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util/grub-protect: Support NV index mode

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This commit implements the missing NV index mode support in grub-protect.
NV index mode stores the sealed key in the TPM non-volatile memory (NVRAM)
instead of a file. There are two supported types of TPM handles.

1. Persistent handle (0x81000000~0x81FFFFFF)
   Only the raw format is supported due to the limitation of persistent
   handles. This grub-protect command seals the key into the
   persistent handle 0x81000000.

  # grub-protect \
      --protector=tpm2 \
      --action=add \
      --tpm2-bank=sha256 \
      --tpm2-pcrs=7,11 \
      --tpm2-keyfile=luks-key \
      --tpm2-nvindex=0x81000000

2. NV index handle (0x1000000~0x1FFFFFF)
   Both TPM 2.0 Key File format and the raw format are supported by NV
   index handles. Here is the grub-protect command to seal the key in
   TPM 2.0 Key File format into the NV index handle 0x1000000.

  # grub-protect \
      --protector=tpm2 \
      --action=add \
      --tpm2key \
      --tpm2-bank=sha256 \
      --tpm2-pcrs=7,11 \
      --tpm2-keyfile=luks-key \
      --tpm2-nvindex=0x1000000

Besides the "add" action, the corresponding "remove" action is also
introduced. To remove the data from a persistent or NV index handle,
just use "--tpm2-nvindex=HANDLE" combining with "--tpm2-evict". This
sample command removes the data from the NV index handle 0x1000000.

  # grub-protect \
      --protector=tpm2 \
      --action=remove \
      --tpm2-evict \
      --tpm2-nvindex=0x1000000

Also set and check the boolean variables with true/false instead of 1/0.

Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
This commit is contained in:
Gary Lin 2025-04-07 16:29:21 +08:00 committed by Daniel Kiper
parent cd9cb944d9
commit 5934bf51cb
1 changed files with 287 additions and 56 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

