Client Side Encryption

New in MongoDB 4.2 client side encryption allows administrators and developers to encrypt specific data fields in addition to other MongoDB encryption features.

With field level encryption, developers can encrypt fields client side without any server-side configuration or directives. Client-side field level encryption supports workloads where applications must guarantee that unauthorized parties, including server administrators, cannot read the encrypted data.

Note

This guide uses the Observable implicits as covered in the Quick Start Primer.

Installation

The recommended way to get started using field level encryption in your project is with a dependency management system. Field level encryption requires additional packages to be installed as well as the driver itself.
See the installation for instructions on how to install the MongoDB driver.

libmongocrypt

There is a separate jar file containinglibmongocrypt bindings.


<dependencies>
    <dependency>
        <groupId>org.mongodb</groupId>
        <artifactId>mongodb-crypt</artifactId>
        <version>1.2.1</version>
    </dependency>
</dependencies>


  dependencies {
      implementation 'org.mongodb:mongodb-crypt:1.2.1'
  }


  libraryDependencies += "org.mongodb" %% "mongodb-crypt" % "1.2.1"

mongocryptd configuration

libmongocrypt requires the mongocryptd daemon / process to be running. A specific daemon / process uri can be configured in the AutoEncryptionSettings class by setting mongocryptdURI in the extraOptions.

Examples

The following is a sample app that assumes the key and schema have already been created in MongoDB. The example uses a local key, however using either of the AWS / Azure / GCP Key Management Service is also an option. The data in the encryptedField field is automatically encrypted on the insert and decrypted when using find on the client side. The following code snippet comes from the ClientSideEncryptionSimpleTour.java example code that can be found with the driver source on github:

import java.security.SecureRandom

import org.mongodb.scala.{AutoEncryptionSettings, Document, MongoClient, MongoClientSettings}
import tour.Helpers._

import scala.collection.JavaConverters._

/**
 * ClientSideEncryption Simple tour
 */
object ClientSideEncryptionSimpleTour {

  /**
   * Run this main method to see the output of this quick example.
   *
   * Requires the mongodb-crypt library in the class path and mongocryptd on the system path.
   *
   * @param args ignored args
   */
  def main(args: Array[String]): Unit = {
    val localMasterKey = new Array[Byte](96)
    new SecureRandom().nextBytes(localMasterKey)

    val kmsProviders = Map("local" -> Map[String, AnyRef]("key" -> localMasterKey).asJava).asJava

    val keyVaultNamespace = "admin.datakeys"

    val autoEncryptionSettings = AutoEncryptionSettings.builder()
      .keyVaultNamespace(keyVaultNamespace).kmsProviders(kmsProviders).build()

    val clientSettings = MongoClientSettings.builder()
      .autoEncryptionSettings(autoEncryptionSettings).build()

    val mongoClient = MongoClient(clientSettings)
    val collection = mongoClient.getDatabase("test").getCollection("coll")

    collection.drop().headResult()

    collection.insertOne(Document("encryptedField" -> "123456789")).headResult()

    collection.find().first().printHeadResult()

    // release resources
    mongoClient.close()
  }
}

Note

Auto encryption is an enterprise only feature.

The following example shows how to configure the AutoEncryptionSettings instance to create a new key and setting the json schema map. The full code snippet can be found in ClientSideEncryptionAutoEncryptionSettingsTour.java:

import java.security.SecureRandom
import java.util.Base64

import scala.collection.JavaConverters._
import org.mongodb.scala._
import org.mongodb.scala.bson.BsonDocument
import org.mongodb.scala.model.vault.DataKeyOptions
import org.mongodb.scala.vault.ClientEncryptions
import tour.Helpers._

...

