Add support for the TPM2_DictionaryAttackParameters and TPM2_DictionaryAttackLockReset commands.
Change the command file and the help accordingly.
Signed-off-by: Miquel Raynal miquel.raynal@bootlin.com --- cmd/tpm.c | 69 +++++++++++++++++++++++++++++++++++++++++++++ include/tpm.h | 26 +++++++++++++++++ lib/tpm.c | 89 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 184 insertions(+)
diff --git a/cmd/tpm.c b/cmd/tpm.c index eab914ce5f..3648d05581 100644 --- a/cmd/tpm.c +++ b/cmd/tpm.c @@ -480,6 +480,58 @@ static int do_tpm_init(cmd_tbl_t *cmdtp, int flag, return report_return_code(tpm_init()); }
+static int do_tpm_dam_reset_counter(cmd_tbl_t *cmdtp, int flag, + int argc, char *const argv[]) +{ + const char *pw = (argc < 2) ? NULL : argv[1]; + const ssize_t pw_sz = pw ? strlen(pw) : 0; + + if (argc > 2) + return CMD_RET_USAGE; + + if (pw_sz > TPM2_DIGEST_LENGTH) + return -EINVAL; + + return report_return_code(tpm2_dam_reset_counter(pw, pw_sz)); +} + +static int do_tpm_dam_set_parameters(cmd_tbl_t *cmdtp, int flag, + int argc, char *const argv[]) +{ + const char *pw = (argc < 5) ? NULL : argv[4]; + const ssize_t pw_sz = pw ? strlen(pw) : 0; + /* + * No Dictionary Attack Mitigation (DAM) means: + * maxtries = 0xFFFFFFFF, recovery_time = 1, lockout_recovery = 0 + */ + unsigned long int max_tries; + unsigned long int recovery_time; + unsigned long int lockout_recovery; + + if (argc < 4 || argc > 5) + return CMD_RET_USAGE; + + if (pw_sz > TPM2_DIGEST_LENGTH) + return -EINVAL; + + if (strict_strtoul(argv[1], 0, &max_tries)) + return CMD_RET_USAGE; + + if (strict_strtoul(argv[2], 0, &recovery_time)) + return CMD_RET_USAGE; + + if (strict_strtoul(argv[3], 0, &lockout_recovery)) + return CMD_RET_USAGE; + + debug("Changing dictionary attack parameters:\n"); + debug("- maxTries: %lu\n- recoveryTime: %lu\n- lockoutRecovery: %lu\n", + max_tries, recovery_time, lockout_recovery); + + return report_return_code(tpm2_dam_set_parameters(pw, pw_sz, max_tries, + recovery_time, + lockout_recovery)); +} + static int do_tpm_force_clear(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) { @@ -901,6 +953,10 @@ static cmd_tbl_t tpm_commands[] = { do_tpm_self_test_full, "", ""), U_BOOT_CMD_MKENT(continue_self_test, 0, 1, do_tpm_continue_self_test, "", ""), + U_BOOT_CMD_MKENT(dam_reset_counter, 0, 1, + do_tpm_dam_reset_counter, "", ""), + U_BOOT_CMD_MKENT(dam_set_parameters, 0, 1, + do_tpm_dam_set_parameters, "", ""), U_BOOT_CMD_MKENT(force_clear, 0, 1, do_tpm_force_clear, "", ""), U_BOOT_CMD_MKENT(physical_enable, 0, 1, @@ -1010,6 +1066,19 @@ U_BOOT_CMD(tpm, CONFIG_SYS_MAXARGS, 1, do_tpm, " get_capability <cap_area|capability> <sub_cap|property> <addr> <count>\n" " - Read <count> bytes of TPM capability indexed by <cap_area|capability>\n" " and <sub_cap|property> to memory address <addr>.\n" +"Lockout/Dictionary attack Commands:\n" +" dam_reset_counter [<password>]\n" +" - If the TPM is not in a LOCKOUT state, reset the internal error\n" +" counter (TPMv2 only)\n" +" dam_set_parameters <maxTries> <recoveryTime> <lockoutRecovery> [<password>]\n" +" - If the TPM is not in a LOCKOUT state, set the dictionary attack\n" +" parameters:\n" +" * maxTries: maximum number of failures before lockout.\n" +" 0 means always locking.\n" +" * recoveryTime: time before decrementation of the error counter,\n" +" 0 means no lockout.\n" +" * lockoutRecovery: time of a lockout (before the next try)\n" +" 0 means a reboot is needed.