[PATCH] efi/tpcm: Add TPCM module support

* [PATCH] efi/tpcm: Add TPCM module support
@ 2024-10-31 11:34 chench246
  2025-05-14 12:12 ` Fwd: " hao chen
  0 siblings, 1 reply; 9+ messages in thread
From: chench246 @ 2024-10-31 11:34 UTC (permalink / raw)
  To: grub-devel; +Cc: chench246, hao chen

From: chench246 <chench246@hotmail.com>

TPCM(Trusted Platform Control Module) is a Chinese standard and has similar function
to tpm, but tpcm adds the function of active monitoring and control to the system.
It can realize active startup measurement when the system starts,as well as dynamic
measurement and monitoring when the program is running, further enhance the security
of the system.

Signed-off-by: hao chen <chench246@gmail.com>
---
 grub-core/Makefile.core.def   |   7 ++
 grub-core/commands/efi/tpcm.c | 163 ++++++++++++++++++++++++++++++++++
 grub-core/commands/tpcm.c     |  99 +++++++++++++++++++++
 include/grub/efi/tpcm.h       |  60 +++++++++++++
 include/grub/err.h            |   3 +-
 5 files changed, 331 insertions(+), 1 deletion(-)
 create mode 100755 grub-core/commands/efi/tpcm.c
 create mode 100755 grub-core/commands/tpcm.c
 create mode 100644 include/grub/efi/tpcm.h

diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index 063ef5dd7..f1250601b 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -2562,6 +2562,13 @@ module = {
   enable = efi;
 };
 
