pub const STEAM_ALPHABET: &[u8; 26] = b"23456789BCDFGHJKMNPQRTVWXY";Expand description
The alphabet Steam Guard draws its five characters from.
Steam runs ordinary RFC 6238 arithmetic — SHA-1, a 30-second step — and then
encodes the truncated value in base 26 instead of base 10. Nothing else about
it differs, which is why it is a Kind rather than an Algorithm: the
HMAC is the same, the rendering is not.