From 0079d836f3e51f1c4b9e67dee026217a7c13cc47 Mon Sep 17 00:00:00 2001
From: Frank Morgner <frankmorgner@gmail.com>
Date: Fri, 8 Mar 2019 22:02:30 +0100
Subject: [PATCH] pkcs11: truncate oversized labels with '...'

---
 src/pkcs11/misc.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/pkcs11/misc.c b/src/pkcs11/misc.c
index 9408080b..c3f5bb4e 100644
--- a/src/pkcs11/misc.c
+++ b/src/pkcs11/misc.c
@@ -43,16 +43,26 @@ static struct sc_to_cryptoki_error_conversion sc_to_cryptoki_error_map[]  = {
 
 void strcpy_bp(u8 * dst, const char *src, size_t dstsize)
 {
-	size_t c;
-
-	if (!dst || !src || !dstsize)
+	if (!dst || !dstsize)
 		return;
 
 	memset((char *)dst, ' ', dstsize);
 
-	c = strlen(src) > dstsize ? dstsize : strlen(src);
+	if (src) {
+		size_t src_len = strlen(src);
 
-	memcpy((char *)dst, src, c);
+		if (src_len > dstsize) {
+			/* string will be truncated */
+			memcpy((char *)dst, src, dstsize);
+			if (dstsize > 3) {
+				/* show truncation with '...' */
+				/* FIXME avoid breaking an UTF-8 character on multiple bytes */
+				memset((char *)dst + dstsize - 3, '.', 3);
+			}
+		} else {
+			memcpy((char *)dst, src, src_len);
+		}
+	}
 }