TCTI: Add null tcti.

A tcti module which can only used for tcti initialization is added.

Signed-off-by: Juergen Repp <[email protected]>

Makefile.am

@@ -383,6 +383,25 @@ src_tss2_tcti_libtss2_tcti_pcap_la_SOURCES  = \
 endif # ENABLE_TCTI_PCAP
 EXTRA_DIST += lib/tss2-tcti-pcap.map
 
+# tcti null library
+if ENABLE_TCTI_NULL
+libtss2_tcti_null = src/tss2-tcti/libtss2-tcti-null.la
+tss2_HEADERS += $(srcdir)/include/tss2/tss2_tcti_null.h
+lib_LTLIBRARIES += $(libtss2_tcti_null)
+pkgconfig_DATA += lib/tss2-tcti-null.pc
+
+if HAVE_LD_VERSION_SCRIPT
+src_tss2_tcti_libtss2_tcti_null_la_LDFLAGS  = -Wl,--version-script=$(srcdir)/lib/tss2-tcti-null.map
+endif # HAVE_LD_VERSION_SCRIPT
+src_tss2_tcti_libtss2_tcti_null_la_LIBADD   = $(libtss2_tctildr) $(libtss2_mu) $(libutil) $(libutilio)
+src_tss2_tcti_libtss2_tcti_null_la_SOURCES  = \
+    src/tss2-tcti/tcti-common.c \
+    src/tss2-tcti/tcti-null.c \
+    src/tss2-tcti/tcti-null.h
+endif # ENABLE_TCTI_NULL
+EXTRA_DIST += lib/tss2-tcti-null.map
+
+
 # tcti libtpms library
 if ENABLE_TCTI_LIBTPMS
 libtss2_tcti_libtpms = src/tss2-tcti/libtss2-tcti-libtpms.la

configure.ac

@@ -15,7 +15,7 @@ m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])]) #Backward compatible setti
 
 AC_CONFIG_HEADERS([config.h])
 
-AC_CONFIG_FILES([Makefile Doxyfile lib/tss2-sys.pc lib/tss2-esys.pc lib/tss2-mu.pc lib/tss2-tcti-device.pc lib/tss2-tcti-mssim.pc lib/tss2-tcti-swtpm.pc lib/tss2-tcti-pcap.pc lib/tss2-tcti-libtpms.pc lib/tss2-rc.pc lib/tss2-tctildr.pc lib/tss2-fapi.pc lib/tss2-tcti-cmd.pc lib/tss2-policy.pc lib/tss2-tcti-spi-helper.pc lib/tss2-tcti-spi-ltt2go.pc lib/tss2-tcti-spidev.pc lib/tss2-tcti-spi-ftdi.pc lib/tss2-tcti-i2c-helper.pc lib/tss2-tcti-i2c-ftdi.pc])
+AC_CONFIG_FILES([Makefile Doxyfile lib/tss2-sys.pc lib/tss2-esys.pc lib/tss2-mu.pc lib/tss2-tcti-device.pc lib/tss2-tcti-mssim.pc lib/tss2-tcti-swtpm.pc lib/tss2-tcti-pcap.pc lib/tss2-tcti-null.pc lib/tss2-tcti-libtpms.pc lib/tss2-rc.pc lib/tss2-tctildr.pc lib/tss2-fapi.pc lib/tss2-tcti-cmd.pc lib/tss2-policy.pc lib/tss2-tcti-spi-helper.pc lib/tss2-tcti-spi-ltt2go.pc lib/tss2-tcti-spidev.pc lib/tss2-tcti-spi-ftdi.pc lib/tss2-tcti-i2c-helper.pc lib/tss2-tcti-i2c-ftdi.pc])
 
 # propagate configure arguments to distcheck
 AC_SUBST([DISTCHECK_CONFIGURE_FLAGS],[$ac_configure_args])
@@ -278,6 +278,12 @@ AC_ARG_ENABLE([tcti-pcap],
             [enable_tcti_pcap=yes])
 AM_CONDITIONAL([ENABLE_TCTI_PCAP], [test "x$enable_tcti_pcap" != xno])
 
