From 4f189a51742fe833805aea21760244e00a7583b2 Mon Sep 17 00:00:00 2001
From: Frank Morgner <frankmorgner@gmail.com>
Date: Wed, 20 Sep 2017 10:13:26 +0200
Subject: [PATCH] check for digits in case of BCD encoded PIN

---
 src/libopensc/sec.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/libopensc/sec.c b/src/libopensc/sec.c
index 024b2162..ff2f650f 100644
--- a/src/libopensc/sec.c
+++ b/src/libopensc/sec.c
@@ -258,6 +258,9 @@ int sc_build_pin(u8 *buf, size_t buflen, struct sc_pin_cmd_pin *pin, int pad)
 		if (pin_len > 2 * buflen)
 			return SC_ERROR_BUFFER_TOO_SMALL;
 		for (i = j = 0; j < pin_len; j++) {
+			if (!isdigit(pin->data[j])) {
+				return SC_ERROR_INVALID_DATA;
+			}
 			buf[i] <<= 4;
 			buf[i] |= pin->data[j] & 0xf;
 			if (j & 1)