Crypto (JCE)
Since Camel 2.3
Only producer is supported
With Camel cryptographic endpoints and Java’s Cryptographic extension it is easy to create Digital Signatures for Exchanges. Camel provides a pair of flexible endpoints which get used in concert to create a signature for an exchange in one part of the exchange’s workflow and then verify the signature in a later part of the workflow.
Maven users will need to add the following dependency to their pom.xml
for this component:
<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>
Introduction
Digital signatures make use of Asymmetric Cryptographic techniques to sign messages. From a (very) high level, the algorithms use pairs of complimentary keys with the special property that data encrypted with one key can only be decrypted with the other. One, the private key, is closely guarded and used to 'sign' the message while the other, public key, is shared around to anyone interested in verifying the signed messages. Messages are signed by using the private key to encrypting a digest of the message. This encrypted digest is transmitted along with the message. On the other side the verifier recalculates the message digest and uses the public key to decrypt the digest in the signature. If both digests match the verifier knows only the holder of the private key could have created the signature.
Camel uses the Signature service from the Java Cryptographic Extension to do all the heavy cryptographic lifting required to create exchange signatures. The following are some excellent resources for explaining the mechanics of Cryptography, Message digests and Digital Signatures and how to leverage them with the JCE.
-
Bruce Schneier’s Applied Cryptography
-
Beginning Cryptography with Java by David Hook
-
The ever insightful Wikipedia Digital_signatures
URI format
As mentioned Camel provides a pair of crypto endpoints to create and verify signatures
crypto:sign:name[?options]
crypto:verify:name[?options]
-
crypto:sign
creates the signature and stores it in the Header keyed by the constantorg.apache.camel.component.crypto.DigitalSignatureConstants.SIGNATURE
, i.e."CamelDigitalSignature"
. -
crypto:verify
will read in the contents of this header and do the verification calculation.
In order to correctly function, the sign and verify process needs a pair
of keys to be shared, signing requiring a PrivateKey
and verifying a
PublicKey
(or a Certificate
containing one). Using the JCE it is
very simple to generate these key pairs but it is usually most secure to
use a KeyStore to house and share your keys. The DSL is very flexible
about how keys are supplied and provides a number of mechanisms.
Note a crypto:sign
endpoint is typically defined in one route and the
complimentary crypto:verify
in another, though for simplicity in the
examples they appear one after the other. It goes without saying that
both signing and verifying should be configured identically.
Options
The Crypto (JCE) component supports 21 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
algorithm (producer) |
Sets the JCE name of the Algorithm that should be used for the signer. |
SHA256withRSA |
String |
alias (producer) |
Sets the alias used to query the KeyStore for keys and {link java.security.cert.Certificate Certificates} to be used in signing and verifying exchanges. This value can be provided at runtime via the message header org.apache.camel.component.crypto.DigitalSignatureConstants#KEYSTORE_ALIAS |
String |
|
certificateName (producer) |
Sets the reference name for a PrivateKey that can be found in the registry. |
String |
|
keystore (producer) |
Sets the KeyStore that can contain keys and Certficates for use in signing and verifying exchanges. A KeyStore is typically used with an alias, either one supplied in the Route definition or dynamically via the message header CamelSignatureKeyStoreAlias. If no alias is supplied and there is only a single entry in the Keystore, then this single entry will be used. |
KeyStore |
|
keystoreName (producer) |
Sets the reference name for a Keystore that can be found in the registry. |
String |
|
lazyStartProducer (producer) |
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. |
false |
boolean |
privateKey (producer) |
Set the PrivateKey that should be used to sign the exchange |
PrivateKey |
|
privateKeyName (producer) |
Sets the reference name for a PrivateKey that can be found in the registry. |
String |
|
provider (producer) |
Set the id of the security provider that provides the configured Signature algorithm. |
String |
|
publicKeyName (producer) |
references that should be resolved when the context changes |
String |
|
secureRandomName (producer) |
Sets the reference name for a SecureRandom that can be found in the registry. |
String |
|
signatureHeaderName (producer) |
Set the name of the message header that should be used to store the base64 encoded signature. This defaults to 'CamelDigitalSignature' |
String |
|
autowiredEnabled (advanced) |
Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. |
true |
boolean |
bufferSize (advanced) |
Set the size of the buffer used to read in the Exchange payload data. |
2048 |
Integer |
certificate (advanced) |
Set the Certificate that should be used to verify the signature in the exchange based on its payload. |
