MyBC

Brief example

In the command line, to build BC v1.67:

npm install -g @jbuhacoff/mybc
git clone https://github.com/bcgit/bc-java && cd bc-java
git checkout -b mybc-1.67 tags/r1rv67
mybc prebuild
export JDKPATH="$JAVA_HOME"
sh ./build15+
mybc postbuild

In your Maven project:

<dependency>
    <groupId>my.bouncycastle</groupId>
    <artifactId>bcprov-jdk15on</artifactId>
    <version>1.67</version>
</dependency>

The example only show bcprov but the tool builds all the BC jars: bcmail, bcpg, bcpkix, bcprov-ext, bcprov, bctest, and bctls.

Dependencies

NodeJS 10+ and NPM to install mybc.

Git to clone the BouncyCastle source code from GitHub.

Java 8, Ant, and Maven to build BouncyCastle.

Background

Some projects need to use a recent version of BouncyCastle in an environment where the Java framework (web server, Android, etc.) already has an earlier version of BouncyCastle in the classpath, which is loaded before the application's version.

If you have a similar situation, you might see errors like this one at runtime:

java.security.NoSuchAlgorithmException: no such algorithm: SHA256withRSA/PSS for provider BC

This happens because at runtime your application is linked to the system's earlier version of BouncyCastle that does not support that algorithm, and the version that you bundled with your application is ignored.

A workaround is to rename the BouncyCastle packages and the "BC" provider name so they won't conflict with the pre-installed earlier BouncyCastle version.

The mybc tool automates the process so you can easily generate modified .jar files to use in your project.

An existing project SpongyCastle did this and even published the resulting artifacts to Maven Central, but at the time of this writing, hasn't been updated for two years and is several versions behind BouncyCastle. It's not clear if that effort will continue, and anyway there is another issue which might inhibit you from using it: you trust BouncyCastle -- but should you extend that trust to altered binaries published by someone else?

So the approach here is to make it easy for you to implement the same workaround using your own copy of the BouncyCastle source code. The tool itself is simple and the source is on GitHub with a BSD 2-clause license. You can inspect the source for assurance that it only does what it's intended to do, and you can fork this repository and customize it as needed.

Customize

You can specify the following options to mybc prebuild, shown here with the default values:

• --providerName MyBC the custom provider name to use in your application
• --packageName my.bouncycastle the custom Java package name to use in your application
• --displayName MyBouncyCastle the human-readable name for this custom version of BouncyCastle

You can specify the following options to mybc postbuild, shown here with the default values:

• --groupId my.bouncycastle used to install the customized jars in the local Maven repository

Here is a complete example with the default values specified:

mybc prebuild --providerName MyBC --packageName my.bouncycastle --displayName MyBouncyCastle
export JDKPATH="$JAVA_HOME"
sh ./build15+
mybc postbuild --groupId my.bouncycastle

In your Maven project:

<dependency>
    <groupId>my.bouncycastle</groupId>
    <artifactId>bcprov-jdk15on</artifactId>
    <version>1.67</version>
</dependency>

SpongyCastle

If you're already using SpongyCastle, here is how to create a drop-in replacement with a newer version (the artifactId may differ so you will need to update this in your dependency management system):

mybc prebuild --providerName SC --packageName org.spongycastle --displayName SpongyCastle
sh ./build15+
mybc postbuild --groupId com.madgag.spongycastle

In your Maven project:

<dependency>
    <groupId>com.madgag.spongycastle</groupId>
    <artifactId>bcprov-jdk15on</artifactId>
    <version>1.67</version>
</dependency>

Usage notes

Use the --trace option to see extra output:

mybc prebuild --trace
sh ./build15+
mybc postbuild --trace

If you need to run mybc prebuild again, you have to reset the working directory first:

1. delete the build directory
2. reset the repository to the last commit before working directory changes (git reset --hard)
3. run mybc prebuild, sh ./build15+, then mybc postbuild

If you need to run mybc postbuild again, you only need to reset part of the output directory first:

1. delete everything under build/mybc except for prebuild-ant.xml and prebuild-data.json
2. run mybc postbuild

Related

Very old threads about the classpath issue on Android:

http://bouncy-castle.1462172.n4.nabble.com/Bouncy-Castle-and-Android-td1467774.html

http://bouncy-castle.1462172.n4.nabble.com/Removing-BC-from-Android-td2074914.html

Discussion about whether to continue releasing SpongyCastle:

https://github.com/rtyley/spongycastle/issues/34