Fix for a bug in base64_encode:
  util.c:70
    change 'const char *ib = in_buf;'
    to     'const uint8_t *ib = in_buf;'

Fix for a bug in base64_inflate_size:
  util.h:246
    change 'return 4*((len+2)/3);'
    to     'return 4*((len+2)/3)+1;'