# File lib/authlogic/crypto_providers/wordpress.rb, line 18
        def encode_64(input, length)
          output = ""
          i = 0
          while i < length
            value = input[i]
            i += 1
            break if value.nil?
            output += ITOA64[value & 0x3f, 1]
            value |= input[i] << 8 if i < length
            output += ITOA64[(value >> 6) & 0x3f, 1]

            i += 1
            break if i >= length
            value |= input[i] << 16 if i < length
            output += ITOA64[(value >> 12) & 0x3f, 1]

            i += 1
            break if i >= length
            output += ITOA64[(value >> 18) & 0x3f, 1]
          end
          output
        end