Remove EvaluationContextProvider from MPE & MPP

This reverts commit ebe3bf8b1e836035a2d905b98c0de18ee1481cdb.

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-mongodb-parent</artifactId>
-	<version>3.3.0-SNAPSHOT</version>
+	<version>3.3.0-FLE-SNAPSHOT</version>
 	<packaging>pom</packaging>
 
 	<name>Spring Data MongoDB</name>

spring-data-mongodb-benchmarks/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>3.3.0-SNAPSHOT</version>
+		<version>3.3.0-FLE-SNAPSHOT</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

spring-data-mongodb-distribution/pom.xml

@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>3.3.0-SNAPSHOT</version>
+		<version>3.3.0-FLE-SNAPSHOT</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

spring-data-mongodb/pom.xml

@@ -11,7 +11,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-mongodb-parent</artifactId>
-		<version>3.3.0-SNAPSHOT</version>
+		<version>3.3.0-FLE-SNAPSHOT</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

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

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * 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 org.springframework.data.mongodb.core;
+
+/**
+ * Encryption algorithms supported by MongoDB Client Side Field Level Encryption.
+ *
+ * @author Christoph Strobl
+ * @since 3.3
+ */
+public final class EncryptionAlgorithms {
+
+	public static final String AEAD_AES_256_CBC_HMAC_SHA_512_Deterministic = "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic";
+	public static final String AEAD_AES_256_CBC_HMAC_SHA_512_Random = "AEAD_AES_256_CBC_HMAC_SHA_512-Random";
+
+}

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

@@ -20,13 +20,19 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.EnumSet;
 import java.util.List;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
 
+import org.bson.Document;
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
+import org.springframework.data.mongodb.core.mapping.BasicMongoPersistentEntity;
+import org.springframework.data.mongodb.core.mapping.Encrypted;
 import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
 import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
+import org.springframework.data.mongodb.core.schema.IdentifiableJsonSchemaProperty.EncryptedJsonSchemaProperty;
 import org.springframework.data.mongodb.core.schema.IdentifiableJsonSchemaProperty.ObjectJsonSchemaProperty;
 import org.springframework.data.mongodb.core.schema.JsonSchemaObject;
 import org.springframework.data.mongodb.core.schema.JsonSchemaObject.Type;
@@ -34,10 +40,12 @@ import org.springframework.data.mongodb.core.schema.JsonSchemaProperty;
 import org.springframework.data.mongodb.core.schema.MongoJsonSchema;
 import org.springframework.data.mongodb.core.schema.MongoJsonSchema.MongoJsonSchemaBuilder;
 import org.springframework.data.mongodb.core.schema.TypedJsonSchemaObject;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.ObjectUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * {@link MongoJsonSchemaCreator} implementation using both {@link MongoConverter} and {@link MappingContext} to obtain
@@ -52,6 +60,7 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 
 	private final MongoConverter converter;
 	private final MappingContext<MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext;
+	private final Predicate<JsonSchemaPropertyContext> filter;
 
 	/**
 	 * Create a new instance of {@link MappingMongoJsonSchemaCreator}.
@@ -61,10 +70,24 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 	@SuppressWarnings("unchecked")
 	MappingMongoJsonSchemaCreator(MongoConverter converter) {
 
+		this(converter, (MappingContext<MongoPersistentEntity<?>, MongoPersistentProperty>) converter.getMappingContext(),
+				(property) -> true);
+	}
+
+	@SuppressWarnings("unchecked")
+	MappingMongoJsonSchemaCreator(MongoConverter converter,
+			MappingContext<MongoPersistentEntity<?>, MongoPersistentProperty> mappingContext,
+			Predicate<JsonSchemaPropertyContext> filter) {
+
 		Assert.notNull(converter, "Converter must not be null!");
 		this.converter = converter;
-		this.mappingContext = (MappingContext<MongoPersistentEntity<?>, MongoPersistentProperty>) converter
-				.getMappingContext();
+		this.mappingContext = mappingContext;
+		this.filter = filter;
+	}
+
+	@Override
+	public MongoJsonSchemaCreator filter(Predicate<JsonSchemaPropertyContext> filter) {
+		return new MappingMongoJsonSchemaCreator(converter, mappingContext, filter);
 	}
 
 	/*
@@ -75,13 +98,35 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 	public MongoJsonSchema createSchemaFor(Class<?> type) {
 
 		MongoPersistentEntity<?> entity = mappingContext.getRequiredPersistentEntity(type);
+		if (entity instanceof BasicMongoPersistentEntity) {
+			((BasicMongoPersistentEntity<?>) entity).getEvaluationContext(null);
+		}
+
 		MongoJsonSchemaBuilder schemaBuilder = MongoJsonSchema.builder();
 
+		{
+			Encrypted encrypted = entity.findAnnotation(Encrypted.class);
+			if (encrypted != null) {
+
+				Document encryptionMetadata = new Document();
+
+				Collection<Object> encryptionKeyIds = entity.getEncryptionKeyIds();
+				if (!CollectionUtils.isEmpty(encryptionKeyIds)) {
+					encryptionMetadata.append("keyId", encryptionKeyIds);
+				}
+
+				if (StringUtils.hasText(encrypted.algorithm())) {
+					encryptionMetadata.append("algorithm", encrypted.algorithm());
+				}
+
+				schemaBuilder.encryptionMetadata(encryptionMetadata);
+			}
+		}
+
 		List<JsonSchemaProperty> schemaProperties = computePropertiesForEntity(Collections.emptyList(), entity);
 		schemaBuilder.properties(schemaProperties.toArray(new JsonSchemaProperty[0]));
 
 		return schemaBuilder.build();
-
 	}
 
 	private List<JsonSchemaProperty> computePropertiesForEntity(List<MongoPersistentProperty> path,
@@ -93,6 +138,11 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 
 			List<MongoPersistentProperty> currentPath = new ArrayList<>(path);
 
+			if (!filter.test(new PropertyContext(
+					currentPath.stream().map(PersistentProperty::getName).collect(Collectors.joining(".")), nested))) {
+				continue;
+			}
+
 			if (path.contains(nested)) { // cycle guard
 				schemaProperties.add(createSchemaProperty(computePropertyFieldName(CollectionUtils.lastElement(currentPath)),
 						Object.class, false));
@@ -120,15 +170,38 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 
 		String fieldName = computePropertyFieldName(property);
 
