d3_merkle4.html

<script>
/**
 * [js-sha256]{@link https://github.com/emn178/js-sha256}
 *
 * @version 0.9.0
 * @author Chen, Yi-Cyuan [emn178@gmail.com]
 * @copyright Chen, Yi-Cyuan 2014-2017
 * @license MIT
 */
/*jslint bitwise: true */
(function () {
  'use strict';

  var ERROR = 'input is invalid type';
  var WINDOW = typeof window === 'object';
  var root = WINDOW ? window : {};
  if (root.JS_SHA256_NO_WINDOW) {
    WINDOW = false;
  }
  var WEB_WORKER = !WINDOW && typeof self === 'object';
  var NODE_JS = !root.JS_SHA256_NO_NODE_JS && typeof process === 'object' && process.versions && process.versions.node;
  if (NODE_JS) {
    root = global;
  } else if (WEB_WORKER) {
    root = self;
  }
  var COMMON_JS = !root.JS_SHA256_NO_COMMON_JS && typeof module === 'object' && module.exports;
  var AMD = typeof define === 'function' && define.amd;
  var ARRAY_BUFFER = !root.JS_SHA256_NO_ARRAY_BUFFER && typeof ArrayBuffer !== 'undefined';
  var HEX_CHARS = '0123456789abcdef'.split('');
  var EXTRA = [-2147483648, 8388608, 32768, 128];
  var SHIFT = [24, 16, 8, 0];
  var K = [
    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
    0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
    0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
    0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
    0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
  ];
  var OUTPUT_TYPES = ['hex', 'array', 'digest', 'arrayBuffer'];

  var blocks = [];

  if (root.JS_SHA256_NO_NODE_JS || !Array.isArray) {
    Array.isArray = function (obj) {
      return Object.prototype.toString.call(obj) === '[object Array]';
    };
  }

  if (ARRAY_BUFFER && (root.JS_SHA256_NO_ARRAY_BUFFER_IS_VIEW || !ArrayBuffer.isView)) {
    ArrayBuffer.isView = function (obj) {
      return typeof obj === 'object' && obj.buffer && obj.buffer.constructor === ArrayBuffer;
    };
  }

  var createOutputMethod = function (outputType, is224) {
    return function (message) {
      return new Sha256(is224, true).update(message)[outputType]();
    };
  };

  var createMethod = function (is224) {
    var method = createOutputMethod('hex', is224);
    if (NODE_JS) {
      method = nodeWrap(method, is224);
    }
    method.create = function () {
      return new Sha256(is224);
    };
    method.update = function (message) {
      return method.create().update(message);
    };
    for (var i = 0; i < OUTPUT_TYPES.length; ++i) {
      var type = OUTPUT_TYPES[i];
      method[type] = createOutputMethod(type, is224);
    }
    return method;
  };

  var nodeWrap = function (method, is224) {
    var crypto = eval("require('crypto')");
    var Buffer = eval("require('buffer').Buffer");
    var algorithm = is224 ? 'sha224' : 'sha256';
    var nodeMethod = function (message) {
      if (typeof message === 'string') {
        return crypto.createHash(algorithm).update(message, 'utf8').digest('hex');
      } else {
        if (message === null || message === undefined) {
          throw new Error(ERROR);
        } else if (message.constructor === ArrayBuffer) {
          message = new Uint8Array(message);
        }
      }
      if (Array.isArray(message) || ArrayBuffer.isView(message) ||
        message.constructor === Buffer) {
        return crypto.createHash(algorithm).update(new Buffer(message)).digest('hex');
      } else {
        return method(message);
      }
    };
    return nodeMethod;
  };

  var createHmacOutputMethod = function (outputType, is224) {
    return function (key, message) {
      return new HmacSha256(key, is224, true).update(message)[outputType]();
    };
  };

