Page History

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Crypto

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component

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for

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Digital

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Signatures

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Available
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as
...
of
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Camel
...
2.3
...
With
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Camel
...
cryptographic
...
endpoints
...
and
...
Java's
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Cryptographic
...
extension
...
it
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is
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easy
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to
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create
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Digital
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Signatures
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for
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Exchange
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s.
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Camel
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provides
...
a
...
pair
...
of
...
flexible
...
endpoints
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which
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get
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used
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in
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concert
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to
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create
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a
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signature
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for
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an
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exchange
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in
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one
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part
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of
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the
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exchange's
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workflow
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and
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then
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verify
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the
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signature
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in
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a
...
later
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part
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of
...
the
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workflow.
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Maven
...
users
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will
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need
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to
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add
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the
...
following
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dependency
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to
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their
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`pom.xml`
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for
...
this
...
component:
...
...

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 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

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crypto:sign

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creates

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the

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signature

...

and

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stores

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it

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in

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the

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Header

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keyed

...

by

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the

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constant org.apache.camel.component.crypto.DigitalSignatureConstants.SIGNATURE, i.e.

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"CamelDigitalSignature"

...

.
crypto:verify

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will

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read

...

in

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the

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contents

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of

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this

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header

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and

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do

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the

...

verification

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calculation.

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In

...

order

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to

...

correctly

...

function,

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the

...

sign

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and

...

verify

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process

...

needs

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a

...

pair

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of

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keys

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to

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be

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shared,

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signing

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requiring

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a

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PrivateKey

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and

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verifying

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a

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PublicKey

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(or

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a

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Certificate

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containing

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one).

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Using

...

the

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JCE

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it

...

is

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very

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simple

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to

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generate

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these

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key

...

pairs

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but

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it

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is

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usually

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most

...

secure

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to

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use

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a

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KeyStore

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to

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house

...

and

...

share

...

your

...

keys.

...

The

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DSL

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is

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very

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flexible

...

about

...

how

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keys

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are

...

supplied

...

and

...

provides

...

a

...

number

...

of

...

mechanisms.

...

Note

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a

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crypto:sign

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endpoint

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is

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typically

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defined

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in

...

one

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route

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and

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the

...

complimentary

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crypto:verify

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in

...

another,

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though

...

for

...

simplicity

...

in

...

the

...

examples

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they

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appear

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one

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after

...

the

...

other.

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It

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goes

...

without

...

saying

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that

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both

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signing

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and

...

verifying

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should

...

be

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configured

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identically.

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Options

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Name	Type	Default	Description
`algorithm`	`String`	`SHA1WithDSA`	The name of the JCE Signature algorithm that will be used.
`alias`	`String`	`null`	An alias name that will be used to select a key from the keystore.
`bufferSize`	`Integer`	`2048`	the size of the buffer used in the signature process.
`certificate`	`Certificate`	`null`	A Certificate used to verify the signature of the exchange's payload. Either this or a Public Key is required.
`keystore`	`KeyStore`	`null`	A reference to a JCE Keystore that stores keys and certificates used to sign and verify.
keyStoreParameters Camel 2.14.1	KeyStoreParameters	null	A reference to a Camel KeyStoreParameters Object which wraps a Java KeyStore Object
`provider`	`String`	`null`	The name of the JCE Security Provider that should be used.
`privateKey`	`PrivateKey`	`null`	The private key used to sign the exchange's payload.
`publicKey`	`PublicKey`	`null`	The public key used to verify the signature of the exchange's payload.
`secureRandom`	`secureRandom`	`null`	A reference to a `SecureRandom` object that will be used to initialize the Signature service.
`password`	`char[]`	`null`	The password to access the private key from the keystore
`clearHeaders`	`String`	`true`	Remove camel crypto headers from Message after a verify operation (value can be `"true"`/`"false"`).

Using

1) Raw keys

The most basic way to way to sign and verify an exchange is with a KeyPair as follows.{snippet:id=basic|lang=java|url=camel/trunk/components/camel-crypto/src/test/java/org/apache/camel/component/crypto/SignatureTests.java}

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The

...

same

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can

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be

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achieved

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with

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the

...

Spring

...

XML

...

Extensions

...

using

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references

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to

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keys

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{snippet:id=basic|lang=xml|url=camel/trunk/components/camel-crypto/src/test/resources/org/apache/camel/component/crypto/SpringSignatureTests.xml}

...

2)

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KeyStores

...

and

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Aliases.