+		JsonSchemaProperty schemaProperty;
 		if (property.isCollectionLike()) {
-			return createSchemaProperty(fieldName, targetType, required);
+			schemaProperty = createSchemaProperty(fieldName, targetType, required);
 		} else if (property.isMap()) {
-			return createSchemaProperty(fieldName, Type.objectType(), required);
+			schemaProperty = createSchemaProperty(fieldName, Type.objectType(), required);
 		} else if (ClassUtils.isAssignable(Enum.class, targetType)) {
-			return createEnumSchemaProperty(fieldName, targetType, required);
+			schemaProperty = createEnumSchemaProperty(fieldName, targetType, required);
+		} else {
+			schemaProperty = createSchemaProperty(fieldName, targetType, required);
 		}
 
-		return createSchemaProperty(fieldName, targetType, required);
+		return applyEncryptionDataIfNecessary(property, schemaProperty);
+	}
+
+	@Nullable
+	private JsonSchemaProperty applyEncryptionDataIfNecessary(MongoPersistentProperty property,
+			JsonSchemaProperty schemaProperty) {
+
+		Encrypted encrypted = property.findAnnotation(Encrypted.class);
+		if (encrypted == null) {
+			return schemaProperty;
+		}
+
+		EncryptedJsonSchemaProperty enc = new EncryptedJsonSchemaProperty(schemaProperty);
+		if (StringUtils.hasText(encrypted.algorithm())) {
+			enc = enc.algorithm(encrypted.algorithm());
+		}
+		if (!ObjectUtils.isEmpty(encrypted.keyId())) {
+			enc = enc.keys(property.getEncryptionKeyIds());
+		}
+		return enc;
+
 	}
 
 	private JsonSchemaProperty createObjectSchemaPropertyForEntity(List<MongoPersistentProperty> path,
@@ -207,4 +280,30 @@ class MappingMongoJsonSchemaCreator implements MongoJsonSchemaCreator {
 
 		return JsonSchemaProperty.required(property);
 	}
+
+	class PropertyContext implements JsonSchemaPropertyContext {
+
+		private String path;
+		private MongoPersistentProperty property;
+
+		public PropertyContext(String path, MongoPersistentProperty property) {
+			this.path = path;
+			this.property = property;
+		}
+
+		@Override
+		public String getPath() {
+			return path;
+		}
+
+		@Override
+		public MongoPersistentProperty getProperty() {
+			return property;
+		}
+
+		@Override
+		public <T> MongoPersistentEntity<T> resolveEntity(MongoPersistentProperty property) {
+			return (MongoPersistentEntity<T>) mappingContext.getPersistentEntity(property);
+		}
+	}
 }

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

@@ -15,7 +15,23 @@
  */
 package org.springframework.data.mongodb.core;
 
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.Predicate;
+
+import org.springframework.data.mapping.PersistentProperty;
+import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
+import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
+import org.springframework.data.mongodb.core.convert.NoOpDbRefResolver;
+import org.springframework.data.mongodb.core.mapping.Encrypted;
+import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentEntity;
+import org.springframework.data.mongodb.core.mapping.MongoPersistentProperty;
+import org.springframework.data.mongodb.core.mapping.MongoSimpleTypes;
+import org.springframework.data.mongodb.core.mapping.Unwrapped.Nullable;
+import org.springframework.data.mongodb.core.schema.JsonSchemaProperty;
 import org.springframework.data.mongodb.core.schema.MongoJsonSchema;
 import org.springframework.util.Assert;
 
@@ -46,6 +62,7 @@ import org.springframework.util.Assert;
  * {@link org.bson.types.ObjectId} like {@link String} will be mapped to {@code type : 'object'} unless there is more
  * specific information available via the {@link org.springframework.data.mongodb.core.mapping.MongoId} annotation.
  * </p>
+ * {@link Encrypted} properties will contain {@literal encrypt} information.
  *
  * @author Christoph Strobl
  * @since 2.2
@@ -60,6 +77,88 @@ public interface MongoJsonSchemaCreator {
 	 */
 	MongoJsonSchema createSchemaFor(Class<?> type);
 
+	/**
+	 * Filter matching {@link JsonSchemaProperty properties}.
+	 *
+	 * @param filter the {@link Predicate} to evaluate for inclusion. Must not be {@literal null}.
+	 * @return new instance of {@link MongoJsonSchemaCreator}.
+	 * @since 3.3
+	 */
+	MongoJsonSchemaCreator filter(Predicate<JsonSchemaPropertyContext> filter);
+
+	/**
+	 * The context in which a specific {@link #getProperty()} is encountered during schema creation.
+	 * 
+	 * @since 3.3
+	 */
+	interface JsonSchemaPropertyContext {
+
+		/**
+		 * The path to a given field/property in dot notation.
+		 * 
+		 * @return never {@literal null}.
+		 */
+		String getPath();
+
+		/**
+		 * The current property.
+		 * 
+		 * @return never {@literal null}.
+		 */
+		MongoPersistentProperty getProperty();
+
+		/**
+		 * Obtain the {@link MongoPersistentEntity} for a given property.
+		 * 
+		 * @param property must not be {@literal null}.
+		 * @param <T>
+		 * @return {@literal null} if the property is not an entity. It is nevertheless recommend to check
+		 *         {@link PersistentProperty#isEntity()} first.
+		 */
+		@Nullable
+		<T> MongoPersistentEntity<T> resolveEntity(MongoPersistentProperty property);
+
+	}
+
+	/**
+	 * A filter {@link Predicate} that matches {@link Encrypted encrypted properties} and those having nested ones.
+	 *
+	 * @return new instance of {@link Predicate}.
+	 * @since 3.3
+	 */
+	static Predicate<JsonSchemaPropertyContext> encryptedOnly() {
+
+		return new Predicate<JsonSchemaPropertyContext>() {
+
+			// cycle guard
+			private final Set<MongoPersistentProperty> seen = new HashSet<>();
+
+			@Override
+			public boolean test(JsonSchemaPropertyContext context) {
+				return extracted(context.getProperty(), context);
+			}
+
+			private boolean extracted(MongoPersistentProperty property, JsonSchemaPropertyContext context) {
+				if (property.isAnnotationPresent(Encrypted.class)) {
+					return true;
+				}
+
+				if (!property.isEntity() || seen.contains(property)) {
+					return false;
+				}
+
+				seen.add(property);
+
+				for (MongoPersistentProperty nested : context.resolveEntity(property)) {
+					if (extracted(nested, context)) {
+						return true;
+					}
+				}
+				return false;
+			}
+		};
+	}
+
 	/**
 	 * Creates a new {@link MongoJsonSchemaCreator} that is aware of conversions applied by the given
 	 * {@link MongoConverter}.
@@ -72,4 +171,41 @@ public interface MongoJsonSchemaCreator {
 		Assert.notNull(mongoConverter, "MongoConverter must not be null!");
 		return new MappingMongoJsonSchemaCreator(mongoConverter);
 	}
+
+	/**
+	 * Creates a new {@link MongoJsonSchemaCreator} that is aware of type mappings and potential
+	 * {@link org.springframework.data.spel.spi.EvaluationContextExtension extensions}.
+	 *
+	 * @param mappingContext must not be {@literal null}.
+	 * @return new instance of {@link MongoJsonSchemaCreator}.
+	 * @since 3.3
+	 */
+	static MongoJsonSchemaCreator create(MappingContext mappingContext) {
+
+		MappingMongoConverter converter = new MappingMongoConverter(NoOpDbRefResolver.INSTANCE, mappingContext);
+		converter.setCustomConversions(MongoCustomConversions.create(config -> {}));
+		converter.afterPropertiesSet();
+
+		return create(converter);
+	}
+
+	/**
+	 * Creates a new {@link MongoJsonSchemaCreator} that does not consider potential extensions - suitable for testing. We
+	 * recommend to use {@link #create(MappingContext)}.
+	 *
+	 * @return new instance of {@link MongoJsonSchemaCreator}.
+	 * @since 3.3
+	 */
+	static MongoJsonSchemaCreator create() {
+
+		MongoMappingContext mappingContext = new MongoMappingContext();
+		mappingContext.setSimpleTypeHolder(MongoSimpleTypes.HOLDER);
+		mappingContext.afterPropertiesSet();
+
+		MappingMongoConverter converter = new MappingMongoConverter(NoOpDbRefResolver.INSTANCE, mappingContext);
+		converter.setCustomConversions(MongoCustomConversions.create(config -> {}));
+		converter.afterPropertiesSet();
+
+		return create(converter);
+	}
 }

