Crypto

Available as of Camel 2.3
PGP Available as of Camel 2.9

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.

Options

Name	Type	Default	Description
`algorithm`	`String`	`DES/CBC/PKCS5Padding`	The JCE algorithm name indicating the cryptographic algorithm that will be used.
`algorithmParameterSpec`	`java.security.spec.AlgorithmParameterSpec`	`null`	A JCE AlgorithmParameterSpec used to initialize the Cipher.
`bufferSize`	`Integer`	`2048`	the size of the buffer used in the signature process.
`cryptoProvider`	`String`	`null`	The name of the JCE Security Provider that should be used.
`initializationVector`	`byte[]`	`null`	A byte array containing the Initialization Vector that will be used to initialize the Cipher.
`inline`	`boolean`	`false`	Flag indicating that the configured IV should be inlined into the encrypted data stream.
`macAlgorithm`	`String`	`null`	The JCE algorithm name indicating the Message Authentication algorithm.
`shouldAppendHMAC`	`boolean`	`null`	Flag indicating that a Message Authentication Code should be calculated and appended to the encrypted data.

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:

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>


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.





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

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.





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





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.





or with spring.





For more information of the use of Initialization Vectors, consult


	http://en.wikipedia.org/wiki/Initialization_vector
	http://www.herongyang.com/Cryptography/
	http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation



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





or with spring.





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





or with spring.





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"







or with spring.





PGPDataFormat Options



 Name 
 Type 
 Default 
 Description 


 keyUserid 
 String 
 null 
 The userid of the key in the PGP keyring. 


 password 
 String 
 null 
 Password used when opening the private key (not used for encryption). 


 keyFileName 
 String 
 null 
 Filename of the keyring; must be accessible as a classpath resource (but you can specify a location in the file system by using the "file:" prefix). 


 encryptionKeyRing 
 byte[] 
 null 
 Since camel 2.12.1; encryption keyring; you can not set the keyFileName and encryptionKeyRing at the same time. 


 signatureKeyUserid 
 String 
 null 
 Since Camel 2.11.0; optional userid of the key in the PGP keyring to use for signing (during encryption) or signature verification (during decryption) .


 signaturePassword 
 String 
 null 
 Since Camel 2.11.0; optional password used when opening the private key used for signing (during encryption). 


 signatureKeyFileName 
 String 
 null 
 Since Camel 2.11.0; optional filename of the keyring to use for signing (during encryption) or for signature verification (during decryption); must be accessible as a classpath resource (but you can specify a location in the file system by using the "file:" prefix). 


 signatureKeyRing 
 byte[] 
 null 
 Since camel 2.12.1; signature keyring; you can not set the signatureKeyFileName and signatureKeyRing at the same time. 


 algorithm 
 int 
 SymmetricKeyAlgorithmTags.CAST5 
 Since camel 2.12.2; symmetric key encryption algorithm; possible values are defined in org.bouncycastle.bcpg.SymmetricKeyAlgorithmTags; for example 2 (= TRIPLE DES), 3 (= CAST5), 4 (= BLOWFISH), 6 (= DES), 7 (= AES_128). Only relevant for encrypting. 


 hashAlgorithm 
 int 
 HashAlgorithmTags.SHA1 
 Since camel 2.12.2: signature hash algorithm; possible values are defined in org.bouncycastle.bcpg.HashAlgorithmTags; for example 2 (= SHA1), 8 (= SHA256), 9 (= SHA384), 10 (= SHA512), 11 (=SHA224). Only relevant for signing. 


 armored 
 boolean 
 false 
 This option will cause PGP to base64 encode the encrypted text, making it available for copy/paste, etc. 


 integrity 
 boolean 
 true 
 Adds an integrity check/sign into the encryption file. 


 passphraseAccessor 
 PGPPassphraseAccessor 
 null 
 Since Camel 2.12.2; provides passphrases corresponding to user Ids.  If no passpharase can be found from the option password or signaturePassword and from the headers CamelPGPDataFormatKeyPassword or CamelPGPDataFormatSignatureKeyPassword then the passphrase is feteched from the passphrase accessor. You provide a bean which implements the interface PGPPassphraseAccessor. A default implementation is given by PGPPassphraseAccessorDefault.  The passphrase accessor is especially useful in the decrypt case; see chapter 'Usaage of Passphrase Accessor'  below. 





PGPDataFormat Message Headers
You can override the PGPDataFormat options by applying below headers into message dynamically.





 Name 
 Type 
 Description 


 CamelPGPDataFormatKeyFileName 
 String 
 Since Camel 2.11.0; filename of the keyring; will override existing setting directly on the PGPDataFormat. 


