This library implements the secure C11 Annex K functions on top of most libc implementations, which are missing from them. The ISO TR24731 Bounds Checking Interface documents indicate that the key motivation for the new specification is to help mitigate the ever increasing security attacks, specifically the buffer overrun. The rationale document says "Buffer overrun attacks continue to be a security problem. Roughly 10% of vulnerability reports cataloged by CERT from 01/01/2005 to 07/01/2005 involved buffer overflows. Preventing buffer overruns is the primary, but not the only, motivation for this technical report." The rationale document continues "that these only mitigate, that is lessen, security problems. When used properly, these functions decrease the danger buffer overrun attacks. Source code may remain vulnerable due to other bugs and security issues. The highest level of security is achieved by building in layers of security utilizing multiple strategies." The rationale document lists the following key points for TR24731: Guard against overflowing a buffer Do not produce unterminated strings Do not unexpectedly truncate strings Provide a library useful to existing code Preserve the null terminated string datatype Only require local edits to programs Library based solution Support compile-time checking Make failures obvious Zero buffers, null strings Runtime-constraint handler mechanism Support re-entrant code Consistent naming scheme Have a uniform pattern for the function parameters and return type Deference to existing technology and the following can be added... provide a library of functions with like behavior provide a library of functions that promote and increase code safety and security provide a library of functions that are efficient The C11 Standard adopted many of these points, and added some secure _s variants in the Annex K. The Microsoft Windows/MINGW secure API did the same, but deviated in some functions from the standard. Besides Windows (with its msvcrt, ucrt, reactos msvcrt and wine msvcrt variants) only the unused stlport, Android's Bionic, Huawei securec and Embarcadero implemented this C11 secure Annex K API so far. They are still missing from glibc, musl, FreeBSD, darwin and DragonFly libc, OpenBSD libc, newlib, dietlibc, uClibc, minilibc. lssndrbarbieri@gmail.com Alessandro Barbieri https://github.com/rurban/safeclib/issues rurban/safeclib enable C11 invoke_safe_{str,mem}_constraint_handler for less performance, bigger size and more flexibility enable additional functions not defined in the C11 specification Enable NFKC and NFKD modes for wcsnorm enable to null out the remaining part of a string if it is not completely used Include unsafe std C11 functions: tmpnam_s enable Valgrind on the unit tests