[PATCH] implement policy_pcr commands to lock NV-indexes behind a PCR

niek.nooijens at omron.com niek.nooijens at omron.com
Wed Feb 21 01:12:21 CET 2024


Hi dan

This might be because I used the checkpatch.pl script.
Here's one without it.

Niek

=========================START PATCH =======================
From de056f510156a2fa1b4b439e1fa1f44516aa8add Mon Sep 17 00:00:00 2001
From: Niek Nooijens <niek.nooijens at omron.com>
Date: Tue, 20 Feb 2024 13:42:57 +0900
Subject: [PATCH] [TPM] implement commands to lock NV-indexes behind a PCR
 policy

Added commands are:
- start auth session
- flush context
- policyPCR
- getPolicyDigest

Signed-off-by: Niek Nooijens <niek.nooijens at omron.com>
---
 cmd/tpm-v2.c         | 258 +++++++++++++++++++++++++++++++
 include/tpm-common.h |   2 +
 include/tpm-v2.h     | 126 ++++++++++++---
 lib/tpm-v2.c         | 355 +++++++++++++++++++++++++++++++++++++------
 lib/tpm_api.c        |   4 +-
 5 files changed, 669 insertions(+), 76 deletions(-)

diff --git a/cmd/tpm-v2.c b/cmd/tpm-v2.c
index 7e479b9dfe..6b6f4629ea 100644
--- a/cmd/tpm-v2.c
+++ b/cmd/tpm-v2.c
@@ -356,6 +356,221 @@ static int do_tpm_pcr_setauthvalue(struct cmd_tbl *cmdtp, int flag,
                                          key, key_sz));
 }