\n" #if defined(CONFIG_TPM_FLUSH_RESOURCES) || defined(CONFIG_TPM_LIST_RESOURCES) "Resource management functions\n" #endif diff --git a/include/tpm.h b/include/tpm.h index 369119fc1b..4d062584f9 100644 --- a/include/tpm.h +++ b/include/tpm.h @@ -60,6 +60,8 @@ enum tpm2_command_codes { TPM2_CC_SELF_TEST = 0x0143, TPM2_CC_CLEAR = 0x0126, TPM2_CC_CLEARCONTROL = 0x0127, + TPM2_CC_DAM_RESET = 0x0139, + TPM2_CC_DAM_PARAMETERS = 0x013A, TPM2_CC_GET_CAPABILITY = 0x017A, TPM2_CC_PCR_READ = 0x017E, TPM2_CC_PCR_EXTEND = 0x0182, @@ -594,6 +596,30 @@ uint32_t tpm_tsc_physical_presence(uint16_t presence); */ uint32_t tpm_read_pubek(void *data, size_t count);
+/** + * Issue a TPM2_DictionaryAttackLockReset command. + * + * @param pw Password + * @param pw_sz Length of the password + * @return return code of the operation + */ +int tpm2_dam_reset_counter(const char *pw, const ssize_t pw_sz); + +/** + * Issue a TPM2_DictionaryAttackLockParameters command. + * + * @param pw Password + * @param pw_sz Length of the password + * @param max_tries Count of authorizations before lockout + * @param recovery_time Time before decrementation of the failure count + * @param lockout_recovery Time to wait after a lockout + * @return return code of the operation + */ +int tpm2_dam_set_parameters(const char *pw, const ssize_t pw_sz, + unsigned int max_tries, + unsigned int recovery_time, + unsigned int lockout_recovery); + /** * Issue a TPM_ForceClear or a TPM2_Clear command. * diff --git a/lib/tpm.c b/lib/tpm.c index f15611ee92..4987a4ce8c 100644 --- a/lib/tpm.c +++ b/lib/tpm.c @@ -703,6 +703,95 @@ uint32_t tpm_read_pubek(void *data, size_t count) return 0; }
+int tpm2_dam_reset_counter(const char *pw, const ssize_t pw_sz) +{ + 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_DAM_RESET), /* Command code */ + + /* HANDLE */ + U32_TO_ARRAY(TPM2_RH_LOCKOUT), /* TPM resource handle */ + + /* 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) + return TPM_LIB_ERROR; + + /* + * 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); +} + +int tpm2_dam_set_parameters(const char *pw, const ssize_t pw_sz, + unsigned int max_tries, unsigned int recovery_time, + unsigned int lockout_recovery) +{ + u8 command_v2[COMMAND_BUFFER_SIZE] = { + U16_TO_ARRAY(TPM2_ST_SESSIONS), /* TAG */ + U32_TO_ARRAY(27 + pw_sz + 12), /* Length */ + U32_TO_ARRAY(TPM2_CC_DAM_PARAMETERS), /* Command code */ + + /* HANDLE */ + U32_TO_ARRAY(TPM2_RH_LOCKOUT), /* TPM resource handle */ + + /* 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) */ + + /* LOCKOUT PARAMETERS */ + /* STRIGIFY32(max_tries) Max tries (0, always lock) */ + /* STRIGIFY32(recovery_time) Recovery time (0, no lock) */ + /* STRIGIFY32(lockout_recovery) Lockout recovery */ + }; + unsigned int offset = 27; + int ret; + + if (!is_tpmv2) + return TPM_LIB_ERROR; + + /* + * Fill the command structure starting from the first buffer: + * - the password (if any) + * - max tries + * - recovery time + * - lockout recovery + */ + ret = pack_byte_string(command_v2, sizeof(command_v2), "sddd", + offset, pw, pw_sz, + offset + pw_sz, max_tries, + offset + pw_sz + 4, recovery_time, + offset + pw_sz + 8, lockout_recovery); + offset += pw_sz + 12; + if (ret) + return TPM_LIB_ERROR; + + return tpm_sendrecv_command(command_v2, NULL, NULL); +} + int tpm_force_clear(u32 handle, const char *pw, const ssize_t pw_sz) { const u8 command_v1[10] = {