BNF RFC 2253 introduces concewpt of special characters that can occur in the attribute value only if they are escaped by "\".

Special characters are following: "," / "=" / "+" / "<" / ">" / "#" / ";"

However following constructor calls:

new X500Principal("CN=<");
new X500Principal("CN=>");
new X500Principal("CN==");

do not cause IAE

Note, that subsequent gerName() call returns escaped special characters.

For example, (new X500Principal("CN==")).getName() returns "CN=\\="