+AC_ARG_ENABLE([tcti-null],
+            [AS_HELP_STRING([--disable-tcti-null],
+                            [don't build the tcti-null module])],,
+            [enable_tcti_null=yes])
+AM_CONDITIONAL([ENABLE_TCTI_NULL], [test "x$enable_tcti_null" != xno])
+
 AC_ARG_ENABLE([tcti-libtpms],
             [AS_HELP_STRING([--disable-tcti-libtpms],
                             [don't build the tcti-libtpms module])],

include/tss2/tss2_tcti_null.h

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (c) 2020 Infineon Technologies AG
+ * All rights reserved.
+ */
+#ifndef TSS2_TCTI_NULL_H
+#define TSS2_TCTI_NULL_H
+
+#include "tss2_tcti.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+TSS2_RC Tss2_Tcti_Null_Init (
+    TSS2_TCTI_CONTEXT *tctiContext,
+    size_t *size,
+    const char *conf);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* TSS2_TCTI_NULL_H */

lib/tss2-tcti-null.def

@@ -0,0 +1,4 @@
+LIBRARY tss2-tcti-null
+EXPORTS
+    Tss2_Tcti_Info
+    Tss2_Tcti_Null_Init

lib/tss2-tcti-null.map

@@ -0,0 +1,7 @@
+{
+    global:
+        Tss2_Tcti_Info;
+        Tss2_Tcti_Null_Init;
+    local:
+        *;
+};

lib/tss2-tcti-null.pc.in

@@ -0,0 +1,12 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: tss2-tcti-null
+Description: TCTI library for debugging at the TCTI interface.
+URL: https://github.com/tpm2-software/tpm2-tss
+Version: @VERSION@
+Requires.private: tss2-tctildr
+Cflags: -I${includedir}
+Libs: -ltss2-tcti-null -L${libdir}

