Re: [U-Boot] [PATCH v2 11/19] tpm: add TPM2_Clear command support

Hi Miquel,

On 29 March 2018 at 15:43, Miquel Raynal miquel.raynal@bootlin.com wrote:

Add support for the TPM2_Clear command.

Change the command file and the help accordingly.

Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com

cmd/tpm.c | 29 ++++++++++++++++++++++++++--- cmd/tpm_test.c | 6 +++--- include/tpm.h | 21 +++++++++++++++++---- lib/tpm.c | 42 ++++++++++++++++++++++++++++++++++++++---- 4 files changed, 84 insertions(+), 14 deletions(-)

diff --git a/cmd/tpm.c b/cmd/tpm.c index fc9ef9d4a3..32921e1a70 100644 --- a/cmd/tpm.c +++ b/cmd/tpm.c @@ -454,6 +454,29 @@ static int do_tpm_init(cmd_tbl_t *cmdtp, int flag, return report_return_code(tpm_init()); }

+static int do_tpm_force_clear(cmd_tbl_t *cmdtp, int flag,

•                         int argc, char * const argv[])
  

+{

•   u32 handle = 0;
  

•   const char *pw = (argc < 3) ? NULL : argv[2];
  

•   const ssize_t pw_sz = pw ? strlen(pw) : 0;
  

•   if (argc < 2 || argc > 3)
  

•           return CMD_RET_USAGE;
  

•   if (pw_sz > TPM2_DIGEST_LENGTH)
  

•           return -EINVAL;
  

•   if (!strcasecmp("TPM2_RH_LOCKOUT", argv[1]))
  

•           handle = TPM2_RH_LOCKOUT;
  

•   else if (!strcasecmp("TPM2_RH_PLATFORM", argv[1]))
  

•           handle = TPM2_RH_PLATFORM;
  

•   else
  

•           return CMD_RET_USAGE;
  

•   return report_return_code(tpm_force_clear(handle, pw, pw_sz));
  

+}

#define TPM_COMMAND_NO_ARG(cmd) \ static int do_##cmd(cmd_tbl_t *cmdtp, int flag, \ int argc, char * const argv[]) \ @@ -465,7 +488,6 @@ static int do_##cmd(cmd_tbl_t *cmdtp, int flag, \

TPM_COMMAND_NO_ARG(tpm_self_test_full) TPM_COMMAND_NO_ARG(tpm_continue_self_test) -TPM_COMMAND_NO_ARG(tpm_force_clear) TPM_COMMAND_NO_ARG(tpm_physical_enable) TPM_COMMAND_NO_ARG(tpm_physical_disable)

@@ -951,8 +973,9 @@ U_BOOT_CMD(tpm, CONFIG_SYS_MAXARGS, 1, do_tpm, " physical_set_deactivated 0|1\n" " - Set deactivated flag.\n" "Admin Ownership Commands:\n" -" force_clear\n" -" - Issue TPM_ForceClear command.\n" +" force_clear [<type>]\n" +" - Issue TPM_[Force]Clear command, with <type> one of (TPMv2 only):\n" +" * TPM2_RH_LOCKOUT, TPM2_RH_PLATFORM.\n" " tsc_physical_presence flags\n" " - Set TPM device's Physical Presence flags to <flags>.\n" "The Capability Commands:\n" diff --git a/cmd/tpm_test.c b/cmd/tpm_test.c index 37ad2ff33d..da40dbc423 100644 --- a/cmd/tpm_test.c +++ b/cmd/tpm_test.c @@ -176,7 +176,7 @@ static int test_fast_enable(void) TPM_CHECK(tpm_get_flags(&disable, &deactivated, NULL)); printf("\tdisable is %d, deactivated is %d\n", disable, deactivated); for (i = 0; i < 2; i++) {

•           TPM_CHECK(tpm_force_clear());
  

•           TPM_CHECK(tpm_force_clear(0, NULL, 0));
            TPM_CHECK(tpm_get_flags(&disable, &deactivated, NULL));
            printf("\tdisable is %d, deactivated is %d\n", disable,
                   deactivated);
  

@@ -458,7 +458,7 @@ static int test_write_limit(void) TPM_CHECK(TlclStartupIfNeeded()); TPM_CHECK(tpm_self_test_full()); TPM_CHECK(tpm_tsc_physical_presence(PRESENCE));

•   TPM_CHECK(tpm_force_clear());
  

•   TPM_CHECK(tpm_force_clear(0, NULL, 0));
    TPM_CHECK(tpm_physical_enable());
    TPM_CHECK(tpm_physical_set_deactivated(0));
  
  

@@ -477,7 +477,7 @@ static int test_write_limit(void) }

    /* Reset write count */

•   TPM_CHECK(tpm_force_clear());
  

•   TPM_CHECK(tpm_force_clear(0, NULL, 0));
    TPM_CHECK(tpm_physical_enable());
    TPM_CHECK(tpm_physical_set_deactivated(0));
  