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

@@ -17,8 +17,12 @@ package org.springframework.data.mongodb.core.mapping;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import org.springframework.data.annotation.Id;
@@ -28,6 +32,9 @@ import org.springframework.data.mapping.MappingException;
 import org.springframework.data.mapping.PropertyHandler;
 import org.springframework.data.mapping.model.BasicPersistentEntity;
 import org.springframework.data.mongodb.MongoCollectionUtils;
+import org.springframework.data.mongodb.util.encryption.EncryptionUtils;
+import org.springframework.data.spel.ExpressionDependencies;
+import org.springframework.data.util.Lazy;
 import org.springframework.data.util.TypeInformation;
 import org.springframework.expression.EvaluationContext;
 import org.springframework.expression.Expression;
@@ -212,6 +219,11 @@ public class BasicMongoPersistentEntity<T> extends BasicPersistentEntity<T, Mong
 		return super.getEvaluationContext(rootObject);
 	}
 
+	@Override
+	public EvaluationContext getEvaluationContext(Object rootObject, ExpressionDependencies dependencies) {
+		return super.getEvaluationContext(rootObject, dependencies);
+	}
+
 	private void verifyFieldUniqueness() {
 
 		AssertFieldNameUniquenessHandler handler = new AssertFieldNameUniquenessHandler();
@@ -360,6 +372,32 @@ public class BasicMongoPersistentEntity<T> extends BasicPersistentEntity<T, Mong
 		}
 	}
 
+	@Override
+	public Collection<Object> getEncryptionKeyIds() {
+
+		Encrypted encrypted = findAnnotation(Encrypted.class);
+		if (encrypted == null) {
+			return null;
+		}
+
+		if (ObjectUtils.isEmpty(encrypted.keyId())) {
+			return Collections.emptySet();
+		}
+
+		Lazy<EvaluationContext> evaluationContext = Lazy.of(() -> {
+
+			EvaluationContext ctx = getEvaluationContext(null);
+			ctx.setVariable("target", getType().getSimpleName());
+			return ctx;
+		});
+
+		List<Object> target = new ArrayList<>();
+		for (String keyId : encrypted.keyId()) {
+			target.add(EncryptionUtils.resolveKeyId(keyId, evaluationContext));
+		}
+		return target;
+	}
+
 	/**
 	 * @author Christoph Strobl
 	 * @since 1.6

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

@@ -16,7 +16,11 @@
 package org.springframework.data.mongodb.core.mapping;
 
 import java.math.BigInteger;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 import org.bson.types.ObjectId;
@@ -30,7 +34,12 @@ import org.springframework.data.mapping.model.FieldNamingStrategy;
 import org.springframework.data.mapping.model.Property;
 import org.springframework.data.mapping.model.PropertyNameFieldNamingStrategy;
 import org.springframework.data.mapping.model.SimpleTypeHolder;
+import org.springframework.data.mongodb.util.encryption.EncryptionUtils;
+import org.springframework.data.util.Lazy;
+import org.springframework.expression.EvaluationContext;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
 import org.springframework.lang.Nullable;
+import org.springframework.util.ObjectUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -300,4 +309,43 @@ public class BasicMongoPersistentProperty extends AnnotationBasedPersistentPrope
 		return isAnnotationPresent(TextScore.class);
 	}
 
+	/**
+	 * Obtain the {@link EvaluationContext} for a specific root object.
+	 * 
+	 * @param rootObject can be {@literal null}.
+	 * @return never {@literal null}.
+	 * @since 3.3
+	 */
+	public EvaluationContext getEvaluationContext(@Nullable Object rootObject) {
+
+		if (getOwner() instanceof BasicMongoPersistentEntity) {
+			return ((BasicMongoPersistentEntity) getOwner()).getEvaluationContext(rootObject);
+		}
+		return rootObject != null ? new StandardEvaluationContext(rootObject) : new StandardEvaluationContext();
+	}
+
+	@Override
+	public Collection<Object> getEncryptionKeyIds() {
+
+		Encrypted encrypted = findAnnotation(Encrypted.class);
+		if (encrypted == null) {
+			return null;
+		}
+
+		if (ObjectUtils.isEmpty(encrypted.keyId())) {
+			return Collections.emptySet();
+		}
+
+		Lazy<EvaluationContext> evaluationContext = Lazy.of(() -> {
+			EvaluationContext ctx = getEvaluationContext(null);
+			ctx.setVariable("target", getOwner().getType().getSimpleName() + "." + getName());
+			return ctx;
+		});
+
+		List<Object> target = new ArrayList<>();
+		for (String keyId : encrypted.keyId()) {
+			target.add(EncryptionUtils.resolveKeyId(keyId, evaluationContext));
+		}
+		return target;
+	}
 }

