Artifact Checksum support

Identifier:

org.eclipse.equinox.p2.artifact.repository.artifactChecksums

Since:

2.4.0

Description:

Provides a mapping from checksum algorithm id and java.security.MessageDigest implementations.

p2 detects errors which may have been introduced during artifact transmission/storage by calculating artifact checksum using MD5 hash function. As a collision attack and a chosen-prefix collision attack against MD5 have been demonstrated in public, it can be used but only to detect unintentional corruption. Current implementation is not extensible and doesn't allow to use other, more collision-resistant, hash functions.

With this extension point, any java.security.MessageDigest from Java Security API can be used to check integrity of artifacts. For more information on these APIs, see Java Cryptography Architecture (JCA) Reference Guide.

Configuration Markup:

<!ELEMENT extension (artifactChecksum+)>

<!ATTLIST extension

point CDATA #REQUIRED

id CDATA #IMPLIED

name CDATA #IMPLIED>

<!ELEMENT artifactChecksum EMPTY>

<!ATTLIST artifactChecksum

id CDATA #REQUIRED

algorithm CDATA #REQUIRED

providerName CDATA #IMPLIED

warnInsecure (true | false)

priority CDATA "0"

publish (true | false) "true">

id - id of the checksum algorithm, i.e. sha-512. As other tools will rely on this id, consider using some well-defined value (i.e. Hash Function Textual Names ).
algorithm - Name of the message digest algorithm as expected by java.security.MessageDigest's method getInstance(String). Also check the MessageDigest section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.
providerName - For custom security provider, name of the security provider that provides this message digest implementation, the value returned by java.security.Provider.getName().
warnInsecure - Since 1.4.300 Set to true if this algorithm is now considered as insecure. A warning will be logged when this algorithm is used. An artifact that has no checksums or checksums only for insecure algorithms will emit a warning to user.
priority - Gives a priority of this algorithm, algorithms with higher priority are preffered if multiple ones are applicable.
publish - Controls if this checksum should be published when assembling a repository.

Examples:

To enable support for MessageDigest implementation which is provided by a statically registered Provider, contributing bundle should only register an extension:


<extension point="org.eclipse.equinox.p2.artifact.repository.artifactChecksums">
  <artifactChecksum
   algorithm="SHA3-512"
   id="sha3-512">
  </artifactChecksum>
</extension>

If the MessageDigest implementation is provided by a custom security provider (from the contributing bundle itself or some other bundle), it should be registered first with the Framework service registry under interface java.security.Provider:


import java.security.Provider;
import java.util.Dictionary;
import java.util.Hashtable;

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceRegistration;

...

Dictionary<String, Object> props = new Hashtable<>();
props.put("providerName", "BC");
ServiceRegistration<Provider> registration = context.registerService(Provider.class, new BouncyCastleProvider(), props);

and then register an extension using providerName attribute:


<extension point="org.eclipse.equinox.p2.artifact.repository.artifactChecksums">
  <artifactChecksum
   algorithm="Whirlpool"
   id="whirlpool"
   providerName="BC">
  </artifactChecksum>
</extension>

Supplied Implementation:

Contributes a checksum algorithm with id sha-256 and maps it to SHA-256 MessageDigest implementation.

Copyright (c) 2015, 2018 Mykola Nikishov. This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which accompanies this distribution, and is available at https://www.eclipse.org/legal/epl-v20.html/ SPDX-License-Identifier: EPL-2.0