343
util/grub-protect.c
View File

@ -61,7 +61,8 @@ typedef enum protect_opt
PROTECT_OPT_TPM2_KEYFILE,
PROTECT_OPT_TPM2_OUTFILE,
PROTECT_OPT_TPM2_EVICT,
PROTECT_OPT_TPM2_TPM2KEY
PROTECT_OPT_TPM2_TPM2KEY,
PROTECT_OPT_TPM2_NVINDEX,
} protect_opt_t;
/* Option flags to keep track of specified arguments */
@ -79,7 +80,8 @@ typedef enum protect_arg
PROTECT_ARG_TPM2_KEYFILE = 1 << 7,
PROTECT_ARG_TPM2_OUTFILE = 1 << 8,
PROTECT_ARG_TPM2_EVICT = 1 << 9,
PROTECT_ARG_TPM2_TPM2KEY = 1 << 10
PROTECT_ARG_TPM2_TPM2KEY = 1 << 10,
PROTECT_ARG_TPM2_NVINDEX = 1 << 11
} protect_arg_t;
typedef enum protect_protector
@ -111,6 +113,7 @@ typedef struct protect_args
const char *tpm2_outfile;
bool tpm2_evict;
bool tpm2_tpm2key;
TPM_HANDLE_t tpm2_nvindex;
} protect_args_t;
static struct argp_option protect_options[] =
@ -224,6 +227,15 @@ static struct argp_option protect_options[] =
N_("Use TPM 2.0 Key File format."),
.group = 0
},
{
.name = "tpm2-nvindex",
.key = PROTECT_OPT_TPM2_NVINDEX,
.arg = "NUM",
.flags = 0,
.doc =
N_("Store the sealed key in a persistent or NV index handle."),
.group = 0
},
/* End of list */
{ 0, 0, 0, 0, 0, 0 }
};
@ -668,8 +680,8 @@ extern asn1_static_node tpm2key_asn1_tab[];
#define TPM2KEY_SEALED_KEY_OID "2.23.133.10.1.5"
static grub_err_t
protect_tpm2_export_tpm2key (const protect_args_t *args,
tpm2_sealed_key_t *sealed_key)
protect_tpm2_export_tpm2key (const protect_args_t *args, tpm2_sealed_key_t *sealed_key,
void **der_buf, int *der_buf_size)
{
const char *sealed_key_oid = TPM2KEY_SEALED_KEY_OID;
asn1_node asn1_def = NULL;
@ -689,12 +701,13 @@ protect_tpm2_export_tpm2key (const protect_args_t *args,
};
struct grub_tpm2_buffer pub_buf;
struct grub_tpm2_buffer priv_buf;
void *der_buf = NULL;
int der_buf_size = 0;
int i;
int ret;
grub_err_t err;
if (der_buf == NULL)
return GRUB_ERR_BAD_ARGUMENT;
for (i = 0; i < args->tpm2_pcr_count; i++)
TPMS_PCR_SELECTION_SelectPCR (&pcr_sel.pcrSelections[0], args->tpm2_pcrs[i]);
@ -844,8 +857,8 @@ protect_tpm2_export_tpm2key (const protect_args_t *args,
}
/* Create the DER binary */
der_buf_size = 0;
ret = asn1_der_coding (tpm2key, "", NULL, &der_buf_size, NULL);
*der_buf_size = 0;
ret = asn1_der_coding (tpm2key, "", NULL, der_buf_size, NULL);
if (ret != ASN1_MEM_ERROR)
{
fprintf (stderr, "Failed to get DER size: 0x%x\n", ret);
@ -853,15 +866,15 @@ protect_tpm2_export_tpm2key (const protect_args_t *args,
goto error;
}
der_buf = grub_malloc (der_buf_size);
if (der_buf == NULL)
*der_buf = grub_malloc (*der_buf_size);
if (*der_buf == NULL)
{
fprintf (stderr, "Failed to allocate memory for DER encoding\n");
err = GRUB_ERR_OUT_OF_MEMORY;
goto error;
}
ret = asn1_der_coding (tpm2key, "", der_buf, &der_buf_size, NULL);
ret = asn1_der_coding (tpm2key, "", *der_buf, der_buf_size, NULL);
if (ret != ASN1_SUCCESS)
{
fprintf (stderr, "DER coding error: 0x%x\n", ret);
@ -869,13 +882,7 @@ protect_tpm2_export_tpm2key (const protect_args_t *args,
goto error;
}
err = protect_write_file (args->tpm2_outfile, der_buf, der_buf_size);
if (err != GRUB_ERR_NONE)
fprintf (stderr, N_("Could not write tpm2key file (%s).\n"), strerror (errno));
error:
grub_free (der_buf);
if (tpm2key)
asn1_delete_structure (&tpm2key);
@ -883,10 +890,8 @@ protect_tpm2_export_tpm2key (const protect_args_t *args,