+static int do_tpm_nv_define(struct cmd_tbl *cmdtp, int flag,
+              int argc, char *const argv[])
+{
+     struct udevice *dev;
+     struct tpm_chip_priv *priv;
+     u32 nv_addr, nv_size, rc;
+     void *policy_addr = NULL;
+     size_t policy_size = 0;
+     int ret;
+
+     u32 nv_attributes = TPMA_NV_PLATFORMCREATE | TPMA_NV_OWNERWRITE | TPMA_NV_OWNERREAD | TPMA_NV_PPWRITE | TPMA_NV_PPREAD;
+
+     if (argc < 3 && argc > 7)
+           return CMD_RET_USAGE;
+
+     ret = get_tpm(&dev);
+     if (ret)
+           return ret;
+
+     priv = dev_get_uclass_priv(dev);
+     if (!priv)
+           return -EINVAL;
+
+     nv_addr = simple_strtoul(argv[1], NULL, 0);
+
+     nv_size = simple_strtoul(argv[2], NULL, 0);
+
+     if (argc > 3)
+           nv_attributes = simple_strtoul(argv[3], NULL, 0);
+
+     if (argc > 4) {
+           policy_addr = map_sysmem(simple_strtoul(argv[4], NULL, 0), 0);
+           nv_attributes |= (TPMA_NV_POLICYREAD | TPMA_NV_POLICYWRITE); //obligated, might as well force it
+           if (argc < 5)
+                 return CMD_RET_USAGE;
+           policy_size = simple_strtoul(argv[5], NULL, 0);
+     }
+
+     rc = tpm2_nv_define_space(dev, nv_addr, nv_size, nv_attributes, policy_addr, policy_size);
+
+     if (rc)
+           printf("ERROR: nv_define #%u returns: 0x%x\n", nv_addr, rc);
+
+     if (policy_addr)
+           unmap_sysmem(policy_addr);
+
+     return report_return_code(rc);
+}
+
+static int do_tpm_nv_undefine(struct cmd_tbl *cmdtp, int flag,
+              int argc, char *const argv[])
+{
+     struct udevice *dev;
+     u32 nv_addr, ret, rc;
+
+     ret = get_tpm(&dev);
+     if (ret)
+           return ret;
+
+     if (argc != 2)
+           return CMD_RET_USAGE;
+
+     nv_addr = simple_strtoul(argv[1], NULL, 0);
+     rc = tpm2_nv_undefine_space(dev, nv_addr);
+
+     return report_return_code(rc);
+}
+
+static int do_tpm_nv_read_value(struct cmd_tbl *cmdtp, int flag,
+              int argc, char *const argv[])
+{
+     struct udevice *dev;
+     u32 nv_addr, nv_size, rc;
+     void *session_addr = NULL;
+     int ret;
+     void *out_data;
+
+     ret = get_tpm(&dev);
+     if (ret)
+           return ret;
+
+     if (argc < 4)
+           return CMD_RET_USAGE;
+
+     nv_addr = simple_strtoul(argv[1], NULL, 0);
+
+     nv_size = simple_strtoul(argv[2], NULL, 0);
+
+     out_data = map_sysmem(simple_strtoul(argv[3], NULL, 0), 0);
+
+     if (argc == 5)
+           session_addr = map_sysmem(simple_strtoul(argv[4], NULL, 0), 0);
+
+     rc = tpm2_nv_read_value(dev, nv_addr, out_data, nv_size, session_addr);
+
+     if (rc)
+           printf("ERROR: nv_read #%u returns: #%u\n", nv_addr, rc);
+
+     unmap_sysmem(out_data);
+     return report_return_code(rc);
+}
+
+static int do_tpm_nv_write_value(struct cmd_tbl *cmdtp, int flag,
+              int argc, char *const argv[]) //TODO: session handle from auth session!
+{
+     struct udevice *dev;
+     u32 nv_addr, nv_size, rc;
+     void *session_addr = NULL;
+     int ret;
+
+     ret = get_tpm(&dev);
+           if (ret)
+                 return ret;
+
+           if (argc < 4)
+                 return CMD_RET_USAGE;
+
+     nv_addr = simple_strtoul(argv[1], NULL, 0); //tpm_addr
+
+     nv_size = simple_strtoul(argv[2], NULL, 0); //size
+
+     void *data_to_write = map_sysmem(simple_strtoul(argv[3], NULL, 0), 0);
+
+     if (argc == 5)
+           session_addr = map_sysmem(simple_strtoul(argv[4], NULL, 0), 0);
+
+     rc = tpm2_nv_write_value(dev, nv_addr, data_to_write, nv_size, session_addr);
+
+     if (rc)
+           printf("ERROR: nv_write #%u returns: #%u\n", nv_addr, rc);
+
+     unmap_sysmem(session_addr);
+     unmap_sysmem(data_to_write);
+     return report_return_code(rc);
+}
+
+static int do_start_auth_session(struct cmd_tbl *cmdtp, int flag,
+int argc, char *const argv[])
+{
+     struct udevice *dev;
+     u32 rc;
+     u8 session_type = TPM_SE_POLICY;
+     int ret;
+
+     ret = get_tpm(&dev);
+
+     if (argc < 2)
+           return CMD_RET_USAGE;
+
+     void *data_to_write = map_sysmem(simple_strtoul(argv[1], NULL, 0), 0);
+
+     if (argc > 2)
+           session_type = simple_strtoul(argv[2], NULL, 0);
+
+     rc = tpm2_start_auth_session(dev, data_to_write, session_type);
+
+     if (rc)
+           printf("ERROR: start_auth_session returns: #%u\n", rc);
+
+     unmap_sysmem(data_to_write);
+     return report_return_code(rc);
+}
+
+static int do_flush_context(struct cmd_tbl *cmdtp, int flag,
+int argc, char *const argv[])
+{
+     struct udevice *dev;
+     u32 rc;
+     int ret;
+
+     ret = get_tpm(&dev);
+
+     if (argc < 2)
+           return CMD_RET_USAGE;
+
+     void *data_to_read = map_sysmem(simple_strtoul(argv[1], NULL, 0), 0);
+     u32 session_handle = *((u32 *)data_to_read);
+
+     rc = tpm2_flush_context(dev, session_handle);
+
+     if (rc)
+           printf("ERROR: flush_context returns: #%u\n", rc);
+
+     unmap_sysmem(data_to_read);
+     return report_return_code(rc);
+}
+
+static int do_policy_pcr(struct cmd_tbl *cmdtp, int flag,
+int argc, char *const argv[])
+{
+     struct udevice *dev;
+     u32 rc, pcr;
+     int ret;
+
+     ret = get_tpm(&dev);
+
+     if (argc != 4)
+                 return CMD_RET_USAGE;
+
+     void *data_to_read = map_sysmem(simple_strtoul(argv[1], NULL, 0), 0);
+     u32 session_handle = *((u32 *)data_to_read);
+     pcr = simple_strtoul(argv[2], NULL, 0);
+
+     void *out_digest = map_sysmem(simple_strtoul(argv[3], NULL, 0), 0);
+
+     rc = tpm2_set_policy_pcr(dev, session_handle, pcr, out_digest);
+
+     if (rc)
+           printf("ERROR: policy_pcr returns: #%u\n", rc);
+
+     unmap_sysmem(data_to_read);
+     unmap_sysmem(out_digest);
+     return report_return_code(rc);
+}
+
 static struct cmd_tbl tpm2_commands[] = {
      U_BOOT_CMD_MKENT(device, 0, 1, do_tpm_device, "", ""),
      U_BOOT_CMD_MKENT(info, 0, 1, do_tpm_info, "", ""),
@@ -375,6 +590,13 @@ static struct cmd_tbl tpm2_commands[] = {
                   do_tpm_pcr_setauthpolicy, "", ""),
      U_BOOT_CMD_MKENT(pcr_setauthvalue, 0, 1,
                   do_tpm_pcr_setauthvalue, "", ""),
+     U_BOOT_CMD_MKENT(nv_define, 0, 1, do_tpm_nv_define, "", ""),
+     U_BOOT_CMD_MKENT(nv_undefine, 0, 1, do_tpm_nv_undefine, "", ""),
+     U_BOOT_CMD_MKENT(nv_read, 0, 1, do_tpm_nv_read_value, "", ""),
+     U_BOOT_CMD_MKENT(nv_write, 0, 1, do_tpm_nv_write_value, "", ""),
+     U_BOOT_CMD_MKENT(start_auth_session, 0, 1, do_start_auth_session, "", ""),
+     U_BOOT_CMD_MKENT(flush_context, 0, 1, do_flush_context, "", ""),
+     U_BOOT_CMD_MKENT(policy_pcr, 0, 1, do_policy_pcr, "", ""),
 };