+module = {
+  name = tpcm;
+  common = commands/tpcm.c;
+  efi = commands/efi/tpcm.c;
+  enable = x86_64_efi;
+};
+
 module = {
   name = tr;
   common = commands/tr.c;
diff --git a/grub-core/commands/efi/tpcm.c b/grub-core/commands/efi/tpcm.c
new file mode 100755
index 000000000..bc97e800c
--- /dev/null
+++ b/grub-core/commands/efi/tpcm.c
@@ -0,0 +1,163 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *  EFI TPCM support code.
+ */
+
+#include <grub/err.h>
+#include <grub/efi/tpcm.h>
+
+
+static grub_uint32_t g_measured_id = STAGE_START;
+
+/*
+    get_tpcm_stage:
+      TPCM does not make a distinction with the type of
+    measured target, so we use g_measured_id directly
+    for the stage.
+ */
+static grub_uint32_t get_tpcm_stage(void)
+{
+    grub_uint32_t stage = STAGE_INVALID;
+
+    stage = g_measured_id;
+
+    if (stage < STAGE_START || stage > STAGE_END)
+        stage = STAGE_INVALID;
+
+    return stage;
+}
+
+/*
+    update_measured_id:
+      update g_measured_id +1 every time measured, and g_measured_id
+    will never be decreased.
+ */
+static void update_measured_id(void)
+{
+    g_measured_id++;
+}
+
+/*
+    measure_memory:
+      measure the memery region--(addr, size) through the TPCM protocol.
+    if TPCM protocol is not exist in BIOS, it will return SUCC to keep
+    compatible with non-measurement-support bios; if TPCM protocol is
+    exist but not enabled, it will also return SUCC.
+ */
+static grub_err_t measure_memory(enum grub_file_type type __attribute__((unused)),
+                                 char *desc,
+                                 grub_addr_t addr,
+                                 grub_size_t size)
+{
+    grub_efi_handle_t   *handles = 0;
+    grub_efi_uintn_t    num_handles;
+    grub_efi_handle_t   grub_c2p_handle = 0;
+    grub_err_t  test_c2p_err = GRUB_ERR_BAD_OS;
+    grub_guid_t         c2p_guid = C2PGUID;
+    grub_uint32_t       measure_result = 0;
+    grub_uint32_t       control_result = 0;
+    grub_efi_boolean_t    verify_enable = 0;
+    grub_size_t         desc_len = 0;
+
+    handles = grub_efi_locate_handle(GRUB_EFI_BY_PROTOCOL, &c2p_guid, NULL, &num_handles);
+    if (handles && (num_handles > 0))
+    {
+        struct c2p_protocol *c2p;
+
+        grub_c2p_handle = handles[0];
+        grub_dprintf ("tpcm", "measue memory addr 0x%lx size 0x%lx  \n", addr, size);
+        c2p = grub_efi_open_protocol(grub_c2p_handle, &c2p_guid,
+                                      GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+        if (c2p)
+        {
+            verify_enable = c2p->verify_is_enabled (c2p);
+            if (verify_enable)
+            {
+                struct addr_range range;
+                grub_efi_status_t status = 0;
+                grub_uint32_t stage = STAGE_INVALID;
+
+                range.start  = addr;
+                range.length = size;
+
+                stage = get_tpcm_stage();
+                if (stage != STAGE_INVALID)
+                {
+                    desc_len = grub_strlen(desc) + 1;
+                    status = c2p->verify_raw (c2p, stage, (grub_uint64_t)desc, desc_len, 1, &range, &measure_result, &control_result);
+                    if ((!status) && ((control_result & MEASURE_ACTION_MASK) == 0) )
+                    {
+                        grub_dprintf ("tpcm", "verify_raw success. stage[%d]desc:[%s]\n", stage, desc);
+                        test_c2p_err = GRUB_ERR_NONE;
+                    }
+                    else
+                    {
+                        grub_dprintf ("tpcm", "verify_raw error\n");
+                        while(1) 
+                        {
+                            grub_error (GRUB_ERR_TPCM_VERIFY, "tpcm verify error. stage[%d]desc[%s]\n", stage, desc);
+                            asm volatile ("hlt");
+                        }
+                    }
+                }
+                else {
+                    grub_dprintf ("tpcm", "invalid stage\n");
+                }
+
+                update_measured_id();
+
+            }
+            else {
+                grub_dprintf ("tpcm", "image verify not enabled\n");
+                test_c2p_err = GRUB_ERR_NONE;
+            }
+        }
+        else
+            grub_dprintf ("tpcm", "open c2p protocol failed\n");
+    }
+    else
+    {
+        /* keep compatible with non-measurement-support bios. */
+        grub_dprintf ("tpcm", "not found C2P protocol\n");
+        test_c2p_err = GRUB_ERR_NONE;
+    }
+
+    return test_c2p_err;
+}
+
+/*
+    grub_tpcm_measure_memory:
+ */
+grub_err_t grub_tpcm_measure_memory(void *context, grub_addr_t buf, grub_size_t size)
+{
+    char *p_context = (char *)context;
+    char *p, *p_desc;
+    char tmp[TPCM_MAX_BUF_SIZE] = {'0'};
+    enum grub_file_type type;
+
+    if (!p_context)