}
static grub_err_t
protect_tpm2_export_sealed_key (const char *filepath,
tpm2_sealed_key_t *sealed_key)
protect_tpm2_export_raw (tpm2_sealed_key_t *sealed_key, void **out_buf, int *out_buf_size)
{
grub_err_t err;
struct grub_tpm2_buffer buf;
grub_tpm2_buffer_init (&buf);
@ -896,13 +901,98 @@ protect_tpm2_export_sealed_key (const char *filepath,
if (buf.error != 0)
return GRUB_ERR_BAD_ARGUMENT;
err = protect_write_file (filepath, buf.data, buf.size);
if (err != GRUB_ERR_NONE)
fprintf (stderr, N_("Could not write sealed key file (%s).\n"), strerror (errno));
*out_buf_size = buf.size;
*out_buf = grub_malloc (buf.size);
if (*out_buf == NULL)
{
fprintf (stderr, N_("Could not allocate memory for the raw format key.\n"));
return GRUB_ERR_OUT_OF_MEMORY;
}
grub_memcpy (*out_buf, buf.data, buf.size);
return GRUB_ERR_NONE;
}
static grub_err_t
protect_tpm2_export_persistent (protect_args_t *args,
TPM_HANDLE_t srk_handle,
tpm2_sealed_key_t *sealed_key)
{
TPMS_AUTH_COMMAND_t authCmd = {0};
TPM2B_NAME_t name = {0};
TPM_HANDLE_t sealed_handle;
TPM_RC_t rc;
grub_err_t err = GRUB_ERR_NONE;
/* Load the sealed key and associate it with the SRK */
authCmd.sessionHandle = TPM_RS_PW;
rc = grub_tpm2_load (srk_handle, &authCmd, &sealed_key->private, &sealed_key->public,
&sealed_handle, &name, NULL);
if (rc != TPM_RC_SUCCESS)
{
fprintf (stderr, "Failed to load sealed key (TPM2_Load: %x).\n", rc);
return GRUB_ERR_BAD_DEVICE;
}
/* Make the sealed key object persistent */
authCmd.sessionHandle = TPM_RS_PW;
rc = grub_tpm2_evictcontrol (TPM_RH_OWNER, sealed_handle, &authCmd, args->tpm2_nvindex, NULL);
if (rc != TPM_RC_SUCCESS)
{
fprintf (stderr, "Failed to make sealed key persistent with handle 0x%x (TPM2_EvictControl: 0x%x).\n", args->tpm2_nvindex, rc);
err = GRUB_ERR_BAD_DEVICE;
goto exit;
}
exit:
grub_tpm2_flushcontext (sealed_handle);
return err;
}
static grub_err_t
protect_tpm2_export_nvindex (protect_args_t *args, void *data, int data_size)
{
TPMS_AUTH_COMMAND_t authCmd = {0};
TPM2B_NV_PUBLIC_t pub_info = {0};
TPM2B_MAX_NV_BUFFER_t nv_data = {0};
TPM_RC_t rc;
if (data_size > TPM_MAX_NV_BUFFER_SIZE || data_size < 0)
{
fprintf (stderr, N_("Invalid tpm2key size for TPM NV buffer\n"));
return GRUB_ERR_OUT_OF_RANGE;
}
pub_info.nvPublic.nvIndex = args->tpm2_nvindex;
pub_info.nvPublic.nameAlg = TPM_ALG_SHA256;
pub_info.nvPublic.attributes = TPMA_NV_OWNERWRITE | TPMA_NV_OWNERREAD;
pub_info.nvPublic.dataSize = (grub_uint16_t) data_size;
authCmd.sessionHandle = TPM_RS_PW;
rc = grub_tpm2_nv_definespace (TPM_RH_OWNER, &authCmd, NULL, &pub_info);
if (rc != TPM_RC_SUCCESS)
{
fprintf (stderr, "Failed to define NV space for 0x%x (TPM2_NV_DefineSpace: 0x%x)\n", args->tpm2_nvindex, rc);
return GRUB_ERR_BAD_DEVICE;
}
authCmd.sessionHandle = TPM_RS_PW;
grub_memcpy (nv_data.buffer, data, data_size);
nv_data.size = (grub_uint16_t) data_size;
rc = grub_tpm2_nv_write (TPM_RH_OWNER, args->tpm2_nvindex, &authCmd, &nv_data, 0);
if (rc != TPM_RC_SUCCESS)
{
fprintf (stderr, "Failed to write data into 0x%x (TPM2_NV_Write: 0x%x)\n", args->tpm2_nvindex, rc);
return GRUB_ERR_BAD_DEVICE;
}
return GRUB_ERR_NONE;
}
static grub_err_t
protect_tpm2_add (protect_args_t *args)
{
