diff --git a/src/utils/common.c b/src/utils/common.c
index 0bdc38d..5cf0d57 100644
--- a/src/utils/common.c
+++ b/src/utils/common.c
@@ -8,6 +8,7 @@
 
 #include "includes.h"
 
+#include "common/ieee802_11_defs.h"
 #include "common.h"
 
 
@@ -609,7 +610,7 @@
  */
 const char * wpa_ssid_txt(const u8 *ssid, size_t ssid_len)
 {
-	static char ssid_txt[32 * 4 + 1];
+	static char ssid_txt[SSID_MAX_LEN * 4 + 1];
 
 	if (ssid == NULL) {
 		ssid_txt[0] = '\0';
@@ -1087,3 +1088,9 @@
 
 	return res_size;
 }
+
+
+int is_ctrl_char(char c)
+{
+	return c > 0 && c < 32;
+}
diff --git a/src/utils/common.h b/src/utils/common.h
index a0eda4a..88318f5 100644
--- a/src/utils/common.h
+++ b/src/utils/common.h
@@ -554,6 +554,7 @@
 		   char *outp, size_t out_size);
 size_t utf8_unescape(const char *inp, size_t in_size,
 		     char *outp, size_t out_size);
+int is_ctrl_char(char c);
 
 
 /*
diff --git a/src/utils/utils_module_tests.c b/src/utils/utils_module_tests.c
index 4b97dad..b2c7e08 100644
--- a/src/utils/utils_module_tests.c
+++ b/src/utils/utils_module_tests.c
@@ -9,6 +9,7 @@
 #include "utils/includes.h"
 
 #include "utils/common.h"
+#include "common/ieee802_11_defs.h"
 #include "utils/bitfield.h"
 #include "utils/ext_password.h"
 #include "utils/trace.h"
@@ -340,6 +341,9 @@
 	u8 bin[3];
 	int errors = 0;
 	struct wpa_freq_range_list ranges;
+	size_t len;
+	const char *txt;
+	u8 ssid[255];
 
 	wpa_printf(MSG_INFO, "common tests");
 
@@ -395,6 +399,16 @@
 	if (utf8_escape("a", 0, buf, sizeof(buf)) != 1 || buf[0] != 'a')
 		errors++;
 
+	os_memset(ssid, 0, sizeof(ssid));
+	txt = wpa_ssid_txt(ssid, sizeof(ssid));
+	len = os_strlen(txt);
+	/* Verify that SSID_MAX_LEN * 4 buffer limit is enforced. */
+	if (len != SSID_MAX_LEN * 4) {
+		wpa_printf(MSG_ERROR,
+			   "Unexpected wpa_ssid_txt() result with too long SSID");
+		errors++;
+	}
+
 	if (errors) {
 		wpa_printf(MSG_ERROR, "%d common test(s) failed", errors);
 		return -1;