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✏️ Editing: paperkey.html

<!doctype html>
<html moznomarginboxes mozdisallowselectionprint>
<!--
    Notes:
        This may never cause external network connections. Everything needs to included in this file.
        No minified libraries. Everything needs to be auditable and in preferred form of modification.

This file includes two libraries inline:
            Kazuhiko Arase's qrcode-generator library (unpatched)
            Chris Veness's sha256 implementation (locally modified to utf8Encode)
        Both are MIT licensed.
        As this script doesn’t interact with any untrusted parties / components it should be safe to
        use local embedded copies of these libraries.
-->

<head>
<title>BorgBackup Printable Key Template</title>
<meta http-equiv="Content-Type" content="text/html; charset=Utf-8">
<script>
// https://github.com/kazuhikoarase/qrcode-generator/blob/master/js/qrcode.js
//---------------------------------------------------------------------
//
// QR Code Generator for JavaScript
//
// Copyright (c) 2009 Kazuhiko Arase
//
// URL: http://www.d-project.com/
//
// Licensed under the MIT license:
//  http://www.opensource.org/licenses/mit-license.php
//
// The word 'QR Code' is registered trademark of
// DENSO WAVE INCORPORATED
//  https://www.denso-wave.com/qrcode/faqpatent-e.html
//
//---------------------------------------------------------------------

var qrcode = function() {

//---------------------------------------------------------------------
  // qrcode
  //---------------------------------------------------------------------

/**
   * qrcode
   * @param typeNumber 1 to 40
   * @param errorCorrectionLevel 'L','M','Q','H'
   */
  var qrcode = function(typeNumber, errorCorrectionLevel) {

var PAD0 = 0xEC;
    var PAD1 = 0x11;

var _typeNumber = typeNumber;
    var _errorCorrectionLevel = QRErrorCorrectionLevel[errorCorrectionLevel];
    var _modules = null;
    var _moduleCount = 0;
    var _dataCache = null;
    var _dataList = new Array();

var _this = {};

var makeImpl = function(test, maskPattern) {

_moduleCount = _typeNumber * 4 + 17;
      _modules = function(moduleCount) {
        var modules = new Array(moduleCount);
        for (var row = 0; row < moduleCount; row += 1) {
          modules[row] = new Array(moduleCount);
          for (var col = 0; col < moduleCount; col += 1) {
            modules[row][col] = null;
          }
        }
        return modules;
      }(_moduleCount);

setupPositionProbePattern(0, 0);
      setupPositionProbePattern(_moduleCount - 7, 0);
      setupPositionProbePattern(0, _moduleCount - 7);
      setupPositionAdjustPattern();
      setupTimingPattern();
      setupTypeInfo(test, maskPattern);

if (_typeNumber >= 7) {
        setupTypeNumber(test);
      }

if (_dataCache == null) {
        _dataCache = createData(_typeNumber, _errorCorrectionLevel, _dataList);
      }

mapData(_dataCache, maskPattern);
    };

var setupPositionProbePattern = function(row, col) {

for (var r = -1; r <= 7; r += 1) {

if (row + r <= -1 || _moduleCount <= row + r) continue;

for (var c = -1; c <= 7; c += 1) {

if (col + c <= -1 || _moduleCount <= col + c) continue;

if ( (0 <= r && r <= 6 && (c == 0 || c == 6) )
              || (0 <= c && c <= 6 && (r == 0 || r == 6) )
              || (2 <= r && r <= 4 && 2 <= c && c <= 4) ) {
            _modules[row + r][col + c] = true;
          } else {
            _modules[row + r][col + c] = false;
          }
        }
      }
    };

var getBestMaskPattern = function() {

var minLostPoint = 0;
      var pattern = 0;

for (var i = 0; i < 8; i += 1) {

makeImpl(true, i);

var lostPoint = QRUtil.getLostPoint(_this);

if (i == 0 || minLostPoint > lostPoint) {
          minLostPoint = lostPoint;
          pattern = i;
        }
      }

return pattern;
    };

var setupTimingPattern = function() {

for (var r = 8; r < _moduleCount - 8; r += 1) {
        if (_modules[r][6] != null) {
          continue;
        }
        _modules[r][6] = (r % 2 == 0);
      }

for (var c = 8; c < _moduleCount - 8; c += 1) {
        if (_modules[6][c] != null) {
          continue;
        }
        _modules[6][c] = (c % 2 == 0);
      }
    };

var setupPositionAdjustPattern = function() {

var pos = QRUtil.getPatternPosition(_typeNumber);

for (var i = 0; i < pos.length; i += 1) {

for (var j = 0; j < pos.length; j += 1) {

var row = pos[i];
          var col = pos[j];

if (_modules[row][col] != null) {
            continue;
          }

for (var r = -2; r <= 2; r += 1) {

for (var c = -2; c <= 2; c += 1) {

if (r == -2 || r == 2 || c == -2 || c == 2
                  || (r == 0 && c == 0) ) {
                _modules[row + r][col + c] = true;
              } else {
                _modules[row + r][col + c] = false;
              }
            }
          }
        }
      }
    };

var setupTypeNumber = function(test) {

var bits = QRUtil.getBCHTypeNumber(_typeNumber);

for (var i = 0; i < 18; i += 1) {
        var mod = (!test && ( (bits >> i) & 1) == 1);
        _modules[Math.floor(i / 3)][i % 3 + _moduleCount - 8 - 3] = mod;
      }

for (var i = 0; i < 18; i += 1) {
        var mod = (!test && ( (bits >> i) & 1) == 1);
        _modules[i % 3 + _moduleCount - 8 - 3][Math.floor(i / 3)] = mod;
      }
    };

var setupTypeInfo = function(test, maskPattern) {

var data = (_errorCorrectionLevel << 3) | maskPattern;
      var bits = QRUtil.getBCHTypeInfo(data);

// vertical
      for (var i = 0; i < 15; i += 1) {

var mod = (!test && ( (bits >> i) & 1) == 1);

if (i < 6) {
          _modules[i][8] = mod;
        } else if (i < 8) {
          _modules[i + 1][8] = mod;
        } else {
          _modules[_moduleCount - 15 + i][8] = mod;
        }
      }

// horizontal
      for (var i = 0; i < 15; i += 1) {

var mod = (!test && ( (bits >> i) & 1) == 1);

if (i < 8) {
          _modules[8][_moduleCount - i - 1] = mod;
        } else if (i < 9) {
          _modules[8][15 - i - 1 + 1] = mod;
        } else {
          _modules[8][15 - i - 1] = mod;
        }
      }

// fixed module
      _modules[_moduleCount - 8][8] = (!test);
    };

var mapData = function(data, maskPattern) {

var inc = -1;
      var row = _moduleCount - 1;
      var bitIndex = 7;
      var byteIndex = 0;
      var maskFunc = QRUtil.getMaskFunction(maskPattern);

for (var col = _moduleCount - 1; col > 0; col -= 2) {

if (col == 6) col -= 1;

while (true) {

for (var c = 0; c < 2; c += 1) {

if (_modules[row][col - c] == null) {

var dark = false;

if (byteIndex < data.length) {
                dark = ( ( (data[byteIndex] >>> bitIndex) & 1) == 1);
              }

var mask = maskFunc(row, col - c);

if (mask) {
                dark = !dark;
              }

_modules[row][col - c] = dark;
              bitIndex -= 1;

if (bitIndex == -1) {
                byteIndex += 1;
                bitIndex = 7;
              }
            }
          }

row += inc;

if (row < 0 || _moduleCount <= row) {
            row -= inc;
            inc = -inc;
            break;
          }
        }
      }
    };

var createBytes = function(buffer, rsBlocks) {

var offset = 0;

var maxDcCount = 0;
      var maxEcCount = 0;

var dcdata = new Array(rsBlocks.length);
      var ecdata = new Array(rsBlocks.length);

for (var r = 0; r < rsBlocks.length; r += 1) {

var dcCount = rsBlocks[r].dataCount;
        var ecCount = rsBlocks[r].totalCount - dcCount;

maxDcCount = Math.max(maxDcCount, dcCount);
        maxEcCount = Math.max(maxEcCount, ecCount);