  

diff --git a/include/tpm.h b/include/tpm.h index 38d7cb899d..2f17166662 100644 --- a/include/tpm.h +++ b/include/tpm.h @@ -43,13 +43,23 @@ enum tpm_startup_type { };

enum tpm2_startup_types {

•   TPM2_SU_CLEAR   = 0x0000,
  

•   TPM2_SU_STATE   = 0x0001,
  

•   TPM2_SU_CLEAR           = 0x0000,
  

•   TPM2_SU_STATE           = 0x0001,
  

+};

+enum tpm2_handles {

Please add comment to enum

•   TPM2_RH_OWNER           = 0x40000001,
  

•   TPM2_RS_PW              = 0x40000009,
  

•   TPM2_RH_LOCKOUT         = 0x4000000A,
  

•   TPM2_RH_ENDORSEMENT     = 0x4000000B,
  

•   TPM2_RH_PLATFORM        = 0x4000000C,
  

};

enum tpm2_command_codes { TPM2_CC_STARTUP = 0x0144, TPM2_CC_SELF_TEST = 0x0143,

•   TPM2_CC_CLEAR           = 0x0126,
  

•   TPM2_CC_CLEARCONTROL    = 0x0127,
    TPM2_CC_GET_CAPABILITY  = 0x017A,
    TPM2_CC_PCR_READ        = 0x017E,
    TPM2_CC_PCR_EXTEND      = 0x0182,
  

@@ -567,11 +577,14 @@ uint32_t tpm_tsc_physical_presence(uint16_t presence); uint32_t tpm_read_pubek(void *data, size_t count);

/**

• • Issue a TPM_ForceClear command.

• • Issue a TPM_ForceClear or a TPM2_Clear command.
• • @param handle Handle
• • @param pw Password
• • @param pw_sz Length of the password
  • @return return code of the operation
  */

-uint32_t tpm_force_clear(void); +int tpm_force_clear(u32 handle, const char *pw, const ssize_t pw_sz);

/**

• Issue a TPM_PhysicalEnable command.

diff --git a/lib/tpm.c b/lib/tpm.c index 3cc2888267..9a46ac09e6 100644 --- a/lib/tpm.c +++ b/lib/tpm.c @@ -608,13 +608,47 @@ uint32_t tpm_read_pubek(void *data, size_t count) return 0; }

-uint32_t tpm_force_clear(void) +int tpm_force_clear(u32 handle, const char *pw, const ssize_t pw_sz) {

•   const uint8_t command[10] = {
  

•           0x0, 0xc1, 0x0, 0x0, 0x0, 0xa, 0x0, 0x0, 0x0, 0x5d,
  

•   const u8 command_v1[10] = {
  

•           U16_TO_ARRAY(0xc1),
  

•           U32_TO_ARRAY(10),
  

•           U32_TO_ARRAY(0x5d),
    };
  

•   u8 command_v2[COMMAND_BUFFER_SIZE] = {
  

•           U16_TO_ARRAY(TPM2_ST_SESSIONS), /* TAG */
  

•           U32_TO_ARRAY(27 + pw_sz),       /* Length */
  

•           U32_TO_ARRAY(TPM2_CC_CLEAR),    /* Command code */
  

Here we have both v1 and v2 commands. Perhaps we should have a Kconfig option to enable v2 support? Or do you think it is not a big addition in terms of code side?

One way to do this would be to have an inline function which can tell if you are using v2:

static inline bool tpm_v2(void) { return IS_ENABLED(CONFIG_TPM_V2) && further things... }

static inline bool tpm_v1(void) { return IS_ENABLED(CONFIG_TPM_V1) && further things... }

•   return tpm_sendrecv_command(command, NULL, NULL);
  

•           /* HANDLE */
  

•           U32_TO_ARRAY(handle),           /* TPM resource handle */
  

If we really need these, perhaps tpm_u32() is a better name that U32_TO_ARRAY() ?

•           /* AUTH_SESSION */
  

•           U32_TO_ARRAY(9 + pw_sz),        /* Authorization size */
  

•           U32_TO_ARRAY(TPM2_RS_PW),       /* Session handle */
  

•           U16_TO_ARRAY(0),                /* Size of <nonce> */
  

•                                           /* <nonce> (if any) */
  

•           0,                              /* Attributes: Cont/Excl/Rst */
  

•           U16_TO_ARRAY(pw_sz),            /* Size of <hmac/password> */
  

•           /* STRING(pw)                      <hmac/password> (if any) */
  

•   };
  

•   unsigned int offset = 27;
  

•   int ret;
  

•   if (!is_tpmv2)
  

•           tpm_sendrecv_command(command_v1, NULL, NULL);
  

•   /*
  

•    * Fill the command structure starting from the first buffer:
  

•    *     - the password (if any)
  

•    */
  

•   ret = pack_byte_string(command_v2, sizeof(command_v2), "s",
  

•                          offset, pw, pw_sz);
  

•   offset += pw_sz;
  

•   if (ret)
  

•           return TPM_LIB_ERROR;
  

•   return tpm_sendrecv_command(command_v2, NULL, NULL);
  

}

uint32_t tpm_physical_enable(void)

2.14.1

Regards, Simon