Certificate |
|
clearHeaders (advanced) |
Determines if the Signature specific headers be cleared after signing and verification. Defaults to true, and should only be made otherwise at your extreme peril as vital private information such as Keys and passwords may escape if unset. |
true |
boolean |
configuration (advanced) |
To use the shared DigitalSignatureConfiguration as configuration |
DigitalSignatureConfiguration |
|
keyStoreParameters (advanced) |
Sets the KeyStore that can contain keys and Certficates for use in signing and verifying exchanges based on the given KeyStoreParameters. A KeyStore is typically used with an alias, either one supplied in the Route definition or dynamically via the message header CamelSignatureKeyStoreAlias. If no alias is supplied and there is only a single entry in the Keystore, then this single entry will be used. |
KeyStoreParameters |
|
publicKey (advanced) |
Set the PublicKey that should be used to verify the signature in the exchange. |
PublicKey |
|
secureRandom (advanced) |
Set the SecureRandom used to initialize the Signature service |
SecureRandom |
|
password (security) |
Sets the password used to access an aliased PrivateKey in the KeyStore. |
String |
The Crypto (JCE) endpoint is configured using URI syntax:
crypto:cryptoOperation:name
with the following path and query parameters:
Path Parameters (2 parameters):
Name | Description | Default | Type |
---|---|---|---|
cryptoOperation |
Required Set the Crypto operation from that supplied after the crypto scheme in the endpoint uri e.g. crypto:sign sets sign as the operation. There are 2 enums and the value can be one of: sign, verify |
CryptoOperation |
|
name |
Required The logical name of this operation. |
String |
Query Parameters (20 parameters):
Name | Description | Default | Type |
---|---|---|---|
algorithm (producer) |
Sets the JCE name of the Algorithm that should be used for the signer. |
SHA256withRSA |
String |
alias (producer) |
Sets the alias used to query the KeyStore for keys and {link java.security.cert.Certificate Certificates} to be used in signing and verifying exchanges. This value can be provided at runtime via the message header org.apache.camel.component.crypto.DigitalSignatureConstants#KEYSTORE_ALIAS |
String |
|
certificateName (producer) |
Sets the reference name for a PrivateKey that can be found in the registry. |
String |
|
keystore (producer) |
Sets the KeyStore that can contain keys and Certficates for use in signing and verifying exchanges. A KeyStore is typically used with an alias, either one supplied in the Route definition or dynamically via the message header CamelSignatureKeyStoreAlias. If no alias is supplied and there is only a single entry in the Keystore, then this single entry will be used. |
KeyStore |
|
keystoreName (producer) |
Sets the reference name for a Keystore that can be found in the registry. |
String |
|
lazyStartProducer (producer) |
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. |
false |
boolean |
privateKey (producer) |
Set the PrivateKey that should be used to sign the exchange |
PrivateKey |
|
privateKeyName (producer) |
Sets the reference name for a PrivateKey that can be found in the registry. |
String |
|
provider (producer) |
Set the id of the security provider that provides the configured Signature algorithm. |
String |
|
publicKeyName (producer) |
references that should be resolved when the context changes |
String |
|
secureRandomName (producer) |
Sets the reference name for a SecureRandom that can be found in the registry. |
String |
|
signatureHeaderName (producer) |
Set the name of the message header that should be used to store the base64 encoded signature. This defaults to 'CamelDigitalSignature' |
String |
|
bufferSize (advanced) |
Set the size of the buffer used to read in the Exchange payload data. |
2048 |
Integer |
certificate (advanced) |
Set the Certificate that should be used to verify the signature in the exchange based on its payload. |
Certificate |
|
clearHeaders (advanced) |
Determines if the Signature specific headers be cleared after signing and verification. Defaults to true, and should only be made otherwise at your extreme peril as vital private information such as Keys and passwords may escape if unset. |
true |
boolean |
keyStoreParameters (advanced) |
Sets the KeyStore that can contain keys and Certficates for use in signing and verifying exchanges based on the given KeyStoreParameters. A KeyStore is typically used with an alias, either one supplied in the Route definition or dynamically via the message header CamelSignatureKeyStoreAlias. If no alias is supplied and there is only a single entry in the Keystore, then this single entry will be used. |
KeyStoreParameters |
|
publicKey (advanced) |
Set the PublicKey that should be used to verify the signature in the exchange. |
PublicKey |
|
secureRandom (advanced) |
Set the SecureRandom used to initialize the Signature service |
SecureRandom |
|
synchronous (advanced) |
Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). |
false |
boolean |
password (security) |
Sets the password used to access an aliased PrivateKey in the KeyStore. |
String |
Using
Raw keys
The most basic way to way to sign and verify an exchange is with a KeyPair as follows.
