Enforce TLS peer certificate verification (client and server)

2 files changed, 10 insertions, 2 deletions

diff --git a/vespalib/src/vespa/vespalib/net/tls/impl/openssl_tls_context_impl.cpp b/vespalib/src/vespa/vespalib/net/tls/impl/openssl_tls_context_impl.cpp
index defa8a91650..27250dd43fc 100644
--- a/vespalib/src/vespa/vespalib/net/tls/impl/openssl_tls_context_impl.cpp
+++ b/vespalib/src/vespa/vespalib/net/tls/impl/openssl_tls_context_impl.cpp
@@ -162,9 +162,9 @@ OpenSslTlsContextImpl::OpenSslTlsContextImpl(const TransportSecurityOptions& ts_
     verify_private_key();
     enable_ephemeral_key_exchange();
     disable_compression();
+    enforce_peer_certificate_verification();
     // TODO set accepted cipher suites!
     // TODO `--> If not set in options, use Modern spec from https://wiki.mozilla.org/Security/Server_Side_TLS
-    // TODO set peer verification flags!
 }
 
 OpenSslTlsContextImpl::~OpenSslTlsContextImpl() = default;
@@ -259,4 +259,11 @@ void OpenSslTlsContextImpl::disable_compression() {
     ::SSL_CTX_set_options(_ctx.get(), SSL_OP_NO_COMPRESSION);
 }
 
+void OpenSslTlsContextImpl::enforce_peer_certificate_verification() {
+    // We require full mutual certificate verification. No way to configure
+    // out of this, at least not for the time being.
+    // TODO verification callback for custom CN/SAN etc checks.
+    SSL_CTX_set_verify(_ctx.get(), SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT, nullptr);
+}
+
 }
diff --git a/vespalib/src/vespa/vespalib/net/tls/impl/openssl_tls_context_impl.h b/vespalib/src/vespa/vespalib/net/tls/impl/openssl_tls_context_impl.h
index 208629d913a..72f9f3b570d 100644
--- a/vespalib/src/vespa/vespalib/net/tls/impl/openssl_tls_context_impl.h
+++ b/vespalib/src/vespa/vespalib/net/tls/impl/openssl_tls_context_impl.h
@@ -23,6 +23,7 @@ private:
     // Enable use of ephemeral key exchange (ECDHE), allowing forward secrecy.
     void enable_ephemeral_key_exchange();
     void disable_compression();
+    void enforce_peer_certificate_verification();
 };
 
-}
\ No newline at end of file
+}