DATAMONGO-2306 - Polishing.

Add Nullable annotation to nullable method args. Remove IV from JSON Schema as it is not listed in Mongo specs.

Tweak wording in docs. Parse encryption-settings-ref for MongoClientOptions. Add support for KeyId's in encrypted JSON schema properties.

Original pull request: #766.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/config/MongoParsingUtils.java

@@ -35,6 +35,7 @@ import org.w3c.dom.Element;
  * @author Oliver Gierke
  * @author Thomas Darimont
  * @author Christoph Strobl
+ * @author Mark Paluch
  */
 @SuppressWarnings("deprecation")
 abstract class MongoParsingUtils {
@@ -92,6 +93,7 @@ abstract class MongoParsingUtils {
 		setPropertyValue(clientOptionsDefBuilder, optionsElement, "heartbeat-socket-timeout", "heartbeatSocketTimeout");
 		setPropertyValue(clientOptionsDefBuilder, optionsElement, "ssl", "ssl");
 		setPropertyReference(clientOptionsDefBuilder, optionsElement, "ssl-socket-factory-ref", "sslSocketFactory");
+		setPropertyReference(clientOptionsDefBuilder, optionsElement, "encryption-settings-ref", "autoEncryptionSettings");
 		setPropertyValue(clientOptionsDefBuilder, optionsElement, "server-selection-timeout", "serverSelectionTimeout");
 
 		mongoClientBuilder.addPropertyValue("mongoClientOptions", clientOptionsDefBuilder.getBeanDefinition());

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/MongoEncryptionSettingsFactoryBean.java

@@ -20,6 +20,7 @@ import java.util.Map;
 
 import org.bson.BsonDocument;
 import org.springframework.beans.factory.FactoryBean;
+import org.springframework.lang.Nullable;
 
 import com.mongodb.AutoEncryptionSettings;
 import com.mongodb.MongoClientSettings;
@@ -104,7 +105,7 @@ public class MongoEncryptionSettingsFactoryBean implements FactoryBean<AutoEncry
 				.build();
 	}
 
-	private <K, V> Map<K, V> orEmpty(Map<K, V> source) {
+	private <K, V> Map<K, V> orEmpty(@Nullable Map<K, V> source) {
 		return source != null ? source : Collections.emptyMap();
 	}
 

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/schema/IdentifiableJsonSchemaProperty.java

@@ -18,9 +18,12 @@ package org.springframework.data.mongodb.core.schema;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.LinkedHashSet;
+import java.util.List;
 import java.util.Set;
+import java.util.UUID;
 
 import org.bson.Document;
+
 import org.springframework.data.domain.Range;
 import org.springframework.data.mongodb.core.schema.TypedJsonSchemaObject.ArrayJsonSchemaObject;
 import org.springframework.data.mongodb.core.schema.TypedJsonSchemaObject.BooleanJsonSchemaObject;
@@ -1057,8 +1060,8 @@ public class IdentifiableJsonSchemaProperty<T extends JsonSchemaObject> implemen
 
 		private final JsonSchemaProperty targetProperty;
 		private final @Nullable String algorithm;
-		private final @Nullable char[] keyId;
-		private final @Nullable char[] iv;
+		private final @Nullable String keyId;
+		private final @Nullable List<UUID> keyIds;
 
 		/**
 		 * Create new instance of {@link EncryptedJsonSchemaProperty} wrapping the given {@link JsonSchemaProperty target}.
@@ -1069,14 +1072,14 @@ public class IdentifiableJsonSchemaProperty<T extends JsonSchemaObject> implemen
 			this(target, null, null, null);
 		}
 
-		private EncryptedJsonSchemaProperty(JsonSchemaProperty target, @Nullable String algorithm, @Nullable char[] keyId,
-				@Nullable char[] iv) {
+		private EncryptedJsonSchemaProperty(JsonSchemaProperty target, @Nullable String algorithm, @Nullable String keyId,
+				@Nullable List<UUID> keyIds) {
 
 			Assert.notNull(target, "Target must not be null!");
 			this.targetProperty = target;
 			this.algorithm = algorithm;
 			this.keyId = keyId;
-			this.iv = iv;
+			this.keyIds = keyIds;
 		}
 
