diff --git a/src/tls12.c b/src/tls12.c
index 958dbfac..915f5ec6 100644
--- a/src/tls12.c
+++ b/src/tls12.c
@@ -82,10 +82,6 @@ int tls_send_record(TLS_CONNECT *conn)
 	while (left) {
 		n = tls_socket_send(conn->sock, conn->record + conn->record_offset, left, 0);
 		if (n < 0) {
-
-			fprintf(stderr, "send() return %d\n", n);
-			fprintf(stderr, "send() errno %d\n", errno);
-
 			if (errno == EAGAIN && errno == EWOULDBLOCK) {
 				return TLS_ERROR_SEND_AGAIN;
 			} else if (errno == EINTR) {
diff --git a/src/tls13.c b/src/tls13.c
index 383f541c..5698bb55 100644
--- a/src/tls13.c
+++ b/src/tls13.c
@@ -6859,10 +6859,6 @@ int tls13_recv_client_hello(TLS_CONNECT *conn)
 		int common_cipher_suites[4];
 		size_t common_cipher_suites_cnt;
 
-		if (!conn->ctx->cert_chains) {
-			error_print();
-			return -1;
-		}
 		if (!conn->ctx->cert_chains_len) {
 			error_print();
 			return -1;
diff --git a/tools/tls13_client.c b/tools/tls13_client.c
index a07454c6..b96d4213 100644
--- a/tools/tls13_client.c
+++ b/tools/tls13_client.c
@@ -176,7 +176,7 @@ int tls13_client_main(int argc, char *argv[])
 			char *cipher_suite_name;
 			int cipher_suite;
 			if (cipher_suites_cnt >= sizeof(cipher_suites)/sizeof(cipher_suites[0])) {
-				fprintf(stderr, "%s: too much -cipher_suite\n", prog);
+				fprintf(stderr, "%s: too many -cipher_suite options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
@@ -230,7 +230,7 @@ int tls13_client_main(int argc, char *argv[])
 			psk_dhe_ke = 1;
 		} else if (!strcmp(*argv, "-psk_identity")) {
 			if (psk_identities_cnt > sizeof(psk_identities)/sizeof(psk_identities[0])) {
-				fprintf(stderr, "%s: too much -psk_identity\n", prog);
+				fprintf(stderr, "%s: too many -psk_identity options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
@@ -239,7 +239,7 @@ int tls13_client_main(int argc, char *argv[])
 			char *cipher_suite_name;
 			int cipher_suite;
 			if (psk_cipher_suites_cnt > sizeof(psk_cipher_suites)/sizeof(psk_cipher_suites[0])) {
-				fprintf(stderr, "%s: too much -psk_cipher_suite\n", prog);
+				fprintf(stderr, "%s: too many -psk_cipher_suite options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
@@ -252,7 +252,7 @@ int tls13_client_main(int argc, char *argv[])
 		} else if (!strcmp(*argv, "-psk_key")) {
 			char *psk_key_hex;
 			if (psk_keys_cnt > sizeof(psk_keys)/sizeof(psk_keys[0])) {
-				fprintf(stderr, "%s: too much -psk_key\n", prog);
+				fprintf(stderr, "%s: too many -psk_key options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
@@ -272,7 +272,7 @@ int tls13_client_main(int argc, char *argv[])
 			char *supported_group_name;
 			int supported_group;
 			if (supported_groups_cnt >= sizeof(supported_groups)/sizeof(supported_groups[0])) {
-				fprintf(stderr, "%s: too much -supported_group\n", prog);
+				fprintf(stderr, "%s: too many -supported_group options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
@@ -286,7 +286,7 @@ int tls13_client_main(int argc, char *argv[])
 			char *sig_alg_name;
 			int sig_alg;
 			if (sig_algs_cnt >= sizeof(sig_algs)/sizeof(sig_algs[0])) {
-				fprintf(stderr, "%s: too much -sig_alg\n", prog);
+				fprintf(stderr, "%s: too many -sig_alg options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
@@ -376,7 +376,7 @@ bad:
 	// CA certificates
 	if (cacertfile) {
 		if (tls_ctx_set_ca_certificates(&ctx, cacertfile, verify_depth) != 1) {
-			fprintf(stderr, "%s: load CA certificates file '%s' failure\n", prog, cacertfile);
+			fprintf(stderr, "%s: failed to load certificate '%s'\n", prog, cacertfile);
 			goto end;
 		}
 	}
@@ -384,11 +384,11 @@ bad:
 	// CertificateRequest
 	if (certfile) {
 		if (!keyfile) {
-			fprintf(stderr, "%s: option '-key' required\n", prog);
+			fprintf(stderr, "%s: option -key is required\n", prog);
 			goto end;
 		}
 		if (!pass) {
-			fprintf(stderr, "%s: option '-pass' requried\n", prog);
+			fprintf(stderr, "%s: option -pass is requried\n", prog);
 			goto end;
 		}
 		if (tls_ctx_add_certificate_chain_and_key(&ctx, certfile, keyfile, pass) != 1) {
@@ -690,7 +690,6 @@ bad:
 
