Libstringprep is an implementation of the IETF stringprep
specification, licensed under the LGPL.

Currently the API include the following definitions and functions:

Function: extern int stringprep (char *in, int maxlen, int flags,
                                 stringprep_profile * profile);

     Perform stringprep on a zero terminated UTF-8 string.  Since the
     stringprep operation can expand the string, maxlen indicate how
     large the buffer holding the string is.  See below for valid
     flags options.  The profile indicates processing details, see the
     profile header files, such as stringprep_generic.h and
     stringprep_nameprep.h for two examples.  Your application can
     define new profiles, possibly re-using the generic stringprep
     tables that always will be part of the library.  Note that you
     must convert strings entered in the systems locale into UTF-8
     before using this function.

Type: STRINGPREP_NO_NFKC
Type: STRINGPREP_NO_BIDI

     Valid options to the FLAGS parameter of stringprep().
     STRINGPREP_NO_NFKC disables the NFKC normalization, as well as
     selecting the non-NFKC case folding tables. STRINGPREP_NO_BIDI
     disables the BIDI step.

Macro: STRINGPREP_VERSION

     CPP definition, a string with version of the stringprep header file.

Function: extern char *stringprep_check_version (char *req_version);

     Check that the the version of the library is at minimum the one
     given as a string in REQ_VERSION and return the actual version
     string of the library; return NULL if the condition is not met.
     If `NULL' is passed to this function no check is done and only the
     version string is returned.

Libstringprep has at some point in time passed the self tests on the
following systems, but no guarantees.

  - alphaev67-dec-osf5.0 (Tru64 UNIX C, Tru64 make -- iconv failed!)
  - i686-pc-linux-gnu (Debian Sid, iconv ok)
  - i686-pc-linux-gnu (RedHat 7.2, iconv ok)
  - mips-sgi-irix6.5 (MIPS C compiler, IRIX make, iconv ok)
  - rs6000-ibm-aix4.3.2.0 (GCC 2.9-aix43-000718, GNU make, iconv failed!)
  - rs6000-ibm-aix4.3.2.0 (IBM C for AIX compiler, AIX make, iconv failed!)
  - sparc-sun-solaris2.6 (Sun WorkShop Compiler C 5.0, non-GNU make)
  - sparc-sun-solaris2.8 (Sun WorkShop Compiler C 6.0U2, SUN make, iconv ok)
  - sparc-sun-solaris2.8 (GCC 3.1, GNU make, iconv ok)

Libstringprep is unstable and in its early steps of development.  You
should expect it to not work as well as having security problems.

Things left to do below.  If you like to start working on anything,
please let me know so work duplication can be avoided.

  - Optimize it, the table searching is slow (but does it matter?).
  - Port applications to use libstringprep.
  - Include tables for more stringprep profiles.
  - Add texi documentation.
  - Implement rest of IDN?  Possibly separate project.

For more information see <URL:http://josefsson.org/libstringprep/>.

Send all bug reports by electronic mail to bug-libstringprep@josefsson.org.