 		/**
@@ -1113,19 +1116,23 @@ public class IdentifiableJsonSchemaProperty<T extends JsonSchemaObject> implemen
 		 * @return new instance of {@link EncryptedJsonSchemaProperty}.
 		 */
 		public EncryptedJsonSchemaProperty algorithm(String algorithm) {
-			return new EncryptedJsonSchemaProperty(targetProperty, algorithm, keyId, iv);
+			return new EncryptedJsonSchemaProperty(targetProperty, algorithm, keyId, keyIds);
 		}
 
 		/**
 		 * @param key
 		 * @return
 		 */
-		public EncryptedJsonSchemaProperty keyId(char[] key) {
-			return new EncryptedJsonSchemaProperty(targetProperty, algorithm, key, iv);
+		public EncryptedJsonSchemaProperty keyId(String keyId) {
+			return new EncryptedJsonSchemaProperty(targetProperty, algorithm, keyId, null);
 		}
 
-		public EncryptedJsonSchemaProperty keyId(String key) {
-			return keyId(key.toCharArray());
+		/**
+		 * @param keyId
+		 * @return
+		 */
+		public EncryptedJsonSchemaProperty keys(UUID... keyId) {
+			return new EncryptedJsonSchemaProperty(targetProperty, algorithm, null, Arrays.asList(keyId));
 		}
 
 		/*
@@ -1141,7 +1148,9 @@ public class IdentifiableJsonSchemaProperty<T extends JsonSchemaObject> implemen
 			Document enc = new Document();
 
 			if (!ObjectUtils.isEmpty(keyId)) {
-				enc.append("keyId", new String(keyId));
+				enc.append("keyId", keyId);
+			} else if (!ObjectUtils.isEmpty(keyIds)) {
+				enc.append("keyId", keyIds);
 			}
 
 			Type type = extractPropertyType(propertySpecification);

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/schema/MongoJsonSchemaUnitTests.java

@@ -19,6 +19,8 @@ import static org.springframework.data.mongodb.core.schema.JsonSchemaProperty.*;
 import static org.springframework.data.mongodb.test.util.Assertions.*;
 
 import java.util.Arrays;
+import java.util.Collections;
+import java.util.UUID;
 
 import org.bson.Document;
 import org.junit.Test;
@@ -87,6 +89,22 @@ public class MongoJsonSchemaUnitTests {
 								.append("algorithm", "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic").append("bsonType", "string"))))));
 	}
 
+	@Test // DATAMONGO-2306
+	public void rendersEncryptedPropertyWithKeyIdCorrectly() {
+
+		UUID uuid = UUID.randomUUID();
+		MongoJsonSchema schema = MongoJsonSchema.builder().properties( //
+				encrypted(string("ssn")) //
+						.aead_aes_256_cbc_hmac_sha_512_deterministic() //
+						.keys(uuid) //
+		).build();
+
+		assertThat(schema.toDocument()).isEqualTo(new Document("$jsonSchema",
+				new Document("type", "object").append("properties",
+						new Document("ssn", new Document("encrypt", new Document("keyId", Collections.singletonList(uuid))
+								.append("algorithm", "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic").append("bsonType", "string"))))));
+	}
+
 	@Test // DATAMONGO-1835
 	public void throwsExceptionOnNullRoot() {
 		assertThatIllegalArgumentException().isThrownBy(() -> MongoJsonSchema.of((JsonSchemaObject) null));

src/main/asciidoc/reference/mongo-json-schema.adoc

@@ -208,7 +208,7 @@ template.find(query(matchingDocumentStructure(schema)), Person.class);
 [[mongo.jsonSchema.encrypted-fields]]
 ==== Encrypted Fields
 
-MongoDB 4.2 https://docs.mongodb.com/master/core/security-client-side-encryption/[Field Level Encryption] allows to directly secure certain properties.
+MongoDB 4.2 https://docs.mongodb.com/master/core/security-client-side-encryption/[Field Level Encryption] allows to directly encrypt individual properties.
 
 Properties can be wrapped within an encrypted property when setting up the JSON Schema as shown in the example below.
 
@@ -225,7 +225,7 @@ MongoJsonSchema schema = MongoJsonSchema.builder()
 ----
 ====
 
-NOTE: Make sure to set the drivers `com.mongodb.AutoEncryptionSettings` to use client side encryption.
+NOTE: Make sure to set the drivers `com.mongodb.AutoEncryptionSettings` to use client-side encryption. MongoDB does not support encryption for all field types. Specific data types require deterministic encryption to preserve equality comparison functionality.
 
 [[mongo.jsonSchema.types]]
 ==== JSON Schema Types