@ -911,6 +1001,8 @@ protect_tpm2_add (protect_args_t *args)
grub_size_t key_size;
TPM_HANDLE_t srk;
TPM2B_DIGEST_t policy_digest;
void *out_buf = NULL;
int out_buf_size;
tpm2_sealed_key_t sealed_key;
err = protect_tpm2_open_device (args->tpm2_device);
@ -940,15 +1032,51 @@ protect_tpm2_add (protect_args_t *args)
if (err != GRUB_ERR_NONE)
goto exit3;
if (args->tpm2_tpm2key != 0)
err = protect_tpm2_export_tpm2key (args, &sealed_key);
if (args->tpm2_tpm2key == true)
{
err = protect_tpm2_export_tpm2key (args, &sealed_key, &out_buf, &out_buf_size);
if (err != GRUB_ERR_NONE)
{
fprintf (stderr, N_("Could not export to TPM 2.0 Key File format\n"));
goto exit3;
}
}
else
err = protect_tpm2_export_sealed_key (args->tpm2_outfile, &sealed_key);
if (err != GRUB_ERR_NONE)
goto exit3;
{
err = protect_tpm2_export_raw (&sealed_key, &out_buf, &out_buf_size);
if (err != GRUB_ERR_NONE)
{
fprintf (stderr, N_("Could not export to the raw format\n"));
goto exit3;
}
}
if (args->tpm2_outfile != NULL)
{
err = protect_write_file (args->tpm2_outfile, out_buf, out_buf_size);
if (err != GRUB_ERR_NONE)
{
fprintf (stderr, N_("Could not write key file (%s).\n"), strerror (errno));
goto exit3;
}
}
if (TPM_HT_IS_NVINDEX (args->tpm2_nvindex) == true)
{
err = protect_tpm2_export_nvindex (args, out_buf, out_buf_size);
if (err != GRUB_ERR_NONE)
goto exit3;
}
else if (TPM_HT_IS_PERSISTENT (args->tpm2_nvindex) == true)
{
err = protect_tpm2_export_persistent (args, srk, &sealed_key);
if (err != GRUB_ERR_NONE)
goto exit3;
}
exit3:
grub_tpm2_flushcontext (srk);
grub_free (out_buf);
exit2:
grub_free (key);
@ -960,14 +1088,66 @@ protect_tpm2_add (protect_args_t *args)
}
static grub_err_t
protect_tpm2_remove (protect_args_t *args)
protect_tpm2_evict (TPM_HANDLE_t handle)
{
TPM_RC_t rc;
TPM2B_PUBLIC_t public;
TPMS_AUTH_COMMAND_t authCommand = {0};
TPMS_AUTH_COMMAND_t authCmd = {0};
/* Find the persistent handle */
rc = grub_tpm2_readpublic (handle, NULL, &public);
if (rc != TPM_RC_SUCCESS)
{
fprintf (stderr, "Handle 0x%x not found.\n", handle);
return GRUB_ERR_BAD_ARGUMENT;
}
/* Evict the persistent handle */
authCmd.sessionHandle = TPM_RS_PW;
rc = grub_tpm2_evictcontrol (TPM_RH_OWNER, handle, &authCmd, handle, NULL);
if (rc != TPM_RC_SUCCESS)
{
fprintf (stderr, "Failed to evict handle 0x%x (TPM2_EvictControl: 0x%x).\n", handle, rc);
return GRUB_ERR_BAD_DEVICE;
}
return GRUB_ERR_NONE;
}
static grub_err_t
protect_tpm2_nv_undefine (TPM_HANDLE_t handle)
{
TPM_RC_t rc;
TPM2B_NV_PUBLIC_t nv_public;
TPMS_AUTH_COMMAND_t authCmd = {0};
TPM2B_NAME_t nv_name;
/* Find the nvindex handle */
rc = grub_tpm2_nv_readpublic (handle, NULL, &nv_public, &nv_name);
if (rc != TPM_RC_SUCCESS)
{
fprintf (stderr, "Handle 0x%x not found.\n", handle);
return GRUB_ERR_BAD_ARGUMENT;
}
/* Undefine the nvindex handle */
authCmd.sessionHandle = TPM_RS_PW;
rc = grub_tpm2_nv_undefinespace (TPM_RH_OWNER, handle, &authCmd);
if (rc != TPM_RC_SUCCESS)
{
fprintf (stderr, "Failed to undefine handle 0x%x (TPM2_NV_UndefineSpace: 0x%x).\n", handle, rc);
return GRUB_ERR_BAD_DEVICE;
}
return GRUB_ERR_NONE;
}
static grub_err_t
protect_tpm2_remove (protect_args_t *args)
{
grub_err_t err;
if (args->tpm2_evict == 0)
if (args->tpm2_evict == false)
{
