From f2a29a3be14de787f303d84cc444d01027d62b74 Mon Sep 17 00:00:00 2001
From: Susant Sahani <ssahani@gmail.com>
Date: Mon, 13 May 2024 12:49:11 +0530
Subject: [PATCH] DTLS: Enable certificate verification

---
 src/netlog/netlog-dtls.c     | 23 +++++++++++++++++------
 src/netlog/netlog-dtls.h     |  5 ++++-
 src/netlog/systemd-netlogd.c |  4 ++--
 3 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/src/netlog/netlog-dtls.c b/src/netlog/netlog-dtls.c
index be511ba..b4114d8 100644
--- a/src/netlog/netlog-dtls.c
+++ b/src/netlog/netlog-dtls.c
@@ -125,6 +125,17 @@ int dtls_connect(DTLSManager *m, SocketAddress *address) {
         BIO_ctrl(bio, BIO_CTRL_DGRAM_SET_CONNECTED, 0, &address);
         SSL_set_bio(ssl , bio, bio);
 
+        /* Cerification verification  */
+        if (m->auth_mode != OPEN_SSL_CERTIFICATE_AUTH_MODE_NONE && m->auth_mode != OPEN_SSL_CERTIFICATE_AUTH_MODE_INVALID) {
+                log_debug("TLS: enable certificate verification");
+
+                SSL_set_ex_data(ssl, 0, m);
+                SSL_set_verify(ssl, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, ssl_verify_certificate_validity);
+        } else {
+                log_debug("TLS: disable certificate verification");
+                SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
+        }
+
         r = SSL_connect(ssl);
         if (r <= 0)
                 return log_error_errno(SYNTHETIC_ERRNO(ENOMEM),
@@ -150,10 +161,6 @@ int dtls_connect(DTLSManager *m, SocketAddress *address) {
                         log_debug("DTLS: No certificates.");
         }
 
-        /* Set reference in SSL obj */
-        SSL_set_ex_data(ssl, 0, NULL);
-        SSL_set_ex_data(ssl, 1, NULL);
-
         /* Set and activate timeouts */
         BIO_ctrl(bio, BIO_CTRL_DGRAM_SET_RECV_TIMEOUT, 0, &timeout);
 
@@ -192,13 +199,17 @@ void dtls_manager_free(DTLSManager *m) {
         free(m);
 }
 
-int dtls_manager_init(DTLSManager **ret) {
+int dtls_manager_init(OpenSSLCertificateAuthMode auth_mode, DTLSManager **ret) {
         _cleanup_(dtls_manager_freep) DTLSManager *m = NULL;
 
-        m = new0(DTLSManager, 1);
+        m = new(DTLSManager, 1);
         if (!m)
                 return log_oom();
 
+        *m = (DTLSManager) {
+           .auth_mode = auth_mode,
+        };
+
         *ret = TAKE_PTR(m);
         return 0;
 }
diff --git a/src/netlog/netlog-dtls.h b/src/netlog/netlog-dtls.h
index e8db2bb..ba530d9 100644
--- a/src/netlog/netlog-dtls.h
+++ b/src/netlog/netlog-dtls.h
@@ -7,6 +7,7 @@
 
 #include "socket-util.h"
 #include "openssl-util.h"
+#include "netlog-tls.h"
 
 typedef struct DTLSManager DTLSManager;
 
@@ -17,10 +18,12 @@ struct DTLSManager {
 
         int fd;
         bool connected;
+
+        OpenSSLCertificateAuthMode auth_mode;
 };
 
 void dtls_manager_free(DTLSManager *m);
-int dtls_manager_init(DTLSManager **ret);
+int dtls_manager_init(OpenSSLCertificateAuthMode auth_mode, DTLSManager **ret);
 
 int dtls_connect(DTLSManager *m, SocketAddress *addr);
 void dtls_disconnect(DTLSManager *m);
diff --git a/src/netlog/systemd-netlogd.c b/src/netlog/systemd-netlogd.c
index d17637b..fcbaa4e 100644
--- a/src/netlog/systemd-netlogd.c
+++ b/src/netlog/systemd-netlogd.c
@@ -173,10 +173,10 @@ int main(int argc, char **argv) {
 
         switch (m->protocol) {
                 case SYSLOG_TRANSMISSION_PROTOCOL_DTLS:
-                        r = dtls_manager_init(&m->dtls);
+                        r = dtls_manager_init(m->auth_mode, &m->dtls);
                         break;
                 case SYSLOG_TRANSMISSION_PROTOCOL_TLS:
-                        r = tls_manager_init( m->auth_mode, &m->tls);
+                        r = tls_manager_init(m->auth_mode, &m->tls);
                         break;
                 default:
                         break;