diff --git a/include/iscsi-private.h b/include/iscsi-private.h
index 6bd72a4..69781ef 100644
--- a/include/iscsi-private.h
+++ b/include/iscsi-private.h
@@ -98,7 +98,7 @@ struct iscsi_in_pdu {
 void iscsi_free_iscsi_in_pdu(struct iscsi_context *iscsi, struct iscsi_in_pdu *in);
 
 /* size of chap response field */
-#define MAX_CHAP_R_SIZE 20 /* md5:16  sha1:20 */
+#define MAX_CHAP_R_SIZE 32 /* md5:16  sha1:20 */
 
 /* max length of chap challange */
 #define MAX_CHAP_C_LENGTH 2048
diff --git a/lib/login.c b/lib/login.c
index 120c8c2..73a6d62 100644
--- a/lib/login.c
+++ b/lib/login.c
@@ -936,7 +936,7 @@ iscsi_login_add_chap_response(struct iscsi_context *iscsi, struct iscsi_pdu *pdu
 
 	/* bidirectional chap */
 	if (iscsi->target_user[0]) {
-		char target_chap_c[MAX_CHAP_R_SIZE * 2];
+		char target_chap_c[MAX_CHAP_R_SIZE * 2] = {0};
 
 		iscsi->target_chap_i++;
 		snprintf(str, MAX_STRING_SIZE, "CHAP_I=%d",