Don't allow asn1_parse2 to recurse arbitrarily deep. Constrain to a max

depth of 128 - For oss-fuzz issue 13802
ok jsing@

1 files changed, 5 insertions, 1 deletions

diff --git a/src/lib/libcrypto/asn1/asn1_par.c b/src/lib/libcrypto/asn1/asn1_par.c
index f4b39e81cd..21f92d298d 100644
--- a/src/lib/libcrypto/asn1/asn1_par.c
+++ b/src/lib/libcrypto/asn1/asn1_par.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: asn1_par.c,v 1.26 2018/11/09 04:11:06 tb Exp $ */
+/* $OpenBSD: asn1_par.c,v 1.27 2019/03/24 16:07:25 beck Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -130,6 +130,10 @@ asn1_parse2(BIO *bp, const unsigned char **pp, long length, int offset,
         p = *pp;
         tot = p + length;
         op = p - 1;
+        if (depth > 128) {
+                BIO_printf(bp, "Max depth exceeded\n");
+                goto end;
+        }
         while ((p < tot) && (op < p)) {
                 op = p;
                 j = ASN1_get_object(&p, &len, &tag, &xclass, length);