class ROTP::Base32
Constants
- CHARS
- MASK
- SHIFT
Public Class Methods
decode(str)
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# File lib/rotp/base32.rb, line 12 def decode(str) buffer = 0 idx = 0 bits_left = 0 str = str.tr('=', '').upcase result = [] str.split('').each do |char| buffer = buffer << SHIFT buffer = buffer | (decode_quint(char) & MASK) bits_left = bits_left + SHIFT if bits_left >= 8 result[idx] = (buffer >> (bits_left - 8)) & 255 idx = idx + 1 bits_left = bits_left - 8 end end result.pack('c*') end
encode(b)
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# File lib/rotp/base32.rb, line 31 def encode(b) data = b.unpack('c*') out = String.new buffer = data[0] idx = 1 bits_left = 8 while bits_left > 0 || idx < data.length if bits_left < SHIFT if idx < data.length buffer = buffer << 8 buffer = buffer | (data[idx] & 255) bits_left = bits_left + 8 idx = idx + 1 else pad = SHIFT - bits_left buffer = buffer << pad bits_left = bits_left + pad end end val = MASK & (buffer >> (bits_left - SHIFT)) bits_left = bits_left - SHIFT out.concat(CHARS[val]) end return out end
random(byte_length = 20)
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Defaults to 160 bit long secret (meaning a 32 character long base32 secret)
# File lib/rotp/base32.rb, line 58 def random(byte_length = 20) rand_bytes = SecureRandom.random_bytes(byte_length) self.encode(rand_bytes) end
random_base32(str_len = 32)
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Prevent breaking changes
# File lib/rotp/base32.rb, line 64 def random_base32(str_len = 32) byte_length = str_len * 5/8 random(byte_length) end
Private Class Methods
decode_quint(q)
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# File lib/rotp/base32.rb, line 71 def decode_quint(q) CHARS.index(q) || raise(Base32Error, "Invalid Base32 Character - '#{q}'") end