dcdata[r] = new Array(dcCount);

for (var i = 0; i < dcdata[r].length; i += 1) {
          dcdata[r][i] = 0xff & buffer.getBuffer()[i + offset];
        }
        offset += dcCount;

var rsPoly = QRUtil.getErrorCorrectPolynomial(ecCount);
        var rawPoly = qrPolynomial(dcdata[r], rsPoly.getLength() - 1);

var modPoly = rawPoly.mod(rsPoly);
        ecdata[r] = new Array(rsPoly.getLength() - 1);
        for (var i = 0; i < ecdata[r].length; i += 1) {
          var modIndex = i + modPoly.getLength() - ecdata[r].length;
          ecdata[r][i] = (modIndex >= 0)? modPoly.getAt(modIndex) : 0;
        }
      }

var totalCodeCount = 0;
      for (var i = 0; i < rsBlocks.length; i += 1) {
        totalCodeCount += rsBlocks[i].totalCount;
      }

var data = new Array(totalCodeCount);
      var index = 0;

for (var i = 0; i < maxDcCount; i += 1) {
        for (var r = 0; r < rsBlocks.length; r += 1) {
          if (i < dcdata[r].length) {
            data[index] = dcdata[r][i];
            index += 1;
          }
        }
      }

for (var i = 0; i < maxEcCount; i += 1) {
        for (var r = 0; r < rsBlocks.length; r += 1) {
          if (i < ecdata[r].length) {
            data[index] = ecdata[r][i];
            index += 1;
          }
        }
      }

return data;
    };

var createData = function(typeNumber, errorCorrectionLevel, dataList) {

var rsBlocks = QRRSBlock.getRSBlocks(typeNumber, errorCorrectionLevel);

var buffer = qrBitBuffer();

for (var i = 0; i < dataList.length; i += 1) {
        var data = dataList[i];
        buffer.put(data.getMode(), 4);
        buffer.put(data.getLength(), QRUtil.getLengthInBits(data.getMode(), typeNumber) );
        data.write(buffer);
      }

// calc num max data.
      var totalDataCount = 0;
      for (var i = 0; i < rsBlocks.length; i += 1) {
        totalDataCount += rsBlocks[i].dataCount;
      }

if (buffer.getLengthInBits() > totalDataCount * 8) {
        throw new Error('code length overflow. ('
          + buffer.getLengthInBits()
          + '>'
          + totalDataCount * 8
          + ')');
      }

// end code
      if (buffer.getLengthInBits() + 4 <= totalDataCount * 8) {
        buffer.put(0, 4);
      }

// padding
      while (buffer.getLengthInBits() % 8 != 0) {
        buffer.putBit(false);
      }

// padding
      while (true) {

if (buffer.getLengthInBits() >= totalDataCount * 8) {
          break;
        }
        buffer.put(PAD0, 8);

if (buffer.getLengthInBits() >= totalDataCount * 8) {
          break;
        }
        buffer.put(PAD1, 8);
      }

return createBytes(buffer, rsBlocks);
    };

_this.addData = function(data) {
      var newData = qr8BitByte(data);
      _dataList.push(newData);
      _dataCache = null;
    };

_this.isDark = function(row, col) {
      if (row < 0 || _moduleCount <= row || col < 0 || _moduleCount <= col) {
        throw new Error(row + ',' + col);
      }
      return _modules[row][col];
    };

_this.getModuleCount = function() {
      return _moduleCount;
    };

_this.make = function() {
      makeImpl(false, getBestMaskPattern() );
    };

_this.createTableTag = function(cellSize, margin) {

cellSize = cellSize || 2;
      margin = (typeof margin == 'undefined')? cellSize * 4 : margin;

var qrHtml = '';

qrHtml += '<table style="';
      qrHtml += ' border-width: 0px; border-style: none;';
      qrHtml += ' border-collapse: collapse;';
      qrHtml += ' padding: 0px; margin: ' + margin + 'px;';
      qrHtml += '">';
      qrHtml += '<tbody>';

for (var r = 0; r < _this.getModuleCount(); r += 1) {

qrHtml += '<tr>';

for (var c = 0; c < _this.getModuleCount(); c += 1) {
          qrHtml += '<td style="';
          qrHtml += ' border-width: 0px; border-style: none;';
          qrHtml += ' border-collapse: collapse;';
          qrHtml += ' padding: 0px; margin: 0px;';
          qrHtml += ' width: ' + cellSize + 'px;';
          qrHtml += ' height: ' + cellSize + 'px;';
          qrHtml += ' background-color: ';
          qrHtml += _this.isDark(r, c)? '#000000' : '#ffffff';
          qrHtml += ';';
          qrHtml += '"/>';
        }

qrHtml += '</tr>';
      }

qrHtml += '</tbody>';
      qrHtml += '</table>';

return qrHtml;
    };

_this.createSvgTag = function(cellSize, margin) {

cellSize = cellSize || 2;
      margin = (typeof margin == 'undefined')? cellSize * 4 : margin;
      var size = _this.getModuleCount() * cellSize + margin * 2;
      var c, mc, r, mr, qrSvg='', rect;

rect = 'l' + cellSize + ',0 0,' + cellSize +
        ' -' + cellSize + ',0 0,-' + cellSize + 'z ';

qrSvg += '<svg';
      qrSvg += ' width="' + size + 'px"';
      qrSvg += ' height="' + size + 'px"';
      qrSvg += ' xmlns="http://www.w3.org/2000/svg"';
      qrSvg += '>';
      qrSvg += '<path d="';

for (r = 0; r < _this.getModuleCount(); r += 1) {
        mr = r * cellSize + margin;
        for (c = 0; c < _this.getModuleCount(); c += 1) {
          if (_this.isDark(r, c) ) {
            mc = c*cellSize+margin;
            qrSvg += 'M' + mc + ',' + mr + rect;
          }
        }
      }

qrSvg += '" stroke="transparent" fill="black"/>';
      qrSvg += '</svg>';

return qrSvg;
    };

_this.createImgTag = function(cellSize, margin) {

cellSize = cellSize || 2;
      margin = (typeof margin == 'undefined')? cellSize * 4 : margin;

var size = _this.getModuleCount() * cellSize + margin * 2;
      var min = margin;
      var max = size - margin;

return createImgTag(size, size, function(x, y) {
        if (min <= x && x < max && min <= y && y < max) {
          var c = Math.floor( (x - min) / cellSize);
          var r = Math.floor( (y - min) / cellSize);
          return _this.isDark(r, c)? 0 : 1;
        } else {
          return 1;
        }
      } );
    };

return _this;
  };

//---------------------------------------------------------------------
  // qrcode.stringToBytes
  //---------------------------------------------------------------------

qrcode.stringToBytes = function(s) {
    var bytes = new Array();
    for (var i = 0; i < s.length; i += 1) {
      var c = s.charCodeAt(i);
      bytes.push(c & 0xff);
    }
    return bytes;
  };

//---------------------------------------------------------------------
  // qrcode.createStringToBytes
  //---------------------------------------------------------------------

/**
   * @param unicodeData base64 string of byte array.
   * [16bit Unicode],[16bit Bytes], ...
   * @param numChars
   */
  qrcode.createStringToBytes = function(unicodeData, numChars) {

// create conversion map.

var unicodeMap = function() {

var bin = base64DecodeInputStream(unicodeData);
      var read = function() {
        var b = bin.read();
        if (b == -1) throw new Error();
        return b;
      };

return unicodeMap;
    }();

var unknownChar = '?'.charCodeAt(0);

return function(s) {
      var bytes = new Array();
      for (var i = 0; i < s.length; i += 1) {
        var c = s.charCodeAt(i);
        if (c < 128) {
          bytes.push(c);
        } else {
          var b = unicodeMap[s.charAt(i)];
          if (typeof b == 'number') {
            if ( (b & 0xff) == b) {
              // 1byte
              bytes.push(b);
            } else {
              // 2bytes
              bytes.push(b >>> 8);
              bytes.push(b & 0xff);
            }
          } else {
            bytes.push(unknownChar);
          }
        }
      }
      return bytes;
    };
  };