  var createHmacMethod = function (is224) {
    var method = createHmacOutputMethod('hex', is224);
    method.create = function (key) {
      return new HmacSha256(key, is224);
    };
    method.update = function (key, message) {
      return method.create(key).update(message);
    };
    for (var i = 0; i < OUTPUT_TYPES.length; ++i) {
      var type = OUTPUT_TYPES[i];
      method[type] = createHmacOutputMethod(type, is224);
    }
    return method;
  };

  function Sha256(is224, sharedMemory) {
    if (sharedMemory) {
      blocks[0] = blocks[16] = blocks[1] = blocks[2] = blocks[3] =
        blocks[4] = blocks[5] = blocks[6] = blocks[7] =
        blocks[8] = blocks[9] = blocks[10] = blocks[11] =
        blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
      this.blocks = blocks;
    } else {
      this.blocks = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0];
    }

    if (is224) {
      this.h0 = 0xc1059ed8;
      this.h1 = 0x367cd507;
      this.h2 = 0x3070dd17;
      this.h3 = 0xf70e5939;
      this.h4 = 0xffc00b31;
      this.h5 = 0x68581511;
      this.h6 = 0x64f98fa7;
      this.h7 = 0xbefa4fa4;
    } else { // 256
      this.h0 = 0x6a09e667;
      this.h1 = 0xbb67ae85;
      this.h2 = 0x3c6ef372;
      this.h3 = 0xa54ff53a;
      this.h4 = 0x510e527f;
      this.h5 = 0x9b05688c;
      this.h6 = 0x1f83d9ab;
      this.h7 = 0x5be0cd19;
    }

    this.block = this.start = this.bytes = this.hBytes = 0;
    this.finalized = this.hashed = false;
    this.first = true;
    this.is224 = is224;
  }

  Sha256.prototype.update = function (message) {
    if (this.finalized) {
      return;
    }
    var notString, type = typeof message;
    if (type !== 'string') {
      if (type === 'object') {
        if (message === null) {
          throw new Error(ERROR);
        } else if (ARRAY_BUFFER && message.constructor === ArrayBuffer) {
          message = new Uint8Array(message);
        } else if (!Array.isArray(message)) {
          if (!ARRAY_BUFFER || !ArrayBuffer.isView(message)) {
            throw new Error(ERROR);
          }
        }
      } else {
        throw new Error(ERROR);
      }
      notString = true;
    }
    var code, index = 0, i, length = message.length, blocks = this.blocks;

    while (index < length) {
      if (this.hashed) {
        this.hashed = false;
        blocks[0] = this.block;
        blocks[16] = blocks[1] = blocks[2] = blocks[3] =
          blocks[4] = blocks[5] = blocks[6] = blocks[7] =
          blocks[8] = blocks[9] = blocks[10] = blocks[11] =
          blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
      }

      if (notString) {
        for (i = this.start; index < length && i < 64; ++index) {
          blocks[i >> 2] |= message[index] << SHIFT[i++ & 3];
        }
      } else {
        for (i = this.start; index < length && i < 64; ++index) {
          code = message.charCodeAt(index);
          if (code < 0x80) {
            blocks[i >> 2] |= code << SHIFT[i++ & 3];
          } else if (code < 0x800) {
            blocks[i >> 2] |= (0xc0 | (code >> 6)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
          } else if (code < 0xd800 || code >= 0xe000) {
            blocks[i >> 2] |= (0xe0 | (code >> 12)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | ((code >> 6) & 0x3f)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
          } else {
            code = 0x10000 + (((code & 0x3ff) << 10) | (message.charCodeAt(++index) & 0x3ff));
            blocks[i >> 2] |= (0xf0 | (code >> 18)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | ((code >> 12) & 0x3f)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | ((code >> 6) & 0x3f)) << SHIFT[i++ & 3];
            blocks[i >> 2] |= (0x80 | (code & 0x3f)) << SHIFT[i++ & 3];
          }
        }
      }

      this.lastByteIndex = i;
      this.bytes += i - this.start;
      if (i >= 64) {
        this.block = blocks[16];
        this.start = i - 64;
        this.hash();
        this.hashed = true;
      } else {
        this.start = i;
      }
    }
    if (this.bytes > 4294967295) {
      this.hBytes += this.bytes / 4294967296 << 0;
      this.bytes = this.bytes % 4294967296;
    }
    return this;
  };

