bitcoin-s/secp256k1jni/README.md

Secp256k1jni

This project gives people a convenient way to use libsecp256k1 on the JVM without compiling natives themselves.

Currently we have support for natives on

1. linux 32 bit
2. linux 64 bit
3. mac osx 64 bit

This uses a zero depdency library called native-lib-loader. The does the appropriate loading of the library onto your classpath to be accessed. To tell if you have access to libsecp256k1 you can do the following

sbt:root> project secp256k1jni
[info] Set current project to bitcoin-s-secp256k1jni (in build file:/home/chris/dev/bitcoin-s-core/)
sbt:bitcoin-s-secp256k1jni> console
[info] Starting scala interpreter...
Welcome to Scala 2.12.7 (Java HotSpot(TM) 64-Bit Server VM, Java 1.8.0_191).
Type in expressions for evaluation. Or try :help.

scala> import org.bitcoin.Secp256k1Context;

scala> Secp256k1Context.isEnabled()
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
res0: Boolean = true

Adding secp256k1jni to your project

To add bitcoin-s-secp256k1jni to your project you add it like this

"org.bitcoins" % "bitcoin-s-secp256k1jni" % "0.0.1"

or with maven

<dependency>
  <groupId>org.bitcoins</groupId>
  <artifactId>bitcoin-s-secp256k1jni</artifactId>
  <version>0.0.1</version>
</dependency>

Using secp256k1

The file NativeSecp256k1.java contains basic functionality for

1. Verifying digital signatures
2. Producing digital signatures
3. Computing a public key from a private key
4. tweaking keys
5. Checking public key validity

Binaries

The binaries provided here are PGP signed, to give at least some assurances that nothing funny has happened to them.

macOS 64 bit

bitcoin-s/secp256k1jni/natives/osx_64 $ find -type f -exec sha256sum {} \; | \
        sort -k 2 | sha256sum | cut --fields 1 --delimiter=" " | \
        gpg --clearsign --output hashed-dir.sig --detach-sig

bitcoin-s/secp256k1jni/natives/osx_64 $ cat hashed-dir.sig
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

341d768b915d989db82c1fb94b29faec9509ad45e30a27c217feb121747789ce
-----BEGIN PGP SIGNATURE-----

iQEzBAEBCgAdFiEEcQE9FyWyvvLjrwybHk0b2DvgrM0FAlxPHuQACgkQHk0b2Dvg
rM07EwgApXWPlVKMDP7Z8RQhhDmlnycTJxFaw315TH2IKDMEtCA0mBGY8UOy7jis
ZtQEyUQdspBnLW6RHeEBhkDlQzjMS3G4K2T2D1r2eL4vXf7dnZ2CUSy7N9Gd8Lsy
Tcdi9a/GSyFu1RCtmklCZ75/oECPlmNctdOY30+5FDIfWIcTHqKebfDstTqeYGbd
0+U5N2xDI/07g5jCF1EsgiqvFkXZEjI/44xlxWon6GtbiYR/n+MHzgwBi5XqNs2p
0t3Tvx5NbJiVVn7K2ThQFaW4ap/bqggZh1ddT/v2Wq0BH+UX6b6Abrq0tD5+ZPst
5+tz19oEa9XK+X/DDkFrT4WEMDpyIw==
=CauS
-----END PGP SIGNATURE-----

bitcoin-s/secp256k1jni/natives/osx_64 $ gpg --verify hashed-dir.sig
gpg: Signature made Mon 28 Jan 2019 04:25:24 PM CET
gpg:                using RSA key 71013D1725B2BEF2E3AF0C9B1E4D1BD83BE0ACCD
gpg: Good signature from "Torkel Rogstad <torkel@suredbits.com>" [ultimate]

Linux 32 bit

TODO

Linux 64 bit

TODO