//---------------------------------------------------------------------
  // QRMode
  //---------------------------------------------------------------------

var QRMode = {
    MODE_NUMBER :    1 << 0,
    MODE_ALPHA_NUM : 1 << 1,
    MODE_8BIT_BYTE : 1 << 2,
    MODE_KANJI :     1 << 3
  };

//---------------------------------------------------------------------
  // QRErrorCorrectionLevel
  //---------------------------------------------------------------------

var QRErrorCorrectionLevel = {
    L : 1,
    M : 0,
    Q : 3,
    H : 2
  };

//---------------------------------------------------------------------
  // QRMaskPattern
  //---------------------------------------------------------------------

var QRMaskPattern = {
    PATTERN000 : 0,
    PATTERN001 : 1,
    PATTERN010 : 2,
    PATTERN011 : 3,
    PATTERN100 : 4,
    PATTERN101 : 5,
    PATTERN110 : 6,
    PATTERN111 : 7
  };

//---------------------------------------------------------------------
  // QRUtil
  //---------------------------------------------------------------------

var QRUtil = function() {

var PATTERN_POSITION_TABLE = [
      [],
      [6, 18],
      [6, 22],
      [6, 26],
      [6, 30],
      [6, 34],
      [6, 22, 38],
      [6, 24, 42],
      [6, 26, 46],
      [6, 28, 50],
      [6, 30, 54],
      [6, 32, 58],
      [6, 34, 62],
      [6, 26, 46, 66],
      [6, 26, 48, 70],
      [6, 26, 50, 74],
      [6, 30, 54, 78],
      [6, 30, 56, 82],
      [6, 30, 58, 86],
      [6, 34, 62, 90],
      [6, 28, 50, 72, 94],
      [6, 26, 50, 74, 98],
      [6, 30, 54, 78, 102],
      [6, 28, 54, 80, 106],
      [6, 32, 58, 84, 110],
      [6, 30, 58, 86, 114],
      [6, 34, 62, 90, 118],
      [6, 26, 50, 74, 98, 122],
      [6, 30, 54, 78, 102, 126],
      [6, 26, 52, 78, 104, 130],
      [6, 30, 56, 82, 108, 134],
      [6, 34, 60, 86, 112, 138],
      [6, 30, 58, 86, 114, 142],
      [6, 34, 62, 90, 118, 146],
      [6, 30, 54, 78, 102, 126, 150],
      [6, 24, 50, 76, 102, 128, 154],
      [6, 28, 54, 80, 106, 132, 158],
      [6, 32, 58, 84, 110, 136, 162],
      [6, 26, 54, 82, 110, 138, 166],
      [6, 30, 58, 86, 114, 142, 170]
    ];
    var G15 = (1 << 10) | (1 << 8) | (1 << 5) | (1 << 4) | (1 << 2) | (1 << 1) | (1 << 0);
    var G18 = (1 << 12) | (1 << 11) | (1 << 10) | (1 << 9) | (1 << 8) | (1 << 5) | (1 << 2) | (1 << 0);
    var G15_MASK = (1 << 14) | (1 << 12) | (1 << 10) | (1 << 4) | (1 << 1);

var _this = {};

var getBCHDigit = function(data) {
      var digit = 0;
      while (data != 0) {
        digit += 1;
        data >>>= 1;
      }
      return digit;
    };

_this.getBCHTypeInfo = function(data) {
      var d = data << 10;
      while (getBCHDigit(d) - getBCHDigit(G15) >= 0) {
        d ^= (G15 << (getBCHDigit(d) - getBCHDigit(G15) ) );
      }
      return ( (data << 10) | d) ^ G15_MASK;
    };

_this.getBCHTypeNumber = function(data) {
      var d = data << 12;
      while (getBCHDigit(d) - getBCHDigit(G18) >= 0) {
        d ^= (G18 << (getBCHDigit(d) - getBCHDigit(G18) ) );
      }
      return (data << 12) | d;
    };

_this.getPatternPosition = function(typeNumber) {
      return PATTERN_POSITION_TABLE[typeNumber - 1];
    };

_this.getMaskFunction = function(maskPattern) {

switch (maskPattern) {

case QRMaskPattern.PATTERN000 :
        return function(i, j) { return (i + j) % 2 == 0; };
      case QRMaskPattern.PATTERN001 :
        return function(i, j) { return i % 2 == 0; };
      case QRMaskPattern.PATTERN010 :
        return function(i, j) { return j % 3 == 0; };
      case QRMaskPattern.PATTERN011 :
        return function(i, j) { return (i + j) % 3 == 0; };
      case QRMaskPattern.PATTERN100 :
        return function(i, j) { return (Math.floor(i / 2) + Math.floor(j / 3) ) % 2 == 0; };
      case QRMaskPattern.PATTERN101 :
        return function(i, j) { return (i * j) % 2 + (i * j) % 3 == 0; };
      case QRMaskPattern.PATTERN110 :
        return function(i, j) { return ( (i * j) % 2 + (i * j) % 3) % 2 == 0; };
      case QRMaskPattern.PATTERN111 :
        return function(i, j) { return ( (i * j) % 3 + (i + j) % 2) % 2 == 0; };

default :
        throw new Error('bad maskPattern:' + maskPattern);
      }
    };

_this.getErrorCorrectPolynomial = function(errorCorrectLength) {
      var a = qrPolynomial([1], 0);
      for (var i = 0; i < errorCorrectLength; i += 1) {
        a = a.multiply(qrPolynomial([1, QRMath.gexp(i)], 0) );
      }
      return a;
    };

_this.getLengthInBits = function(mode, type) {

if (1 <= type && type < 10) {

// 1 - 9

switch(mode) {
        case QRMode.MODE_NUMBER    : return 10;
        case QRMode.MODE_ALPHA_NUM : return 9;
        case QRMode.MODE_8BIT_BYTE : return 8;
        case QRMode.MODE_KANJI     : return 8;
        default :
          throw new Error('mode:' + mode);
        }

} else if (type < 27) {

// 10 - 26

switch(mode) {
        case QRMode.MODE_NUMBER    : return 12;
        case QRMode.MODE_ALPHA_NUM : return 11;
        case QRMode.MODE_8BIT_BYTE : return 16;
        case QRMode.MODE_KANJI     : return 10;
        default :
          throw new Error('mode:' + mode);
        }

} else if (type < 41) {

// 27 - 40

switch(mode) {
        case QRMode.MODE_NUMBER    : return 14;
        case QRMode.MODE_ALPHA_NUM : return 13;
        case QRMode.MODE_8BIT_BYTE : return 16;
        case QRMode.MODE_KANJI     : return 12;
        default :
          throw new Error('mode:' + mode);
        }

} else {
        throw new Error('type:' + type);
      }
    };

_this.getLostPoint = function(qrcode) {

var moduleCount = qrcode.getModuleCount();

var lostPoint = 0;

// LEVEL1

for (var row = 0; row < moduleCount; row += 1) {
        for (var col = 0; col < moduleCount; col += 1) {

var sameCount = 0;
          var dark = qrcode.isDark(row, col);

for (var r = -1; r <= 1; r += 1) {

if (row + r < 0 || moduleCount <= row + r) {
              continue;
            }

for (var c = -1; c <= 1; c += 1) {

if (col + c < 0 || moduleCount <= col + c) {
                continue;
              }

if (r == 0 && c == 0) {
                continue;
              }

if (dark == qrcode.isDark(row + r, col + c) ) {
                sameCount += 1;
              }
            }
          }

if (sameCount > 5) {
            lostPoint += (3 + sameCount - 5);
          }
        }
      };

// LEVEL2

for (var row = 0; row < moduleCount - 1; row += 1) {
        for (var col = 0; col < moduleCount - 1; col += 1) {
          var count = 0;
          if (qrcode.isDark(row, col) ) count += 1;
          if (qrcode.isDark(row + 1, col) ) count += 1;
          if (qrcode.isDark(row, col + 1) ) count += 1;
          if (qrcode.isDark(row + 1, col + 1) ) count += 1;
          if (count == 0 || count == 4) {
            lostPoint += 3;
          }
        }
      }