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The
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JCE
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provides
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a
...
very
...
versatile
...
keystore
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concept
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for
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housing
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pairs
...
of
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private
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keys
...
and
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certificates,
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keeping
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them
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encrypted
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and
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password
...
protected.
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They
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can
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be
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retrieved
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by
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applying
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an
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alias
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to
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the
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retrieval
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APIs.
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There
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are
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a
...
number
...
of
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ways
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to
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get
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keys
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and
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Certificates
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into
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a
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keystore,
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most
...
often
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this
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is
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done
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with
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the
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external
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'keytool'
...
application.
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This
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is
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a
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good
...
example
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of
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using
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keytool
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to
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create
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a
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KeyStore
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with
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a
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self
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signed
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Cert
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and
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Private
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key.
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The
...
examples
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use
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a
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Keystore
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with
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a
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key
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and
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cert
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aliased
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by
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'bob'.
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The
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password
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for
...
the
...
keystore
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and
...
the
...
key
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is
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'letmein'
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The
...
following
...
shows
...
how
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to
...
use
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a
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Keystore
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via
...
the
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Fluent
...
builders,
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it
...
also
...
shows
...
how
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to
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load
...
and
...
initialize
...
the
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keystore.
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{snippet:id=keystore|lang=java|url=camel/trunk/components/camel-crypto/src/test/java/org/apache/camel/component/crypto/SignatureTests.java}
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Again
...
in
...
Spring
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a
...
ref
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is
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used
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to
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lookup
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an
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actual
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keystore
...
instance.
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{snippet:id=keystore|lang=xml|url=camel/trunk/components/camel-crypto/src/test/resources/org/apache/camel/component/crypto/SpringSignatureTests.xml}
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3)

...

Changing

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JCE

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Provider

...

and

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Algorithm

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Changing
...
the
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Signature
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algorithm
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or
...
the
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Security
...
provider
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is
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a
...
simple
...
matter
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of
...
specifying
...
their
...
names.
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You
...
will
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need
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to
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also
...
use
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Keys
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that
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are
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compatible
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with
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the
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algorithm
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you
...
choose.
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{snippet:id=algorithm|lang=java|url=camel/trunk/components/camel-crypto/src/test/java/org/apache/camel/component/crypto/SignatureTests.java}
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{snippet:id=provider|lang=java|url=camel/trunk/components/camel-crypto/src/test/java/org/apache/camel/component/crypto/SignatureTests.java}
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or
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{snippet:id=algorithm|lang=xml|url=camel/trunk/components/camel-crypto/src/test/resources/org/apache/camel/component/crypto/SpringSignatureTests.xml}
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{snippet:id=provider|lang=xml|url=camel/trunk/components/camel-crypto/src/test/resources/org/apache/camel/component/crypto/SpringSignatureTests.xml}
...

4)

...

Changing

...

the

...

Signature

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Message

...

Header

...

It
...
may
...
be
...
desirable
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to
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change
...
the
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message
...
header
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used
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to
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store
...
the
...
signature.
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A
...
different
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header
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name
...
can
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be
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specified
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in
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the
...
route
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definition
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as
...
follows
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{snippet:id=signature-header|lang=java|url=camel/trunk/components/camel-crypto/src/test/java/org/apache/camel/component/crypto/SignatureTests.java}
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or
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{snippet:id=signature-header|lang=xml|url=camel/trunk/components/camel-crypto/src/test/resources/org/apache/camel/component/crypto/SpringSignatureTests.xml}
...

5)

...

Changing

...

the

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buffersize

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In
...
case
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you
...
need
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to
...
update
...
the
...
size
...
of
...
the
...
buffer...
...
{snippet:id=buffersize|lang=java|url=camel/trunk/components/camel-crypto/src/test/java/org/apache/camel/component/crypto/SignatureTests.java}
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or
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{snippet:id=buffersize|lang=xml|url=camel/trunk/components/camel-crypto/src/test/resources/org/apache/camel/component/crypto/SpringSignatureTests.xml}
...

6)

...

Supplying

...

Keys

...

dynamically.

...

When
...
using
...
a
...
Recipient
...
list
...
or
...
similar
...
EIP
...
the
...
recipient
...
of
...
an
...
exchange
...
can
...
vary
...
dynamically.
...
Using
...
the
...
same
...
key
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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`
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,
...
`"CamelSignaturePrivateKey"`
...
`Exchange.SIGNATURE_PUBLIC_KEY_OR_CERT`
...
,
...
`"CamelSignaturePublicKeyOrCert"`
...
{snippet:id=headerkey|lang=java|url=camel/trunk/components/camel-crypto/src/test/java/org/apache/camel/component/crypto/SignatureTests.java}
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or
...
{snippet:id=headerkey|lang=xml|url=camel/trunk/components/camel-crypto/src/test/resources/org/apache/camel/component/crypto/SpringSignatureTests.xml}
...
Even
...
better
...
would
...
be
...
to
...
dynamically
...
supply
...
a
...
keystore
...
alias.
...
Again
...
the
...
alias
...
can
...
be
...
supplied
...
in
...
a
...
message
...
header
...
`Exchange.KEYSTORE_ALIAS`
...
,
...
`"CamelSignatureKeyStoreAlias"`
...
{snippet:id=alias|lang=java|url=camel/trunk/components/camel-crypto/src/test/java/org/apache/camel/component/crypto/SignatureTests.java}
...
or
...
{snippet:id=alias|lang=xml|url=camel/trunk/components/camel-crypto/src/test/resources/org/apache/camel/component/crypto/SpringSignatureTests.xml}
...
The
...
header
...
would
...
be
...
set
...
as
...
follows
...
...
Endpoint See Also
Crypto Crypto is also available as a Data Format

Child pages

Versions Compared

Old Version 9

New Version Current

Key

Crypto

component

for

Digital

Signatures

Introduction

URI format

Options

Using

1) Raw keys

2)

KeyStores

and

Aliases.

3)

Changing

JCE

Provider

and

Algorithm

4)

Changing

the

Signature

Message

Header

5)

Changing

the

buffersize

6)

Supplying

Keys

dynamically.