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

@@ -0,0 +1,112 @@
+/*
+ * Copyright 2021. the original author or authors.
+ *
+ * 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 org.springframework.data.mongodb.core.mapping;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * {@link Encrypted} provides data required for MongoDB Client Side Field Level Encryption that is applied during schema
+ * resolution. It can be applied on top level (typically those types annotated with {@link Document} to provide the
+ * {@literal encryptMetadata}.
+ *
+ * <pre class="code">
+ * &#64;Document
+ * &#64;Encrypted(keyId = "4fPYFM9qSgyRAjgQ2u+IMQ==")
+ * public class Patient {
+ * 	 private ObjectId id;
+ * 	 private String name;
+ *
+ * 	 &#64;Field("publisher_ac")
+ * 	 &#64;DocumentReference(lookup = "{ 'acronym' : ?#{#target} }") private Publisher publisher;
+ * }
+ *
+ * "encryptMetadata": {
+ *    "keyId": [
+ *      {
+ *        "$binary": {
+ *          "base64": "4fPYFM9qSgyRAjgQ2u+IMQ==",
+ *          "subType": "04"
+ *        }
+ *      }
+ *    ]
+ *  }
+ * </pre>
+ * 
+ * <br />
+ * On property level it is used for deriving field specific {@literal encrypt} settings.
+ *
+ * <pre class="code">
+ * public class Patient {
+ * 	 private ObjectId id;
+ * 	 private String name;
+ *
+ * 	 &#64;Encrypted(keyId = "4fPYFM9qSgyRAjgQ2u+IMQ==", algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic")
+ * 	 private String ssn;
+ * }
+ *
+ * "ssn" : {
+ *   "encrypt": {
+ *      "keyId": [
+ *        {
+ *          "$binary": {
+ *            "base64": "4fPYFM9qSgyRAjgQ2u+IMQ==",
+ *            "subType": "04"
+ *          }
+ *        }
+ *      ],
+ *      "algorithm" : "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic",
+ *      "bsonType" : "string"
+ *    }
+ *  }
+ * </pre>
+ * 
+ * @author Christoph Strobl
+ * @since 3.3
+ */
+@Documented
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ ElementType.TYPE, ElementType.FIELD })
+public @interface Encrypted {
+
+	/**
+	 * Get the {@code keyId} to use. The value must resolve to either the UUID representation of the key or a base64
+	 * encoded value representing the UUID value.
+	 * <p />
+	 * On {@link ElementType#TYPE} level the {@link #keyId()} can be left empty if explicitly set for fields. <br />
+	 * On {@link ElementType#FIELD} level the {@link #keyId()} can be left empty if inherited from
+	 * {@literal encryptMetadata}.
+	 *
+	 * @return the key id to use. May contain a parsable {@link org.springframework.expression.Expression expression}. In
+	 *         this case the {@code #target} variable will hold the target element name.
+	 */
+	String[] keyId() default {};
+
+	/**
+	 * Set the algorithm to use.
+	 * <p />
+	 * On {@link ElementType#TYPE} level the {@link #algorithm()} can be left empty if explicitly set for fields. <br />
+	 * On {@link ElementType#FIELD} level the {@link #algorithm()} can be left empty if inherited from
+	 * {@literal encryptMetadata}.
+	 *
+	 * @return the encryption algorithm.
+	 * @see org.springframework.data.mongodb.core.EncryptionAlgorithms
+	 */
+	String algorithm() default "";
+}

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

@@ -46,6 +46,9 @@ public class MongoMappingContext extends AbstractMappingContext<MongoPersistentE
 	private FieldNamingStrategy fieldNamingStrategy = DEFAULT_NAMING_STRATEGY;
 	private boolean autoIndexCreation = false;
 
+	@Nullable
+	private ApplicationContext applicationContext;
+
 	/**
 	 * Creates a new {@link MongoMappingContext}.
 	 */
@@ -103,6 +106,8 @@ public class MongoMappingContext extends AbstractMappingContext<MongoPersistentE
 	 */
 	@Override
 	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
+
+		this.applicationContext = applicationContext;
 		super.setApplicationContext(applicationContext);
 	}
 
@@ -145,4 +150,10 @@ public class MongoMappingContext extends AbstractMappingContext<MongoPersistentE
 
 		return new UnwrappedMongoPersistentEntity<>(entity, new UnwrapEntityContext(persistentProperty));
 	}
+
+	@Nullable
+	public ApplicationContext getApplicationContext() {
+		return this.applicationContext;
+	}
+
 }

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

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mongodb.core.mapping;
 
+import java.util.Collection;
+
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.model.MutablePersistentEntity;
 import org.springframework.lang.Nullable;
@@ -102,4 +104,11 @@ public interface MongoPersistentEntity<T> extends MutablePersistentEntity<T, Mon
 		return false;
 	}
 
+	/**
+	 * @return the resolved encryption keyIds if applicable. An empty {@link Collection} if no keyIds specified.
+	 *         {@literal null} no {@link Encrypted} annotation found.
+	 * @since 3.3
+	 */
+	@Nullable
+	Collection<Object> getEncryptionKeyIds();
 }

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

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.mongodb.core.mapping;
 
+import java.util.Collection;
+
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.mapping.PersistentEntity;
@@ -160,6 +162,13 @@ public interface MongoPersistentProperty extends PersistentProperty<MongoPersist
 		return isEntity() && isAnnotationPresent(Unwrapped.class);
 	}
 
+	/**
+	 * @return the resolved encryption keyIds if applicable. An empty {@link Collection} if no keyIds specified.
+	 *         {@literal null} no {@link Encrypted} annotation found.
+	 * @since 3.3
+	 */
+	Collection<Object> getEncryptionKeyIds();
+
 	/**
 	 * Simple {@link Converter} implementation to transform a {@link MongoPersistentProperty} into its field name.
 	 *

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

@@ -17,6 +17,7 @@ package org.springframework.data.mongodb.core.mapping;
 
 import java.lang.annotation.Annotation;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Spliterator;
@@ -323,4 +324,9 @@ class UnwrappedMongoPersistentEntity<T> implements MongoPersistentEntity<T> {
 	public boolean isUnwrapped() {
 		return context.getProperty().isUnwrapped();
 	}
+
+	@Override
+	public Collection<Object> getEncryptionKeyIds() {
+		return delegate.getEncryptionKeyIds();
+	}
 }

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

@@ -18,6 +18,7 @@ package org.springframework.data.mongodb.core.mapping;
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.util.Collection;
 
 import org.springframework.data.mapping.Association;
 import org.springframework.data.mapping.PersistentEntity;
@@ -268,6 +269,11 @@ class UnwrappedMongoPersistentProperty implements MongoPersistentProperty {
 		return delegate.isUnwrapped();
 	}
 
+	@Override
+	public Collection<Object> getEncryptionKeyIds() {
+		return delegate.getEncryptionKeyIds();
+	}
+
 	@Override
 	@Nullable
 	public Class<?> getComponentType() {

