asn_mime: Harden strip_end() against empty strings

Signed-off-by: Joshua Rogers <MegaManSec@users.noreply.github.com>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/28881)

diff --git a/crypto/asn1/asn_mime.c b/crypto/asn1/asn_mime.c
index b85f734e66796cd46376ed60a7e2644936da30db..c2aceffc1cf7b05ed02ed0b44778af3aadcf7fb7 100644 (file)
--- a/crypto/asn1/asn_mime.c
+++ b/crypto/asn1/asn_mime.c
@@ -877,7 +877,7 @@ static char *strip_start(char *name)
 static char *strip_end(char *name)
 {
     char *p, c;
-    if (!name)
+    if (!name || *name == '\0')
         return NULL;
     /* Look for first non whitespace or quote */
     for (p = name + strlen(name) - 1; p >= name; p--) {