jbe/bsw@0: local alphabet = {
jbe/bsw@0:   "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
jbe/bsw@0:   "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z",
jbe/bsw@0:   "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m",
jbe/bsw@0:   "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z",
jbe/bsw@0:   "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "+", "/"
jbe/bsw@0: }
jbe/bsw@0: 
jbe/bsw@0: function encode.mime.base64(str)
jbe/bsw@0:   local parts = {}
jbe/bsw@0:   local pos = 1
jbe/bsw@0:   local block_count = 0
jbe/bsw@0:   while pos <= #str do
jbe/bsw@0:     local s = string.sub(str, pos, pos + 2)
jbe/bsw@0:     local n = 0
jbe/bsw@0:     for i = 1, 3 do
jbe/bsw@0:       n = n * 256
jbe/bsw@0:       if i <= #s then
jbe/bsw@0:         n = n + string.byte(string.sub(s, i, i))
jbe/bsw@0:       end
jbe/bsw@0:     end
jbe/bsw@0:     parts[#parts+1] = alphabet[math.floor(n / 262144) + 1]
jbe/bsw@0:     parts[#parts+1] = alphabet[math.floor(n / 4096) % 64 + 1]
jbe/bsw@0:     if #s > 1 then
jbe/bsw@0:       parts[#parts+1] = alphabet[math.floor(n / 64) % 64 + 1]
jbe/bsw@0:     else
jbe/bsw@0:       parts[#parts+1] = "="
jbe/bsw@0:     end
jbe/bsw@0:     if #s > 2 then
jbe/bsw@0:       parts[#parts+1] = alphabet[n % 64 + 1]
jbe/bsw@0:     else
jbe/bsw@0:       parts[#parts+1] = "="
jbe/bsw@0:     end
jbe/bsw@0:     block_count = block_count + 1
jbe/bsw@0:     if block_count == 19 then
jbe/bsw@0:       parts[#parts+1] = "\r\n"
jbe/bsw@0:       block_count = 0
jbe/bsw@0:     end
jbe/bsw@0:     pos = pos + #s
jbe/bsw@0:   end
jbe/bsw@0:   if block_count > 0 then
jbe/bsw@0:     parts[#parts+1] = "\r\n"
jbe/bsw@0:   end
jbe/bsw@0:   return table.concat(parts)
jbe/bsw@0: end