Chapter 73. Crypto (Java Cryptographic Extension) DataFormat

Available as of Camel version 2.3

The Crypto Data Format integrates the Java Cryptographic Extension into Camel, allowing simple and flexible encryption and decryption of messages using Camel’s familiar marshall and unmarshal formatting mechanism. It assumes marshalling to mean encryption to cyphertext and unmarshalling to mean decryption back to the original plaintext. This data format implements only symmetric (shared-key) encryption and decyption.

73.1. CryptoDataFormat Options

The Crypto (Java Cryptographic Extension) dataformat supports 10 options which are listed below.

NameDefaultJava TypeDescription

algorithm

DES/CBC/PKCS5Padding

String

The JCE algorithm name indicating the cryptographic algorithm that will be used. Is by default DES/CBC/PKCS5Padding.

cryptoProvider

 

String

The name of the JCE Security Provider that should be used.

keyRef

 

String

Refers to the secret key to lookup from the register to use.

initVectorRef

 

String

Refers to a byte array containing the Initialization Vector that will be used to initialize the Cipher.

algorithmParameterRef

 

String

A JCE AlgorithmParameterSpec used to initialize the Cipher. Will lookup the type using the given name as a java.security.spec.AlgorithmParameterSpec type.

buffersize

 

Integer

The size of the buffer used in the signature process.

macAlgorithm

HmacSHA1

String

The JCE algorithm name indicating the Message Authentication algorithm.

shouldAppendHMAC

false

Boolean

Flag indicating that a Message Authentication Code should be calculated and appended to the encrypted data.

inline

false

Boolean

Flag indicating that the configured IV should be inlined into the encrypted data stream. Is by default false.

contentTypeHeader

false

Boolean

Whether the data format should set the Content-Type header with the type from the data format if the data format is capable of doing so. For example application/xml for data formats marshalling to XML, or application/json for data formats marshalling to JSon etc.

73.2. Basic Usage

At its most basic all that is required to encrypt/decrypt an exchange is a shared secret key. If one or more instances of the Crypto data format are configured with this key the format can be used to encrypt the payload in one route (or part of one) and decrypted in another. For example, using the Java DSL as follows:

KeyGenerator generator = KeyGenerator.getInstance("DES");

CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES", generator.generateKey());

from("direct:basic-encryption")
    .marshal(cryptoFormat)
    .to("mock:encrypted")
    .unmarshal(cryptoFormat)
    .to("mock:unencrypted");

In Spring the dataformat is configured first and then used in routes

<camelContext id="camel" xmlns="http://camel.apache.org/schema/spring">
  <dataFormats>
    <crypto id="basic" algorithm="DES" keyRef="desKey" />
  </dataFormats>
    ...
  <route>
    <from uri="direct:basic-encryption" />
    <marshal ref="basic" />
    <to uri="mock:encrypted" />
    <unmarshal ref="basic" />
    <to uri="mock:unencrypted" />
  </route>
</camelContext>

73.3. Specifying the Encryption Algorithm

Changing the algorithm is a matter of supplying the JCE algorithm name. If you change the algorithm you will need to use a compatible key.

KeyGenerator generator = KeyGenerator.getInstance("DES");

CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES", generator.generateKey());
cryptoFormat.setShouldAppendHMAC(true);
cryptoFormat.setMacAlgorithm("HmacMD5");

from("direct:hmac-algorithm")
    .marshal(cryptoFormat)
    .to("mock:encrypted")
    .unmarshal(cryptoFormat)
    .to("mock:unencrypted");

A list of the available algorithms in Java 7 is available via the Java Cryptography Architecture Standard Algorithm Name Documentation.

73.4. Specifying an Initialization Vector

Some crypto algorithms, particularly block algorithms, require configuration with an initial block of data known as an Initialization Vector. In the JCE this is passed as an AlgorithmParameterSpec when the Cipher is initialized. To use such a vector with the CryptoDataFormat you can configure it with a byte[] containing the required data e.g.

KeyGenerator generator = KeyGenerator.getInstance("DES");
byte[] initializationVector = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07};

CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES/CBC/PKCS5Padding", generator.generateKey());
cryptoFormat.setInitializationVector(initializationVector);

from("direct:init-vector")
    .marshal(cryptoFormat)
    .to("mock:encrypted")
    .unmarshal(cryptoFormat)
    .to("mock:unencrypted");

or with spring, suppling a reference to a byte[]

<crypto id="initvector" algorithm="DES/CBC/PKCS5Padding" keyRef="desKey" initVectorRef="initializationVector" />

The same vector is required in both the encryption and decryption phases. As it is not necessary to keep the IV a secret, the DataFormat allows for it to be inlined into the encrypted data and subsequently read out in the decryption phase to initialize the Cipher. To inline the IV set the /oinline flag.

