[PATCH] winhttp: Handle TLS close notify in netconn_is_alive().

[Paul Gofman]

Signed-off-by: Paul Gofman <pgofman at codeweavers.com>
---
    Server may decide to close the connection that we have cached. In that case it may send
    'Close notify' encrypted alert and then close the connection. Gnutls processes that
    [1] and returns zero length record from gnutls_record_recv().

    We currently check for EOF on socket in netconn_is_alive(). But in that case the socket
    has 31 byte of data in the buffer while the socket is de facto closed already. read_ssl_chunk()
    will process this message leaving the socket in the EOF state. If there is
    some unrelated message it should stay in peek_msg buffer. read_ssl_chunk() should not
    block on receiving the data as the socket is in the non blocking state.

    1. https://gitlab.com/gnutls/gnutls/-/blob/3.7.2/lib/record.c#L881

 dlls/winhttp/net.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/dlls/winhttp/net.c b/dlls/winhttp/net.c
index 8597179dc3e..3016608404a 100644
--- a/dlls/winhttp/net.c
+++ b/dlls/winhttp/net.c
@@ -616,11 +616,31 @@ DWORD netconn_set_timeout( struct netconn *netconn, BOOL send, int value )
 
 BOOL netconn_is_alive( struct netconn *netconn )
 {
+    SIZE_T size;
     int len;
     char b;
     DWORD err;
+    BOOL eof;
 
     set_blocking( netconn, FALSE );
+    if (netconn->secure)
+    {
+        while (!netconn->peek_msg && !(err = read_ssl_chunk( netconn, NULL, 0, &size, &eof )) && !eof)
+            ;
+
+        TRACE("Checking secure connection, err %d.\n", err);
+
+        if (netconn->peek_msg || err == WSAEWOULDBLOCK)
+        {
+            set_blocking( netconn, TRUE );
+            return TRUE;
+        }
+        if (err != SEC_E_OK && err != SEC_E_INCOMPLETE_MESSAGE)
+        {
+            set_blocking( netconn, TRUE );
+            return FALSE;
+        }
+    }
     len = sock_recv( netconn->socket, &b, 1, MSG_PEEK );
     err = WSAGetLastError();
     set_blocking( netconn, TRUE );
-- 
2.31.1