  Sha256.prototype.finalize = function () {
    if (this.finalized) {
      return;
    }
    this.finalized = true;
    var blocks = this.blocks, i = this.lastByteIndex;
    blocks[16] = this.block;
    blocks[i >> 2] |= EXTRA[i & 3];
    this.block = blocks[16];
    if (i >= 56) {
      if (!this.hashed) {
        this.hash();
      }
      blocks[0] = this.block;
      blocks[16] = blocks[1] = blocks[2] = blocks[3] =
        blocks[4] = blocks[5] = blocks[6] = blocks[7] =
        blocks[8] = blocks[9] = blocks[10] = blocks[11] =
        blocks[12] = blocks[13] = blocks[14] = blocks[15] = 0;
    }
    blocks[14] = this.hBytes << 3 | this.bytes >>> 29;
    blocks[15] = this.bytes << 3;
    this.hash();
  };

  Sha256.prototype.hash = function () {
    var a = this.h0, b = this.h1, c = this.h2, d = this.h3, e = this.h4, f = this.h5, g = this.h6,
      h = this.h7, blocks = this.blocks, j, s0, s1, maj, t1, t2, ch, ab, da, cd, bc;

    for (j = 16; j < 64; ++j) {
      // rightrotate
      t1 = blocks[j - 15];
      s0 = ((t1 >>> 7) | (t1 << 25)) ^ ((t1 >>> 18) | (t1 << 14)) ^ (t1 >>> 3);
      t1 = blocks[j - 2];
      s1 = ((t1 >>> 17) | (t1 << 15)) ^ ((t1 >>> 19) | (t1 << 13)) ^ (t1 >>> 10);
      blocks[j] = blocks[j - 16] + s0 + blocks[j - 7] + s1 << 0;
    }

    bc = b & c;
    for (j = 0; j < 64; j += 4) {
      if (this.first) {
        if (this.is224) {
          ab = 300032;
          t1 = blocks[0] - 1413257819;
          h = t1 - 150054599 << 0;
          d = t1 + 24177077 << 0;
        } else {
          ab = 704751109;
          t1 = blocks[0] - 210244248;
          h = t1 - 1521486534 << 0;
          d = t1 + 143694565 << 0;
        }
        this.first = false;
      } else {
        s0 = ((a >>> 2) | (a << 30)) ^ ((a >>> 13) | (a << 19)) ^ ((a >>> 22) | (a << 10));
        s1 = ((e >>> 6) | (e << 26)) ^ ((e >>> 11) | (e << 21)) ^ ((e >>> 25) | (e << 7));
        ab = a & b;
        maj = ab ^ (a & c) ^ bc;
        ch = (e & f) ^ (~e & g);
        t1 = h + s1 + ch + K[j] + blocks[j];
        t2 = s0 + maj;
        h = d + t1 << 0;
        d = t1 + t2 << 0;
      }
      s0 = ((d >>> 2) | (d << 30)) ^ ((d >>> 13) | (d << 19)) ^ ((d >>> 22) | (d << 10));
      s1 = ((h >>> 6) | (h << 26)) ^ ((h >>> 11) | (h << 21)) ^ ((h >>> 25) | (h << 7));
      da = d & a;
      maj = da ^ (d & b) ^ ab;
      ch = (h & e) ^ (~h & f);
      t1 = g + s1 + ch + K[j + 1] + blocks[j + 1];
      t2 = s0 + maj;
      g = c + t1 << 0;
      c = t1 + t2 << 0;
      s0 = ((c >>> 2) | (c << 30)) ^ ((c >>> 13) | (c << 19)) ^ ((c >>> 22) | (c << 10));
      s1 = ((g >>> 6) | (g << 26)) ^ ((g >>> 11) | (g << 21)) ^ ((g >>> 25) | (g << 7));
      cd = c & d;
      maj = cd ^ (c & a) ^ da;
      ch = (g & h) ^ (~g & e);
      t1 = f + s1 + ch + K[j + 2] + blocks[j + 2];
      t2 = s0 + maj;
      f = b + t1 << 0;
      b = t1 + t2 << 0;
      s0 = ((b >>> 2) | (b << 30)) ^ ((b >>> 13) | (b << 19)) ^ ((b >>> 22) | (b << 10));
      s1 = ((f >>> 6) | (f << 26)) ^ ((f >>> 11) | (f << 21)) ^ ((f >>> 25) | (f << 7));
      bc = b & c;
      maj = bc ^ (b & d) ^ cd;
      ch = (f & g) ^ (~f & h);
      t1 = e + s1 + ch + K[j + 3] + blocks[j + 3];
      t2 = s0 + maj;
      e = a + t1 << 0;
      a = t1 + t2 << 0;
    }

