/// <summary>
/// Apply the SASLprep profile [RFC4013] of the "stringprep" algorithm [RFC3454] as the normalization
/// algorithm to a UTF-8 [RFC3629] encoded string.
/// </summary>
/// <param name="input">the string to prep.</param>
/// <param name="allowUnassigned">true if the name may contain unassigned code points.</param>
/// <returns> the prepped name.
/// @throws StringprepException If the name cannot be prepped with
/// this profile.
/// @throws NullPointerException If the name is null.
/// </returns>
public static string SaslPrep(string input, bool allowUnassigned)
{
if (input == null)
{
throw new System.NullReferenceException();
}
StringBuilder s = new StringBuilder(input);
// Unassigned Code Points
if (!allowUnassigned && Stringprep.Contains(s, RFC3454.A1))
{
throw new StringprepException(StringprepException.CONTAINS_UNASSIGNED);
}
// Mapping
Stringprep.Filter(s, RFC3454.B1);
Stringprep.Map(s, RFC3454.C12, C11Replace);
// Normalization
s = new StringBuilder(NFKC.NormalizeNFKC(s.ToString()));
// Prohibited Output
if (Stringprep.Contains(s, RFC3454.C12) || // - Non-ASCII space characters [StringPrep, C.1.2]
Stringprep.Contains(s, RFC3454.C21) || // - ASCII control characters [StringPrep, C.2.1]
Stringprep.Contains(s, RFC3454.C22) || // - Non-ASCII control characters [StringPrep, C.2.2]
Stringprep.Contains(s, RFC3454.C3) || // - Private Use characters [StringPrep, C.3]
Stringprep.Contains(s, RFC3454.C4) || // - Non-character code points [StringPrep, C.4]
Stringprep.Contains(s, RFC3454.C5) || // - Surrogate code points [StringPrep, C.5]
Stringprep.Contains(s, RFC3454.C6) || // - Inappropriate for plain text characters [StringPrep, C.6]
Stringprep.Contains(s, RFC3454.C7) || // - Inappropriate for canonical representation characters [StringPrep, C.7]
Stringprep.Contains(s, RFC3454.C8)) // - Change display properties or deprecated characters [StringPrep, C.8]
{
// Table C.9 only contains code points > 0xFFFF which Java doesn't handle
throw new StringprepException(StringprepException.CONTAINS_PROHIBITED);
}
// Bidirectional Characters
bool r = Stringprep.Contains(s, RFC3454.D1);
bool l = Stringprep.Contains(s, RFC3454.D2);
// RFC 3454, section 6, requirement 1: already handled above (table C.8)
// RFC 3454, section 6, requirement 2
if (r && l)
{
throw new StringprepException(StringprepException.BIDI_BOTHRAL);
}
// RFC 3454, section 6, requirement 3
if (r)
{
if (!Stringprep.Contains(s[0], RFC3454.D1) || !Stringprep.Contains(s[s.Length - 1], RFC3454.D1))
{
throw new StringprepException(StringprepException.BIDI_LTRAL);
}
}
return(s.ToString());
}