 struct cmd_tbl *get_tpm2_commands(unsigned int *size)
@@ -453,4 +675,40 @@ U_BOOT_CMD(tpm2, CONFIG_SYS_MAXARGS, 1, do_tpm, "Issue a TPMv2.x command",
 "    <pcr>: index of the PCR\n"
 "    <key>: secret to protect the access of PCR #<pcr>\n"
 "    <password>: optional password of the PLATFORM hierarchy\n"
+"\n"
+"nv_define <tpm_addr> <size> [<attributes> <policy_digest_addr> <policy_size>]\n"
+"    Define new nv index in the TPM at <tpm_addr> with size <size>\n"
+"    <tpm_addr>: the internal address used within the TPM for the NV-index\n"
+"    <attributes>: is described in tpm-v2.h enum tpm_index_attrs. Note; Always use TPMA_NV_PLATFORMCREATE!\n"
+"                  will default to: TPMA_NV_PLATFORMCREATE|TPMA_NV_OWNERWRITE|TPMA_NV_OWNERREAD|TPMA_NV_PPWRITE|TPMA_NV_PPREAD\n"
+"    <policy_digest_addr>: address to a policy digest. (e.g. a PCR value)\n"
+"    <policy_size>: size of the digest in bytes\n"
+"nv_undefine <tpm_addr>\n"
+"    delete nv index\n"
+"nv_read <tpm_addr> <size> <data_addr> [<session_handle_addr>]\n"
+"    Read data stored in TPM nv_memory at <tpm_addr> with size <size>\n"
+"    <tpm_addr>: the internal address used within the TPM for the NV-index\n"
+"    <size>: datasize in bytes\n"
+"    <data_addr>: memory address where to store the data read from the TPM\n"
+"    <session_handle_addr>: addr where the session handle is stored\n"
+"nv_write <tpm_addr> <size> <data_addr> [<session_handle_addr>]\n"
+"    Write data to the TPM's nv_memory at <tpm_addr> with size <size>\n"
+"    <tpm_addr>: the internal address used within the TPM for the NV-index\n"
+"    <size>: datasize in bytes\n"
+"    <data_addr>: memory address of the data to be written to the TPM's NV-index\n"
+"    <session_handle_addr>: addr where the session handle is stored\n"
+"start_auth_session <session_handle_addr> [<session_type>]\n"
+"    Start an authorization session and store it's handle at <session_handle_addr>\n"
+"     <session_handle_addr>: addr where to store the handle data (4 bytes)\n"
+"     <session_type>: type of session: 0x00 for HMAC, 0x01 for policy, 0x03 for trial\n"
+"                    will default to 0x01 (TPM_SE_POLICY) if not provided\n"
+"                    to create a policy, use TPM_SE_TRIAL (0x03), to authenticate TPM_SE_POLICY (0x01)\n"
+"flush_context <session_handle_addr>\n"
+"    flush/terminate a session which's handle is stored at <session_handle_addr>\n"
+"     <session_handle_addr>: addr where the session handle is stored\n"
+"policy_pcr <session_handle_addr> <pcr> <digest_addr>\n"
+"    create a policy to authorize using a PCR\n"
+"    <session_handle_addr>: addr where the session handle is stored\n"
+"    <pcr>: index of the PCR\n"
+"    <digest_addr>: addr where to store the policy digest (for nv_define/nv_read/write)\n"
 );
diff --git a/include/tpm-common.h b/include/tpm-common.h
index 1ba81386ce..5620454da7 100644
--- a/include/tpm-common.h
+++ b/include/tpm-common.h
@@ -69,6 +69,8 @@ struct tpm_chip_priv {
      uint pcr_count;
      uint pcr_select_min;
      bool plat_hier_disabled;
+     u16 nonce_sz;
+     u8 nonce[32]; //NONCE_TPM_SIZE;
 };

 /**
diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index 33dd103767..5b60883777 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -301,7 +301,8 @@ enum tpm2_startup_types {
  */
 enum tpm2_handles {
      TPM2_RH_OWNER           = 0x40000001,
-     TPM2_RS_PW        = 0x40000009,
+     TPM2_RH_NULL            = 0x40000007,
+     TPM2_RS_PW              = 0x40000009,
      TPM2_RH_LOCKOUT         = 0x4000000A,
      TPM2_RH_ENDORSEMENT     = 0x4000000B,
      TPM2_RH_PLATFORM  = 0x4000000C,
@@ -325,24 +326,30 @@ enum tpm2_handles {
  * @TPM2_CC_PCR_SETAUTHVAL: TPM2_PCR_SetAuthValue().
  */
 enum tpm2_command_codes {
-     TPM2_CC_STARTUP         = 0x0144,
-     TPM2_CC_SELF_TEST = 0x0143,
-     TPM2_CC_HIER_CONTROL    = 0x0121,
-     TPM2_CC_CLEAR           = 0x0126,
-     TPM2_CC_CLEARCONTROL    = 0x0127,
-     TPM2_CC_HIERCHANGEAUTH  = 0x0129,
-     TPM2_CC_NV_DEFINE_SPACE = 0x012a,
-     TPM2_CC_PCR_SETAUTHPOL  = 0x012C,
-     TPM2_CC_NV_WRITE  = 0x0137,
-     TPM2_CC_NV_WRITELOCK    = 0x0138,
-     TPM2_CC_DAM_RESET = 0x0139,
-     TPM2_CC_DAM_PARAMETERS  = 0x013A,
-     TPM2_CC_NV_READ         = 0x014E,
-     TPM2_CC_GET_CAPABILITY  = 0x017A,
-     TPM2_CC_GET_RANDOM      = 0x017B,
-     TPM2_CC_PCR_READ  = 0x017E,
-     TPM2_CC_PCR_EXTEND      = 0x0182,
-     TPM2_CC_PCR_SETAUTHVAL  = 0x0183,
+     TPM2_CC_STARTUP                     = 0x0144,
+     TPM2_CC_SELF_TEST             = 0x0143,
+     TPM2_CC_HIER_CONTROL          = 0x0121,
+     TPM2_CC_CLEAR                       = 0x0126,
+     TPM2_CC_CLEARCONTROL          = 0x0127,
+     TPM2_CC_HIERCHANGEAUTH        = 0x0129,
+     TPM2_CC_NV_DEFINE_SPACE       = 0x012a,
+     TPM2_CC_NV_UNDEFINE_SPACE     = 0x0122,
+     TPM2_CC_PCR_SETAUTHPOL        = 0x012C,
+     TPM2_CC_CREATE_PRIMARY        = 0x0131,
+     TPM2_CC_NV_WRITE              = 0x0137,
+     TPM2_CC_NV_WRITELOCK          = 0x0138,
+     TPM2_CC_DAM_RESET             = 0x0139,
+     TPM2_CC_DAM_PARAMETERS        = 0x013A,
+     TPM2_CC_NV_READ               = 0x014E,
+     TPM2_CC_FLUSH_CONTEXT         = 0x0165,
+     TPM2_CC_START_AUTH_SESSION    = 0x0176,
+     TPM2_CC_GET_CAPABILITY        = 0x017A,
+     TPM2_CC_GET_RANDOM            = 0x017B,
+     TPM2_CC_PCR_READ              = 0x017E,
+     TPM2_CC_POLICY_PCR                  = 0x017F,
+     TPM2_CC_PCR_EXTEND                  = 0x0182,
+     TPM2_CC_PCR_SETAUTHVAL        = 0x0183,
+     TPM2_CC_POLICY_GET_DIGEST     = 0x0189,
 };

