EntitiesError::InvalidEntity(err) => err.to_string(),
+                    };
+                    Ok(Answer::fail_bad_request(vec![err_message]))
+                },
+                Ok(_entities) => {
+                    Ok(Answer::Success { result: "null".to_string() })
+                }
+            }
+        }
+    }
+}
+
 #[derive(Debug, Serialize, Deserialize)]
 struct JavaInterfaceCall {
     pub call: String,