// LEVEL3

for (var row = 0; row < moduleCount; row += 1) {
        for (var col = 0; col < moduleCount - 6; col += 1) {
          if (qrcode.isDark(row, col)
              && !qrcode.isDark(row, col + 1)
              &&  qrcode.isDark(row, col + 2)
              &&  qrcode.isDark(row, col + 3)
              &&  qrcode.isDark(row, col + 4)
              && !qrcode.isDark(row, col + 5)
              &&  qrcode.isDark(row, col + 6) ) {
            lostPoint += 40;
          }
        }
      }

for (var col = 0; col < moduleCount; col += 1) {
        for (var row = 0; row < moduleCount - 6; row += 1) {
          if (qrcode.isDark(row, col)
              && !qrcode.isDark(row + 1, col)
              &&  qrcode.isDark(row + 2, col)
              &&  qrcode.isDark(row + 3, col)
              &&  qrcode.isDark(row + 4, col)
              && !qrcode.isDark(row + 5, col)
              &&  qrcode.isDark(row + 6, col) ) {
            lostPoint += 40;
          }
        }
      }

// LEVEL4

var darkCount = 0;

for (var col = 0; col < moduleCount; col += 1) {
        for (var row = 0; row < moduleCount; row += 1) {
          if (qrcode.isDark(row, col) ) {
            darkCount += 1;
          }
        }
      }

var ratio = Math.abs(100 * darkCount / moduleCount / moduleCount - 50) / 5;
      lostPoint += ratio * 10;

return lostPoint;
    };

return _this;
  }();

//---------------------------------------------------------------------
  // QRMath
  //---------------------------------------------------------------------

var QRMath = function() {

var EXP_TABLE = new Array(256);
    var LOG_TABLE = new Array(256);

// initialize tables
    for (var i = 0; i < 8; i += 1) {
      EXP_TABLE[i] = 1 << i;
    }
    for (var i = 8; i < 256; i += 1) {
      EXP_TABLE[i] = EXP_TABLE[i - 4]
        ^ EXP_TABLE[i - 5]
        ^ EXP_TABLE[i - 6]
        ^ EXP_TABLE[i - 8];
    }
    for (var i = 0; i < 255; i += 1) {
      LOG_TABLE[EXP_TABLE[i] ] = i;
    }

var _this = {};

_this.glog = function(n) {

if (n < 1) {
        throw new Error('glog(' + n + ')');
      }

return LOG_TABLE[n];
    };

_this.gexp = function(n) {

while (n < 0) {
        n += 255;
      }

while (n >= 256) {
        n -= 255;
      }

return EXP_TABLE[n];
    };

return _this;
  }();

//---------------------------------------------------------------------
  // qrPolynomial
  //---------------------------------------------------------------------

function qrPolynomial(num, shift) {

if (typeof num.length == 'undefined') {
      throw new Error(num.length + '/' + shift);
    }

var _this = {};

_this.getAt = function(index) {
      return _num[index];
    };

_this.getLength = function() {
      return _num.length;
    };

_this.multiply = function(e) {

var num = new Array(_this.getLength() + e.getLength() - 1);

for (var i = 0; i < _this.getLength(); i += 1) {
        for (var j = 0; j < e.getLength(); j += 1) {
          num[i + j] ^= QRMath.gexp(QRMath.glog(_this.getAt(i) ) + QRMath.glog(e.getAt(j) ) );
        }
      }

return qrPolynomial(num, 0);
    };

_this.mod = function(e) {

if (_this.getLength() - e.getLength() < 0) {
        return _this;
      }

var ratio = QRMath.glog(_this.getAt(0) ) - QRMath.glog(e.getAt(0) );

var num = new Array(_this.getLength() );
      for (var i = 0; i < _this.getLength(); i += 1) {
        num[i] = _this.getAt(i);
      }

for (var i = 0; i < e.getLength(); i += 1) {
        num[i] ^= QRMath.gexp(QRMath.glog(e.getAt(i) ) + ratio);
      }

// recursive call
      return qrPolynomial(num, 0).mod(e);
    };

return _this;
  };

//---------------------------------------------------------------------
  // QRRSBlock
  //---------------------------------------------------------------------

var QRRSBlock = function() {

var RS_BLOCK_TABLE = [

// L
      // M
      // Q
      // H

// 1
      [1, 26, 19],
      [1, 26, 16],
      [1, 26, 13],
      [1, 26, 9],

// 2
      [1, 44, 34],
      [1, 44, 28],
      [1, 44, 22],
      [1, 44, 16],

// 3
      [1, 70, 55],
      [1, 70, 44],
      [2, 35, 17],
      [2, 35, 13],

// 4
      [1, 100, 80],
      [2, 50, 32],
      [2, 50, 24],
      [4, 25, 9],

// 5
      [1, 134, 108],
      [2, 67, 43],
      [2, 33, 15, 2, 34, 16],
      [2, 33, 11, 2, 34, 12],

// 6
      [2, 86, 68],
      [4, 43, 27],
      [4, 43, 19],
      [4, 43, 15],

// 7
      [2, 98, 78],
      [4, 49, 31],
      [2, 32, 14, 4, 33, 15],
      [4, 39, 13, 1, 40, 14],

// 8
      [2, 121, 97],
      [2, 60, 38, 2, 61, 39],
      [4, 40, 18, 2, 41, 19],
      [4, 40, 14, 2, 41, 15],

// 9
      [2, 146, 116],
      [3, 58, 36, 2, 59, 37],
      [4, 36, 16, 4, 37, 17],
      [4, 36, 12, 4, 37, 13],

// 10
      [2, 86, 68, 2, 87, 69],
      [4, 69, 43, 1, 70, 44],
      [6, 43, 19, 2, 44, 20],
      [6, 43, 15, 2, 44, 16],

// 11
      [4, 101, 81],
      [1, 80, 50, 4, 81, 51],
      [4, 50, 22, 4, 51, 23],
      [3, 36, 12, 8, 37, 13],

// 12
      [2, 116, 92, 2, 117, 93],
      [6, 58, 36, 2, 59, 37],
      [4, 46, 20, 6, 47, 21],
      [7, 42, 14, 4, 43, 15],

// 13
      [4, 133, 107],
      [8, 59, 37, 1, 60, 38],
      [8, 44, 20, 4, 45, 21],
      [12, 33, 11, 4, 34, 12],

// 14
      [3, 145, 115, 1, 146, 116],
      [4, 64, 40, 5, 65, 41],
      [11, 36, 16, 5, 37, 17],
      [11, 36, 12, 5, 37, 13],

// 15
      [5, 109, 87, 1, 110, 88],
      [5, 65, 41, 5, 66, 42],
      [5, 54, 24, 7, 55, 25],
      [11, 36, 12, 7, 37, 13],

// 16
      [5, 122, 98, 1, 123, 99],
      [7, 73, 45, 3, 74, 46],
      [15, 43, 19, 2, 44, 20],
      [3, 45, 15, 13, 46, 16],

// 17
      [1, 135, 107, 5, 136, 108],
      [10, 74, 46, 1, 75, 47],
      [1, 50, 22, 15, 51, 23],
      [2, 42, 14, 17, 43, 15],

// 18
      [5, 150, 120, 1, 151, 121],
      [9, 69, 43, 4, 70, 44],
      [17, 50, 22, 1, 51, 23],
      [2, 42, 14, 19, 43, 15],

// 19
      [3, 141, 113, 4, 142, 114],
      [3, 70, 44, 11, 71, 45],
      [17, 47, 21, 4, 48, 22],
      [9, 39, 13, 16, 40, 14],

// 20
      [3, 135, 107, 5, 136, 108],
      [3, 67, 41, 13, 68, 42],
      [15, 54, 24, 5, 55, 25],
      [15, 43, 15, 10, 44, 16],

// 21
      [4, 144, 116, 4, 145, 117],
      [17, 68, 42],
      [17, 50, 22, 6, 51, 23],
      [19, 46, 16, 6, 47, 17],

// 22
      [2, 139, 111, 7, 140, 112],
      [17, 74, 46],
      [7, 54, 24, 16, 55, 25],
      [34, 37, 13],

// 23
      [4, 151, 121, 5, 152, 122],
      [4, 75, 47, 14, 76, 48],
      [11, 54, 24, 14, 55, 25],
      [16, 45, 15, 14, 46, 16],

