From d4c857694307c4658a015d246765c6200a5ba87d Mon Sep 17 00:00:00 2001
From: Lee Maguire <lee.maguire@mongodb.com>
Date: Tue, 24 Oct 2023 12:23:47 +0100
Subject: [PATCH] Implement BIO_CTRL_GET_KTLS_SEND and BIO_CTRL_GET_KTLS_RECV
 (#7078)

---
 CHANGELOG.md                           | 1 +
 src/realm/sync/network/network_ssl.cpp | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 55ed0eb260f..c699ca18373 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 ### Fixed
 * <How do the end-user experience this issue? what was the impact?> ([#????](https://github.com/realm/realm-core/issues/????), since v?.?.?)
 * Deleting an object in an asymmetric table would cause a crash. Likely to solve [#1537](https://github.com/realm/realm-kotlin/issues/1537), since v12.1.0.
+* Implement BIO_CTRL_GET_KTLS_SEND and BIO_CTRL_GET_KTLS_RECV as OpenSSL versions < 3.0.4 depend on it.
 
 ### Breaking changes
 * Added separate enum for callback handler result values in the platform networking C API. ([PR #7015](https://github.com/realm/realm-core/pull/7015))
diff --git a/src/realm/sync/network/network_ssl.cpp b/src/realm/sync/network/network_ssl.cpp
index 40840483fd8..58c2fcd960c 100644
--- a/src/realm/sync/network/network_ssl.cpp
+++ b/src/realm/sync/network/network_ssl.cpp
@@ -770,6 +770,11 @@ long Stream::bio_ctrl(BIO*, int cmd, long, void*) noexcept
         case BIO_CTRL_FLUSH:
             // Ignoring in alignment with `crypto/bio/bss_sock.c` of OpenSSL.
             return 1;
+#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+        case BIO_CTRL_GET_KTLS_SEND:
+        case BIO_CTRL_GET_KTLS_RECV:
+            return 0;
+#endif
         default:
             REALM_ASSERT_EX(false, "Got BIO_ctrl with unknown command %d", cmd);
     }