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

@@ -16,7 +16,9 @@
 package org.springframework.data.mongodb.core.schema;
 
 import org.bson.Document;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.CollectionUtils;
 
 /**
  * Value object representing a MongoDB-specific JSON schema which is the default {@link MongoJsonSchema} implementation.
@@ -29,18 +31,44 @@ class DefaultMongoJsonSchema implements MongoJsonSchema {
 
 	private final JsonSchemaObject root;
 
-	DefaultMongoJsonSchema(JsonSchemaObject root) {
+	@Nullable //
+	private final Document encryptionMetadata;
+
+	DefaultMongoJsonSchema(JsonSchemaObject root) {
+		this(root, null);
+	}
+
+	/**
+	 * Create new instance of {@link DefaultMongoJsonSchema}.
+	 *
+	 * @param root the schema root element.
+	 * @param encryptionMetadata can be {@literal null}.
+	 * @since 3.3
+	 */
+	DefaultMongoJsonSchema(JsonSchemaObject root, @Nullable Document encryptionMetadata) {
+
+		Assert.notNull(root, "Root schema object must not be null!");
 
-		Assert.notNull(root, "Root must not be null!");
 		this.root = root;
+		this.encryptionMetadata = encryptionMetadata;
 	}
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.schema.MongoJsonSchema#toDocument()
+	 * @see org.springframework.data.mongodb.core.schema.MongoJsonSchema#schema()
 	 */
 	@Override
-	public Document toDocument() {
-		return new Document("$jsonSchema", root.toDocument());
+	public Document schemaDocument() {
+
+		Document schemaDocument = new Document();
+
+		// we want this to be the first element rendered, so it reads nice when printed to json
+		if (!CollectionUtils.isEmpty(encryptionMetadata)) {
+			schemaDocument.append("encryptMetadata", encryptionMetadata);
+		}
+
+		schemaDocument.putAll(root.toDocument());
+
+		return schemaDocument;
 	}
 }

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

@@ -36,10 +36,10 @@ class DocumentJsonSchema implements MongoJsonSchema {
 
 	/*
 	 * (non-Javadoc)
-	 * @see org.springframework.data.mongodb.core.schema.MongoJsonSchema#toDocument()
+	 * @see org.springframework.data.mongodb.core.schema.MongoJsonSchema#schema()
 	 */
 	@Override
-	public Document toDocument() {
-		return new Document("$jsonSchema", new Document(document));
+	public Document schemaDocument() {
+		return new Document(document);
 	}
 }

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

@@ -523,6 +523,10 @@ public class IdentifiableJsonSchemaProperty<T extends JsonSchemaObject> implemen
 		public ObjectJsonSchemaProperty generatedDescription() {
 			return new ObjectJsonSchemaProperty(identifier, jsonSchemaObjectDelegate.generatedDescription());
 		}
+
+		public List<JsonSchemaProperty> getProperties() {
+			return jsonSchemaObjectDelegate.getProperties();
+		}
 	}
 
 	/**
@@ -1060,7 +1064,7 @@ public class IdentifiableJsonSchemaProperty<T extends JsonSchemaObject> implemen
 		private final JsonSchemaProperty targetProperty;
 		private final @Nullable String algorithm;
 		private final @Nullable String keyId;
-		private final @Nullable List<UUID> keyIds;
+		private final @Nullable List<?> keyIds;
 
 		/**
 		 * Create new instance of {@link EncryptedJsonSchemaProperty} wrapping the given {@link JsonSchemaProperty target}.
@@ -1072,7 +1076,7 @@ public class IdentifiableJsonSchemaProperty<T extends JsonSchemaObject> implemen
 		}
 
 		private EncryptedJsonSchemaProperty(JsonSchemaProperty target, @Nullable String algorithm, @Nullable String keyId,
-				@Nullable List<UUID> keyIds) {
+				@Nullable List<?> keyIds) {
 
 			Assert.notNull(target, "Target must not be null!");
 			this.targetProperty = target;
@@ -1134,6 +1138,14 @@ public class IdentifiableJsonSchemaProperty<T extends JsonSchemaObject> implemen
 			return new EncryptedJsonSchemaProperty(targetProperty, algorithm, null, Arrays.asList(keyId));
 		}
 
+		/**
+		 * @param keyId must not be {@literal null}.
+		 * @return new instance of {@link EncryptedJsonSchemaProperty}.
+		 */
+		public EncryptedJsonSchemaProperty keys(Object... keyId) {
+			return new EncryptedJsonSchemaProperty(targetProperty, algorithm, null, Arrays.asList(keyId));
+		}
+
 		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.data.mongodb.core.schema.JsonSchemaObject#toDocument()

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

@@ -20,6 +20,7 @@ import java.util.Set;
 
 import org.bson.Document;
 import org.springframework.data.mongodb.core.schema.TypedJsonSchemaObject.ObjectJsonSchemaObject;
+import org.springframework.lang.Nullable;
 
 /**
  * Interface defining MongoDB-specific JSON schema object. New objects can be built with {@link #builder()}, for
@@ -62,13 +63,25 @@ import org.springframework.data.mongodb.core.schema.TypedJsonSchemaObject.Object
 public interface MongoJsonSchema {
 
 	/**
-	 * Create the {@link Document} containing the specified {@code $jsonSchema}. <br />
+	 * Create the {@code $jsonSchema} {@link Document} containing the specified {@link #schemaDocument()}. <br />
 	 * Property and field names need to be mapped to the domain type ones by running the {@link Document} through a
 	 * {@link org.springframework.data.mongodb.core.convert.JsonSchemaMapper} to apply field name customization.
 	 *
 	 * @return never {@literal null}.
 	 */
-	Document toDocument();
+	default Document toDocument() {
+		return new Document("$jsonSchema", schemaDocument());
+	}
+
+	/**
+	 * Create the {@link Document} defining the schema. <br />
+	 * Property and field names need to be mapped to the domain type ones by running the {@link Document} through a
+	 * {@link org.springframework.data.mongodb.core.convert.JsonSchemaMapper} to apply field name customization.
+	 *
+	 * @return never {@literal null}.
+	 * @since 3.3
+	 */
+	Document schemaDocument();
 
 	/**
 	 * Create a new {@link MongoJsonSchema} for a given root object.
@@ -108,6 +121,9 @@ public interface MongoJsonSchema {
 
 		private ObjectJsonSchemaObject root;
 
+		@Nullable //
+		private Document encryptionMetadata;
+
 		MongoJsonSchemaBuilder() {
 			root = new ObjectJsonSchemaObject();
 		}
@@ -266,13 +282,23 @@ public interface MongoJsonSchema {
 			return this;
 		}
 