The same can be achieved with the Spring XML Extensions using references to keys
KeyStores and Aliases.
The JCE provides a very versatile keystore concept for housing pairs of private keys and certificates, keeping them encrypted and password protected. They can be retrieved by applying an alias to the retrieval APIs. There are a number of ways to get keys and Certificates into a keystore, most often this is done with the external 'keytool' application. This is a good example of using keytool to create a KeyStore with a self signed Cert and Private key.
The examples use a Keystore with a key and cert aliased by 'bob'. The password for the keystore and the key is 'letmein'
The following shows how to use a Keystore via the Fluent builders, it also shows how to load and initialize the keystore.
Again in Spring a ref is used to lookup an actual keystore instance.
Changing JCE Provider and Algorithm
Changing the Signature algorithm or the Security provider is a simple matter of specifying their names. You will need to also use Keys that are compatible with the algorithm you choose.
or
Changing the Signature Message Header
It may be desirable to change the message header used to store the signature. A different header name can be specified in the route definition as follows
or
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 be neither feasible nor desirable. It would be useful to be able to specify signature keys dynamically on a per-exchange basis. The exchange could then be dynamically enriched with the key of its target recipient prior to signing. To facilitate this the signature mechanisms allow for keys to be supplied dynamically via the message headers below
-
Exchange.SIGNATURE_PRIVATE_KEY
,"CamelSignaturePrivateKey"
-
Exchange.SIGNATURE_PUBLIC_KEY_OR_CERT
,"CamelSignaturePublicKeyOrCert"
or
Even better would be to dynamically supply a keystore alias. Again the alias can be supplied in a message header
-
Exchange.KEYSTORE_ALIAS
,"CamelSignatureKeyStoreAlias"
or
The header would be set as follows
Exchange unsigned = getMandatoryEndpoint("direct:alias-sign").createExchange();
unsigned.getIn().setBody(payload);
unsigned.getIn().setHeader(DigitalSignatureConstants.KEYSTORE_ALIAS, "bob");
unsigned.getIn().setHeader(DigitalSignatureConstants.KEYSTORE_PASSWORD, "letmein".toCharArray());
template.send("direct:alias-sign", unsigned);
Exchange signed = getMandatoryEndpoint("direct:alias-sign").createExchange();
signed.getIn().copyFrom(unsigned.getOut());
signed.getIn().setHeader(KEYSTORE_ALIAS, "bob");
template.send("direct:alias-verify", signed);
Spring Boot Auto-Configuration
When using crypto with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-crypto-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
The component supports 49 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
camel.component.crypto.algorithm |
Sets the JCE name of the Algorithm that should be used for the signer. |
SHA256withRSA |
String |
camel.component.crypto.alias |
Sets the alias used to query the KeyStore for keys and {link java.security.cert.Certificate Certificates} to be used in signing and verifying exchanges. This value can be provided at runtime via the message header org.apache.camel.component.crypto.DigitalSignatureConstants#KEYSTORE_ALIAS |
String |
|
camel.component.crypto.autowired-enabled |
Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. |
true |
Boolean |
camel.component.crypto.buffer-size |
Set the size of the buffer used to read in the Exchange payload data. |
2048 |
Integer |
camel.component.crypto.certificate |
Set the Certificate that should be used to verify the signature in the exchange based on its payload. The option is a java.security.cert.Certificate type. |
Certificate |
|
camel.component.crypto.certificate-name |
Sets the reference name for a PrivateKey that can be found in the registry. |
String |
|
camel.component.crypto.clear-headers |
Determines if the Signature specific headers be cleared after signing and verification. Defaults to true, and should only be made otherwise at your extreme peril as vital private information such as Keys and passwords may escape if unset. |