    this.h0 = this.h0 + a << 0;
    this.h1 = this.h1 + b << 0;
    this.h2 = this.h2 + c << 0;
    this.h3 = this.h3 + d << 0;
    this.h4 = this.h4 + e << 0;
    this.h5 = this.h5 + f << 0;
    this.h6 = this.h6 + g << 0;
    this.h7 = this.h7 + h << 0;
  };

  Sha256.prototype.hex = function () {
    this.finalize();

    var h0 = this.h0, h1 = this.h1, h2 = this.h2, h3 = this.h3, h4 = this.h4, h5 = this.h5,
      h6 = this.h6, h7 = this.h7;

    var hex = HEX_CHARS[(h0 >> 28) & 0x0F] + HEX_CHARS[(h0 >> 24) & 0x0F] +
      HEX_CHARS[(h0 >> 20) & 0x0F] + HEX_CHARS[(h0 >> 16) & 0x0F] +
      HEX_CHARS[(h0 >> 12) & 0x0F] + HEX_CHARS[(h0 >> 8) & 0x0F] +
      HEX_CHARS[(h0 >> 4) & 0x0F] + HEX_CHARS[h0 & 0x0F] +
      HEX_CHARS[(h1 >> 28) & 0x0F] + HEX_CHARS[(h1 >> 24) & 0x0F] +
      HEX_CHARS[(h1 >> 20) & 0x0F] + HEX_CHARS[(h1 >> 16) & 0x0F] +
      HEX_CHARS[(h1 >> 12) & 0x0F] + HEX_CHARS[(h1 >> 8) & 0x0F] +
      HEX_CHARS[(h1 >> 4) & 0x0F] + HEX_CHARS[h1 & 0x0F] +
      HEX_CHARS[(h2 >> 28) & 0x0F] + HEX_CHARS[(h2 >> 24) & 0x0F] +
      HEX_CHARS[(h2 >> 20) & 0x0F] + HEX_CHARS[(h2 >> 16) & 0x0F] +
      HEX_CHARS[(h2 >> 12) & 0x0F] + HEX_CHARS[(h2 >> 8) & 0x0F] +
      HEX_CHARS[(h2 >> 4) & 0x0F] + HEX_CHARS[h2 & 0x0F] +
      HEX_CHARS[(h3 >> 28) & 0x0F] + HEX_CHARS[(h3 >> 24) & 0x0F] +
      HEX_CHARS[(h3 >> 20) & 0x0F] + HEX_CHARS[(h3 >> 16) & 0x0F] +
      HEX_CHARS[(h3 >> 12) & 0x0F] + HEX_CHARS[(h3 >> 8) & 0x0F] +
      HEX_CHARS[(h3 >> 4) & 0x0F] + HEX_CHARS[h3 & 0x0F] +
      HEX_CHARS[(h4 >> 28) & 0x0F] + HEX_CHARS[(h4 >> 24) & 0x0F] +
      HEX_CHARS[(h4 >> 20) & 0x0F] + HEX_CHARS[(h4 >> 16) & 0x0F] +
      HEX_CHARS[(h4 >> 12) & 0x0F] + HEX_CHARS[(h4 >> 8) & 0x0F] +
      HEX_CHARS[(h4 >> 4) & 0x0F] + HEX_CHARS[h4 & 0x0F] +