// 24
      [6, 147, 117, 4, 148, 118],
      [6, 73, 45, 14, 74, 46],
      [11, 54, 24, 16, 55, 25],
      [30, 46, 16, 2, 47, 17],

// 25
      [8, 132, 106, 4, 133, 107],
      [8, 75, 47, 13, 76, 48],
      [7, 54, 24, 22, 55, 25],
      [22, 45, 15, 13, 46, 16],

// 26
      [10, 142, 114, 2, 143, 115],
      [19, 74, 46, 4, 75, 47],
      [28, 50, 22, 6, 51, 23],
      [33, 46, 16, 4, 47, 17],

// 27
      [8, 152, 122, 4, 153, 123],
      [22, 73, 45, 3, 74, 46],
      [8, 53, 23, 26, 54, 24],
      [12, 45, 15, 28, 46, 16],

// 28
      [3, 147, 117, 10, 148, 118],
      [3, 73, 45, 23, 74, 46],
      [4, 54, 24, 31, 55, 25],
      [11, 45, 15, 31, 46, 16],

// 29
      [7, 146, 116, 7, 147, 117],
      [21, 73, 45, 7, 74, 46],
      [1, 53, 23, 37, 54, 24],
      [19, 45, 15, 26, 46, 16],

// 30
      [5, 145, 115, 10, 146, 116],
      [19, 75, 47, 10, 76, 48],
      [15, 54, 24, 25, 55, 25],
      [23, 45, 15, 25, 46, 16],

// 31
      [13, 145, 115, 3, 146, 116],
      [2, 74, 46, 29, 75, 47],
      [42, 54, 24, 1, 55, 25],
      [23, 45, 15, 28, 46, 16],

// 32
      [17, 145, 115],
      [10, 74, 46, 23, 75, 47],
      [10, 54, 24, 35, 55, 25],
      [19, 45, 15, 35, 46, 16],

// 33
      [17, 145, 115, 1, 146, 116],
      [14, 74, 46, 21, 75, 47],
      [29, 54, 24, 19, 55, 25],
      [11, 45, 15, 46, 46, 16],

// 34
      [13, 145, 115, 6, 146, 116],
      [14, 74, 46, 23, 75, 47],
      [44, 54, 24, 7, 55, 25],
      [59, 46, 16, 1, 47, 17],

// 35
      [12, 151, 121, 7, 152, 122],
      [12, 75, 47, 26, 76, 48],
      [39, 54, 24, 14, 55, 25],
      [22, 45, 15, 41, 46, 16],

// 36
      [6, 151, 121, 14, 152, 122],
      [6, 75, 47, 34, 76, 48],
      [46, 54, 24, 10, 55, 25],
      [2, 45, 15, 64, 46, 16],

// 37
      [17, 152, 122, 4, 153, 123],
      [29, 74, 46, 14, 75, 47],
      [49, 54, 24, 10, 55, 25],
      [24, 45, 15, 46, 46, 16],

// 38
      [4, 152, 122, 18, 153, 123],
      [13, 74, 46, 32, 75, 47],
      [48, 54, 24, 14, 55, 25],
      [42, 45, 15, 32, 46, 16],

// 39
      [20, 147, 117, 4, 148, 118],
      [40, 75, 47, 7, 76, 48],
      [43, 54, 24, 22, 55, 25],
      [10, 45, 15, 67, 46, 16],

// 40
      [19, 148, 118, 6, 149, 119],
      [18, 75, 47, 31, 76, 48],
      [34, 54, 24, 34, 55, 25],
      [20, 45, 15, 61, 46, 16]
    ];

var qrRSBlock = function(totalCount, dataCount) {
      var _this = {};
      _this.totalCount = totalCount;
      _this.dataCount = dataCount;
      return _this;
    };

var _this = {};

var getRsBlockTable = function(typeNumber, errorCorrectionLevel) {

switch(errorCorrectionLevel) {
      case QRErrorCorrectionLevel.L :
        return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 0];
      case QRErrorCorrectionLevel.M :
        return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 1];
      case QRErrorCorrectionLevel.Q :
        return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 2];
      case QRErrorCorrectionLevel.H :
        return RS_BLOCK_TABLE[(typeNumber - 1) * 4 + 3];
      default :
        return undefined;
      }
    };

_this.getRSBlocks = function(typeNumber, errorCorrectionLevel) {

var rsBlock = getRsBlockTable(typeNumber, errorCorrectionLevel);

if (typeof rsBlock == 'undefined') {
        throw new Error('bad rs block @ typeNumber:' + typeNumber +
            '/errorCorrectionLevel:' + errorCorrectionLevel);
      }

var length = rsBlock.length / 3;

var list = new Array();

for (var i = 0; i < length; i += 1) {

var count = rsBlock[i * 3 + 0];
        var totalCount = rsBlock[i * 3 + 1];
        var dataCount = rsBlock[i * 3 + 2];

for (var j = 0; j < count; j += 1) {
          list.push(qrRSBlock(totalCount, dataCount) );
        }
      }

return list;
    };

return _this;
  }();

//---------------------------------------------------------------------
  // qrBitBuffer
  //---------------------------------------------------------------------

var qrBitBuffer = function() {

var _buffer = new Array();
    var _length = 0;

var _this = {};

_this.getBuffer = function() {
      return _buffer;
    };

_this.getAt = function(index) {
      var bufIndex = Math.floor(index / 8);
      return ( (_buffer[bufIndex] >>> (7 - index % 8) ) & 1) == 1;
    };

_this.put = function(num, length) {
      for (var i = 0; i < length; i += 1) {
        _this.putBit( ( (num >>> (length - i - 1) ) & 1) == 1);
      }
    };

_this.getLengthInBits = function() {
      return _length;
    };

_this.putBit = function(bit) {

var bufIndex = Math.floor(_length / 8);
      if (_buffer.length <= bufIndex) {
        _buffer.push(0);
      }

if (bit) {
        _buffer[bufIndex] |= (0x80 >>> (_length % 8) );
      }

_length += 1;
    };

return _this;
  };

//---------------------------------------------------------------------
  // qr8BitByte
  //---------------------------------------------------------------------

var qr8BitByte = function(data) {

var _mode = QRMode.MODE_8BIT_BYTE;
    var _data = data;
    var _bytes = qrcode.stringToBytes(data);

var _this = {};

_this.getMode = function() {
      return _mode;
    };

_this.getLength = function(buffer) {
      return _bytes.length;
    };

_this.write = function(buffer) {
      for (var i = 0; i < _bytes.length; i += 1) {
        buffer.put(_bytes[i], 8);
      }
    };

return _this;
  };

//=====================================================================
  // GIF Support etc.
  //

//---------------------------------------------------------------------
  // byteArrayOutputStream
  //---------------------------------------------------------------------

var byteArrayOutputStream = function() {

var _bytes = new Array();

var _this = {};

_this.writeByte = function(b) {
      _bytes.push(b & 0xff);
    };

_this.writeShort = function(i) {
      _this.writeByte(i);
      _this.writeByte(i >>> 8);
    };

_this.writeBytes = function(b, off, len) {
      off = off || 0;
      len = len || b.length;
      for (var i = 0; i < len; i += 1) {
        _this.writeByte(b[i + off]);
      }
    };

_this.writeString = function(s) {
      for (var i = 0; i < s.length; i += 1) {
        _this.writeByte(s.charCodeAt(i) );
      }
    };

_this.toByteArray = function() {
      return _bytes;
    };

_this.toString = function() {
      var s = '';
      s += '[';
      for (var i = 0; i < _bytes.length; i += 1) {
        if (i > 0) {
          s += ',';
        }
        s += _bytes[i];
      }
      s += ']';
      return s;
    };

return _this;
  };

//---------------------------------------------------------------------
  // base64EncodeOutputStream
  //---------------------------------------------------------------------

var base64EncodeOutputStream = function() {

var _buffer = 0;
    var _buflen = 0;
    var _length = 0;
    var _base64 = '';

var _this = {};

var writeEncoded = function(b) {
      _base64 += String.fromCharCode(encode(b & 0x3f) );
    };