 /**
@@ -384,6 +391,16 @@ enum tpm2_algorithms {
      TPM2_ALG_SHA512         = 0x0D,
      TPM2_ALG_NULL           = 0x10,
      TPM2_ALG_SM3_256  = 0x12,
+     TPM2_ALG_ECC            = 0x23,
+};
+
+/**
+ * TPM2 session types.
+ */
+enum tpm2_se {
+     TPM_SE_HMAC             = 0x00,
+     TPM_SE_POLICY           = 0x01,
+     TPM_SE_TRIAL            = 0x03,
 };

 extern const enum tpm2_algorithms tpm2_supported_algorithms[4];
@@ -700,6 +717,51 @@ u32 tpm2_self_test(struct udevice *dev, enum tpm2_yes_no full_test);
 u32 tpm2_clear(struct udevice *dev, u32 handle, const char *pw,
             const ssize_t pw_sz);

+/**
+ * Issue a TPM2_StartAuthSession command. (chaining several commands together that need authorization)
+ *
+ * @dev          TPM device
+ * @session_handle     Pointer to memory where to store the session handle.
+ * @session_type tpm2_se value to indicate session type (usually TPM_SE_POLICY)
+ *
+ * Return: code of the operation
+ */
+u32 tpm2_start_auth_session(struct udevice *dev, u32 *session_handle, u8 session_type);
+/**
+ * Issue a TPM2_FlushContext command. (for ending the authorization session)
+ *
+ * @dev          TPM device
+ * @session_handle     Authorization session to be terminated.
+ *
+ * Return: code of the operation
+ */
+u32 tpm2_flush_context(struct udevice *dev, u32 session_handle);
+
+/**
+ * Issue a TPM2_PolicyPCR command. (for authenticating using a PCR value)
+ *
+ * @dev          TPM device
+ * @session_handle     policy session handle started with start_auth_session.
+ * @index  Index of the PCR
+ *
+ * @note   For now only 1 PCR selection is supported,
+ *               since the value of one PCR can be extended with the value of another.
+ *               This achieves the same effect as selecting multiple PCR's
+ * @out_digest   addr where to write the digest
+ * Return: code of the operation
+ */
+u32 tpm2_set_policy_pcr(struct udevice *dev, u32 session_handle, u32 index, void *out_digest);
+
+/**
+ * Issue a TPM2_getPolicyDigest command.
+ *
+ * @dev          TPM device
+ * @session_handle     policy session handle started with start_auth_session.
+ * @out_digest   addr where to write the digest (size is always 0x20 / TPM2_SHA256_DIGEST_SIZE)
+ * Return: code of the operation
+ */
+u32 tpm2_get_policy_digest(struct udevice *dev, u32 session_handle, void *out_digest);
+
 /**
  * Issue a TPM_NV_DefineSpace command
  *
@@ -709,6 +771,7 @@ u32 tpm2_clear(struct udevice *dev, u32 handle, const char *pw,
  * @space_index        index of the area
  * @space_size         size of area in bytes
  * @nv_attributes      TPM_NV_ATTRIBUTES of the area
+ * @session_handle     handle to a session. can be TPM2_RS_PW
  * @nv_policy          policy to use
  * @nv_policy_size     size of the policy
  * Return: return code of the operation
@@ -717,6 +780,17 @@ u32 tpm2_nv_define_space(struct udevice *dev, u32 space_index,
                   size_t space_size, u32 nv_attributes,
                   const u8 *nv_policy, size_t nv_policy_size);

+/**
+ * Issue a TPM_NV_UnDefineSpace command
+ *
+ * This allows a space to be removed. Needed because TPM_clear doesn't clear platform entries
+ *
+ * @dev                TPM device
+ * @space_index        index of the area
+ * Return: return code of the operation
+ */
+u32 tpm2_nv_undefine_space(struct udevice *dev, u32 space_index);
+
 /**
  * Issue a TPM2_PCR_Extend command.
  *
@@ -734,13 +808,14 @@ u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm,
 /**
  * Read data from the secure storage
  *
- * @dev          TPM device
- * @index  Index of data to read
- * @data   Place to put data
- * @count  Number of bytes of data
+ * @dev                      TPM device
+ * @index              Index of data to read
+ * @data               Place to put data
+ * @count              Number of bytes of data
+ * @session_handle     handle of a running authorization session. if NULL->password authorization
  * Return: code of the operation
  */
-u32 tpm2_nv_read_value(struct udevice *dev, u32 index, void *data, u32 count);
+u32 tpm2_nv_read_value(struct udevice *dev, u32 index, void *data, u32 count, u32 *session_handle);

 /**
  * Write data to the secure storage
@@ -749,10 +824,11 @@ u32 tpm2_nv_read_value(struct udevice *dev, u32 index, void *data, u32 count);
  * @index  Index of data to write
  * @data   Data to write
  * @count  Number of bytes of data
+ * @session_handle     handle of a running authorization session. if NULL->password authorization
  * Return: code of the operation
  */
 u32 tpm2_nv_write_value(struct udevice *dev, u32 index, const void *data,
-                 u32 count);
+                 u32 count, u32 *session_handle);

 /**
  * Issue a TPM2_PCR_Read command.
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index 68eaaa639f..3d5e4e8343 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -786,19 +786,192 @@ u32 tpm2_clear(struct udevice *dev, u32 handle, const char *pw,
      return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
 }