      HEX_CHARS[(h5 >> 28) & 0x0F] + HEX_CHARS[(h5 >> 24) & 0x0F] +
      HEX_CHARS[(h5 >> 20) & 0x0F] + HEX_CHARS[(h5 >> 16) & 0x0F] +
      HEX_CHARS[(h5 >> 12) & 0x0F] + HEX_CHARS[(h5 >> 8) & 0x0F] +
      HEX_CHARS[(h5 >> 4) & 0x0F] + HEX_CHARS[h5 & 0x0F] +
      HEX_CHARS[(h6 >> 28) & 0x0F] + HEX_CHARS[(h6 >> 24) & 0x0F] +
      HEX_CHARS[(h6 >> 20) & 0x0F] + HEX_CHARS[(h6 >> 16) & 0x0F] +
      HEX_CHARS[(h6 >> 12) & 0x0F] + HEX_CHARS[(h6 >> 8) & 0x0F] +
      HEX_CHARS[(h6 >> 4) & 0x0F] + HEX_CHARS[h6 & 0x0F];
    if (!this.is224) {
      hex += HEX_CHARS[(h7 >> 28) & 0x0F] + HEX_CHARS[(h7 >> 24) & 0x0F] +
        HEX_CHARS[(h7 >> 20) & 0x0F] + HEX_CHARS[(h7 >> 16) & 0x0F] +
        HEX_CHARS[(h7 >> 12) & 0x0F] + HEX_CHARS[(h7 >> 8) & 0x0F] +
        HEX_CHARS[(h7 >> 4) & 0x0F] + HEX_CHARS[h7 & 0x0F];
    }
    return hex;
  };

  Sha256.prototype.toString = Sha256.prototype.hex;

  Sha256.prototype.digest = function () {
    this.finalize();

    var h0 = this.h0, h1 = this.h1, h2 = this.h2, h3 = this.h3, h4 = this.h4, h5 = this.h5,
      h6 = this.h6, h7 = this.h7;

    var arr = [
      (h0 >> 24) & 0xFF, (h0 >> 16) & 0xFF, (h0 >> 8) & 0xFF, h0 & 0xFF,
      (h1 >> 24) & 0xFF, (h1 >> 16) & 0xFF, (h1 >> 8) & 0xFF, h1 & 0xFF,
      (h2 >> 24) & 0xFF, (h2 >> 16) & 0xFF, (h2 >> 8) & 0xFF, h2 & 0xFF,
      (h3 >> 24) & 0xFF, (h3 >> 16) & 0xFF, (h3 >> 8) & 0xFF, h3 & 0xFF,
      (h4 >> 24) & 0xFF, (h4 >> 16) & 0xFF, (h4 >> 8) & 0xFF, h4 & 0xFF,
      (h5 >> 24) & 0xFF, (h5 >> 16) & 0xFF, (h5 >> 8) & 0xFF, h5 & 0xFF,
      (h6 >> 24) & 0xFF, (h6 >> 16) & 0xFF, (h6 >> 8) & 0xFF, h6 & 0xFF
    ];
    if (!this.is224) {
      arr.push((h7 >> 24) & 0xFF, (h7 >> 16) & 0xFF, (h7 >> 8) & 0xFF, h7 & 0xFF);
    }
    return arr;
  };

