PevPot Stretch

High performance hash stretch for pevpot's provably fair lottery!

This repository includes both a node library and a stand-alone command line tool.

For the node library just grab with npm:

npm install pevpot-stretch

and use

var stetch = require('pevpot-stetch');
stetch(
  "00000000000000000ef86b27c174df6a412c0ce43eab1d532034555749294137",
  100000,
  function(err, data) {
    console.log('Stretch callback was called with: ', err, data);
  }
);

And the simple utility to stretch a blockhash for the pevpot lottery. Based on openssl with an iteration counter changed from int to long to support 64 bit iterations

Compiling

Linux: gcc -O3 stretch.c -o stretch -lssl -lcrypto

OSX: clang -O3 stretch.c -o stretch -O3 -g -Wall -I/usr/local/Cellar/openssl/1.0.2d_1/include/ -L/usr/local/Cellar/openssl/1.0.2d_1/lib -lcrypto

Usage

./stetch blockhash [iterations]

(If iterations is not provided, default to the pevpot 5 billion)

Test Vectors:

./stetch 00000000000000000ef86b27c174df6a412c0ce43eab1d532034555749294137 100000

39aed3d2eff372916100106e355384495d1794320d4c3cb4c2e0e48cc36bbd06

./stretch 000000000000000009b7fb236187f120a0c86eb8785f099a8d197dd34b9d2553

6e466cdd13cc80b1137addf46362bbe3714fc9bf7faef9aba930554d3e080ba5

Credits

• OpenSSL (original code)
• Dooglus original extraction