_this.writeByte = function(n) {

_buffer = (_buffer << 8) | (n & 0xff);
      _buflen += 8;
      _length += 1;

while (_buflen >= 6) {
        writeEncoded(_buffer >>> (_buflen - 6) );
        _buflen -= 6;
      }
    };

_this.flush = function() {

if (_buflen > 0) {
        writeEncoded(_buffer << (6 - _buflen) );
        _buffer = 0;
        _buflen = 0;
      }

if (_length % 3 != 0) {
        // padding
        var padlen = 3 - _length % 3;
        for (var i = 0; i < padlen; i += 1) {
          _base64 += '=';
        }
      }
    };

_this.toString = function() {
      return _base64;
    };

return _this;
  };

//---------------------------------------------------------------------
  // base64DecodeInputStream
  //---------------------------------------------------------------------

var base64DecodeInputStream = function(str) {

var _str = str;
    var _pos = 0;
    var _buffer = 0;
    var _buflen = 0;

var _this = {};

_this.read = function() {

while (_buflen < 8) {

if (_pos >= _str.length) {
          if (_buflen == 0) {
            return -1;
          }
          throw new Error('unexpected end of file./' + _buflen);
        }

var c = _str.charAt(_pos);
        _pos += 1;

if (c == '=') {
          _buflen = 0;
          return -1;
        } else if (c.match(/^\s$/) ) {
          // ignore if whitespace.
          continue;
        }

_buffer = (_buffer << 6) | decode(c.charCodeAt(0) );
        _buflen += 6;
      }

var n = (_buffer >>> (_buflen - 8) ) & 0xff;
      _buflen -= 8;
      return n;
    };

return _this;
  };

//---------------------------------------------------------------------
  // gifImage (B/W)
  //---------------------------------------------------------------------

var gifImage = function(width, height) {

var _width = width;
    var _height = height;
    var _data = new Array(width * height);

var _this = {};

_this.setPixel = function(x, y, pixel) {
      _data[y * _width + x] = pixel;
    };

_this.write = function(out) {

//---------------------------------
      // GIF Signature

out.writeString('GIF87a');

//---------------------------------
      // Screen Descriptor

out.writeShort(_width);
      out.writeShort(_height);

out.writeByte(0x80); // 2bit
      out.writeByte(0);
      out.writeByte(0);

//---------------------------------
      // Global Color Map

// black
      out.writeByte(0x00);
      out.writeByte(0x00);
      out.writeByte(0x00);

// white
      out.writeByte(0xff);
      out.writeByte(0xff);
      out.writeByte(0xff);

//---------------------------------
      // Image Descriptor

out.writeString(',');
      out.writeShort(0);
      out.writeShort(0);
      out.writeShort(_width);
      out.writeShort(_height);
      out.writeByte(0);

//---------------------------------
      // Local Color Map

//---------------------------------
      // Raster Data

var lzwMinCodeSize = 2;
      var raster = getLZWRaster(lzwMinCodeSize);

out.writeByte(lzwMinCodeSize);

var offset = 0;

while (raster.length - offset > 255) {
        out.writeByte(255);
        out.writeBytes(raster, offset, 255);
        offset += 255;
      }

out.writeByte(raster.length - offset);
      out.writeBytes(raster, offset, raster.length - offset);
      out.writeByte(0x00);

//---------------------------------
      // GIF Terminator
      out.writeString(';');
    };

var bitOutputStream = function(out) {

var _out = out;
      var _bitLength = 0;
      var _bitBuffer = 0;

var _this = {};

_this.write = function(data, length) {

if ( (data >>> length) != 0) {
          throw new Error('length over');
        }

while (_bitLength + length >= 8) {
          _out.writeByte(0xff & ( (data << _bitLength) | _bitBuffer) );
          length -= (8 - _bitLength);
          data >>>= (8 - _bitLength);
          _bitBuffer = 0;
          _bitLength = 0;
        }

_bitBuffer = (data << _bitLength) | _bitBuffer;
        _bitLength = _bitLength + length;
      };

_this.flush = function() {
        if (_bitLength > 0) {
          _out.writeByte(_bitBuffer);
        }
      };

return _this;
    };

var getLZWRaster = function(lzwMinCodeSize) {

var clearCode = 1 << lzwMinCodeSize;
      var endCode = (1 << lzwMinCodeSize) + 1;
      var bitLength = lzwMinCodeSize + 1;

// Setup LZWTable
      var table = lzwTable();

for (var i = 0; i < clearCode; i += 1) {
        table.add(String.fromCharCode(i) );
      }
      table.add(String.fromCharCode(clearCode) );
      table.add(String.fromCharCode(endCode) );

var byteOut = byteArrayOutputStream();
      var bitOut = bitOutputStream(byteOut);

// clear code
      bitOut.write(clearCode, bitLength);

var dataIndex = 0;

var s = String.fromCharCode(_data[dataIndex]);
      dataIndex += 1;

while (dataIndex < _data.length) {

var c = String.fromCharCode(_data[dataIndex]);
        dataIndex += 1;

if (table.contains(s + c) ) {

s = s + c;

} else {

bitOut.write(table.indexOf(s), bitLength);

if (table.size() < 0xfff) {

if (table.size() == (1 << bitLength) ) {
              bitLength += 1;
            }

table.add(s + c);
          }

s = c;
        }
      }

bitOut.write(table.indexOf(s), bitLength);

// end code
      bitOut.write(endCode, bitLength);

bitOut.flush();

return byteOut.toByteArray();
    };

var lzwTable = function() {

var _map = {};
      var _size = 0;

var _this = {};

_this.add = function(key) {
        if (_this.contains(key) ) {
          throw new Error('dup key:' + key);
        }
        _map[key] = _size;
        _size += 1;
      };

_this.size = function() {
        return _size;
      };

_this.indexOf = function(key) {
        return _map[key];
      };

_this.contains = function(key) {
        return typeof _map[key] != 'undefined';
      };

return _this;
    };

return _this;
  };

var createImgTag = function(width, height, getPixel, alt) {

var gif = gifImage(width, height);
    for (var y = 0; y < height; y += 1) {
      for (var x = 0; x < width; x += 1) {
        gif.setPixel(x, y, getPixel(x, y) );
      }
    }

var b = byteArrayOutputStream();
    gif.write(b);

var base64 = base64EncodeOutputStream();
    var bytes = b.toByteArray();
    for (var i = 0; i < bytes.length; i += 1) {
      base64.writeByte(bytes[i]);
    }
    base64.flush();

var img = '';
    img += '<img';
    img += '\u0020src="';
    img += 'data:image/gif;base64,';
    img += base64;
    img += '"';
    img += '\u0020width="';
    img += width;
    img += '"';
    img += '\u0020height="';
    img += height;
    img += '"';
    if (alt) {
      img += '\u0020alt="';
      img += alt;
      img += '"';
    }
    img += '/>';

return img;
  };

//---------------------------------------------------------------------
  // returns qrcode function.

return qrcode;
}();

/* jshint node:true *//* global define, escape, unescape */
'use strict';

/**
 * SHA-256 hash function reference implementation.
 *
 * @namespace
 */
var Sha256 = {};

/**
 * Generates SHA-256 hash of string.
 *
 * @param   {string} msg - String to be hashed
 * @returns {string} Hash of msg as hex character string
 */
Sha256.hash = function(msg) {
    // convert string to UTF-8, as SHA only deals with byte-streams
    //msg = msg.utf8Encode();

// constants [§4.2.2]
    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 ];
    // initial hash value [§5.3.1]
    var H = [
        0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 ];

// PREPROCESSING

msg += String.fromCharCode(0x80);  // add trailing '1' bit (+ 0's padding) to string [§5.1.1]

