@chiamine/bls-signatures

Important Notice

This is unofficial patch build for the latest js-bindings of bls-signatures.
Consider this branch as a temporary package instead of the unknown 0.2.5 version package published at the npm registry.

The problem

If you install bls-signatures via npm install bls-signature, you will install bls-signatures of version 0.2.5, whose source code has not yet been published to the original GitHub repository.
(Maybe a developer built and published its private source code into the npm registry)

I created this branch because I'm worried to run this unknown '0.2.5' version of bls-signatures on my own computer.

How to reproduce this unofficial npm package

You will(or should) ask me something like
"How can I trust this unofficial npm package instead of the one in original npm registry?"

I'm telling you how you can trust this package, by showing how to reproduce the content of this repository precisely.

1. Check node/cmake/emscripten exists in your environment or install them if they are missing.
   See https://emscripten.org/docs/getting_started/downloads.html for emscripten installation.
   For my current environment, I use

   • Ubuntu Ubuntu 20.04.2
   • emsdk 2.0.23 (77b065ace39e6ab21446e13f92897f956c80476a)
   • node-14.15.5-64bit
   • cmake 3.16.3

2. Git clone from the trusted source code

cd <directory you like>
git clone https://github.com/Chia-Network/bls-signatures
cd bls-signatures
git checkout 42c3b61fd2c21c0ab8de9e5638d082fe8cb752c7 # You will be warned by git as it is `detached-state` but don't worry.

1. Build js-binding

mkdir js_build && cd js_build
cmake ../ -DCMAKE_TOOLCHAIN_FILE=/PATH-TO-EMSDK-ROOT/emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake
cmake --build . --

1. Check out the products

ls -l js-bindings/

# You will see output like this.
# The files should be the same as contents of this branch except for this README
#
# drwxrwxr-x 4 chiaminejp chiaminejp   4096  June 16 11:09 CMakeFiles
# -rw-rw-r-- 1 chiaminejp chiaminejp  16817  June 16 11:09 Makefile
# -rw-rw-r-- 1 chiaminejp chiaminejp   6591  June 16 11:09 README.md
# -rw-rw-r-- 1 chiaminejp chiaminejp   4091  June 16 11:09 blsjs.d.ts
# -rw-rw-r-- 1 chiaminejp chiaminejp  47671  June 16 11:10 blsjs.js
# -rwxrwxr-x 1 chiaminejp chiaminejp 248515  June 16 11:10 blsjs.wasm
# -rw-rw-r-- 1 chiaminejp chiaminejp   1002  June 16 11:09 cmake_install.cmake
# -rw-rw-r-- 1 chiaminejp chiaminejp 100600  June 16 11:09 package-lock.json
# -rw-rw-r-- 1 chiaminejp chiaminejp   1290  June 16 11:09 package.json
# drwxrwxr-x 2 chiaminejp chiaminejp   4096  June 16 11:09 tests

(4. publish the above content to this branch)
This process is for me only.
After build js-bindings of bls-signature, I always edit README.md to include this 'Important Notice'.
In addition to README.md, I also edit package.json to rename module to @chiamine/bls-signatures.
This is necessary to publish isolated npm package for replacement of official bls-signature@0.2.5.
reason why I need isolated npm package
I once indicated to install this npm module by

npm install Chia-Mine/bls-signatures#npm # Install this npm module from this GitHub repository's npm branch

However, there was an issue where sometimes it unexpectedly installed old npm module instead of the latest commit.
I didn't realize the exact cause, but I guess npm install from GitHub sometimes not working and instead tries to fetch npm files from official npm registry.

So I decided to publish 'scoped' npm module which you can easily install by

npm install @chiamine/bls-signatures # or yarn add @chiamine/bls-signatures

Note: This npm branch is an orphan branch and not a derivation of any other branches.

---

bls-signatures

JavaScript library that implements BLS signatures with aggregation as in Boneh, Drijvers, Neven 2018, using the relic toolkit for cryptographic primitives (pairings, EC, hashing).

This library is a JavaScript port of the Chia Network's BLS lib. We also have typings, so you can use it with TypeScript too!

Usage

npm i @chiamine/bls-signatures --save # or yarn add @chiamine/bls-signatures

Creating keys and signatures

  var loadBls = require("bls-signatures");
  var BLS = await loadBls();
  
  var seed = Uint8Array.from([
    0,  50, 6,  244, 24,  199, 1,  25,  52,  88,  192,
    19, 18, 12, 89,  6,   220, 18, 102, 58,  209, 82,
    12, 62, 89, 110, 182, 9,   44, 20,  254, 22
  ]);
  
  var sk = BLS.AugSchemeMPL.key_gen(seed);
  var pk = sk.get_g1();
  
  var message = Uint8Array.from([1,2,3,4,5]);
  var signature = BLS.AugSchemeMPL.sign(sk, message);
  
  let ok = BLS.AugSchemeMPL.verify(pk, message, signature);
  console.log(ok); // true

Serializing keys and signatures to bytes

  var skBytes = sk.serialize();
  var pkBytes = pk.serialize();
  var signatureBytes = signature.serialize();
  
  console.log(BLS.Util.hex_str(skBytes));
  console.log(BLS.Util.hex_str(pkBytes));
  console.log(BLS.Util.hex_str(signatureBytes));
  

Loading keys and signatures from bytes

  var skc = BLS.PrivateKey.from_bytes(skBytes, false);
  var pk = BLS.G1Element.from_bytes(pkBytes);

  var signature = BLS.G2Element.from_bytes(signatureBytes);