+		/**
+		 * Define the {@literal encryptMetadata} element of the schema.
+		 *
+		 * @param encryptionMetadata can be {@literal null}.
+		 * @since 3.3
+		 */
+		public void encryptionMetadata(@Nullable Document encryptionMetadata) {
+			this.encryptionMetadata = encryptionMetadata;
+		}
+
 		/**
 		 * Obtain the {@link MongoJsonSchema}.
 		 *
 		 * @return new instance of {@link MongoJsonSchema}.
 		 */
 		public MongoJsonSchema build() {
-			return MongoJsonSchema.of(root);
+			return new DefaultMongoJsonSchema(root, encryptionMetadata);
 		}
 	}
 }

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

@@ -437,6 +437,10 @@ public class TypedJsonSchemaObject extends UntypedJsonSchemaObject {
 			return newInstance(description, true, restrictions);
 		}
 
+		public List<JsonSchemaProperty> getProperties() {
+			return properties;
+		}
+
 		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.data.mongodb.core.schema.JsonSchemaObject#toDocument()

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/util/encryption/EncryptionUtils.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * 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 org.springframework.data.mongodb.util.encryption;
+
+import java.util.UUID;
+import java.util.function.Supplier;
+
+import org.springframework.data.mongodb.util.spel.ExpressionUtils;
+import org.springframework.expression.EvaluationContext;
+import org.springframework.expression.Expression;
+import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
+
+/**
+ * Internal utility class for dealing with encryption related matters.
+ *
+ * @author Christoph Strobl
+ * @since 3.3
+ */
+public final class EncryptionUtils {
+
+	/**
+	 * Resolve a given plain {@link String} value into the store native {@literal keyId} format, considering potential
+	 * {@link Expression expressions}. <br />
+	 * The potential keyId is probed against an {@link UUID#fromString(String) UUID value} and the {@literal base64}
+	 * encoded {@code $binary} representation.
+	 *
+	 * @param value the source value to resolve the keyId for. Must not be {@literal null}.
+	 * @param evaluationContext a {@link Supplier} used to provide the {@link EvaluationContext} in case an
+	 *          {@link Expression} is {@link ExpressionUtils#detectExpression(String) detected}.
+	 * @return can be {@literal null}.
+	 * @throws IllegalArgumentException if one of the required arguments is {@literal null}.
+	 */
+	@Nullable
+	public static Object resolveKeyId(String value, Supplier<EvaluationContext> evaluationContext) {
+
+		Assert.notNull(value, "Value must not be null!");
+
+		Object potentialKeyId = value;
+		Expression expression = ExpressionUtils.detectExpression(value);
+		if (expression != null) {
+			potentialKeyId = expression.getValue(evaluationContext.get());
+			if (!(potentialKeyId instanceof String)) {
+				return potentialKeyId;
+			}
+		}
+		try {
+			return UUID.fromString(potentialKeyId.toString());
+		} catch (IllegalArgumentException e) {
+			return org.bson.Document.parse("{ val : { $binary : { base64 : '" + potentialKeyId + "', subType : '04'} } }")
+					.get("val");
+		}
+	}
+}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/util/spel/ExpressionUtils.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2021 the original author or authors.
+ *
+ * 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 org.springframework.data.mongodb.util.spel;
+
+import org.springframework.expression.Expression;
+import org.springframework.expression.ParserContext;
+import org.springframework.expression.common.LiteralExpression;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.lang.Nullable;
+import org.springframework.util.StringUtils;
+
+/**
+ * Internal utility class for dealing with {@link Expression} and potential ones.
+ *
+ * @author Christoph Strobl
+ * @since 3.3
+ */
+public final class ExpressionUtils {
+
+	private static final SpelExpressionParser PARSER = new SpelExpressionParser();
+
+	/**
+	 * Returns a SpEL {@link Expression} if the given {@link String} is actually an expression that does not evaluate to a
+	 * {@link LiteralExpression} (indicating that no subsequent evaluation is necessary).
+	 *
+	 * @param potentialExpression can be {@literal null}
+	 * @return can be {@literal null}.
+	 */
+	@Nullable
+	public static Expression detectExpression(@Nullable String potentialExpression) {
+
+		if (!StringUtils.hasText(potentialExpression)) {
+			return null;
+		}
+
+		Expression expression = PARSER.parseExpression(potentialExpression, ParserContext.TEMPLATE_EXPRESSION);
+		return expression instanceof LiteralExpression ? null : expression;
+	}
+}

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

@@ -19,23 +19,27 @@ import static org.springframework.data.mongodb.test.util.Assertions.*;
 
 import java.util.Collections;
 import java.util.Date;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
 import org.bson.Document;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-
+import org.springframework.context.support.GenericApplicationContext;
 import org.springframework.data.annotation.Transient;
 import org.springframework.data.convert.WritingConverter;
 import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoCustomConversions;
 import org.springframework.data.mongodb.core.convert.NoOpDbRefResolver;
+import org.springframework.data.mongodb.core.mapping.Encrypted;
 import org.springframework.data.mongodb.core.mapping.Field;
 import org.springframework.data.mongodb.core.mapping.FieldType;
 import org.springframework.data.mongodb.core.mapping.MongoId;
 import org.springframework.data.mongodb.core.mapping.MongoMappingContext;
 import org.springframework.data.mongodb.core.schema.MongoJsonSchema;
+import org.springframework.data.spel.spi.EvaluationContextExtension;
+import org.springframework.data.spel.spi.Function;
 
 /**
  * Unit tests for {@link MappingMongoJsonSchemaCreator}.
@@ -95,6 +99,64 @@ public class MappingMongoJsonSchemaCreatorUnitTests {
 				"{ 'type' : 'object', 'properties' : { '_id' : { 'type' : 'object' }, 'nested' : { 'type' : 'object' } } }");
 	}
 