true |
Boolean |
camel.component.crypto.configuration |
To use the shared DigitalSignatureConfiguration as configuration. The option is a org.apache.camel.component.crypto.DigitalSignatureConfiguration type. |
DigitalSignatureConfiguration |
|
camel.component.crypto.enabled |
Whether to enable auto configuration of the crypto component. This is enabled by default. |
Boolean |
|
camel.component.crypto.key-store-parameters |
Sets the KeyStore that can contain keys and Certficates for use in signing and verifying exchanges based on the given KeyStoreParameters. A KeyStore is typically used with an alias, either one supplied in the Route definition or dynamically via the message header CamelSignatureKeyStoreAlias. If no alias is supplied and there is only a single entry in the Keystore, then this single entry will be used. The option is a org.apache.camel.support.jsse.KeyStoreParameters type. |
KeyStoreParameters |
|
camel.component.crypto.keystore |
Sets the KeyStore that can contain keys and Certficates for use in signing and verifying exchanges. A KeyStore is typically used with an alias, either one supplied in the Route definition or dynamically via the message header CamelSignatureKeyStoreAlias. If no alias is supplied and there is only a single entry in the Keystore, then this single entry will be used. The option is a java.security.KeyStore type. |
KeyStore |
|
camel.component.crypto.keystore-name |
Sets the reference name for a Keystore that can be found in the registry. |
String |
|
camel.component.crypto.lazy-start-producer |
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. |
false |
Boolean |
camel.component.crypto.password |
Sets the password used to access an aliased PrivateKey in the KeyStore. |
String |
|
camel.component.crypto.private-key |
Set the PrivateKey that should be used to sign the exchange. The option is a java.security.PrivateKey type. |
PrivateKey |
|
camel.component.crypto.private-key-name |
Sets the reference name for a PrivateKey that can be found in the registry. |
String |
|
camel.component.crypto.provider |
Set the id of the security provider that provides the configured Signature algorithm. |
String |
|
camel.component.crypto.public-key |
Set the PublicKey that should be used to verify the signature in the exchange. The option is a java.security.PublicKey type. |
PublicKey |
|
camel.component.crypto.public-key-name |
references that should be resolved when the context changes |
String |
|
camel.component.crypto.secure-random |
Set the SecureRandom used to initialize the Signature service. The option is a java.security.SecureRandom type. |
SecureRandom |
|
camel.component.crypto.secure-random-name |
Sets the reference name for a SecureRandom that can be found in the registry. |
String |
|
camel.component.crypto.signature-header-name |
Set the name of the message header that should be used to store the base64 encoded signature. This defaults to 'CamelDigitalSignature' |
String |
|
camel.dataformat.crypto.algorithm |
The JCE algorithm name indicating the cryptographic algorithm that will be used. |
String |
|
camel.dataformat.crypto.algorithm-parameter-ref |
A JCE AlgorithmParameterSpec used to initialize the Cipher. Will lookup the type using the given name as a java.security.spec.AlgorithmParameterSpec type. |
String |
|
camel.dataformat.crypto.buffersize |
The size of the buffer used in the signature process. |
Integer |
|
camel.dataformat.crypto.content-type-header |
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. |
false |
Boolean |
camel.dataformat.crypto.crypto-provider |
The name of the JCE Security Provider that should be used. |
String |
|
camel.dataformat.crypto.enabled |
Whether to enable auto configuration of the crypto data format. This is enabled by default. |
Boolean |
|
camel.dataformat.crypto.init-vector-ref |
Refers to a byte array containing the Initialization Vector that will be used to initialize the Cipher. |
String |
|
camel.dataformat.crypto.inline |