KeyGenerator generator = KeyGenerator.getInstance("DES");
byte[] initializationVector = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07};
SecretKey key = generator.generateKey();

CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES/CBC/PKCS5Padding", key);
cryptoFormat.setInitializationVector(initializationVector);
cryptoFormat.setShouldInlineInitializationVector(true);
CryptoDataFormat decryptFormat = new CryptoDataFormat("DES/CBC/PKCS5Padding", key);
decryptFormat.setShouldInlineInitializationVector(true);

from("direct:inline")
    .marshal(cryptoFormat)
    .to("mock:encrypted")
    .unmarshal(decryptFormat)
    .to("mock:unencrypted");

or with spring.

<crypto id="inline" algorithm="DES/CBC/PKCS5Padding" keyRef="desKey" initVectorRef="initializationVector"
  inline="true" />
<crypto id="inline-decrypt" algorithm="DES/CBC/PKCS5Padding" keyRef="desKey" inline="true" />

For more information of the use of Initialization Vectors, consult

73.5. Hashed Message Authentication Codes (HMAC)

To avoid attacks against the encrypted data while it is in transit the CryptoDataFormat can also calculate a Message Authentication Code for the encrypted exchange contents based on a configurable MAC algorithm. The calculated HMAC is appended to the stream after encryption. It is separated from the stream in the decryption phase. The MAC is recalculated and verified against the transmitted version to insure nothing was tampered with in transit.For more information on Message Authentication Codes see http://en.wikipedia.org/wiki/HMAC

KeyGenerator generator = KeyGenerator.getInstance("DES");

CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES", generator.generateKey());
cryptoFormat.setShouldAppendHMAC(true);

from("direct:hmac")
    .marshal(cryptoFormat)
    .to("mock:encrypted")
    .unmarshal(cryptoFormat)
    .to("mock:unencrypted");

or with spring.

<crypto id="hmac" algorithm="DES" keyRef="desKey" shouldAppendHMAC="true" />

By default the HMAC is calculated using the HmacSHA1 mac algorithm though this can be easily changed by supplying a different algorithm name. See here for how to check what algorithms are available through the configured security providers

KeyGenerator generator = KeyGenerator.getInstance("DES");

CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES", generator.generateKey());
cryptoFormat.setShouldAppendHMAC(true);
cryptoFormat.setMacAlgorithm("HmacMD5");

from("direct:hmac-algorithm")
    .marshal(cryptoFormat)
    .to("mock:encrypted")
    .unmarshal(cryptoFormat)
    .to("mock:unencrypted");

or with spring.

<crypto id="hmac-algorithm" algorithm="DES" keyRef="desKey" macAlgorithm="HmacMD5" shouldAppendHMAC="true" />

73.6. Supplying Keys Dynamically

When using a Recipient list or similar EIP the recipient of an exchange can vary dynamically. Using the same key across all recipients may neither be feasible or desirable. It would be useful to be able to specify keys dynamically on a per exchange basis. The exchange could then be dynamically enriched with the key of its target recipient before being processed by the data format. To facilitate this the DataFormat allow for keys to be supplied dynamically via the message headers below

  • CryptoDataFormat.KEY "CamelCryptoKey"
CryptoDataFormat cryptoFormat = new CryptoDataFormat("DES", null);
/**
 * Note: the header containing the key should be cleared after
 * marshalling to stop it from leaking by accident and
 * potentially being compromised. The processor version below is
 * arguably better as the key is left in the header when you use
 * the DSL leaks the fact that camel encryption was used.
 */
from("direct:key-in-header-encrypt")
    .marshal(cryptoFormat)
    .removeHeader(CryptoDataFormat.KEY)
    .to("mock:encrypted");

from("direct:key-in-header-decrypt").unmarshal(cryptoFormat).process(new Processor() {
    public void process(Exchange exchange) throws Exception {
        exchange.getIn().getHeaders().remove(CryptoDataFormat.KEY);
        exchange.getOut().copyFrom(exchange.getIn());
    }
}).to("mock:unencrypted");

or with spring.

<crypto id="nokey" algorithm="DES" />

73.7. Dependencies

To use the Crypto dataformat in your camel routes you need to add the following dependency to your pom.

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-crypto</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

73.8. See Also