+        return GRUB_ERR_BUG;
+
+    p = grub_strchr(p_context, '|');
+    p_desc = p + 1;
+    grub_memcpy(tmp, p_context, (p-p_context));
+    type = grub_strtoul(tmp, 0, 10);
+
+    return measure_memory(type, p_desc, buf, size);
+}
+
diff --git a/grub-core/commands/tpcm.c b/grub-core/commands/tpcm.c
new file mode 100755
index 000000000..1c8bd77ce
--- /dev/null
+++ b/grub-core/commands/tpcm.c
@@ -0,0 +1,99 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *  Core TPCM support code.
+ */
+
+#include <grub/err.h>
+#include <grub/verify.h>
+#include <grub/dl.h>
+#include <grub/efi/tpcm.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+static char context_buf[TPCM_MAX_BUF_SIZE];
+
+static grub_err_t grub_tpcm_verify_init(grub_file_t io,
+                      enum grub_file_type type,
+                      void **context, 
+                      enum grub_verify_flags *flags)
+{
+    grub_memset(context_buf, 0, TPCM_MAX_BUF_SIZE);
+    grub_snprintf(context_buf, TPCM_MAX_BUF_SIZE, "%d|%s", (type & GRUB_FILE_TYPE_MASK), io->name);
+    *context = context_buf;
+    *flags |= GRUB_VERIFY_FLAGS_SINGLE_CHUNK;
+
+    return GRUB_ERR_NONE;
+}
+
+static grub_err_t grub_tpcm_verify_write(void *context, void *buf , grub_size_t size )
+{
+    return grub_tpcm_measure_memory(context, (grub_addr_t)buf, size);
+}
+
+static grub_err_t grub_tpcm_verify_string (char *str, enum grub_verify_string_type type)
+{
+    const char *prefix = NULL;
+    char *description, *context;
+    grub_err_t status;
+
+    switch (type)
+    {
+    case GRUB_VERIFY_KERNEL_CMDLINE:
+      prefix = "kernel_cmdline: ";
+      break;
+    case GRUB_VERIFY_MODULE_CMDLINE:
+      prefix = "module_cmdline: ";
+      break;
+    case GRUB_VERIFY_COMMAND:
+      prefix = "grub_cmd: ";
+      break;
+    }
+
+    context = grub_zalloc(grub_strlen (str) + grub_strlen (prefix) + 1 + 4);  /* 4 for type */
+    if (!context)
+        return grub_errno;
+
+    grub_snprintf(context, 4, "%d|", (type & GRUB_FILE_TYPE_MASK));
+    description = context + grub_strlen(context);
+    grub_memcpy(description, prefix, grub_strlen (prefix));
+    grub_memcpy(description + grub_strlen (prefix), str, grub_strlen (str) + 1);
+
+    status = grub_tpcm_measure_memory(context, (grub_addr_t)str, grub_strlen(str));
+
+    grub_free(context);
+
+    return status;
+}
+
+struct grub_file_verifier grub_tpcm_verifier = {
+    .name = "tpcm",
+    .init  = grub_tpcm_verify_init,
+    .write = grub_tpcm_verify_write,
+    .verify_string = grub_tpcm_verify_string,
+};
+
+GRUB_MOD_INIT (tpcm)
+{
+    grub_verifier_register(&grub_tpcm_verifier);
+}
+
+GRUB_MOD_FINI (tpcm)
+{
+    grub_verifier_unregister(&grub_tpcm_verifier);
+}
+
diff --git a/include/grub/efi/tpcm.h b/include/grub/efi/tpcm.h
new file mode 100644
index 000000000..a4e0c765a
--- /dev/null
+++ b/include/grub/efi/tpcm.h
@@ -0,0 +1,60 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2018  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GRUB_EFI_TPCM_HEADER
+#define GRUB_EFI_TPCM_HEADER 1
+
+#include <grub/file.h>
+#include <grub/efi/api.h>
+#include <grub/efi/efi.h>
+
+#define C2PGUID         {0xf89ab5cd, 0x2829, 0x422f, {0xa5, 0xf3, 0x03, 0x28, 0xe0, 0x6c, 0xfc, 0xbb}}
+#define MEASURE_RESULT_MASK          (0xff00)
+#define MEASURE_RESULT_SHIFT         (16)
+#define MEASURE_ACTION_MASK          (0x1)
+#define TPCM_MAX_BUF_SIZE            128
+
+/*
+   stage layout:
+     2000~2999: +1 every time
+*/
+
+#define STAGE_START      2000
+#define STAGE_END        2999
+#define STAGE_INVALID    3000
+
+struct addr_range {
+    grub_uint64_t start;
+    grub_uint64_t length;
+};
+struct c2p_protocol {
+    grub_efi_status_t (__grub_efi_api *verify_raw) (struct c2p_protocol *this,
+                                    grub_uint32_t measure_stage,
+                                    grub_uint64_t image_info,
+                                    grub_uint32_t image_info_size,
+                                    grub_uint32_t num_addr_range,
+                                    struct addr_range ranges[],
+                                    grub_uint32_t *measure_result,
+                                    grub_uint32_t *control_result);
+    grub_efi_boolean_t (__grub_efi_api *verify_is_enabled)(struct c2p_protocol *this);
+};
+typedef struct c2p_protocol c2p_protocol_t;
+
+grub_err_t grub_tpcm_measure_memory(void *context, grub_addr_t buf, grub_size_t size);
+
+#endif
diff --git a/include/grub/err.h b/include/grub/err.h
index 1c07034cd..f5268dd47 100644
--- a/include/grub/err.h
+++ b/include/grub/err.h
@@ -73,7 +73,8 @@ typedef enum
     GRUB_ERR_NET_NO_DOMAIN,
     GRUB_ERR_EOF,
     GRUB_ERR_BAD_SIGNATURE,
-    GRUB_ERR_BAD_FIRMWARE
+    GRUB_ERR_BAD_FIRMWARE,
+    GRUB_ERR_TPCM_VERIFY
   }
 grub_err_t;
 
-- 
2.17.1


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