// convert string msg into 512-bit/16-integer blocks arrays of ints [§5.2.1]
    var l = msg.length/4 + 2; // length (in 32-bit integers) of msg + ‘1’ + appended length
    var N = Math.ceil(l/16);  // number of 16-integer-blocks required to hold 'l' ints
    var M = new Array(N);

for (var i=0; i<N; i++) {
        M[i] = new Array(16);
        for (var j=0; j<16; j++) {  // encode 4 chars per integer, big-endian encoding
            M[i][j] = (msg.charCodeAt(i*64+j*4)<<24) | (msg.charCodeAt(i*64+j*4+1)<<16) |
                      (msg.charCodeAt(i*64+j*4+2)<<8) | (msg.charCodeAt(i*64+j*4+3));
        } // note running off the end of msg is ok 'cos bitwise ops on NaN return 0
    }
    // add length (in bits) into final pair of 32-bit integers (big-endian) [§5.1.1]
    // note: most significant word would be (len-1)*8 >>> 32, but since JS converts
    // bitwise-op args to 32 bits, we need to simulate this by arithmetic operators
    M[N-1][14] = ((msg.length-1)*8) / Math.pow(2, 32); M[N-1][14] = Math.floor(M[N-1][14]);
    M[N-1][15] = ((msg.length-1)*8) & 0xffffffff;

// HASH COMPUTATION [§6.1.2]

var W = new Array(64); var a, b, c, d, e, f, g, h;
    for (var i=0; i<N; i++) {

// 1 - prepare message schedule 'W'
        for (var t=0;  t<16; t++) W[t] = M[i][t];
        for (var t=16; t<64; t++) W[t] = (Sha256.σ1(W[t-2]) + W[t-7] + Sha256.σ0(W[t-15]) + W[t-16]) & 0xffffffff;

// 2 - initialise working variables a, b, c, d, e, f, g, h with previous hash value
        a = H[0]; b = H[1]; c = H[2]; d = H[3]; e = H[4]; f = H[5]; g = H[6]; h = H[7];

// 3 - main loop (note 'addition modulo 2^32')
        for (var t=0; t<64; t++) {
            var T1 = h + Sha256.Σ1(e) + Sha256.Ch(e, f, g) + K[t] + W[t];
            var T2 =     Sha256.Σ0(a) + Sha256.Maj(a, b, c);
            h = g;
            g = f;
            f = e;
            e = (d + T1) & 0xffffffff;
            d = c;
            c = b;
            b = a;
            a = (T1 + T2) & 0xffffffff;
        }
         // 4 - compute the new intermediate hash value (note 'addition modulo 2^32')
        H[0] = (H[0]+a) & 0xffffffff;
        H[1] = (H[1]+b) & 0xffffffff;
        H[2] = (H[2]+c) & 0xffffffff;
        H[3] = (H[3]+d) & 0xffffffff;
        H[4] = (H[4]+e) & 0xffffffff;
        H[5] = (H[5]+f) & 0xffffffff;
        H[6] = (H[6]+g) & 0xffffffff;
        H[7] = (H[7]+h) & 0xffffffff;
    }

return Sha256.toHexStr(H[0]) + Sha256.toHexStr(H[1]) + Sha256.toHexStr(H[2]) + Sha256.toHexStr(H[3]) +
           Sha256.toHexStr(H[4]) + Sha256.toHexStr(H[5]) + Sha256.toHexStr(H[6]) + Sha256.toHexStr(H[7]);
};

/**
 * Rotates right (circular right shift) value x by n positions [§3.2.4].
 * @private
 */
Sha256.ROTR = function(n, x) {
    return (x >>> n) | (x << (32-n));
};

/**
 * Logical functions [§4.1.2].
 * @private
 */
Sha256.Σ0  = function(x) { return Sha256.ROTR(2,  x) ^ Sha256.ROTR(13, x) ^ Sha256.ROTR(22, x); };
Sha256.Σ1  = function(x) { return Sha256.ROTR(6,  x) ^ Sha256.ROTR(11, x) ^ Sha256.ROTR(25, x); };
Sha256.σ0  = function(x) { return Sha256.ROTR(7,  x) ^ Sha256.ROTR(18, x) ^ (x>>>3);  };
Sha256.σ1  = function(x) { return Sha256.ROTR(17, x) ^ Sha256.ROTR(19, x) ^ (x>>>10); };
Sha256.Ch  = function(x, y, z) { return (x & y) ^ (~x & z); };
Sha256.Maj = function(x, y, z) { return (x & y) ^ (x & z) ^ (y & z); };

/**
 * Hexadecimal representation of a number.
 * @private
 */
Sha256.toHexStr = function(n) {
    // note can't use toString(16) as it is implementation-dependent,
    // and in IE returns signed numbers when used on full words
    var s="", v;
    for (var i=7; i>=0; i--) { v = (n>>>(i*4)) & 0xf; s += v.toString(16); }
    return s;
};

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */

/** Extend String object with method to encode multi-byte string to utf8
 *  - monsur.hossa.in/2012/07/20/utf-8-in-javascript.html */
if (typeof String.prototype.utf8Encode == 'undefined') {
    String.prototype.utf8Encode = function() {
        return unescape( encodeURIComponent( this ) );
    };
}

/** Extend String object with method to decode utf8 string to multi-byte */
if (typeof String.prototype.utf8Decode == 'undefined') {
    String.prototype.utf8Decode = function() {
        try {
            return decodeURIComponent( escape( this ) );
        } catch (e) {
            return this; // invalid UTF-8? return as-is
        }
    };
}

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -  */
if (typeof module != 'undefined' && module.exports) module.exports = Sha256; // CommonJs export
if (typeof define == 'function' && define.amd) define([], function() { return Sha256; }); // AMD
</script>
<style>

#typein {
        position: absolute;
        font-family: monospace;
        font-size: 10mm;
        transform-origin: 0 0;
        white-space: pre;
    }

.columns2 {
        -moz-column-count: 2;
        -webkit-column-count: 2;
        column-count: 2;
        -webkit-column-rule: 4mm outset #ddd;
        -moz-column-rule: 4mm outset #ddd;
        column-rule: 4mm outset #ddd;
    }

#title {
        font-size: 6mm;
    }

.placeholder {
        color: #ddd;
    }

@media print {
        @page {
            margin: 0mm; /* disable url etc headers and footers (e.g. chrome, newer firefox) */
        }

html {
            margin: 15mm 20mm;
            padding: 0px;
        }
        * {
            -webkit-print-color-adjust: exact;
        }

#settings {
            display: none;
        }

#printout, body {
            margin: 0px;
            padding: 0px;
        }

#lowermargin {
            display: none;
        }

}

@media screen, projection {
        *[contenteditable] {
            cursor: pointer;
            border: 1px dotted #A4DDED;
        }
        *[contenteditable]:hover,
        *[contenteditable]:focus {
            background: #DEF;
            box-shadow: 0 0 1em 0.5em #DEF;
        }

html {
            background: #999;
            padding: 0.5in;
        }

#settings {
            box-sizing: border-box;
            margin: 0 auto;
            background: #FFF;
            border-radius: 1px;
            box-shadow: 0 0 1in -0.25in rgba(0, 0, 0, 0.5);

margin-bottom: 2cm;
            padding: 10px;
        }

.block {
            display: inline-block;
            vertical-align: top;
        }

.label {
            display: inline-block;
            min-width: 50mm;
        }

#keyfile, #keyfile_expander {
            min-width: 140mm;
        }

.instructions {
            max-width: 140mm;
            padding-bottom: 1rem;
        }

#fileinput {
            display: none;
        }

#printout {
            box-sizing: border-box;
            height: 279mm; /* smallest of US Letter */
            width: 210mm; /* and DIN/ISO A4 */
            /*height: 297mm; use this for real A4 */
            margin: 0 auto;
            overflow: hidden;
            padding: 15mm 20mm 0mm 20mm;
            background: #FFF;
            border-radius: 1px;
            box-shadow: 0 0 1in -0.25in rgba(0, 0, 0, 0.5);
        }