    val keyVaultNamespace = "admin.datakeys"

    val clientEncryptionSettings = ClientEncryptionSettings.builder()
      .keyVaultMongoClientSettings(
        MongoClientSettings.builder().applyConnectionString(ConnectionString("mongodb://localhost")).build())
      .keyVaultNamespace(keyVaultNamespace).kmsProviders(kmsProviders).build()

    val clientEncryption = ClientEncryptions.create(clientEncryptionSettings)

    val dataKey = clientEncryption.createDataKey("local", DataKeyOptions()).headResult()

    val base64DataKeyId = Base64.getEncoder.encodeToString(dataKey.getData)
    val dbName = "test"
    val collName = "coll"
    val autoEncryptionSettings = AutoEncryptionSettings.builder()
      .keyVaultNamespace(keyVaultNamespace)
      .kmsProviders(kmsProviders)
      .schemaMap(Map(s"$dbName.$collName" -> BsonDocument(
        s"""{
            properties: {
              encryptedField: {
                encrypt: {
                  keyId: [{
                    "$$binary": {
                      "base64": "$base64DataKeyId",
                      "subType": "04"
                    }
                  }],
                  bsonType: "string",
                  algorithm: "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic"
                }
              }
            },
            bsonType: "object"
          }""")).asJava)
      .build()

Explicit Encryption and Decryption

Explicit encryption and decryption is a MongoDB community feature and does not use the mongocryptd process. Explicit encryption is provided by the ClientEncryption class. The full code snippet can be found in ClientSideEncryptionExplicitEncryptionAndDecryptionTour.scala:

// This would have to be the same master key as was used to create the encryption key
val localMasterKey = new Array[Byte](96)
new SecureRandom().nextBytes(localMasterKey)

val kmsProviders = Map("local" -> Map[String, AnyRef]("key" -> localMasterKey).asJava).asJava

val keyVaultNamespace = new MongoNamespace("encryption.testKeyVault")

val clientSettings = MongoClientSettings.builder().build()
val mongoClient = MongoClient(clientSettings)

// Set up the key vault for this example
val keyVaultCollection = mongoClient.getDatabase(keyVaultNamespace.getDatabaseName)
  .getCollection(keyVaultNamespace.getCollectionName)
keyVaultCollection.drop().headResult()

// Ensure that two data keys cannot share the same keyAltName.
keyVaultCollection.createIndex(Indexes.ascending("keyAltNames"), new IndexOptions().unique(true)
  .partialFilterExpression(Filters.exists("keyAltNames")))

val collection = mongoClient.getDatabase("test").getCollection("coll")
collection.drop().headResult()

// Create the ClientEncryption instance
val clientEncryptionSettings = ClientEncryptionSettings
  .builder()
  .keyVaultMongoClientSettings(
    MongoClientSettings.builder()
       .applyConnectionString(ConnectionString("mongodb://localhost")).build()
  )
  .keyVaultNamespace(keyVaultNamespace.getFullName)
  .kmsProviders(kmsProviders)
  .build()

val clientEncryption = ClientEncryptions.create(clientEncryptionSettings)

val dataKeyId = clientEncryption.createDataKey("local", DataKeyOptions()).headResult()

// Explicitly encrypt a field
val encryptedFieldValue = clientEncryption.encrypt(BsonString("123456789"),
  EncryptOptions("AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic").keyId(dataKeyId))
    .headResult()

collection.insertOne(Document("encryptedField" -> encryptedFieldValue)).headResult()

val doc = collection.find.first().headResult()
println(doc.toJson())

// Explicitly decrypt the field
println(
    clientEncryption.decrypt(doc.get[BsonBinary]("encryptedField").get).headResult()
)

Explicit Encryption and Auto Decryption

Although automatic encryption requires MongoDB 4.2 enterprise or a MongoDB 4.2 Atlas cluster, automatic decryption is supported for all users. To configure automatic decryption without automatic encryption set bypassAutoEncryption(true). The full code snippet can be found in ClientSideEncryptionExplicitEncryptionOnlyTour.scala:

...
val clientSettings = MongoClientSettings.builder()
    .autoEncryptionSettings(AutoEncryptionSettings.builder()
            .keyVaultNamespace(keyVaultNamespace.getFullName)
            .kmsProviders(kmsProviders)
            .bypassAutoEncryption(true)
            .build())
    .build()
val mongoClient = MongoClient(clientSettings)

...

// Explicitly encrypt a field
val encryptedFieldValue = clientEncryption.encrypt(BsonString("123456789"),
  EncryptOptions("AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic").keyId(dataKeyId))
    .headResult()

collection.insertOne(Document("encryptedField" -> encryptedFieldValue)).headResult()

val doc = collection.find.first().headResult()
println(doc.toJson())

On this page