See bug-report:

	https://core.tcl-lang.org/tcltls/tktview/539d25f105

--- tls.c	2020-10-12 16:39:22.000000000 -0400
+++ tls.c	2023-11-19 21:30:03.357601000 -0500
@@ -62,5 +62,5 @@
 			Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[]);
 
-static SSL_CTX *CTX_Init(State *statePtr, int isServer, int proto, char *key,
+static SSL_CTX *CTX_Init(State *statePtr, int proto, char *key,
 			char *certfile, unsigned char *key_asn1, unsigned char *cert_asn1,
 			int key_asn1_len, int cert_asn1_len, char *CAdir, char *CAfile,
@@ -897,5 +897,5 @@
 	ctx = ((State *)Tcl_GetChannelInstanceData(chan))->ctx;
     } else {
-	if ((ctx = CTX_Init(statePtr, server, proto, keyfile, certfile, key,
+	if ((ctx = CTX_Init(statePtr, proto, keyfile, certfile, key,
     cert, key_len, cert_len, CAdir, CAfile, ciphers,
     DHparams)) == (SSL_CTX*)0) {
@@ -1067,8 +1067,7 @@
 
 static SSL_CTX *
-CTX_Init(statePtr, isServer, proto, keyfile, certfile, key, cert,
+CTX_Init(statePtr, proto, keyfile, certfile, key, cert,
          key_len, cert_len, CAdir, CAfile, ciphers, DHparams)
     State *statePtr;
-    int isServer;
     int proto;
     char *keyfile;