+u32 tpm2_start_auth_session(struct udevice *dev, u32 *session_handle, u8 session_type)
+{
+     const u16 nonce_size    = TPM2_SHA256_DIGEST_SIZE;
+     const int handles_len = sizeof(u32) * 2;
+     uint offset = TPM2_HDR_LEN + handles_len + 2;
+     struct tpm_chip_priv *priv;
+
+     priv = dev_get_uclass_priv(dev);
+           if (!priv)
+                 return TPM_LIB_ERROR;
+
+     u8 command_v2[COMMAND_BUFFER_SIZE] = {
+                 /* header 10 bytes */
+                 tpm_u16(TPM2_ST_NO_SESSIONS), /* TAG */
+                 tpm_u32(offset + nonce_size + 7),/* Length */
+                 tpm_u32(TPM2_CC_START_AUTH_SESSION),/* Command code */
+
+                 /* handles 8 bytes */
+                 tpm_u32(TPM2_RH_NULL),  /* TPMI_DH_OBJECT+ */
+                 tpm_u32(TPM2_RH_NULL),  /* TPMI_DH_ENTITY+ */
+
+                 /* NONCE 32 bytes -> use pack_byte_string() */
+                 tpm_u16(nonce_size),
+                 /* message 7 bytes -> use pack_byte_string() */
+                 //tpm_u16(0), // salt size
+                 //session_type, // session type
+                 //tpm_u16(TPM2_ALG_NULL), // symmetric key algorythm
+                 //tpm_u16(TPM2_ALG_SHA256), // auth hash
+    };
+    u8 Nonce[nonce_size]; //nonce is a random number you use once. (Number ONCE)
+    memset(&Nonce, 2, nonce_size); //should use TPM_get_random() to randomize
+    int ret;
+
+     ret = pack_byte_string(command_v2, sizeof(command_v2), "swbww",
+                 offset, Nonce, nonce_size,
+                 offset + nonce_size, 0, //salt size
+                 offset + nonce_size + 2, session_type,
+                 offset + nonce_size + 3, TPM2_ALG_NULL,
+                 offset + nonce_size + 5, TPM2_ALG_SHA256);
+
+     if (ret)
+           return TPM_LIB_ERROR;
+
+    size_t response_len = COMMAND_BUFFER_SIZE;
+    u8 response[COMMAND_BUFFER_SIZE];
+    u16 tag;
+    u32 size, code;
+
+     ret = tpm_sendrecv_command(dev, command_v2, response, &response_len);
+
+     if (ret)
+           return log_msg_ret("read", ret);
+
+     if (unpack_byte_string(response, response_len, "wdddws",
+                 0, &tag, 2, &size, 6, &code, //header
+                 10, session_handle, //TPMI_SH_AUTH_SESSION
+                 14, &priv->nonce_sz,
+                 16, priv->nonce, TPM2_SHA256_DIGEST_SIZE)) //HACK: we asked for a SHA256, so that's what we'll get. if ret == 0 at least
+           return TPM_LIB_ERROR;
+
+     return ret;
+}
+
+u32 tpm2_flush_context(struct udevice *dev, u32 session_handle)
+{
+     u8 command_v2[COMMAND_BUFFER_SIZE] = {
+                 /* header 10 bytes */
+                 tpm_u16(TPM2_ST_NO_SESSIONS), /* TAG */
+                 tpm_u32(TPM2_HDR_LEN + sizeof(u32)),/* Length */
+                 tpm_u32(TPM2_CC_FLUSH_CONTEXT),/* Command code */
+
+                 /* session handle 4 bytes */
+                 tpm_u32(session_handle),      /* TPMI_DH_CONTEXT+ */
+     };
+     return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
+}
+
+u32 tpm2_set_policy_pcr(struct udevice *dev, u32 session_handle, u32 index, void *out_digest)
+{
+     const int offset = TPM2_HDR_LEN + 6;
+     const int message_len = offset + TPM2_SHA256_DIGEST_SIZE + 10;
+
+     u8 pcr_sel_bit = BIT(index % 8);
+     struct tpm_chip_priv *priv;
+     struct tpml_digest_values digest_list;
+
+     digest_list.count = 1;
+     digest_list.digests->hash_alg = TPM2_ALG_SHA256;
+     tcg2_pcr_read(dev, index, &digest_list);
+
+     u8 pcr_sha_output[TPM2_SHA256_DIGEST_SIZE];
+     sha256_context ctx_256;
+
+     sha256_starts(&ctx_256);
+     sha256_update(&ctx_256, digest_list.digests[0].digest.sha256, TPM2_SHA256_DIGEST_SIZE);
+     sha256_finish(&ctx_256, pcr_sha_output);
+
+     priv = dev_get_uclass_priv(dev);
+           if (!priv)
+                 return TPM_LIB_ERROR;
+
+     u8 idx_array_sz = max(priv->pcr_select_min, DIV_ROUND_UP(index, 8));
+
+     u8 command_v2[COMMAND_BUFFER_SIZE] = {
+                 /* header 10 bytes */
+                 tpm_u16(TPM2_ST_NO_SESSIONS), /* TAG -> TPM2_ST_SESSIONS only for audit or decrypt*/
+                 tpm_u32(message_len),/* Length */
+                 tpm_u32(TPM2_CC_POLICY_PCR),/* Command code */
+                 /* session handle 4 bytes */
+                 tpm_u32(session_handle),      /* TPMI_SH_POLICY */
+                 /* PCR Digest - 32 bytes */
+                 tpm_u16(TPM2_SHA256_DIGEST_SIZE) /*hash size*/
+                 /* digest - 32-bytes */
+                 /* PCR selection */
+                 //tpm_u32(1),                 /* Number of selections */
+                 //tpm_u16(TPM_ALG_SHA256),          /* Algorithm of the hash */
+                 //idx_array_sz,               /* Array size for selection */
+                 /* bitmap(idx)                   Selected PCR bitmap */
+     };
+
+     if (pack_byte_string(command_v2, COMMAND_BUFFER_SIZE, "sdwbbw",
+                 offset, pcr_sha_output, TPM2_SHA256_DIGEST_SIZE,
+                 offset + TPM2_SHA256_DIGEST_SIZE, 1, /* Number of selections */
+                 offset + TPM2_SHA256_DIGEST_SIZE + 4, TPM2_ALG_SHA256, /* Algorithm of the hash */
+                 offset + TPM2_SHA256_DIGEST_SIZE + 6, idx_array_sz, /* Array size for selection */
+                 offset + TPM2_SHA256_DIGEST_SIZE + 7, pcr_sel_bit,/* Selected PCR bitmap */
+                 offset + TPM2_SHA256_DIGEST_SIZE + 8, 0))  /*padding */
+           return TPM_LIB_ERROR;
+
+     int ret = tpm_sendrecv_command(dev, command_v2, NULL, NULL);
+
+     if (ret)
+           return ret;
+
+
+     return tpm2_get_policy_digest(dev, session_handle, out_digest);
+}
+
+u32 tpm2_get_policy_digest(struct udevice *dev, u32 session_handle, void *out_digest)
+{
+     const int message_len = TPM2_HDR_LEN + sizeof(u32);
+
+     u8 command_v2[COMMAND_BUFFER_SIZE] = {
+                 /* header 10 bytes */
+                 tpm_u16(TPM2_ST_NO_SESSIONS), /* TAG -> only audit or decrypt session uses TPM2_ST_SESSIONS */
+                 tpm_u32(message_len),/* Length */
+                 tpm_u32(TPM2_CC_POLICY_GET_DIGEST),/* Command code */
+                 /* session handle 4 bytes */
+                 tpm_u32(session_handle),      /* TPMI_SH_POLICY */
+     };
+
+     size_t response_len = COMMAND_BUFFER_SIZE;
+     u8 response[COMMAND_BUFFER_SIZE];
+     int ret;
+     u16 tag;
+     u32 size, code;
+
+     ret = tpm_sendrecv_command(dev, command_v2, response, &response_len);
+     if (ret)
+           return log_msg_ret("read", ret);
+
+     if (unpack_byte_string(response, response_len, "wdds",
+                 0, &tag, 2, &size, 6, &code,
+                 12, out_digest, TPM2_SHA256_DIGEST_SIZE)) //digest_size
+           return TPM_LIB_ERROR;
+
+     return ret;
+}
+
 u32 tpm2_nv_define_space(struct udevice *dev, u32 space_index,
-                  size_t space_size, u32 nv_attributes,
-                  const u8 *nv_policy, size_t nv_policy_size)
+                 size_t space_size, u32 nv_attributes,
+                 const u8 *nv_policy, size_t nv_policy_size)
 {
      /*
       * Calculate the offset of the nv_policy piece by adding each of the
       * chunks below.
       */
      const int platform_len = sizeof(u32);
-     const int session_hdr_len = 13;
+     const int session_hdr_len = 15;
      const int message_len = 14;
-     uint offset = TPM2_HDR_LEN + platform_len + session_hdr_len +
-           message_len;
+     uint offset = TPM2_HDR_LEN + platform_len + session_hdr_len + message_len;
+     u8 attrs = 0;
+
+     //if(session_handle != TPM2_RS_PW)
+           //attrs = 1; //continue_session (bit 1)
+
      u8 command_v2[COMMAND_BUFFER_SIZE] = {
            /* header 10 bytes */
            tpm_u16(TPM2_ST_SESSIONS),    /* TAG */
@@ -806,20 +979,24 @@ u32 tpm2_nv_define_space(struct udevice *dev, u32 space_index,
            tpm_u32(TPM2_CC_NV_DEFINE_SPACE),/* Command code */