  Sha256.prototype.array = Sha256.prototype.digest;

  Sha256.prototype.arrayBuffer = function () {
    this.finalize();

    var buffer = new ArrayBuffer(this.is224 ? 28 : 32);
    var dataView = new DataView(buffer);
    dataView.setUint32(0, this.h0);
    dataView.setUint32(4, this.h1);
    dataView.setUint32(8, this.h2);
    dataView.setUint32(12, this.h3);
    dataView.setUint32(16, this.h4);
    dataView.setUint32(20, this.h5);
    dataView.setUint32(24, this.h6);
    if (!this.is224) {
      dataView.setUint32(28, this.h7);
    }
    return buffer;
  };

  function HmacSha256(key, is224, sharedMemory) {
    var i, type = typeof key;
    if (type === 'string') {
      var bytes = [], length = key.length, index = 0, code;
      for (i = 0; i < length; ++i) {
        code = key.charCodeAt(i);
        if (code < 0x80) {
          bytes[index++] = code;
        } else if (code < 0x800) {
          bytes[index++] = (0xc0 | (code >> 6));
          bytes[index++] = (0x80 | (code & 0x3f));
        } else if (code < 0xd800 || code >= 0xe000) {
          bytes[index++] = (0xe0 | (code >> 12));
          bytes[index++] = (0x80 | ((code >> 6) & 0x3f));
          bytes[index++] = (0x80 | (code & 0x3f));
        } else {
          code = 0x10000 + (((code & 0x3ff) << 10) | (key.charCodeAt(++i) & 0x3ff));
          bytes[index++] = (0xf0 | (code >> 18));
          bytes[index++] = (0x80 | ((code >> 12) & 0x3f));
          bytes[index++] = (0x80 | ((code >> 6) & 0x3f));
          bytes[index++] = (0x80 | (code & 0x3f));
        }
      }
      key = bytes;
    } else {
      if (type === 'object') {
        if (key === null) {
          throw new Error(ERROR);
        } else if (ARRAY_BUFFER && key.constructor === ArrayBuffer) {
          key = new Uint8Array(key);
        } else if (!Array.isArray(key)) {
          if (!ARRAY_BUFFER || !ArrayBuffer.isView(key)) {
            throw new Error(ERROR);
          }
        }
      } else {
        throw new Error(ERROR);
      }
    }

    if (key.length > 64) {
      key = (new Sha256(is224, true)).update(key).array();
    }

    var oKeyPad = [], iKeyPad = [];
    for (i = 0; i < 64; ++i) {
      var b = key[i] || 0;
      oKeyPad[i] = 0x5c ^ b;
      iKeyPad[i] = 0x36 ^ b;
    }

    Sha256.call(this, is224, sharedMemory);

    this.update(iKeyPad);
    this.oKeyPad = oKeyPad;
    this.inner = true;
    this.sharedMemory = sharedMemory;
  }
  HmacSha256.prototype = new Sha256();

  HmacSha256.prototype.finalize = function () {
    Sha256.prototype.finalize.call(this);
    if (this.inner) {
      this.inner = false;
      var innerHash = this.array();
      Sha256.call(this, this.is224, this.sharedMemory);
      this.update(this.oKeyPad);
      this.update(innerHash);
      Sha256.prototype.finalize.call(this);
    }
  };

  var exports = createMethod();
  exports.sha256 = exports;
  exports.sha224 = createMethod(true);
  exports.sha256.hmac = createHmacMethod();
  exports.sha224.hmac = createHmacMethod(true);

  if (COMMON_JS) {
    module.exports = exports;
  } else {
    root.sha256 = exports.sha256;
    root.sha224 = exports.sha224;
    if (AMD) {
      define(function () {
        return exports;
      });
    }
  }
})();