Create aggregate signatures

  // Generate some more private keys
  seed[0] = 1;
  var sk1 = BLS.AugSchemeMPL.key_gen(seed);
  seed[0] = 2;
  var sk2 = BLS.AugSchemeMPL.key_gen(seed);
  var message2 = Uint8Array.from([1,2,3,4,5,6,7]);
  
  // Generate first sig
  var pk1 = sk1.get_g1();
  var sig1 = BLS.AugSchemeMPL.sign(sk1, message);
  
  // Generate second sig
  var pk2 = sk2.get_g1();
  var sig2 = BLS.AugSchemeMPL.sign(sk2, message2);
  
  // Signatures can be non-interactively combined by anyone
  var aggSig = BLS.AugSchemeMPL.aggregate([sig1, sig2]);
  
  ok = BLS.AugSchemeMPL.aggregate_verify([pk1, pk2], [message, message2], aggSig);
  console.log(ok); // true
  

Arbitrary trees of aggregates

  seed[0] = 3;
  var sk3 = BLS.AugSchemeMPL.key_gen(seed);
  var pk3 = sk3.get_g1();
  var message3 = Uint8Array.from([100, 2, 254, 88, 90, 45, 23]);
  var sig3 = BLS.AugSchemeMPL.sign(sk3, message3);
  
  var aggSigFinal = BLS.AugSchemeMPL.aggregate([aggSig, sig3]);
  ok = BLS.AugSchemeMPL.aggregate_verify([pk1, pk2, pk3], [message, message2, message3], aggSigFinal);
  console.log(ok); // true

Very fast verification with Proof of Possession scheme

  // If the same message is signed, you can use Proof of Posession (PopScheme) for efficiency
  // A proof of possession MUST be passed around with the PK to ensure security.
  var popSig1 = BLS.PopSchemeMPL.sign(sk1, message);
  var popSig2 = BLS.PopSchemeMPL.sign(sk2, message);
  var popSig3 = BLS.PopSchemeMPL.sign(sk3, message);
  var pop1 = BLS.PopSchemeMPL.pop_prove(sk1);
  var pop2 = BLS.PopSchemeMPL.pop_prove(sk2);
  var pop3 = BLS.PopSchemeMPL.pop_prove(sk3);
  
  ok = BLS.PopSchemeMPL.pop_verify(pk1, pop1);
  console.log(ok); // true
  ok = BLS.PopSchemeMPL.pop_verify(pk2, pop2);
  console.log(ok); // true
  ok = BLS.PopSchemeMPL.pop_verify(pk3, pop3);
  console.log(ok); // true
  
  var popSigAgg = BLS.PopSchemeMPL.aggregate([popSig1, popSig2, popSig3]);
  ok = BLS.PopSchemeMPL.fast_aggregate_verify([pk1, pk2, pk3], message, popSigAgg);
  console.log(ok); // true
  
  // Aggregate public key, indistinguishable from a single public key
  var popAggPk = pk1.add(pk2).add(pk3);
  ok = BLS.PopSchemeMPL.verify(popAggPk, message, popSigAgg);
  console.log(ok); // true
  
  // Aggregate private keys
  var aggSk = BLS.PrivateKey.aggregate([sk1, sk2, sk3]);
  ok = (BLS.PopSchemeMPL.sign(aggSk, message).equal_to(popSigAgg));
  console.log(ok); // true

HD keys using EIP-2333

  // You can derive 'child' keys from any key, to create arbitrary trees. 4 byte indeces are used.
  // Hardened (more secure, but no parent pk -> child pk)
  var masterSk = BLS.AugSchemeMPL.key_gen(seed);
  var child = BLS.AugSchemeMPL.derive_child_sk(masterSk, 152);
  var grandChild = BLS.AugSchemeMPL.derive_child_sk(child, 952);
  
  // Unhardened (less secure, but can go from parent pk -> child pk), BIP32 style
  var masterPk = masterSk.get_g1();
  var childU = BLS.AugSchemeMPL.derive_child_sk_unhardened(masterSk, 22);
  var grandchildU = BLS.AugSchemeMPL.derive_child_sk_unhardened(childU, 0);
  
  var childUPk = BLS.AugSchemeMPL.derive_child_pk_unhardened(masterPk, 22);
  var grandchildUPk = BLS.AugSchemeMPL.derive_child_pk_unhardened(childUPk, 0);
  
  ok = (grandchildUPk.equal_to(grandchildU.get_g1()));
  console.log(ok); // true

Please refer to the library's typings for detailed API information. Use cases can be found in the original lib's readme.

Important note on usage: Since this library is a WebAssembly port of the c++ library, JavaScript's automatic memory management isn't available. Please, delete all objects manually if they are not needed anymore by calling the delete method on them, as shown in the example below.

  sk.delete();
  // ...
  pk.delete();
  // ...
  sig1.delete();
  // ...

Build

Building requires Node.js (with npm) and Emscripten to be installed. The build process is the same as for the c++ lib, with one additional step: pass the Emscripten toolchain file as an option to CMake. From the project root directory, run:

#git submodule update --init --recursive
mkdir js_build
cd js_build
cmake ../ -DCMAKE_TOOLCHAIN_FILE={path_to_your_emscripten_installation}/emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake
cmake --build . --

Run the build after any changes to the library, including readme and tests, as the library will be deployed from the build directory, and the build system copies all the files from the source dir.

Run tests

Tests are run in node.js and Firefox, therefore you need to install node.js and Firefox. To run tests, build the library, then go to the js_bindings folder in the build directory and run

npm test