Add size limit to X509_NAME structure.

This adds an explicit limit to the size of an X509_NAME structure. Some
part of OpenSSL (e.g. TLS) already effectively limit the size due to
restrictions on certificate size.

Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 295f3a24919157e2f9021d0b1709353710ad63db)

diff --git a/crypto/asn1/x_name.c b/crypto/asn1/x_name.c
index 737c426f2deacf1a1ac3a08330605de8b18aac21..a858c2993b90f4471690d52088e4aeb7912dac0a 100644 (file)
--- a/crypto/asn1/x_name.c
+++ b/crypto/asn1/x_name.c
@@ -66,6 +66,13 @@
 typedef STACK_OF(X509_NAME_ENTRY) STACK_OF_X509_NAME_ENTRY;
 DECLARE_STACK_OF(STACK_OF_X509_NAME_ENTRY)
 
+/*
+ * Maximum length of X509_NAME: much larger than anything we should
+ * ever see in practice.
+ */
+
+#define X509_NAME_MAX (1024 * 1024)
+
 static int x509_name_ex_d2i(ASN1_VALUE **val,
                             const unsigned char **in, long len,
                             const ASN1_ITEM *it,
@@ -192,6 +199,10 @@ static int x509_name_ex_d2i(ASN1_VALUE **val,
     int i, j, ret;
     STACK_OF(X509_NAME_ENTRY) *entries;
     X509_NAME_ENTRY *entry;
+    if (len > X509_NAME_MAX) {
+        ASN1err(ASN1_F_X509_NAME_EX_D2I, ASN1_R_TOO_LONG);
+        return 0;
+    }
     q = p;
 
     /* Get internal representation of Name */