Commit 6284be5a authored by Miquel Raynal's avatar Miquel Raynal Committed by Tom Rini

tpm: add TPM2_PCR_Extend command support

Add support for the TPM2_PCR_Extend command.

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 bad8ff56
......@@ -7,6 +7,7 @@
#include <common.h>
#include <dm.h>
#include <log.h>
#include <mapmem.h>
#include <tpm-common.h>
#include <tpm-v2.h>
#include "tpm-user-utils.h"
......@@ -74,12 +75,44 @@ static int do_tpm2_clear(cmd_tbl_t *cmdtp, int flag, int argc,
return report_return_code(tpm2_clear(handle, pw, pw_sz));
}
static int do_tpm2_pcr_extend(cmd_tbl_t *cmdtp, int flag, int argc,
char * const argv[])
{
struct udevice *dev;
struct tpm_chip_priv *priv;
u32 index = simple_strtoul(argv[1], NULL, 0);
void *digest = map_sysmem(simple_strtoul(argv[2], NULL, 0), 0);
int ret;
u32 rc;
if (argc != 3)
return CMD_RET_USAGE;
ret = uclass_first_device_err(UCLASS_TPM, &dev);
if (ret)
return ret;
priv = dev_get_uclass_priv(dev);
if (!priv)
return -EINVAL;
if (index >= priv->pcr_count)
return -EINVAL;
rc = tpm2_pcr_extend(index, digest);
unmap_sysmem(digest);
return report_return_code(rc);
}
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, "", ""),
U_BOOT_CMD_MKENT(startup, 0, 1, do_tpm2_startup, "", ""),
U_BOOT_CMD_MKENT(self_test, 0, 1, do_tpm2_self_test, "", ""),
U_BOOT_CMD_MKENT(clear, 0, 1, do_tpm2_clear, "", ""),
U_BOOT_CMD_MKENT(pcr_extend, 0, 1, do_tpm2_pcr_extend, "", ""),
};
cmd_tbl_t *get_tpm_commands(unsigned int *size)
......@@ -111,4 +144,8 @@ U_BOOT_CMD(tpm, CONFIG_SYS_MAXARGS, 1, do_tpm, "Issue a TPMv2.x command",
" <hierarchy> is one of:\n"
" * TPM2_RH_LOCKOUT\n"
" * TPM2_RH_PLATFORM\n"
"pcr_extend <pcr> <digest_addr>\n"
" Extend PCR #<pcr> with digest at <digest_addr>.\n"
" <pcr>: index of the PCR\n"
" <digest_addr>: address of a 32-byte SHA256 digest\n"
);
......@@ -154,4 +154,14 @@ u32 tpm2_self_test(enum tpm2_yes_no full_test);
*/
u32 tpm2_clear(u32 handle, const char *pw, const ssize_t pw_sz);
/**
* Issue a TPM2_PCR_Extend command.
*
* @index Index of the PCR
* @digest Value representing the event to be recorded
*
* @return code of the operation
*/
u32 tpm2_pcr_extend(u32 index, const uint8_t *digest);
#endif /* __TPM_V2_H */
......@@ -77,3 +77,41 @@ u32 tpm2_clear(u32 handle, const char *pw, const ssize_t pw_sz)
return tpm_sendrecv_command(command_v2, NULL, NULL);
}
u32 tpm2_pcr_extend(u32 index, const uint8_t *digest)
{
u8 command_v2[COMMAND_BUFFER_SIZE] = {
tpm_u16(TPM2_ST_SESSIONS), /* TAG */
tpm_u32(33 + TPM2_DIGEST_LEN), /* Length */
tpm_u32(TPM2_CC_PCR_EXTEND), /* Command code */
/* HANDLE */
tpm_u32(index), /* Handle (PCR Index) */
/* 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) */
tpm_u32(1), /* Count (number of hashes) */
tpm_u16(TPM2_ALG_SHA256), /* Algorithm of the hash */
/* STRING(digest) Digest */
};
unsigned int offset = 33;
int ret;
/*
* Fill the command structure starting from the first buffer:
* - the digest
*/
ret = pack_byte_string(command_v2, sizeof(command_v2), "s",
offset, digest, TPM2_DIGEST_LEN);
offset += TPM2_DIGEST_LEN;
if (ret)
return TPM_LIB_ERROR;
return tpm_sendrecv_command(command_v2, NULL, NULL);
}
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