src/tss2-tcti/tcti-null.c

@@ -0,0 +1,173 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (c) 2025 Juergen Repp
+ * All rights reserved.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h" // IWYU pragma: keep
+#endif
+
+#include <inttypes.h>           // for PRIxPTR, uintptr_t, uint8_t, int32_t
+#include <string.h>             // for NULL, size_t, memset
+
+#include "tcti-common.h"        // for TSS2_TCTI_COMMON_CONTEXT, TCTI_STATE_...
+#include "tss2_common.h"        // for TSS2_RC_SUCCESS, TSS2_RC, TSS2_TCTI_R...
+#include "tss2_tcti.h"          // for TSS2_TCTI_CONTEXT, TSS2_TCTI_INFO
+#include "tss2_tpm2_types.h"    // for TPM2_RC_SUCCESS
+#include "util/aux_util.h"      // for UNUSED
+
+#define LOGMODULE tcti
+#include "tcti-null.h"
+#include "tss2_tctildr.h"       // for Tss2_TctiLdr_Finalize, Tss2_TctiLdr_I...
+#include "util/log.h"           // for LOG_WARNING, LOG_ERROR, LOGBLOB_DEBUG
+
+/*
+ * This function wraps the "up-cast" of the opaque TCTI context type to the
+ * type for the null TCTI context. The only safeguard we have to ensure this
+ * operation is possible is the magic number in the null TCTI context.
+ * If passed a NULL context, or the magic number check fails, this function
+ * will return NULL.
+ */
+TSS2_TCTI_NULL_CONTEXT*
+tcti_null_context_cast (TSS2_TCTI_CONTEXT *tcti_ctx)
+{
+    if (tcti_ctx != NULL && TSS2_TCTI_MAGIC (tcti_ctx) == TCTI_NULL_MAGIC) {
+        return (TSS2_TCTI_NULL_CONTEXT*)tcti_ctx;
+    }
+    return NULL;
+}
+
+/*
+ * This function down-casts the null TCTI context to the common context
+ * defined in the tcti-common module.
+ */
+TSS2_TCTI_COMMON_CONTEXT*
+tcti_null_down_cast (TSS2_TCTI_NULL_CONTEXT *tcti_null)
+{
+    if (tcti_null == NULL) {
+        return NULL;
+    }
+    return &tcti_null->common;
+}
+
+TSS2_RC
+tcti_null_transmit (
+    TSS2_TCTI_CONTEXT *tcti_ctx,
+    size_t size,
+    const uint8_t *cmd_buf)
+{
+    UNUSED(tcti_ctx);
+    UNUSED(size);
+    UNUSED(cmd_buf);
+    return TSS2_TCTI_RC_NOT_IMPLEMENTED;
+}
+
+TSS2_RC
+tcti_null_receive (
+    TSS2_TCTI_CONTEXT *tctiContext,
+    size_t *response_size,
+    unsigned char *response_buffer,
+    int32_t timeout)
+{
+    UNUSED(tctiContext);
+    UNUSED(response_size);
+    UNUSED(response_buffer);
+    UNUSED(timeout);
+    return TSS2_TCTI_RC_NOT_IMPLEMENTED;
+}
+
+TSS2_RC
+tcti_null_cancel (
+    TSS2_TCTI_CONTEXT *tctiContext)
+{
+    UNUSED(tctiContext);
+    return TSS2_TCTI_RC_NOT_IMPLEMENTED;
+}
+
+TSS2_RC
+tcti_null_set_locality (
+    TSS2_TCTI_CONTEXT *tctiContext,
+    uint8_t locality)
+{
+    UNUSED(tctiContext);
+    UNUSED(locality);
+    return TSS2_TCTI_RC_NOT_IMPLEMENTED;
+}
+
+TSS2_RC
+tcti_null_get_poll_handles (
+    TSS2_TCTI_CONTEXT *tctiContext,
+    TSS2_TCTI_POLL_HANDLE *handles,
+    size_t *num_handles)
+{
+    UNUSED(tctiContext);
+    UNUSED(handles);
+    UNUSED(num_handles);
+    return TSS2_TCTI_RC_NOT_IMPLEMENTED;
+}
+
+void
+tcti_null_finalize (
+    TSS2_TCTI_CONTEXT *tctiContext)
+{
+    TSS2_TCTI_NULL_CONTEXT *tcti_null = tcti_null_context_cast (tctiContext);
+    TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_null_down_cast (tcti_null);
+    if (tcti_null == NULL) {
+        return;
+    }
+
+    tcti_common->state = TCTI_STATE_FINAL;
+}
+
+/*
+ * This is an implementation of the standard TCTI initialization function for
+ * this module.
+ */
+TSS2_RC
+Tss2_Tcti_Null_Init (
+    TSS2_TCTI_CONTEXT *tctiContext,
+    size_t *size,
+    const char *conf)
+{
+    UNUSED(conf);
+    TSS2_TCTI_NULL_CONTEXT *tcti_null = (TSS2_TCTI_NULL_CONTEXT*) tctiContext;
+    TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_null_down_cast (tcti_null);
+
+    if (tctiContext == NULL && size == NULL) {
+        return TSS2_TCTI_RC_BAD_VALUE;
+    } else if (tctiContext == NULL) {
+        *size = sizeof (TSS2_TCTI_NULL_CONTEXT);
+        return TSS2_RC_SUCCESS;
+    }
+
+    TSS2_TCTI_MAGIC (tcti_common) = TCTI_NULL_MAGIC;
+    TSS2_TCTI_VERSION (tcti_common) = TCTI_VERSION;
+    TSS2_TCTI_TRANSMIT (tcti_common) = tcti_null_transmit;
+    TSS2_TCTI_RECEIVE (tcti_common) = tcti_null_receive;
+    TSS2_TCTI_FINALIZE (tcti_common) = tcti_null_finalize;
+    TSS2_TCTI_CANCEL (tcti_common) = tcti_null_cancel;
+    TSS2_TCTI_GET_POLL_HANDLES (tcti_common) = tcti_null_get_poll_handles;
+    TSS2_TCTI_SET_LOCALITY (tcti_common) = tcti_null_set_locality;
+    TSS2_TCTI_MAKE_STICKY (tcti_common) = tcti_make_sticky_not_implemented;
+    tcti_common->state = TCTI_STATE_TRANSMIT;
+    tcti_common->locality = 3;
+    memset (&tcti_common->header, 0, sizeof (tcti_common->header));
+
+    return TSS2_RC_SUCCESS;
+}
+
+/* public info structure */
+const TSS2_TCTI_INFO tss2_tcti_info = {
+    .version = TCTI_VERSION,
+    .name = "tcti-null",
+    .description = "TCTI module which only provides initialization.",
+    .config_help = "",
+    .init = Tss2_Tcti_Null_Init,
+};
+
+const TSS2_TCTI_INFO*
+Tss2_Tcti_Info (void)
+{
+    return &tss2_tcti_info;
+}

src/tss2-tcti/tcti-null.h

@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (c) 2025 Juergen Repp
+ * All rights reserved.
+ */
+
+#ifndef TCTI_NULL_H
+#define TCTI_NULL_H
+
+#include "tcti-common.h"
+#include "tss2_tcti.h"
+
+#define TCTI_NULL_MAGIC 0x9af45c5d7d9d0d3fULL
+
+typedef struct {
+    const char *child_tcti;
+} tcti_null_conf_t;
+
+typedef struct {
+    TSS2_TCTI_COMMON_CONTEXT common;
+} TSS2_TCTI_NULL_CONTEXT;
+
+#endif /* TCTI_NULL_H */