#lowermargin {
            height: 15mm;
        }
    }

/* center the QR code on the page */
    #qr {
      width: 100%;
      text-align: center;
    }
</style>
</head>
<body>
    <div id="settings">
        <div class="instructions">
           <p>To create a printable key, either paste the contents of your keyfile or a key export in the text field
           below, or select a key export file.</p>
           <p>To create a key export use <pre>borg key export /path/to/repository exportfile.txt</pre></p>
           <p>If you are using keyfile mode, keyfiles are usually stored in $HOME/.config/borg/keys/</p>
           <p>You can edit the parts with light blue border in the print preview below by click into them.</p>
           <p>Key security: This print template will never send anything to remote servers. But keep in mind, that printing
              might involve computers that can store the printed image, for example with cloud printing services, or
              networked printers.<p>
        </div>
        <div class="block">
            <div id="keyfile_expander" style="display:none;"><a href="#" onclick="document.getElementById('keyfile').style.display='inline';document.getElementById('keyfile_expander').style.display='none';">show keyfile</a></div>
            <textarea id="keyfile" rows="10" cols="73"></textarea>
        </div>
        <div class="block">
            <span class="label">QR error correction:</span>
            <select id="errorCorrectionLevel" name="e">
                <option value="L">7% (L)</option>
                <option value="M">15% (M)</option>
                <option value="Q">25% (Q)</option>
                <option value="H" selected="selected">30% (H)</option>
            </select><br>
            <span class="label">QR code size</span><input type="range" id="qrsize" min="45" max="157" value="100"><br>
            <span class="label">Text size</span><input type="range" id="textsize" min="1" max="60" value="27"><br>
            <span class="label">Text columns</span>
            <select id="cols">
                <option value="1">1</option>
                <option value="2" selected="selected">2</option>
            </select><br>

</div>
        <div>
            <input type="file" id="fileinput"/>
            <input type="button" value="update" onclick="update()"/>
        </div>
    </div>

<div id="printout">
        <div id="title" contenteditable>BorgBackup Printable Key Backup</div>
        <div contenteditable>To restore either scan the QR code below, decode it and import it using
<pre>borg key import /path/to/repo scannedfile</pre>

Or run
<pre>borg key import --paper /path/to/repo</pre> and type in the text below.<br><br></div>
        <div id="typein"></div>
        <div id="spacer"></div>
        <div id="qr"></div>
        <div contenteditable>Notes:</div>
        <div id="lowermargin"></div>
    </div>

function placeholder_qrcode() {
    return '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 194 194" width="170mm" height="170mm">' +
                '<path d="m 186,8 0,14 -14,0 0,-14 m 12,12 0,-10 -10,0 0,10 m -162,-8 0,6 6,0 0,-6 m 164,6 -6,0 0,-6 6,0 z M 10,10 20,10 20,20 10,20 M 8,8 8,22 22,22 22,8 m 150,166 0,-2 2,0 0,2 z m 6,-6 -10,0 0,10 10,0 m -8,-8 6,0 0,6 -6,0 z m -158,12 0,-6 6,0 0,6 m 2,-8 0,10 -10,0 0,-10 m 0,0 10,0 m 2,-2 -14,0 0,14 14,0" style="fill: #ddd;"/>' +
                '<text style="font-size:10px;fill:#ddd;stroke:none;stroke-width:1px;" x="47.321415" y="99.851288">QR Code goes here</text>' +
            '</svg>';
}

return '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 194 194" width="194px" height="194px">' +
                '<path d="m 186,8 0,14 -14,0 0,-14 m 12,12 0,-10 -10,0 0,10 m -162,-8 0,6 6,0 0,-6 m 164,6 -6,0 0,-6 6,0 z M 10,10 20,10 20,20 10,20 M 8,8 8,22 22,22 22,8 m 150,166 0,-2 2,0 0,2 z m 6,-6 -10,0 0,10 10,0 m -8,-8 6,0 0,6 -6,0 z m -158,12 0,-6 6,0 0,6 m 2,-8 0,10 -10,0 0,-10 m 0,0 10,0 m 2,-2 -14,0 0,14 14,0" style="fill: #ddd;"/>' +
                '<text style="font-size:10px;fill:#ddd;stroke:none;stroke-width:1px;" x="30" y="90">Key too long for this</text>' +
                '<text style="font-size:10px;fill:#ddd;stroke:none;stroke-width:1px;" x="30" y="110">error correction level</text>' +
            '</svg>'
}

function placeholder_paperkey() {

var res = "BORG PAPER KEY v1\n"
    res += "id: ?? / ?????? ?????? ?????? / ?????? ?????? - ??\n"
    for (var i = 1; i <= 19; i++) {
        res += (i < 10 ? ' ' : '') + i.toString();
        res += ": ?????? ?????? ?????? ?????? ?????? ?????? - ??\n";
    }

return res;
}

var export_ = '';

var lines = text.split('\n');
    var first_line = lines.shift();

var binary = atob(lines.join('\n'));
    export_ += 'BORG PAPER KEY v1\n';
    lines = Math.ceil(binary.length / 18);
    var repoid = first_line.substr(9, 18)
    var complete_checksum = sha256_truncated(binary, 12)
    export_ += 'id: ';
    export_ += lines.toString();
    var checksum = sha256_truncated(lines.toString() + '/' + repoid + '/' + complete_checksum, 2);
    export_ += ' / ' + grouped(repoid) + ' / ' + grouped(complete_checksum) + ' - ' + checksum +  '\n';

var idx = 0
    while (binary.length) {
        idx += 1
        var binline = binary.substr(0, 18);
        checksum = sha256_truncated(String.fromCharCode(idx >> 8) + String.fromCharCode(idx & 0xff) + binline, 2);
        export_ += (idx < 10 ? ' ' : '') + idx.toString();
        export_ += ': ' + grouped(toHex(binline)) + ' - ' + checksum + '\n';
        binary = binary.substr(18);
    }

return export_;
}

function update() {
    var text = document.getElementById('keyfile').value;
    var target = document.getElementById('qr');
    var typein = document.getElementById('typein');

if (!text) {
        typein.innerText = placeholder_paperkey()
        target.innerHTML = placeholder_qrcode();
        var svg = target.children[0];

typein.classList.add("placeholder");
        svg.classList.add("placeholder");
    } else {
        var e = document.getElementById('errorCorrectionLevel').value;
        target.innerHTML = create_qrcode(text, e);
        var svg = target.children[0];
        svg.setAttribute("viewBox", "0 0 " + svg.getAttribute("width").replace("px", "")
                        + " " + svg.getAttribute("height").replace("px", ""));

typein.innerText = create_paperkey(text);

typein.classList.remove("placeholder");
        svg.classList.remove("placeholder");
    }

var printout = document.getElementById('printout');
    var size = document.getElementById('qrsize').value;

typein.style.transform = "scale(" + document.getElementById('textsize').value / 100 + ")";
    if (document.getElementById('cols').value == "2") {
        typein.classList.add("columns2");
    } else {
        typein.classList.remove("columns2");
    }
    document.getElementById('spacer').style.height = typein.getBoundingClientRect().height + "px";

while (true) {
        svg.setAttribute("width", size + "mm");
        svg.setAttribute("height", size + "mm");

if (printout.scrollHeight <= printout.clientHeight || size <= 50) {
            break;
        }
        size -= 1;
    }

};

function updateFromFile() {
    var f = document.getElementById('fileinput').files[0];

if (f) {
        var r = new FileReader();
        r.onload = function(ev) {
            var contents = ev.target.result;
            document.getElementById('keyfile').value = contents;
            document.getElementById('keyfile').style.display='none';
            document.getElementById('keyfile_expander').style.display='block';
            update();
        };
        r.readAsText(f);
    }
}

if (window.File && window.FileReader && window.FileList && window.Blob) {
    document.getElementById('fileinput').style.display='inline';
    document.getElementById('fileinput').addEventListener('change', updateFromFile, false);

if (document.getElementById('fileinput').files.length) {
        updateFromFile();
    }
}

function loaded() {
    document.getElementById('qrsize').addEventListener('change', update, false);
    document.getElementById('qrsize').addEventListener('input', call_soon(update), false);
    document.getElementById('textsize').addEventListener('change', update, false);
    document.getElementById('textsize').addEventListener('input', call_soon(update), false);

document.getElementById('cols').addEventListener('change', update, false);
    document.getElementById('errorCorrectionLevel').addEventListener('change', update, false);

var editables = document.querySelectorAll("*[contenteditable]");
    for (var i = 0; i < editables.length; ++i) {
        editables[i].addEventListener('input', call_soon(update), false);
    }

update();
}

window.addEventListener("load", loaded, false);

</script>

</body>
</html>

MR SKB