class Base58

Constants

ALPHABETS: See en.wikipedia.org/wiki/Base58
BASE: NOTE: If adding new alphabets of non-standard length, this should become a method.

Public Class Methods

base58_to_binary(base58_val, alphabet = :flickr) click to toggle source

Converts a base58 string to an ASCII-8BIT (binary) encoded string. All leading zeroes in the base58 input are preserved and converted to “x00” in the output.

# File lib/base58.rb, line 62
def self.base58_to_binary(base58_val, alphabet = :flickr)
  raise ArgumentError, 'Invalid alphabet selection.' unless ALPHABETS.include?(alphabet)
  nzeroes = base58_val.chars.find_index{|c| c != ALPHABETS[alphabet][0]} || base58_val.length-1
  prefix = nzeroes < 0 ? '' : '00' * nzeroes
  [prefix + Private::int_to_hex(base58_to_int(base58_val, alphabet))].pack('H*')
end

base58_to_int(base58_val, alphabet = :flickr) click to toggle source

Converts a base58 string to a base10 integer.

# File lib/base58.rb, line 19
def self.base58_to_int(base58_val, alphabet = :flickr)
  raise ArgumentError, 'Invalid alphabet selection.' unless ALPHABETS.include?(alphabet)
  int_val = 0
  base58_val.reverse.split(//).each_with_index do |char,index|
    raise ArgumentError, 'Value passed not a valid Base58 String.' if (char_index = ALPHABETS[alphabet].index(char)).nil?
    int_val += (char_index)*(BASE**(index))
  end
  int_val
end

Also aliased as: decode

binary_to_base58(binary_val, alphabet = :flickr, include_leading_zeroes = true) click to toggle source

Converts a ASCII-8BIT (binary) encoded string to a base58 string.

# File lib/base58.rb, line 43
def self.binary_to_base58(binary_val, alphabet = :flickr, include_leading_zeroes = true)
  raise ArgumentError, 'Value passed is not a String.' unless binary_val.is_a?(String)
  raise ArgumentError, 'Value passed is not binary.' unless binary_val.encoding == Encoding::BINARY
  raise ArgumentError, 'Invalid alphabet selection.' unless ALPHABETS.include?(alphabet)
  return int_to_base58(0, alphabet) if binary_val.empty?

  if include_leading_zeroes
    nzeroes = binary_val.bytes.find_index{|b| b != 0} || binary_val.length-1
    prefix = ALPHABETS[alphabet][0] * nzeroes
  else
    prefix = ''
  end

  prefix + int_to_base58(binary_val.unpack('H*')[0].to_i(16), alphabet)
end

decode(base58_val, alphabet = :flickr)

Alias for: base58_to_int

encode(int_val, alphabet = :flickr)

Alias for: int_to_base58

int_to_base58(int_val, alphabet = :flickr) click to toggle source

Converts a base10 integer to a base58 string.

# File lib/base58.rb, line 30
def self.int_to_base58(int_val, alphabet = :flickr)
  raise ArgumentError, 'Value passed is not an Integer.' unless int_val.is_a?(Integer)
  raise ArgumentError, 'Invalid alphabet selection.' unless ALPHABETS.include?(alphabet)
  base58_val = ''
  while(int_val >= BASE)
    mod = int_val % BASE
    base58_val = ALPHABETS[alphabet][mod,1] + base58_val
    int_val = (int_val - mod)/BASE
  end
  ALPHABETS[alphabet][int_val,1] + base58_val
end

Also aliased as: encode