Chapter 249. PGP DataFormat

The PGP dataformat supports 15 options which are listed below.

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

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:

apt-get install gnupg

gpg --gen-key

gpg --import <filename.key

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

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("UserIdOfKey1","passphrase1"); // you must specify the exact User ID!
userId2Passphrase.put("UserIdOfKey2","passphrase2");
PGPPassphraseAccessor passphraseAccessor = new PGPPassphraseAccessorDefault(userId2Passphrase);

PGPDataFormat pgpVerifyAndDecrypt = new PGPDataFormat();
pgpVerifyAndDecrypt.setPassphraseAccessor(passphraseAccessor);
// the method getSecKeyRing() provides the secret keyring as byte array containing the private keys
pgpVerifyAndDecrypt.setEncryptionKeyRing(getSecKeyRing()); // alternatively you can use setKeyFileName(keyfileName)
// the method getPublicKeyRing() provides the public keyring as byte array containing the public keys
pgpVerifyAndDecrypt.setSignatureKeyRing((getPublicKeyRing());  // alternatively you can use setSignatureKeyFileName(signatgureKeyfileName)
// it is not necessary to specify the encryption or signer  User Id

from("direct:start")
         ...
        .unmarshal(pgpVerifyAndDecrypt) // can decrypt/verify messages encrypted/signed by different private/public keys
        ...

Since Camel 2.12.3.

If you verify a signature you not only want to verify the correctness of the signature but you also want check that the signature comes from a certain identity or a specific set of identities. Therefore it is possible to restrict the number of public keys from the public keyring which can be used for the verification of a signature.  

Signature User IDs

// specify the User IDs of the expected signer identities
 List<String> expectedSigUserIds = new ArrayList<String>();
 expectedSigUserIds.add("Trusted company1");
 expectedSigUserIds.add("Trusted company2");
 
 PGPDataFormat pgpVerifyWithSpecificKeysAndDecrypt = new PGPDataFormat();
 pgpVerifyWithSpecificKeysAndDecrypt.setPassword("my password"); // for decrypting with private key
 pgpVerifyWithSpecificKeysAndDecrypt.setKeyFileName(keyfileName);
 pgpVerifyWithSpecificKeysAndDecrypt.setSignatureKeyFileName(signatgureKeyfileName);
 pgpVerifyWithSpecificKeysAndDecrypt.setSignatureKeyUserids(expectedSigUserIds); // if you have only one signer identity then you can also use setSignatureKeyUserid("expected Signer")
 
from("direct:start")
         ...
        .unmarshal(pgpVerifyWithSpecificKeysAndDecrypt)
        ...

Since Camel 2.12.3.

The PGP specification allows that one PGP data format can contain several signatures from different keys. Since Camel 2.13.3 it is possible to create such kind of PGP content via specifying signature User IDs which relate to several private keys in the secret keyring.

Several Signatures

 PGPDataFormat pgpSignAndEncryptSeveralSignerKeys = new PGPDataFormat();
 pgpSignAndEncryptSeveralSignerKeys.setKeyUserid(keyUserid); // for encrypting, you can also use setKeyUserids if you want to encrypt with several keys
 pgpSignAndEncryptSeveralSignerKeys.setKeyFileName(keyfileName);
 pgpSignAndEncryptSeveralSignerKeys.setSignatureKeyFileName(signatgureKeyfileName);
 pgpSignAndEncryptSeveralSignerKeys.setSignaturePassword("sdude"); // here we assume that all private keys have the same password, if this is not the case then you can use setPassphraseAccessor

 List<String> signerUserIds = new ArrayList<String>();
 signerUserIds.add("company old key");
 signerUserIds.add("company new key");
 pgpSignAndEncryptSeveralSignerKeys.setSignatureKeyUserids(signerUserIds);
 
from("direct:start")
         ...
        .marshal(pgpSignAndEncryptSeveralSignerKeys)
        ...

Since *Camel 2.12.3.
*An OpenPGP V4 key can have a primary key and sub-keys. The usage of the keys is indicated by the so called Key Flags. For example, you can have a primary key with two sub-keys; the primary key shall only be used for certifying other keys (Key Flag 0x01), the first sub-key  shall only be used for signing (Key Flag 0x02), and the second sub-key shall only be used for encryption (Key Flag 0x04 or 0x08). The PGP Data Format marshaler takes into account these Key Flags of the primary key and sub-keys in order to determine the right key for signing and encryption. This is necessary because the primary key and its sub-keys have the same User IDs.

Since *Camel 2.13.0.
*You can implement custom key accessors for encryption/signing. The above PGPDataFormat class selects in a certain predefined way the keys which should be used for signing/encryption or verifying/decryption. If you have special requirements how your keys should be selected you should use the PGPKeyAccessDataFormat class instead and implement the interfaces PGPPublicKeyAccessor and PGPSecretKeyAccessor as beans. There are default implementations DefaultPGPPublicKeyAccessor and DefaultPGPSecretKeyAccessor which cache the keys, so that not every time the keyring is parsed when the processor is called.

PGPKeyAccessDataFormat has the same options as PGPDataFormat except password, keyFileName, encryptionKeyRing, signaturePassword, signatureKeyFileName, and signatureKeyRing.

To use the PGP 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>