+	@Test // GH-???
+	public void csfle/*encryptedFieldsOnly*/() {
+
+		MongoJsonSchema schema = MongoJsonSchemaCreator.create() //
+				.filter(MongoJsonSchemaCreator.encryptedOnly()) // filter non encrypted fields
+				.createSchemaFor(Patient.class);
+
+		Document targetSchema = schema.schemaDocument();
+		assertThat(targetSchema).isEqualTo(Document.parse(PATIENT));
+	}
+
+	@Test // GH-???
+	public void csfleCyclic/*encryptedFieldsOnly*/() {
+
+		MongoJsonSchema schema = MongoJsonSchemaCreator.create() //
+				.filter(MongoJsonSchemaCreator.encryptedOnly()) // filter non encrypted fields
+				.createSchemaFor(Cyclic.class);
+
+		Document targetSchema = schema.schemaDocument();
+		assertThat(targetSchema).isNotNull();
+	}
+
+	@Test // GH-???
+	public void csfleWithKeyFromProperties() {
+
+		GenericApplicationContext applicationContext = new GenericApplicationContext();
+		applicationContext.registerBean("encryptionExtension", EncryptionExtension.class, () -> new EncryptionExtension());
+		applicationContext.refresh();
+
+		MongoMappingContext mappingContext = new MongoMappingContext();
+		mappingContext.setApplicationContext(applicationContext);
+		mappingContext.afterPropertiesSet();
+
+		MongoJsonSchema schema = MongoJsonSchemaCreator.create(mappingContext) //
+				.filter(MongoJsonSchemaCreator.encryptedOnly()) //
+				.createSchemaFor(EncryptionMetadataFromProperty.class);
+
+		assertThat(schema.schemaDocument()).isEqualTo(Document.parse(ENC_FROM_PROPERTY_SCHEMA));
+	}
+
+	@Test // GH-???
+	public void csfleWithKeyFromMethod() {
+
+		GenericApplicationContext applicationContext = new GenericApplicationContext();
+		applicationContext.registerBean("encryptionExtension", EncryptionExtension.class, () -> new EncryptionExtension());
+		applicationContext.refresh();
+
+		MongoMappingContext mappingContext = new MongoMappingContext();
+		mappingContext.setApplicationContext(applicationContext);
+		mappingContext.afterPropertiesSet();
+
+		MongoJsonSchema schema = MongoJsonSchemaCreator.create(mappingContext) //
+				.filter(MongoJsonSchemaCreator.encryptedOnly()) //
+				.createSchemaFor(EncryptionMetadataFromMethod.class);
+
+		assertThat(schema.schemaDocument()).isEqualTo(Document.parse(ENC_FROM_METHOD_SCHEMA));
+	}
+
 	// --> TYPES AND JSON
 
 	// --> ENUM
@@ -125,8 +187,7 @@ public class MappingMongoJsonSchemaCreatorUnitTests {
 			"        'collectionProperty' : { 'type' : 'array' }," + //
 			"        'mapProperty' : { 'type' : 'object' }," + //
 			"        'objectProperty' : { 'type' : 'object' }," + //
-			"        'enumProperty' : " + JUST_SOME_ENUM + //
-			"     }" + //
+			"        'enumProperty' : " + JUST_SOME_ENUM + "     }" + //
 			"}";
 
 	static class VariousFieldTypes {
@@ -249,4 +310,209 @@ public class MappingMongoJsonSchemaCreatorUnitTests {
 		}
 	}
 
+	static final String PATIENT = "{" + //
+			"  'type': 'object'," + //
+			"  'encryptMetadata': {" + //
+			"    'keyId': [" + //
+			"      {" + //
+			"        '$binary': {" + //
+			"          'base64': 'xKVup8B1Q+CkHaVRx+qa+g=='," + //
+			"          'subType': '04'" + //
+			"        }" + //
+			"      }" + //
+			"    ]" + //
+			"  }," + //
+			"  'properties': {" + //
+			"    'ssn': {" + //
+			"      'encrypt': {" + //
+			"        'bsonType': 'int'," + //
+			"        'algorithm': 'AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic'" + //
+			"      }" + //
+			"    }," + //
+			"    'bloodType': {" + //
+			"      'encrypt': {" + //
+			"        'bsonType': 'string'," + //
+			"        'algorithm': 'AEAD_AES_256_CBC_HMAC_SHA_512-Random'" + //
+			"      }" + //
+			"    }," + //
+			"    'medicalRecords': {" + //
+			"      'encrypt': {" + //
+			"        'bsonType': 'array'," + //
+			"        'algorithm': 'AEAD_AES_256_CBC_HMAC_SHA_512-Random'" + //
+			"      }" + //
+			"    }," + //
+			"    'insurance': {" + //
+			"      'type': 'object'," + //
+			"      'properties': {" + //
+			"        'policyNumber': {" + //
+			"          'encrypt': {" + //
+			"            'bsonType': 'int'," + //
+			"            'algorithm': 'AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic'" + //
+			"          }" + //
+			"        }" + //
+			"      }" + //
+			"    }" + //
+			"  }" + //
+			"}";
+
+	@Encrypted(keyId = "xKVup8B1Q+CkHaVRx+qa+g==")
+	static class Patient {
+		String name;
+
+		@Encrypted(algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic") //
+		Integer ssn;
+
+		@Encrypted(algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Random") //
+		String bloodType;
+
+		String keyAltNameField;
+
+		@Encrypted(algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Random") //
+		List<Map<String, String>> medicalRecords;
+
+		Insurance insurance;
+	}
+
+	static class Insurance {
+
+		@Encrypted(algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic") //
+		Integer policyNumber;
+
+		String provider;
+	}
+
+	static final String ENC_FROM_PROPERTY_ENTITY_KEY = "C5a5aMB7Ttq4wSJTFeRn8g==";
+	static final String ENC_FROM_PROPERTY_PROPOERTY_KEY = "Mw6mdTVPQfm4quqSCLVB3g=";
+	static final String ENC_FROM_PROPERTY_SCHEMA = "{" + //
+			"  'encryptMetadata': {" + //
+			"    'keyId': [" + //
+			"      {" + //
+			"        '$binary': {" + //
+			"          'base64': '" + ENC_FROM_PROPERTY_ENTITY_KEY + "'," + //
+			"          'subType': '04'" + //
+			"        }" + //
+			"      }" + //
+			"    ]" + //
+			"  }," + //
+			"  'type': 'object'," + //
+			"  'properties': {" + //
+			"    'policyNumber': {" + //
+			"      'encrypt': {" + //
+			"        'keyId': [" + //
+			"          [" + //
+			"            {" + //
+			"              '$binary': {" + //
+			"                'base64': '" + ENC_FROM_PROPERTY_PROPOERTY_KEY + "'," + //
+			"                'subType': '04'" + //
+			"              }" + //
+			"            }" + //
+			"          ]" + //
+			"        ]," + //
+			"        'bsonType': 'int'," + //
+			"        'algorithm': 'AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic'" + //
+			"      }" + //
+			"    }" + //
+			"  }" + //
+			"}";
+
+	@Encrypted(keyId = "#{entityKey}")
+	static class EncryptionMetadataFromProperty {
+
+		@Encrypted(keyId = "#{propertyKey}", algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic") //
+		Integer policyNumber;
+
+		String provider;
+	}
+
+	static final String ENC_FROM_METHOD_ENTITY_KEY = "4fPYFM9qSgyRAjgQ2u+IMQ==";
+	static final String ENC_FROM_METHOD_PROPOERTY_KEY = "+idiseKwTVCJfSKC3iUeYQ==";
+	static final String ENC_FROM_METHOD_SCHEMA = "{" + //
+			"  'encryptMetadata': {" + //
+			"    'keyId': [" + //
+			"      {" + //
+			"        '$binary': {" + //
+			"          'base64': '" + ENC_FROM_METHOD_ENTITY_KEY + "'," + //
+			"          'subType': '04'" + //
+			"        }" + //
+			"      }" + //
+			"    ]" + //
+			"  }," + //
+			"  'type': 'object'," + //
+			"  'properties': {" + //
+			"    'policyNumber': {" + //
+			"      'encrypt': {" + //
+			"        'keyId': [" + //
+			"          [" + //
+			"            {" + //
+			"              '$binary': {" + //
+			"                'base64': '" + ENC_FROM_METHOD_PROPOERTY_KEY + "'," + //
+			"                'subType': '04'" + //
+			"              }" + //
+			"            }" + //
+			"          ]" + //
+			"        ]," + //
+			"        'bsonType': 'int'," + //
+			"        'algorithm': 'AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic'" + //
+			"      }" + //
+			"    }" + //
+			"  }" + //
+			"}";
+
+	@Encrypted(keyId = "#{mongocrypt.keyId(#target)}")
+	static class EncryptionMetadataFromMethod {
+
+		@Encrypted(keyId = "#{mongocrypt.keyId(#target)}", algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic") //
+		Integer policyNumber;
+
+		String provider;
+	}
+
+	public static class EncryptionExtension implements EvaluationContextExtension {
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.spel.spi.EvaluationContextExtension#getExtensionId()
+		 */
+		@Override
+		public String getExtensionId() {
+			return "mongocrypt";
+		}
+
+		/*
+		 * (non-Javadoc)
+		 * @see org.springframework.data.spel.spi.EvaluationContextExtension#getProperties()
+		 */
+		@Override
+		public Map<String, Object> getProperties() {
+
+			Map<String, Object> properties = new LinkedHashMap<>();
+			properties.put("entityKey", ENC_FROM_PROPERTY_ENTITY_KEY);
+			properties.put("propertyKey", ENC_FROM_PROPERTY_PROPOERTY_KEY);
+			return properties;
+		}
+
+		@Override
+		public Map<String, Function> getFunctions() {
+			try {
+				return Collections.singletonMap("keyId",
+						new Function(EncryptionExtension.class.getMethod("keyId", String.class), this));
+			} catch (NoSuchMethodException e) {
+				e.printStackTrace();
+			}
+			return Collections.emptyMap();
+		}
+
+		public String keyId(String target) {
+
+			if (target.equals("EncryptionMetadataFromMethod")) {
+				return ENC_FROM_METHOD_ENTITY_KEY;
+			}
+
+			if (target.equals("EncryptionMetadataFromMethod.policyNumber")) {
+				return ENC_FROM_METHOD_PROPOERTY_KEY;
+			}
+
+			return "xKVup8B1Q+CkHaVRx+qa+g==";
+		}
+	}
 }

