Commit da9c3392 authored by Miquel Raynal's avatar Miquel Raynal Committed by Tom Rini

tpm: add dictionary attack mitigation commands support

Add support for the TPM2_DictionaryAttackParameters and
TPM2_DictionaryAttackLockReset commands.

Change the command file and the help accordingly.
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Simon Glass's avatarSimon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini's avatarTom Rini <trini@konsulko.com>
parent 69cd8f06
......@@ -181,6 +181,59 @@ unmap_data:
return report_return_code(rc);
}
static int do_tpm_dam_reset(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_LEN)
return -EINVAL;
return report_return_code(tpm2_dam_reset(pw, pw_sz));
}
static int do_tpm_dam_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_LEN)
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;
log(LOGC_NONE, LOGL_INFO, "Changing dictionary attack parameters:\n");
log(LOGC_NONE, LOGL_INFO, "- maxTries: %lu", max_tries);
log(LOGC_NONE, LOGL_INFO, "- recoveryTime: %lu\n", recovery_time);
log(LOGC_NONE, LOGL_INFO, "- lockoutRecovery: %lu\n", lockout_recovery);
return report_return_code(tpm2_dam_parameters(pw, pw_sz, max_tries,
recovery_time,
lockout_recovery));
}
static cmd_tbl_t tpm2_commands[] = {
U_BOOT_CMD_MKENT(info, 0, 1, do_tpm_info, "", ""),
U_BOOT_CMD_MKENT(init, 0, 1, do_tpm_init, "", ""),
......@@ -190,6 +243,8 @@ static cmd_tbl_t tpm2_commands[] = {
U_BOOT_CMD_MKENT(pcr_extend, 0, 1, do_tpm2_pcr_extend, "", ""),
U_BOOT_CMD_MKENT(pcr_read, 0, 1, do_tpm_pcr_read, "", ""),
U_BOOT_CMD_MKENT(get_capability, 0, 1, do_tpm_get_capability, "", ""),
U_BOOT_CMD_MKENT(dam_reset, 0, 1, do_tpm_dam_reset, "", ""),
U_BOOT_CMD_MKENT(dam_parameters, 0, 1, do_tpm_dam_parameters, "", ""),
};
cmd_tbl_t *get_tpm_commands(unsigned int *size)
......@@ -236,4 +291,16 @@ U_BOOT_CMD(tpm, CONFIG_SYS_MAXARGS, 1, do_tpm, "Issue a TPMv2.x command",
" <property>: property\n"
" <addr>: address to store <count> entries of 4 bytes\n"
" <count>: number of entries to retrieve\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"
);
......@@ -191,4 +191,29 @@ u32 tpm2_pcr_read(u32 idx, unsigned int idx_min_sz, void *data,
u32 tpm2_get_capability(u32 capability, u32 property, void *buf,
size_t prop_count);
/**
* Issue a TPM2_DictionaryAttackLockReset command.
*
* @pw Password
* @pw_sz Length of the password
*
* @return code of the operation
*/
u32 tpm2_dam_reset(const char *pw, const ssize_t pw_sz);
/**
* Issue a TPM2_DictionaryAttackParameters command.
*
* @pw Password
* @pw_sz Length of the password
* @max_tries Count of authorizations before lockout
* @recovery_time Time before decrementation of the failure count
* @lockout_recovery Time to wait after a lockout
*
* @return code of the operation
*/
u32 tpm2_dam_parameters(const char *pw, const ssize_t pw_sz,
unsigned int max_tries, unsigned int recovery_time,
unsigned int lockout_recovery);
#endif /* __TPM_V2_H */
......@@ -190,3 +190,86 @@ u32 tpm2_get_capability(u32 capability, u32 property, void *buf,
return 0;
}
u32 tpm2_dam_reset(const char *pw, const ssize_t pw_sz)
{
u8 command_v2[COMMAND_BUFFER_SIZE] = {
tpm_u16(TPM2_ST_SESSIONS), /* TAG */
tpm_u32(27 + pw_sz), /* Length */
tpm_u32(TPM2_CC_DAM_RESET), /* Command code */
/* HANDLE */
tpm_u32(TPM2_RH_LOCKOUT), /* TPM resource handle */
/* AUTH_SESSION */
tpm_u32(9 + pw_sz), /* 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(pw_sz), /* Size of <hmac/password> */
/* STRING(pw) <hmac/password> (if any) */
};
unsigned int offset = 27;
int ret;
/*
* 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);
}
u32 tpm2_dam_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] = {
tpm_u16(TPM2_ST_SESSIONS), /* TAG */
tpm_u32(27 + pw_sz + 12), /* Length */
tpm_u32(TPM2_CC_DAM_PARAMETERS), /* Command code */
/* HANDLE */
tpm_u32(TPM2_RH_LOCKOUT), /* TPM resource handle */
/* AUTH_SESSION */
tpm_u32(9 + pw_sz), /* 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(pw_sz), /* Size of <hmac/password> */
/* STRING(pw) <hmac/password> (if any) */
/* LOCKOUT PARAMETERS */
/* tpm_u32(max_tries) Max tries (0, always lock) */
/* tpm_u32(recovery_time) Recovery time (0, no lock) */
/* tpm_u32(lockout_recovery) Lockout recovery */
};
unsigned int offset = 27;
int ret;
/*
* 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);
}
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