Base58 123456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ

Base58.js

// https://github.com/cryptocoinjs/bs58
function base58encode(buffer) {
    var ALPHABET = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz';
    var ALPHABET_MAP = {};
    for (var i = 0; i < ALPHABET.length; i++) {
        ALPHABET_MAP[ALPHABET.charAt(i)] = i;
    }
    var BASE = 58;
    if (buffer.length === 0)
        return '';
    var i, j, digits = [0];
    for (i = 0; i < buffer.length; i++) {
        for (j = 0; j < digits.length; j++)
            digits[j] <<= 8;
        digits[0] += buffer[i];
        var carry = 0;
        for (j = 0; j < digits.length; ++j) {
            digits[j] += carry;
            carry = digits[j] / BASE | 0;
            digits[j] %= BASE;
        }
        while (carry) {
            digits.push(carry % BASE);
            carry = carry / BASE | 0;
        }
    }
    for (i = 0; buffer[i] === 0 && i < buffer.length - 1; i++)
        digits.push(0);
    return digits.reverse().map(function (digit) {
        return ALPHABET[digit];
    }).join('');
}

// Alternative
// https://github.com/45678/base58
(function() {
  var ALPHABET, ALPHABET_MAP, Base58, i;

  Base58 = (typeof module !== "undefined" && module !== null ? module.exports : void 0) || (window.Base58 = {});

  ALPHABET = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";

  ALPHABET_MAP = {};

  i = 0;

  while (i < ALPHABET.length) {
    ALPHABET_MAP[ALPHABET.charAt(i)] = i;
    i++;
  }

  Base58.encode = function(buffer) {
    var carry, digits, j;
    if (buffer.length === 0) {
      return "";
    }
    i = void 0;
    j = void 0;
    digits = [0];
    i = 0;
    while (i < buffer.length) {
      j = 0;
      while (j < digits.length) {
        digits[j] <<= 8;
        j++;
      }
      digits[0] += buffer[i];
      carry = 0;
      j = 0;
      while (j < digits.length) {
        digits[j] += carry;
        carry = (digits[j] / 58) | 0;
        digits[j] %= 58;
        ++j;
      }
      while (carry) {
        digits.push(carry % 58);
        carry = (carry / 58) | 0;
      }
      i++;
    }
    i = 0;
    while (buffer[i] === 0 && i < buffer.length - 1) {
      digits.push(0);
      i++;
    }
    return digits.reverse().map(function(digit) {
      return ALPHABET[digit];
    }).join("");
  };

  Base58.decode = function(string) {
    var bytes, c, carry, j;
    if (string.length === 0) {
      return new (typeof Uint8Array !== "undefined" && Uint8Array !== null ? Uint8Array : Buffer)(0);
    }
    i = void 0;
    j = void 0;
    bytes = [0];
    i = 0;
    while (i < string.length) {
      c = string[i];
      if (!(c in ALPHABET_MAP)) {
        throw new Error("Non-base58 character");
      }
      j = 0;
      while (j < bytes.length) {
        bytes[j] *= 58;
        j++;
      }
      bytes[0] += ALPHABET_MAP[c];
      carry = 0;
      j = 0;
      while (j < bytes.length) {
        bytes[j] += carry;
        carry = bytes[j] >> 8;
        bytes[j] &= 0xff;
        ++j;
      }
      while (carry) {
        bytes.push(carry & 0xff);
        carry >>= 8;
      }
      i++;
    }
    i = 0;
    while (string[i] === "1" && i < string.length - 1) {
      bytes.push(0);
      i++;
    }
    return new (typeof Uint8Array !== "undefined" && Uint8Array !== null ? Uint8Array : Buffer)(bytes.reverse());
  };

}).call(this);