</script>  
<script>
/**
 * MerkleTree Implementation
 * @version 1.0.0
 * @author Ronny Amarante <me@amaranter.com>
 * https://gist.github.com/amaranter/4c1734fa2ca587a68e8cd9698444647d
 */

//This needs substitution by actual SHA256 function
/*
USAGE
    transaction = ['1', '2', '3', '4','5','6','7','8'],
    tree        = new MerkleTree(transaction);

tree.createTree();
console.log(tree.getOldTransaction());
console.log(tree.getRootHash());
console.log(tree.getHashPathToRoot("3"));

x1 = tree.getHashPathToRoot("5"); //try for all transactions
sha256(x1[5]); //should be equal to Root Hash, and will verify the transaction

*/



function MerkleTree(transactions) {
  this.transactions    = transactions;
  this._oldTransaction = {};
}

MerkleTree.prototype = {

  getOldTransaction: function() { return this._oldTransaction; },

  getRootHash: function() {
    var rootIndex = Object.keys(this._oldTransaction)[Object.keys(this._oldTransaction).length-1]
    return this._oldTransaction[rootIndex]; 
  },

  createTree: function() {
    var transactions = this.transactions,
        temp         = [];

    for (var index = 0; index < this.transactions.length; index += 2) { /** Iterate using 2 step's */
      var transaction_value        = this.transactions[index],
          hash      = { left: '', right: '' },
          position_index   = parseInt(index)+1,
          position_right;

      hash["left"] =  this._oldTransaction[transaction_value] = String(sha256(transaction_value)); /** Apply SHA-256 hash to left pair transaction */
      
      (position_index != this.transactions.length) ? position_right = this.transactions[position_index] : position_right = ''; /** Declare value of right pair */

      if (position_right != '') { /** Verify existence of right pair */
        hash["right"] = String(sha256(position_right)); /** Apply SHA-256 hash to right pair transaction */
        this._oldTransaction[this.transactions[position_index]] = hash["right"] ; /** Persist log */
        temp.push(hash["left"] + hash["right"]); /** Persist merge of both hash's */
      } else {
        temp.push(hash["left"]); /** Persist merge of left pair if donst have right pair */
      }
        
    }

    if (this.transactions.length != 1) {
      this.transactions = temp; /** Store changes of transactions */
      this.createTree(); /** Invoke recursive */
    }

  },

 getHashPathToRoot: function(element){
 
    var myArray = Object.keys(this._oldTransaction);
    var toFind = sha256(element);
    var arrayLength = myArray.length;
    var results = []; 
    results.push(toFind);
    var i = 0;

    while (i < arrayLength) {
  
    if (myArray[i].includes(toFind)) { 
      results.push(myArray[i]); 
      temp1 = sha256(myArray[i]);
      results.push(temp1); 
      toFind = temp1; 

  };
  
  i++;
}

  return results;
 }, 



verifyMerkleMembership: function(element, rootHash, hashPathToRoot){
  
  //By default verification is false
  var verified = false;

  
  //First Test: Hash of element being checked has to be the first element in hashPathToRoot 
  if (!(sha256(element) == hashPathToRoot[0])) { return verified };

  //Second Test .. root hash has to be last element in hashPathToRoot
  if (!(rootHash == hashPathToRoot[hashPathToRoot.length-1])) { return verified };  

  //Third Test: Now all other hashes have to match from initial element to root hash in the path as per hashPathToRoot design
  var i = 1;
  while (i < hashPathToRoot.length-1) {
      if(i%2 == 1){
        //Odd number element must include previous even number element
        if (!(hashPathToRoot[i].includes(hashPathToRoot[i-1]))) { return verified };

        //Hash of odd number element must be same as next even number element
        if (!(sha256(hashPathToRoot[i]) == hashPathToRoot[i+1])){ return verified };
    }
  i=i+2;
  }

  //If all the above tests are passed, verified value can be set to true 
  verified = true ;
  return verified;

}

}

</script>