Tcl_DStringFree(&upperChannelBlocking);
    return res;
}

/*
 *-------------------------------------------------------------------
 *
 * TlsLoadClientCAFileFromMemory -- Load certificates from a client
 *	CA file from VFS into memory.
 *
 * Results:
 *	Number of certificates loaded or 0 for none.
 *
 * Side effects:
 *	Loads CA certificates
 *
 *-------------------------------------------------------------------
 */
static int
TlsLoadClientCAFileFromMemory(Tcl_Interp *interp, SSL_CTX *ctx, Tcl_Obj *file) {
    BIO  *bio  = NULL;
    X509 *cert = NULL;
    X509_STORE *store = NULL;
    Tcl_Obj    *buf = NULL;
    const void *data = NULL;
    X509_NAME  *name = NULL;
    STACK_OF(X509_NAME) *certNames = NULL;
    int ret = 0;
    Tcl_Size len = 0;

    /* Read file into memory */
    Tcl_Channel in = Tcl_FSOpenFileChannel(interp, file, "r", 0);
    if (in == NULL) {
	goto cleanup;
    }
    Tcl_SetChannelOption(interp, in, "-encoding", "binary");
    buf = Tcl_NewObj();
    Tcl_IncrRefCount(buf);

    if (Tcl_ReadChars(in, buf, -1, 0) < 0) {
	Tcl_Close(interp, in);
	goto cleanup;
    }
    Tcl_Close(interp, in);

    data = (const void *) Tcl_GetByteArrayFromObj(buf, &len);
    bio = BIO_new_mem_buf(data, len);
    if (bio == NULL) {
	goto cleanup;
    }

    /* Where the certs go */
    store = SSL_CTX_get_cert_store(ctx);
    if (store == NULL) {
	store = X509_STORE_new();
	if (store == NULL) {
	    goto cleanup;
	}
    }

    /* Where the CA names go */
    certNames = sk_X509_NAME_new_null();
    if (!certNames) {
        goto cleanup;
    }

    /* Attempt to load all certs from the PEM file */
    while ((cert = PEM_read_bio_X509(bio, NULL, 0, NULL)) != NULL) {
        if (X509_STORE_add_cert(store, cert) == 0) {
            X509_free(cert);
            ret = 0;
            goto cleanup;
        }
        /* Copy name to stack before certificate gets freed */
	name = X509_get_subject_name(cert);
        if (name) {
            X509_NAME *name_copy = X509_NAME_dup(name);
            if (!name_copy || !sk_X509_NAME_push(certNames, name_copy)) {
                X509_free(cert);
		ret = 0;
                goto cleanup;
            }
        }
        X509_free(cert);
        ret ++;
    }

    /* At least one cert was added so retain the store and CA list */
    if (ret) {
	if (SSL_CTX_get_cert_store(ctx) == NULL) {
	    SSL_CTX_set_cert_store(ctx, store);
	}
	SSL_CTX_set_client_CA_list(ctx, certNames);
    }

  cleanup:

    if (! ret) {
	/* New store is not required */
	if (store != SSL_CTX_get_cert_store(ctx)) {
	    X509_STORE_free(store);
	}
	/* Cert names will not be used */
	if (certNames) {
	    sk_X509_NAME_pop_free(certNames, X509_NAME_free);
	}
    }

    BIO_free(bio);

    if (buf)
	Tcl_DecrRefCount(buf);

    return ret;
}

/*
 *-------------------------------------------------------------------
 *
 * CTX_Init -- construct a SSL_CTX instance
 *
 * Results:
 *	A valid SSL_CTX instance or NULL.
 *
 * Side effects:
 *	constructs SSL context (CTX)

		abort++;
	    }
	    Tcl_DStringFree(&ds);
	}

	/* Set file of CA certificates in PEM format.  */
	if (CAfile != NULL) {
	    Tcl_Obj *cafileobj = Tcl_NewStringObj(CAfile, -1);
	    Tcl_IncrRefCount(cafileobj);

	    Tcl_Obj *fsinfo = Tcl_FSFileSystemInfo(cafileobj);
	    if (fsinfo) {
		Tcl_IncrRefCount(fsinfo);

		Tcl_Obj *fstype = NULL;
		Tcl_ListObjIndex(interp, fsinfo, 0, &fstype);

		if (Tcl_StringMatch("native", Tcl_GetString(fstype))) {
		    if (!SSL_CTX_load_verify_file(ctx, F2N(CAfile, &ds))) {
			abort++;
		    }
		    Tcl_DStringFree(&ds);

		    /* Set list of CAs to send to client when requesting a client certificate */
		    STACK_OF(X509_NAME) *certNames = SSL_load_client_CA_file(F2N(CAfile, &ds));
		    if (certNames != NULL) {
			SSL_CTX_set_client_CA_list(ctx, certNames);
		    }
		    Tcl_DStringFree(&ds);

		} else {
		    /* Load certificate into memory */
		    if (!TlsLoadClientCAFileFromMemory(interp, ctx, cafileobj)) {
			abort++;
		    }
		}
		Tcl_DecrRefCount(fsinfo);

	    } else {
		abort++; /* Path is not recognized */
	    }
	    Tcl_DecrRefCount(cafileobj);
	}
#endif
    }

    if (abort > 0) {
	/* return error */
    }