utils: Add case-insensitive version of strpfx()

src/libstrongswan/tests/test_utils.c

@@ -187,6 +187,38 @@ START_TEST(test_round)
 }
 END_TEST
 
+/*******************************************************************************
+ * strpfx
+ */
+
+static struct {
+	char *str;
+	char *pfx;
+	bool prefix;
+	bool case_prefix;
+} strpfx_data[] = {
+	{"", "", TRUE, TRUE},
+	{"abc", "", TRUE, TRUE},
+	{"abc", "a", TRUE, TRUE},
+	{"abc", "ab", TRUE, TRUE},
+	{"abc", "abc", TRUE, TRUE},
+	{"abc", "abcd", FALSE, FALSE},
+	{"abc", "AB", FALSE, TRUE},
+	{"ABC", "ab", FALSE, TRUE},
+	{" abc", "abc", FALSE, FALSE},
+};
+
+START_TEST(test_strpfx)
+{
+	bool prefix;
+
+	prefix = strpfx(strpfx_data[_i].str, strpfx_data[_i].pfx);
+	ck_assert(prefix == strpfx_data[_i].prefix);
+	prefix = strcasepfx(strpfx_data[_i].str, strpfx_data[_i].pfx);
+	ck_assert(prefix == strpfx_data[_i].case_prefix);
+}
+END_TEST
+
 /*******************************************************************************
  * memxor
  */
@@ -442,6 +474,10 @@ Suite *utils_suite_create()
 	tcase_add_test(tc, test_round);
 	suite_add_tcase(s, tc);
 
+	tc = tcase_create("string helper");
+	tcase_add_loop_test(tc, test_strpfx, 0, countof(strpfx_data));
+	suite_add_tcase(s, tc);
+
 	tc = tcase_create("memxor");
 	tcase_add_test(tc, test_memxor);
 	tcase_add_test(tc, test_memxor_aligned);

src/libstrongswan/utils/utils.h

@@ -112,6 +112,14 @@ static inline bool strncaseeq(const char *x, const char *y, size_t len)
 	return strncasecmp(x, y, len) == 0;
 }
 
+/**
+ * Helper function that checks if a string starts with a given prefix
+ */
+static inline bool strcasepfx(const char *x, const char *prefix)
+{
+	return strncaseeq(x, prefix, strlen(prefix));
+}
+
 /**
  * NULL-safe strdup variant
  */