 		if (sent_len > 0 && FD_ISSET(conn.sock, &fds_send)) {
 
-
 			// tls13_send 会返回一个 -1 , 但是没有打印错误信息！！！！			
 			if ((ret = tls13_send(&conn, (uint8_t *)send_buf + sent_offset, sent_len, &sentlen)) != 1) {
 				if (ret == TLS_ERROR_SEND_AGAIN || ret == TLS_ERROR_RECV_AGAIN) {
diff --git a/tools/tls13_server.c b/tools/tls13_server.c
index 48381799..8d48a716 100644
--- a/tools/tls13_server.c
+++ b/tools/tls13_server.c
@@ -145,21 +145,21 @@ int tls13_server_main(int argc , char **argv)
 			port = atoi(*(++argv));
 		} else if (!strcmp(*argv, "-cert")) {
 			if (certfiles_cnt >= sizeof(certfiles)/sizeof(certfiles[0])) {
-				fprintf(stderr, "%s: too much -cert\n", prog);
+				fprintf(stderr, "%s: too many -cert options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
 			certfiles[certfiles_cnt++] = *(++argv);
 		} else if (!strcmp(*argv, "-key")) {
 			if (keyfiles_cnt >= sizeof(keyfiles)/sizeof(keyfiles[0])) {
-				fprintf(stderr, "%s: too much -key\n", prog);
+				fprintf(stderr, "%s: too many -key options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
 			keyfiles[keyfiles_cnt++] = *(++argv);
 		} else if (!strcmp(*argv, "-pass")) {
 			if (passes_cnt >= sizeof(passes)/sizeof(passes[0])) {
-				fprintf(stderr, "%s: too much -pass\n", prog);
+				fprintf(stderr, "%s: too many -pass options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
@@ -220,7 +220,7 @@ int tls13_server_main(int argc , char **argv)
 			char *cipher_suite_name;
 			int cipher_suite;
 			if (cipher_suites_cnt >= sizeof(cipher_suites)/sizeof(cipher_suites[0])) {
-				fprintf(stderr, "%s: too much -cipher_suite\n", prog);
+				fprintf(stderr, "%s: too many -cipher_suite options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
@@ -235,7 +235,7 @@ int tls13_server_main(int argc , char **argv)
 			char *supported_group_name;
 			int supported_group;
 			if (supported_groups_cnt >= sizeof(supported_groups)/sizeof(supported_groups[0])) {
-				fprintf(stderr, "%s: too much -supported_group\n", prog);
+				fprintf(stderr, "%s: too many -supported_group options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
@@ -249,7 +249,7 @@ int tls13_server_main(int argc , char **argv)
 			char *sig_alg_name;
 			int sig_alg;
 			if (sig_algs_cnt >= sizeof(sig_algs)/sizeof(sig_algs[0])) {
-				fprintf(stderr, "%s: too much -sig_alg\n", prog);
+				fprintf(stderr, "%s: too many -sig_alg options\n", prog);
 				return -1;
 			}
 			if (--argc < 1) goto bad;
@@ -550,9 +550,7 @@ restart:
 		if (send_len > 0 && FD_ISSET(conn.sock, &fds_send)) {
 			fprintf(stderr, ">>>>>>>> send back\n");
 
-
-			format_bytes(stderr, 0, 0, "tls13_send", buf + send_offset, send_len);
-
+			format_bytes(stderr, 0, 0, "tls13_send", (const uint8_t *)buf + send_offset, send_len);
 
 			if ((ret = tls13_send(&conn, (uint8_t *)buf + send_offset, send_len, &sentlen)) != 1) {
 				if (ret == TLS_ERROR_SEND_AGAIN || ret == TLS_ERROR_RECV_AGAIN) {