Merge "feat(lib): implement strnlen secure and strcpy secure function" into integration

include/lib/libc/string.h

@@ -30,5 +30,7 @@ char *strrchr(const char *p, int ch);
 size_t strlcpy(char * dst, const char * src, size_t dsize);
 size_t strlcat(char * dst, const char * src, size_t dsize);
 char *strtok_r(char *s, const char *delim, char **last);
+size_t strnlen_secure(const char *str, size_t maxlen);
+int strcpy_secure(char *restrict dest, size_t dest_size, const char *restrict src);
 
 #endif /* STRING_H */

lib/libc/libc_common.mk

@@ -21,9 +21,11 @@ LIBC_SRCS	:=	$(addprefix lib/libc/,		\
 			snprintf.c			\
 			strchr.c			\
 			strcmp.c			\
+			strcpy_secure.c		\
 			strlcat.c			\
 			strlcpy.c			\
 			strlen.c			\
+			strnlen_secure.c	\
 			strncmp.c			\
 			strnlen.c			\
 			strrchr.c			\

lib/libc/strcpy_secure.c

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2024-2025, Altera Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <errno.h>
+#include <stddef.h>
+#include <string.h>
+#include <stdint.h>
+
+int strcpy_secure(char *restrict dest, size_t dest_size, const char *restrict src)
+{
+	/* Check for null pointers */
+	if ((dest == NULL) || (src == NULL)) {
+		return -EINVAL;
+	}
+
+	/* Check the destination size valid range */
+	if (dest_size == 0) {
+		return -ERANGE;
+	}
+
+	/* Calculate the length of the source string */
+	size_t src_len = strnlen_secure(src, dest_size);
+
+	/* Check if the source string fits in the destination buffer */
+	if (src_len >= dest_size) {
+		/* Set destination to an empty string */
+		dest[0] = '\0';
+		return -ERANGE;
+	}
+
+	/* Copy the source string to the destination */
+	for (dest[src_len] = '\0'; src_len > 0; src_len--) {
+		dest[src_len - 1] = src[src_len - 1];
+	}
+
+	return 0;
+}

lib/libc/strnlen_secure.c

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2024-2025, Altera Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <string.h>
+
+size_t strnlen_secure(const char *str, size_t maxlen)
+{
+	size_t len = 0;
+
+	if (str == NULL) {
+		return 0;
+	}
+
+	while ((len < maxlen) && (str[len] != '\0')) {
+		len++;
+	}
+
+	return len;
+}