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

@@ -225,6 +225,110 @@ MongoJsonSchema schema = MongoJsonSchema.builder()
 ----
 ====
 
+Instead of defining encrypted fields manually it is possible leverage the `@Encrypted` annotation as shown in the snippet below.
+
+.Client-Side Field Level Encryption via Json Schema
+====
+[source,java]
+----
+@Document
+@Encrypted(keyId = "xKVup8B1Q+CkHaVRx+qa+g==", algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Random") <1>
+static class Patient {
+
+    @Id String id;
+	String name;
+
+	@Encrypted <2>
+	String bloodType;
+
+	@Encrypted(algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic") <3>
+	Integer ssn;
+
+}
+----
+<1> Default encryption settings that will be set for `encryptMetadata`.
+<2> Encrypted field using default encryption settings.
+<3> Encrypted field overriding the default encryption algorithm.
+====
+
+[TIP]
+====
+The `@EncryptedAnnoation` supports resolving keyIds via SpEL Expressions.
+To do so additional environment metadata (via the `MappingContext`) is required and must be provided.
+
+[source,java]
+----
+@Document
+@Encrypted(keyId = "#{mongocrypt.keyId(#target)}")
+static class Patient {
+
+    @Id String id;
+	String name;
+
+	@Encrypted(algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Random")
+	String bloodType;
+
+	@Encrypted(algorithm = "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic")
+	Integer ssn;
+}
+
+MongoJsonSchemaCreator schemaCreator = MongoJsonSchemaCreator.create(mappingContext);
+MongoJsonSchema personSchema = schemaCreator
+    .filter(MongoJsonSchemaCreator.encryptedOnly())
+    .createSchemaFor(Patient.class);
+----
+
+The `mongocrypt.keyId` function is defined via an `EvaluationContextExtension` as shown in the snippet below.
+Providing a custom extension provides the most flexible way of computing keyIds.
+
+[source,java]
+----
+public class EncryptionExtension implements EvaluationContextExtension {
+
+	@Override
+	public String getExtensionId() {
+		return "mongocrypt";
+	}
+
+	@Override
+	public Map<String, Function> getFunctions() {
+		return Collections.singletonMap("keyId", new Function(getMethod("computeKeyId", String.class), this));
+	}
+
+	public String computeKeyId(String target) {
+		// ... lookup via target element name
+	}
+}
+----
+
+To combine derived encryption settings with `AutoEncryptionSettings` in a Spring Boot application use the `MongoClientSettingsBuilderCustomizer`.
+
+[source,java]
+----
+@Bean
+MongoClientSettingsBuilderCustomizer customizer(MappingContext mappingContext) {
+	return (builder) -> {
+
+		// ... keyVaultCollection, kmsProvider, ...
+
+		MongoJsonSchemaCreator schemaCreator = MongoJsonSchemaCreator.create(mappingContext);
+		MongoJsonSchema patientSchema = schemaCreator
+            .filter(MongoJsonSchemaCreator.encryptedOnly())
+            .createSchemaFor(Patient.class);
+
+		AutoEncryptionSettings autoEncryptionSettings = AutoEncryptionSettings.builder()
+            .keyVaultNamespace(keyVaultCollection)
+			.kmsProviders(kmsProviders)
+			.extraOptions(extraOpts)
+			.schemaMap(Collections.singletonMap("db.patient", patientSchema.schemaDocument().toBsonDocument()))
+			.build();
+
+		builder.autoEncryptionSettings(autoEncryptionSettings);
+	};
+}
+----
+====
+
 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]]