strcpy_s

strcpy_s is a secure string copy function defined in the C11 standard (Annex K) as part of the bounds-checking interfaces. It copies a null-terminated source string to a destination buffer while ensuring that the operation does not exceed the buffer's size, preventing buffer overflows. This function is designed to enhance security in C programming by replacing the unsafe standard strcpy function with a safer alternative that includes runtime constraints.

Also known as: strcpy_s function, secure strcpy, C11 strcpy_s, Annex K strcpy_s, strcpy_safe

Why learn strcpy_s?

Developers should use strcpy_s when writing C code that handles string operations in security-critical applications, such as embedded systems, operating systems, or network services, where buffer overflows can lead to vulnerabilities like code execution or crashes. It is particularly useful in environments adhering to safety standards like MISRA C or when aiming to comply with secure coding guidelines, as it helps mitigate common security risks associated with traditional string functions.

Learning Resources

• docs: C11 Standard - Annex K Bounds-checking Interfaces
• docs: Microsoft Docs - strcpy_s, wcscpy_s, _mbscpy_s
• tutorial: Secure Coding in C and C++ - String Handling
• docs: GCC Documentation - _FORTIFY_SOURCE