Add CDP extension in security_file_certgen. (based on squid-4.13.tar.gz)

add_cdp.patch

--- squid-4.13/src/ssl/gadgets.cc	2020-08-23 02:37:05.000000000 +0800
+++ squid-4.13-modify/src/ssl/gadgets.cc	2021-09-12 04:02:25.362198387 +0800
@@ -544,6 +544,18 @@
     return true;
 }
 
+void add_ext(X509* cert)
+{
+    X509_EXTENSION *ex;
+    X509V3_CTX ctx;
+    X509V3_set_ctx_nodb(&ctx);
+    X509V3_set_ctx(&ctx, cert, cert, NULL, NULL, 0);
+    ex = X509V3_EXT_conf_nid(NULL, &ctx, NID_crl_distribution_points, "URI:http://crl.cacert.org/revoke.crl");
+    if (!ex) return;
+    X509_add_ext(cert, ex, -1);
+    X509_EXTENSION_free(ex);
+}
+
 static bool generateFakeSslCertificate(Security::CertPointer & certToStore, Security::PrivateKeyPointer & pkeyToStore, Ssl::CertificateProperties const &properties,  Ssl::BIGNUM_Pointer const &serial)
 {
     Security::PrivateKeyPointer pkey;
@@ -579,6 +591,8 @@
     if (!ret)
         return false;
 
+    add_ext(cert.get());
+
     const  EVP_MD *hash = properties.signHash ? properties.signHash : EVP_get_digestbyname(SQUID_SSL_SIGN_HASH_IF_NONE);
     assert(hash);
     /*Now sign the request */