Flag indicating that the configured IV should be inlined into the encrypted data stream. Is by default false. |
false |
Boolean |
camel.dataformat.crypto.key-ref |
Refers to the secret key to lookup from the register to use. |
String |
|
camel.dataformat.crypto.mac-algorithm |
The JCE algorithm name indicating the Message Authentication algorithm. |
HmacSHA1 |
String |
camel.dataformat.crypto.should-append-h-m-a-c |
Flag indicating that a Message Authentication Code should be calculated and appended to the encrypted data. |
true |
Boolean |
camel.dataformat.pgp.algorithm |
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. |
Integer |
|
camel.dataformat.pgp.armored |
This option will cause PGP to base64 encode the encrypted text, making it available for copy/paste, etc. |
false |
Boolean |
camel.dataformat.pgp.compression-algorithm |
Compression algorithm; possible values are defined in org.bouncycastle.bcpg.CompressionAlgorithmTags; for example 0 (= UNCOMPRESSED), 1 (= ZIP), 2 (= ZLIB), 3 (= BZIP2). Only relevant for encrypting. |
Integer |
|
camel.dataformat.pgp.content-type-header |
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. |
false |
Boolean |
camel.dataformat.pgp.enabled |
Whether to enable auto configuration of the pgp data format. This is enabled by default. |
Boolean |
|
camel.dataformat.pgp.hash-algorithm |
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. |
Integer |
|
camel.dataformat.pgp.integrity |
Adds an integrity check/sign into the encryption file. The default value is true. |
true |
Boolean |
camel.dataformat.pgp.key-file-name |
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). |
String |
|
camel.dataformat.pgp.key-userid |
The user ID of the key in the PGP keyring used during encryption. Can also be only a part of a user ID. For example, if the user ID is Test User then you can use the part Test User or to address the user ID. |
String |
|
camel.dataformat.pgp.password |
Password used when opening the private key (not used for encryption). |
String |
|
camel.dataformat.pgp.provider |
Java Cryptography Extension (JCE) provider, default is Bouncy Castle (BC). Alternatively you can use, for example, the IAIK JCE provider; in this case the provider must be registered beforehand and the Bouncy Castle provider must not be registered beforehand. The Sun JCE provider does not work. |
String |
|
camel.dataformat.pgp.signature-key-file-name |
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). |
String |
|
camel.dataformat.pgp.signature-key-ring |
Keyring used for signing/verifying as byte array. You can not set the signatureKeyFileName and signatureKeyRing at the same time. |
String |
|
camel.dataformat.pgp.signature-key-userid |
User ID of the key in the PGP keyring used for signing (during encryption) or signature verification (during decryption). During the signature verification process the specified User ID restricts the public keys from the public keyring which can be used for the verification. If no User ID is specified for the signature verficiation then any public key in the public keyring can be used for the verification. Can also be only a part of a user ID. For example, if the user ID is Test User then you can use the part Test User or to address the User ID. |
String |
|
camel.dataformat.pgp.signature-password |
Password used when opening the private key used for signing (during encryption). |
String |
|
camel.dataformat.pgp.signature-verification-option |
Controls the behavior for verifying the signature during unmarshaling. There are 4 values possible: optional: The PGP message may or may not contain signatures; if it does contain signatures, then a signature verification is executed. required: The PGP message must contain at least one signature; if this is not the case an exception (PGPException) is thrown. A signature verification is executed. ignore: Contained signatures in the PGP message are ignored; no signature verification is executed. no_signature_allowed: The PGP message must not contain a signature; otherwise an exception (PGPException) is thrown. |
String |