Limit depth of ASN1 parse printing.

Thanks to Guido Vranken <guidovranken@gmail.com> for reporting this issue.
Reviewed-by: NTim Hudson <tjh@openssl.org>

crypto/asn1/asn1_par.c

@@ -62,6 +62,10 @@
 #include <openssl/objects.h>
 #include <openssl/asn1.h>
 
+#ifndef ASN1_PARSE_MAXDEPTH
+#define ASN1_PARSE_MAXDEPTH 128
+#endif
+
 static int asn1_print_info(BIO *bp, int tag, int xclass, int constructed,
                            int indent);
 static int asn1_parse2(BIO *bp, const unsigned char **pp, long length,
@@ -123,6 +127,11 @@ static int asn1_parse2(BIO *bp, const unsigned char **pp, long length,
     /* ASN1_BMPSTRING *bmp=NULL; */
     int dump_indent;
 
+    if (depth > ASN1_PARSE_MAXDEPTH) {
+            BIO_puts(bp, "BAD RECURSION DEPTH\n");
+            goto end;
+    }
+
     dump_indent = 6;            /* Because we know BIO_dump_indent() */
     p = *pp;
     tot = p + length;