            /* handles 4 bytes */
-           tpm_u32(TPM2_RH_PLATFORM),    /* Primary platform seed */
+           tpm_u32(TPM2_RH_PLATFORM),    /* Primary platform seed, requires TPMA_NV_PLATFORMCREATE*/
+

-           /* session header 13 bytes */
+           /* session header 15 bytes */
+           /*null auth session*/
            tpm_u32(9),             /* Header size */
-           tpm_u32(TPM2_RS_PW),          /* Password authorisation */
+           tpm_u32(TPM2_RS_PW),/* auth session handle if it's active, otherwise TPM2_RS_PW*/
            tpm_u16(0),             /* nonce_size */
-           0,                      /* session_attrs */
+           attrs,                        /* session_attrs */
+           tpm_u16(0),             /* HMAC size */
+           /*end auth area*/
            tpm_u16(0),             /* auth_size */

            /* message 14 bytes + policy */
            tpm_u16(message_len + nv_policy_size),    /* size */
            tpm_u32(space_index),
            tpm_u16(TPM2_ALG_SHA256),
-           tpm_u32(nv_attributes),
+           tpm_u32(nv_attributes | TPMA_NV_PLATFORMCREATE),
            tpm_u16(nv_policy_size),
            /*
             * nv_policy
@@ -841,6 +1018,35 @@ u32 tpm2_nv_define_space(struct udevice *dev, u32 space_index,
      return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
 }

+u32 tpm2_nv_undefine_space(struct udevice *dev, u32 space_index)
+{
+     const int platform_len = sizeof(u32);
+     const int session_hdr_len = 13;
+     const int message_len = 4;
+     u8 command_v2[COMMAND_BUFFER_SIZE] = {
+           /* header 10 bytes */
+           tpm_u16(TPM2_ST_SESSIONS),    /* TAG */
+           tpm_u32(TPM2_HDR_LEN + platform_len + session_hdr_len +
+                       message_len),/* Length - header + provision + index + auth area*/
+           tpm_u32(TPM2_CC_NV_UNDEFINE_SPACE),/* Command code */
+
+           /* handles 4 bytes */
+           tpm_u32(TPM2_RH_PLATFORM),    /* Primary platform seed */
+           /* nv_index */
+           tpm_u32(space_index),
+
+           /*null auth session*/
+           tpm_u32(9),             /* Header size */
+           tpm_u32(TPM2_RS_PW),          /* Password authorisation*/
+           tpm_u16(0),             /* nonce_size */
+           0,                      /* session_attrs */
+           tpm_u16(0),             /* HMAC size */
+           /*end auth area*/
+
+     };
+     return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
+}
+
 u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm,
                const u8 *digest, u32 digest_len)
 {
@@ -884,56 +1090,99 @@ u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm,
      return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
 }

