https://github.com/multiformats/java-multihash

A Java implementation of Multihash
https://github.com/multiformats/java-multihash

Last synced: about 1 year ago
JSON representation

A Java implementation of Multihash

• Host: GitHub
• URL: https://github.com/multiformats/java-multihash
• Owner: multiformats
• License: mit
• Created: 2016-10-09T15:58:48.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2025-03-01T13:41:56.000Z (over 1 year ago)
• Last Synced: 2025-03-31T13:17:04.036Z (about 1 year ago)
• Language: Java
• Homepage:
• Size: 425 KB
• Stars: 46
• Watchers: 11
• Forks: 30
• Open Issues: 6
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

          
# java-multihash

[![](https://img.shields.io/badge/made%20by-Protocol%20Labs-blue.svg?style=flat-square)](http://ipn.io)

[![](https://img.shields.io/badge/project-multiformats-blue.svg?style=flat-square)](https://github.com/multiformats/multiformats)

[![](https://img.shields.io/badge/freenode-%23ipfs-blue.svg?style=flat-square)](https://webchat.freenode.net/?channels=%23ipfs)

[![Travis CI](https://img.shields.io/travis/multiformats/java-multihash.svg?style=flat-square&branch=master)](https://travis-ci.org/multiformats/java-multihash)

[![Release](https://jitpack.io/v/multiformats/java-multihash.svg)](https://jitpack.io/#multiformats/java-multihash)

[![](https://img.shields.io/badge/readme%20style-standard-brightgreen.svg?style=flat-square)](https://github.com/RichardLitt/standard-readme)

> A Java implementation of [multihash](https://github.com/multiformats/multihash).

## Install

Simply clone this repository.

## Usage

```java

Multihash b58 = Multihash.decode("QmatmE9msSfkKxoffpHwNLNKgwZG8eT9Bud6YoPab52vpy");

Multihash b36 = Multihash.decode("kmue2y4illvr0m3lt8x6z8iwghtxlzdmkjh957p5rr5cdr9243ugc");

```

Note that this library only decodes & encodes Multihashes, and does not actually include any implementations of the hash functions themselves.

Consumers of this library can use different implementations for different reasons. Here are a few possible implementation choices for each `Multihash.Type`:

* [JDK's `MessageDigest`](https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/security/MessageDigest.html) supports (at least) these:

  * md5 = MD5

  * sha1 = SHA-1

  * sha2-224 = SHA-224

  * sha2-256 = SHA-256

  * sha2-384 = SHA-384

  * sha2-512 = SHA-512

  * sha2-512-224 = SHA-512/224

  * sha2-512-256 = SHA-512/256

  * sha3_224 = SHA3-224

  * sha3_256 = SHA3-256

  * sha3_512 = SHA3-512

* [Google Guava's Hashing](https://github.com/google/guava/wiki/hashingexplained) offers [intentionally only](https://github.com/google/guava/issues/5990#issuecomment-2571350434) these:

  * md5 = `@Deprecated Hashing.md5()`

  * sha1 = `@Deprecated Hashing.sha1()`

  * sha2_256 = `Hashing.sha256()`

  * sha2_512 = `Hashing.sha512()`

  * murmur3 = `Hashing.murmur3_32_fixed()`

* [Google Tink](https://developers.google.com/tink/supported-key-types#mac)

  * AES-CMAC, see [Multicodec Issue #368](https://github.com/multiformats/multicodec/issues/368)

* [BouncyCastle](https://www.bouncycastle.org/documentation/specification_interoperability/)

  * blake2*

  * blake3*

  * shake-*

  * ripemd-*

* [Apache Commons Codec](https://commons.apache.org/proper/commons-codec/)

  * blake3*

  * murmur3

* [Jacksum](https://github.com/jonelo/jacksum)

  * skein*

  * ...

Please contribute an update to this list if you know of any other related libraries.

## Dependency

You can use this project by building the JAR file as specified below, or by using [JitPack](https://jitpack.io/#multiformats/java-multihash/) (also supporting Gradle, SBT, etc).

for Maven, you can add the follwing sections to your POM.XML:

```xml

  

    

        jitpack.io

        https://jitpack.io

    

  

  

    

      com.github.multiformats

      java-multihash

      $LATEST_VERSION

    

  

```

## Testing

`mvn test`

## Building

`mvn package` will build a JAR file with Maven dependency information.

## Releasing

The version number is specified in the `pom.xml` file and must be changed in order to be accurately reflected in the JAR file manifest. A git tag must be added in the format "vx.x.x" for JitPack to work.

## Maintainers

Captain: [@ianopolous](https://github.com/ianopolous).

## Contribute

Contributions welcome. Please check out [the issues](https://github.com/multiformats/java-multihash/issues).

Check out our [contributing document](https://github.com/multiformats/multiformats/blob/master/contributing.md) for more information on how we work, and about contributing in general. Please be aware that all interactions related to multiformats are subject to the IPFS [Code of Conduct](https://github.com/ipfs/community/blob/master/code-of-conduct.md).

Small note: If editing the README, please conform to the [standard-readme](https://github.com/RichardLitt/standard-readme) specification.

## License

[MIT](LICENSE) © 2015 Ian Preston