---title:"mg_base64_decode()"decl_name:"mg_base64_decode"symbol_kind:"func"signature:|int mg_base64_decode(const unsigned char *s, int len, char *dst);---Decode base64-encoded string `s`, `len` into the destination `dst`.Destination has to have enough space to hold decoded buffer.Decoding stops either when all string has been decoded, or invalidcharacter appeared.Destination is '\0'-terminated.Return number of decoded characters. On success, that should be equal to`len`. On error (invalid character) the return value is smaller then `len`.