-u32 tpm2_nv_read_value(struct udevice *dev, u32 index, void *data, u32 count)
+u32 tpm2_nv_read_value(struct udevice *dev, u32 index, void *data, u32 count, u32 *session_handle)
 {
-     u8 command_v2[COMMAND_BUFFER_SIZE] = {
-           /* header 10 bytes */
-           tpm_u16(TPM2_ST_SESSIONS),    /* TAG */
-           tpm_u32(10 + 8 + 4 + 9 + 4),  /* Length */
-           tpm_u32(TPM2_CC_NV_READ),     /* Command code */
+     u32 offset = TPM2_HDR_LEN + 8 + 4 + 6;
+     struct tpm_chip_priv *priv;

-           /* handles 8 bytes */
-           tpm_u32(TPM2_RH_PLATFORM),    /* Primary platform seed */
-           tpm_u32(HR_NV_INDEX + index), /* Password authorisation */
+     priv = dev_get_uclass_priv(dev);

-           /* AUTH_SESSION */
-           tpm_u32(9),             /* Authorization size */
-           tpm_u32(TPM2_RS_PW),          /* Session handle */
-           tpm_u16(0),             /* Size of <nonce> */
-                                   /* <nonce> (if any) */
-           0,                      /* Attributes: Cont/Excl/Rst */
-           tpm_u16(0),             /* Size of <hmac/password> */
-                                   /* <hmac/password> (if any) */
+     if (!priv)
+           return TPM_LIB_ERROR;
+
+     u32 nonce_size = priv->nonce_sz;
+     priv->nonce[nonce_size - 1]++; //increase nonce.
+
+     u32 authorization = TPM2_RS_PW;

-           tpm_u16(count),               /* Number of bytes */
-           tpm_u16(0),             /* Offset */
+     if (session_handle)
+           authorization = *session_handle;
+     else
+           nonce_size = 0; //cannot use nonce when using password authorization
+
+     u8 command_v2[COMMAND_BUFFER_SIZE] = {
+                 /* header 10 bytes */
+                 tpm_u16(TPM2_ST_SESSIONS),    /* TAG */
+                 tpm_u32(offset + nonce_size + 7),   /* Length */
+                 tpm_u32(TPM2_CC_NV_READ),     /* Command code */
+
+                 /* handles 8 bytes */
+                 tpm_u32(index),   /* Primary platform seed */
+                 tpm_u32(index),               /*nv index*/
+
+                 /* AUTH_SESSION */
+                 tpm_u32(9 + nonce_size),                  /* Authorization size - 4 bytes*/
+                 /*auth handle - 9 bytes */
+                 tpm_u32(authorization),
+                 tpm_u16(nonce_size),                /* Size of <nonce> */
+                 /* <nonce> (if any) */
+                 //0,                    /* Attributes: Cont/Excl/Rst */
+                 //tpm_u16(0),                 /* Size of <hmac/password> */
+                 /* <hmac/password> (if any) */
+                 /*end auth handle */
+                 //tpm_u16(count),             /* Number of bytes */
+                 //tpm_u16(0),                 /* Offset */
      };
+
      size_t response_len = COMMAND_BUFFER_SIZE;
      u8 response[COMMAND_BUFFER_SIZE];
      int ret;
      u16 tag;
      u32 size, code;

+     ret = pack_byte_string(command_v2, sizeof(command_v2), "sbwww",
+                 offset, priv->nonce, nonce_size,
+                 offset + nonce_size, 0,
+                 offset + nonce_size + 1, 0,
+                 offset + nonce_size + 3, count,
+                 offset + nonce_size + 5, 0);
+
+     if (ret)
+           return TPM_LIB_ERROR;
+
      ret = tpm_sendrecv_command(dev, command_v2, response, &response_len);
      if (ret)
            return log_msg_ret("read", ret);
+
      if (unpack_byte_string(response, response_len, "wdds",
-                        0, &tag, 2, &size, 6, &code,
-                        16, data, count))
+                 0, &tag, 2, &size, 6, &code,
+                 16, data, count))
            return TPM_LIB_ERROR;

      return 0;
 }

 u32 tpm2_nv_write_value(struct udevice *dev, u32 index, const void *data,
-                 u32 count)
+                 u32 count, u32 *session_handle)
 {
      struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
-     uint offset = 10 + 8 + 4 + 9 + 2;
-     uint len = offset + count + 2;
-     /* Use empty password auth if platform hierarchy is disabled */
-     u32 auth = priv->plat_hier_disabled ? HR_NV_INDEX + index :
-           TPM2_RH_PLATFORM;
+
+     if (!priv)
+           return TPM_LIB_ERROR;
+
+     u32 nonce_size = priv->nonce_sz;
+     priv->nonce[nonce_size - 1]++;
+
+     u32 authorization = TPM2_RS_PW;
+
+     if (session_handle != NULL)
+           authorization = *session_handle;
+     else
+           nonce_size = 0; //cannot use nonce when using password authorization
+
+     uint offset = TPM2_HDR_LEN + 8 + 4 + 6;
+     uint len = offset + nonce_size + count + 7;
+
      u8 command_v2[COMMAND_BUFFER_SIZE] = {
            /* header 10 bytes */
            tpm_u16(TPM2_ST_SESSIONS),    /* TAG */
@@ -941,27 +1190,35 @@ u32 tpm2_nv_write_value(struct udevice *dev, u32 index, const void *data,
            tpm_u32(TPM2_CC_NV_WRITE),    /* Command code */

            /* handles 8 bytes */
-           tpm_u32(auth),                /* Primary platform seed */
-           tpm_u32(HR_NV_INDEX + index), /* Password authorisation */
+           tpm_u32(index),               /* Primary platform seed */
+           tpm_u32(index),               /*nv index*/

