2.11.2.2 Safe/Unsafe Encoding Names

The idea of safe or unsafe encoding names specified by TPMBENC comes from whether or not the multibyte character data for these encodings can contain embedded NULLs. Because the _mbspresend() function uses strlen() to determine the length of the data, an embedded NULL causes the length to be incorrectly set and the wrong number of data bytes are sent.

The default list in sendlen0_unsafe_tpmbenc has the multibyte Unicode encoding names (in uppercase and lowercase, for convenience) which can contain embedded NULLs. You should modify this list as application administration or performance is considered.

• If the file exists but is empty, then Tuxedo assumes all encoding names are safe for MBSTRING self-describing attempts.
• If the file does not exist, then Tuxedo assumes that all encoding names are unsafe to use for MBSTRING self-describing attempts (tperrno will be TPEINVAL).
• If the file exists and contains a list of names, then Tuxedo reads this file once (at _mbsinit()) and stores the list internally. During mbsinit(), the TPMBENC name is compared to the stored list and the buffer is set as safe or unsafe to use. When _mbspresend() is called (sendlen argument is set to zero) and the buffer is marked safe, then the length is set internally by Tuxedo.