+ unsigned char *abuf = NULL, *bbuf = NULL;
+ int alen, blen, ret;
+
+ /* X509_NAME_cmp() itself casts away constness in this way, so
+ * assume it's safe:
+ */
+ alen = i2d_X509_NAME((X509_NAME *)a, &abuf);
+ blen = i2d_X509_NAME((X509_NAME *)b, &bbuf);
+
+ if (alen < 0 || blen < 0)
+ ret = -2;
+ else if (alen != blen)
+ ret = alen - blen;
+ else /* alen == blen */
+ ret = memcmp(abuf, bbuf, alen);
+
+ OPENSSL_free(abuf);
+ OPENSSL_free(bbuf);
+
+ return ret;