            /* AUTH_SESSION */
-           tpm_u32(9),             /* Authorization size */
-           tpm_u32(TPM2_RS_PW),          /* Session handle */
-           tpm_u16(0),             /* Size of <nonce> */
+           tpm_u32(9 + nonce_size),                  /* Authorization size - 4 bytes */
+           /*auth handle - 9 bytes */
+           tpm_u32(authorization),
+           tpm_u16(nonce_size),                /* Size of <nonce> */
                                    /* <nonce> (if any) */
-           0,                      /* Attributes: Cont/Excl/Rst */
-           tpm_u16(0),             /* Size of <hmac/password> */
+           //0,                    /* Attributes: Cont/Excl/Rst */
+           //tpm_u16(0),                 /* Size of <hmac/password> */
                                    /* <hmac/password> (if any) */
-
-           tpm_u16(count),
+           /*end auth handle */
+           //tpm_u16(count),/*size of buffer - 2 bytes*/
+           /*data (buffer)*/
+           /*offset -> the octet offset into the NV Area*/
      };
      size_t response_len = COMMAND_BUFFER_SIZE;
      u8 response[COMMAND_BUFFER_SIZE];
      int ret;

-     ret = pack_byte_string(command_v2, sizeof(command_v2), "sw",
-                        offset, data, count,
-                        offset + count, 0);
+     ret = pack_byte_string(command_v2, sizeof(command_v2), "sbwwsw",
+                 offset, priv->nonce, nonce_size,
+                 offset + nonce_size, 0, //attrs
+                 offset + nonce_size +1, 0, //hmac sz
+                 offset + nonce_size + 3, count,
+                 offset + nonce_size + 5, data, count,
+                 offset + nonce_size + count, 0);
+
      if (ret)
            return TPM_LIB_ERROR;

diff --git a/lib/tpm_api.c b/lib/tpm_api.c
index 39a5121e30..5875e7b085 100644
--- a/lib/tpm_api.c
+++ b/lib/tpm_api.c
@@ -128,7 +128,7 @@ u32 tpm_nv_read_value(struct udevice *dev, u32 index, void *data, u32 count)
      if (tpm_is_v1(dev))
            return tpm1_nv_read_value(dev, index, data, count);
      else if (tpm_is_v2(dev))
-           return tpm2_nv_read_value(dev, index, data, count);
+           return tpm2_nv_read_value(dev, index, data, count, NULL);
      else
            return -ENOSYS;
 }
@@ -139,7 +139,7 @@ u32 tpm_nv_write_value(struct udevice *dev, u32 index, const void *data,
      if (tpm_is_v1(dev))
            return tpm1_nv_write_value(dev, index, data, count);
      else if (tpm_is_v2(dev))
-           return tpm2_nv_write_value(dev, index, data, count);
+           return tpm2_nv_write_value(dev, index, data, count, NULL);
      else
            return -ENOSYS;
 }
--
2.34.1
====================END PATCH============================
________________________________
差出人: Dan Carpenter <dan.carpenter at linaro.org>
送信日時: 2024年2月21日 02:56
宛先: Niek Nooijens / OC-IAB PBD-C DEVEL 1-1 <niek.nooijens at omron.com>
CC: Ilias Apalodimas <ilias.apalodimas at linaro.org>; u-boot at lists.denx.de <u-boot at lists.denx.de>
件名: Re: [PATCH] implement policy_pcr commands to lock NV-indexes behind a PCR

[dan.carpenter at linaro.org からのメールを受け取る頻度は高くありません。これが問題である可能性の理由については、https://aka.ms/LearnAboutSenderIdentification をご覧ください。]

I'm kind of new to u-boot and I'm not really able to review this code
as well as I should.

But also I can't apply the patch.  It seems white space damaged?  The
kernel has a good document on how to do this.  I'm pretty sure u-boot
does as well but I'm new.
https://jpn01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.kernel.org%2Fdoc%2FDocumentation%2Fprocess%2Femail-clients.rst&data=05%7C02%7Cniek.nooijens%40omron.com%7Cfff2a571b0f64e4cee7308dc323d3de9%7C0ecff5a94bef4a7b96eca96579b4ac37%7C0%7C0%7C638440485810051997%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=dU5lPn1UMeoLauNg2lVkRsopKimQ5qwJda11ZRm%2FJhQ%3D&reserved=0<https://www.kernel.org/doc/Documentation/process/email-clients.rst>

Please run your patch through the scripts/checkpatch.pl script.  Stuff
like this triggers a warning:

> +static int do_tpm_nv_write_value(struct cmd_tbl *cmdtp, int flag,
> +                        int argc, char *const argv[]) //TODO: session handle from auth session!
> +{
> +     struct udevice *dev;
> +     u32 nv_addr, nv_size, rc;
> +     void *session_addr = NULL;
> +     int ret;
> +
> +     ret = get_tpm(&dev);
> +           if (ret)
> +                 return ret;
> +
> +           if (argc < 4)
> +                 return CMD_RET_USAGE;


WARNING: suspect code indent for conditional statements (0, 0)
#250: FILE: cmd/tpm-v2.c:437:
+     if (ret)
+           return ret;

WARNING: suspect code indent for conditional statements (0, 0)
#253: FILE: cmd/tpm-v2.c:440:
+     if (argc < 4)
+           return CMD_RET_USAGE;

Also the subject should have a subsystem prefix and the information from
the email should be moved into the commit message.  Currently the commit
message is empty.

> diff --git a/include/tpm-v2.h b/include/tpm-v2.h
> index 33dd103767..5b60883777 100644
> --- a/include/tpm-v2.h
> +++ b/include/tpm-v2.h
> @@ -301,7 +301,8 @@ enum tpm2_startup_types {
>   */
>  enum tpm2_handles {
>       TPM2_RH_OWNER           = 0x40000001,
> -     TPM2_RS_PW        = 0x40000009,
> +     TPM2_RH_NULL            = 0x40000007,
> +     TPM2_RS_PW              = 0x40000009,

Changing TPM2_RS_PW is an unrelated whitespace change.  Do that as a
separate patch.  But I don't get it at all because the TPM2_RS_PW enum
has always been indented correctly as far as I can see.  So it's a
puzzle.

I mean there are a lot of TODOs and I understand that you just wanted a
high level review but I kept getting distracted and lost and I couldn't
apply the patch so it was just really hard to figure out what was going
on.  :(

regards,
dan carpenter



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