...
Crypto
...
component
...
for
...
Digital
...
Signatures
...
Available
...
as
...
of
...
Camel
...
2.3
...
With
...
Camel
...
cryptographic
...
endpoints
...
and
...
Java's
...
Cryptographic
...
extension
...
it
...
is
...
easy
...
to
...
create
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Digital
...
Signatures
...
for
...
...
s.
...
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:
...
...
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
...
crypto:sign
...
- creates
...
- the
...
- signature
...
- and
...
- stores
...
- it
...
- in
...
- the
...
- Header
...
- keyed
...
- by
...
- the
...
- constant
org.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
...
Name | Type | Default | Description |
---|---|---|---|
|
|
| The name of the JCE Signature algorithm that will be used. |
|
|
| An alias name that will be used to select a key from the keystore. |
|
|
| the size of the buffer used in the signature process. |
|
|
| A Certificate used to verify the signature of the exchange's payload. Either this or a Public Key is required. |
|
|
| 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 |
|
|
| The name of the JCE Security Provider that should be used. |
|
|
| The private key used to sign the exchange's payload. |
|
|
| The public key used to verify the signature of the exchange's payload. |
|
|
| A reference to a |
|
|
| The password to access the private key from the keystore |
|
|
| Remove camel crypto headers from Message after a verify operation (value can be |
Using
1) 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
...
...
...
...
using
...
references
...
to
...
keys
...
...
2)
...
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.
...
...
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.
...
...
3)
...
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
...
...
...
4)
...
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
...
...
5)
...
Changing
...
the
...
buffersize
...
In
...
case
...
you
...
need
...
to
...
update
...
the
...
size
...
of
...
the
...
buffer...
...
...
or
...
...
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
...
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
...
...
- Crypto Crypto is also available as a Data Format