Provide safer string copy than strncpy

As per @boxerab suggestion in commit
b9ca882749597e4943e609daba1d3c27694fe2ff

1 files changed, 72 insertions, 0 deletions

diff --git a/src/bin/common/opj_string.h b/src/bin/common/opj_string.h
new file mode 100644
index 00000000..8829926a
--- /dev/null
+++ b/src/bin/common/opj_string.h
@@ -0,0 +1,72 @@
+/*
+ * The copyright in this software is being made available under the 2-clauses
+ * BSD License, included below. This software may be subject to other third
+ * party and contributor rights, including patent rights, and no such rights
+ * are granted under this license.
+ *
+ * Copyright (c) 2015, Matthieu Darbois
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef OPJ_STRING_H
+#define OPJ_STRING_H
+
+#include <errno.h>
+#include <string.h>
+
+/* strnlen is not standard, strlen_s is C11... */
+/* keep in mind there still is a buffer read overflow possible */
+static size_t opj_strnlen_s(const char *src, size_t max_len)
+{
+	size_t len;
+	
+	if (src == NULL) {
+		return 0U;
+	}
+	for (len = 0U; (*src != '\0') && (len < max_len); src++, len++);
+	return len;
+}
+
+/* should be equivalent to C11 function except for the handler */
+/* keep in mind there still is a buffer read overflow possible */
+static int opj_strcpy_s(char* dst, size_t dst_size, const char* src)
+{
+	size_t src_len = 0U;
+	if ((dst == NULL) || (dst_size == 0U)) {
+		return EINVAL;
+	}
+	if (src == NULL) {
+		dst[0] = '\0';
+		return EINVAL;
+	}
+	src_len = opj_strnlen_s(src, dst_size);
+	if (src_len >= dst_size) {
+		return ERANGE;
+	}
+	memcpy(dst, src, src_len);
+	dst[src_len] = '\0';
+	return 0;
+}
+
+#endif /* OPJ_STRING_H */