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'use strict';
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const baseEncodeTables = {
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  26: 'abcdefghijklmnopqrstuvwxyz',
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  32: '123456789abcdefghjkmnpqrstuvwxyz', // no 0lio
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  36: '0123456789abcdefghijklmnopqrstuvwxyz',
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  49: 'abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ', // no lIO
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  52: 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
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  58: '123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ', // no 0lIO
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  62: '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
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  64: '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_',
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};
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function encodeBufferToBase(buffer, base) {
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  const encodeTable = baseEncodeTables[base];
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  if (!encodeTable) {
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    throw new Error('Unknown encoding base' + base);
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  }
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  const readLength = buffer.length;
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  const Big = require('big.js');
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  Big.RM = Big.DP = 0;
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  let b = new Big(0);
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  for (let i = readLength - 1; i >= 0; i--) {
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    b = b.times(256).plus(buffer[i]);
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  }
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  let output = '';
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  while (b.gt(0)) {
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    output = encodeTable[b.mod(base)] + output;
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    b = b.div(base);
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  }
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  Big.DP = 20;
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  Big.RM = 1;
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  return output;
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}
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function getHashDigest(buffer, hashType, digestType, maxLength) {
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  hashType = hashType || 'md5';
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  maxLength = maxLength || 9999;
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  const hash = require('crypto').createHash(hashType);
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  hash.update(buffer);
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  if (
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    digestType === 'base26' ||
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    digestType === 'base32' ||
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    digestType === 'base36' ||
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    digestType === 'base49' ||
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    digestType === 'base52' ||
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    digestType === 'base58' ||
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    digestType === 'base62' ||
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    digestType === 'base64'
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  ) {
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    return encodeBufferToBase(hash.digest(), digestType.substr(4)).substr(
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      0,
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      maxLength
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    );
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  } else {
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    return hash.digest(digestType || 'hex').substr(0, maxLength);
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  }
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}
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module.exports = getHashDigest;
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