 CamelPGPDataFormatEncryptionKeyRing 
 byte[] 
 Since Camel 2.12.1; the encryption keyring; will override existing setting directly on the PGPDataFormat. 


 CamelPGPDataFormatKeyUserid 
 String 
 Since Camel 2.11.0; the userid of the key in the PGP keyring; will override existing setting directly on the PGPDataFormat. 


 CamelPGPDataFormatKeyPassword 
 String 
 Since Camel 2.11.0; password used when opening the private key; will override existing setting directly on the PGPDataFormat. 


 CamelPGPDataFormatSignatureKeyFileName 
 String 
 Since Camel 2.11.0; filename of the signature keyring; will override existing setting directly on the PGPDataFormat. 


 CamelPGPDataFormatSignatureKeyRing 
 byte[] 
 Since Camel 2.12.1; the signature keyring; will override existing setting directly on the PGPDataFormat. 


 CamelPGPDataFormatSignatureKeyUserid 
 String 
 Since Camel 2.11.0; the userid of the signature key in the PGP keyring; will override existing setting directly on the PGPDataFormat. 


 CamelPGPDataFormatSignatureKeyPassword 
 String 
 Since Camel 2.11.0; password used when opening the signature private key; will override existing setting directly on the PGPDataFormat. 


 CamelPGPDataFormatEncryptionAlgorithm 
 int 
 Since Camel 2.12.2; symmetric key encryption algorithm; will override existing setting directly on the PGPDataFormat. 


 CamelPGPDataFormatSignatureHashAlgorithm 
 int 
 Since Camel 2.12.2; signature hash algorithm; will override existing setting directly on the PGPDataFormat. 





Encrypting with PGPDataFormat

The following sample uses the popular PGP format for encrypting/decrypting files using the Bouncy Castle Java libraries:





The following sample performs signing + encryption, and then signature verification + decryption. It uses the same keyring for both signing and encryption, but you can obviously use different keys:





Or using Spring:





To work with the previous example you need the following

	A public keyring file which contains the public keys used to encrypt the data
	A private keyring file which contains the keys used to decrypt the data
	The keyring password



Managing your keyring
To manage the keyring, I use the command line tools, I find this to be the simplest approach in managing the keys. There are also Java libraries available from http://www.bouncycastle.org/java.html if you would prefer to do it that way.


	Install the command line utilities on linux

apt-get install gnupg

	Create your keyring, entering a secure password

gpg --gen-key

	If you need to import someone elses public key so that you can encrypt a file for them.

gpg --import <filename.key

	The following files should now exist and can be used to run the example

ls -l ~/.gnupg/pubring.gpg ~/.gnupg/secring.gpg




Usage of PGP Passphrase Accessor

Since Camel  2.12.2.

A PGP Data Formater can decrypt messages which have been encrypted by different public keys. In this case you must provide the corresponding private keys in the secret keyring and the  passphrases of the private keys in the passphrase accessor.


Map<String, String> userId2Passphrase = new HashMap<String, String>(2);
// add passphrases of several private keys whose corresponding public keys have been used to encrypt the messages
userId2Passphrase.put("key1","passphrase1");
userId2Passphrase.put("key2","passphrase2");
PGPPassphraseAccessor passphraseAccessor = new PGPPassphraseAccessorDefault(userId2Passphrase);

PGPDataFormat pgpVerifyAndDecrypt = new PGPDataFormat();
pgpVerifyAndDecrypt.setPassphraseAccessor(passphraseAccessor);
pgpVerifyAndDecrypt.setEncryptionKeyRing(getSecKeyRing());
// it is not necessary to specify the User Id
 
from("direct:start")
         ...     
        .unmarshal(pgpVerifyAndDecrypt) // can decrypt/verify messages encrypted/signed by different private/public keys
        ...            





	The PGP encrypted data contains a Key ID of the public key which was used to encrypt the data. This Key ID can be used to locate the private key in the secret keyring to decrypt the data. The same mechanism is also used to locate the public key for verifying a signature. Therefore you no longer must specify User IDs for the unmarshaling.
	The functionality is especially useful to support the key exchange. If you want to exchange the private key for decrypting you can accept for a period of time messages which are either encrypted with the old or new corresponding public key.



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>




See Also

	Data Format
	Crypto (Digital Signatures)
	http://www.bouncycastle.org/java.html

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Crypto

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Full Content

Crypto

Options

Basic Usage

Specifying the Encryption Algorithm

Specifying an Initialization Vector

Hashed Message Authentication Codes (HMAC)

Supplying Keys Dynamically

PGPDataFormat Options

PGPDataFormat Message Headers

Encrypting with PGPDataFormat

To work with the previous example you need the following

Managing your keyring

Usage of PGP Passphrase Accessor

Dependencies

See Also

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