in src/main/java/org/apache/accumulo/access/Tokenizer.java [37:46]
static {
IntStream.range(0, 256).forEach(i -> validAuthChars[i] = false);
IntStream numbers = IntStream.rangeClosed('0', '9');
IntStream letters =
IntStream.concat(IntStream.rangeClosed('A', 'Z'), IntStream.rangeClosed('a', 'z'));
IntStream.concat(numbers, letters).forEach(i -> validAuthChars[i] = true);
"_-:./".chars().forEach(c -> validAuthChars[c] = true);
}