printf ("--tpm2-evict not specified, nothing to do.\n");
return GRUB_ERR_NONE;
@ -977,35 +1157,41 @@ protect_tpm2_remove (protect_args_t *args)
if (err != GRUB_ERR_NONE)
return err;
/* Find SRK */
rc = grub_tpm2_readpublic (args->tpm2_srk, NULL, &public);
if (rc != TPM_RC_SUCCESS)
if (args->tpm2_srk != 0)
{
fprintf (stderr, "SRK with handle 0x%x not found.\n", args->tpm2_srk);
err = GRUB_ERR_BAD_ARGUMENT;
goto exit1;
err = protect_tpm2_evict (args->tpm2_srk);
if (err != GRUB_ERR_NONE)
goto exit;
}
/* Evict SRK */
authCommand.sessionHandle = TPM_RS_PW;
rc = grub_tpm2_evictcontrol (TPM_RH_OWNER, args->tpm2_srk, &authCommand, args->tpm2_srk, NULL);
if (rc != TPM_RC_SUCCESS)
if (args->tpm2_nvindex != 0)
{
fprintf (stderr, "Failed to evict SRK with handle 0x%x (TPM2_EvictControl: 0x%x).\n", args->tpm2_srk, rc);
err = GRUB_ERR_BAD_DEVICE;
goto exit2;
if (TPM_HT_IS_PERSISTENT (args->tpm2_nvindex) == true)
{
err = protect_tpm2_evict (args->tpm2_nvindex);
if (err != GRUB_ERR_NONE)
goto exit;
}
else if (TPM_HT_IS_NVINDEX (args->tpm2_nvindex) == true)
{
err = protect_tpm2_nv_undefine (args->tpm2_nvindex);
if (err != GRUB_ERR_NONE)
goto exit;
}
else
{
fprintf (stderr, "Unsupported handle 0x%x\n", args->tpm2_nvindex);
err = GRUB_ERR_BAD_ARGUMENT;
goto exit;
}
}
err = GRUB_ERR_NONE;
exit2:
grub_tpm2_flushcontext (args->tpm2_srk);
exit1:
exit:
protect_tpm2_close_device ();
return GRUB_ERR_NONE;
return err;
}
static grub_err_t
@ -1045,9 +1231,36 @@ protect_tpm2_args_verify (protect_args_t *args)
return GRUB_ERR_BAD_ARGUMENT;
}
if (args->tpm2_outfile == NULL)
if (args->tpm2_outfile == NULL && args->tpm2_nvindex == 0)
{
fprintf (stderr, N_("--tpm2-outfile must be specified.\n"));
fprintf (stderr, N_("--tpm2-outfile or --tpm2-nvindex must be specified.\n"));
return GRUB_ERR_BAD_ARGUMENT;
}
if (args->tpm2_nvindex != 0)
{
if (args->tpm2_tpm2key == true && TPM_HT_IS_PERSISTENT (args->tpm2_nvindex) == true)
{
fprintf (stderr, N_("Persistent handle does not support TPM 2.0 Key File format.\n"));
return GRUB_ERR_BAD_ARGUMENT;
}
if (TPM_HT_IS_PERSISTENT (args->tpm2_nvindex) == false && TPM_HT_IS_NVINDEX (args->tpm2_nvindex) == false)
{
fprintf (stderr, N_("--tpm2-nvindex must be a persistent or NV index handle.\n"));
return GRUB_ERR_BAD_ARGUMENT;
}
if (args->tpm2_nvindex == args->tpm2_srk)
{
fprintf (stderr, N_("--tpm2-nvindex and --tpm2-srk must be different.\n"));
return GRUB_ERR_BAD_ARGUMENT;
}
}
if (args->tpm2_srk != 0 && TPM_HT_IS_PERSISTENT(args->tpm2_srk) == false)
{
fprintf (stderr, N_("--tpm2-srk must be a persistent handle, e.g. 0x81000000.\n"));
return GRUB_ERR_BAD_ARGUMENT;
}
@ -1099,9 +1312,9 @@ protect_tpm2_args_verify (protect_args_t *args)
return GRUB_ERR_BAD_ARGUMENT;
}
if (args->tpm2_srk == 0)
if (args->tpm2_srk == 0 && args->tpm2_nvindex == 0)
{
fprintf (stderr, N_("--tpm2-srk is not specified when --action is 'remove'.\n"));
fprintf (stderr, N_("missing --tpm2-srk or --tpm2-nvindex for --action 'remove'.\n"));
return GRUB_ERR_BAD_ARGUMENT;
}
@ -1274,7 +1487,7 @@ protect_argp_parser (int key, char *arg, struct argp_state *state)
return EINVAL;
}
args->tpm2_evict = 1;
args->tpm2_evict = true;
args->args |= PROTECT_ARG_TPM2_EVICT;
break;
@ -1285,10 +1498,28 @@ protect_argp_parser (int key, char *arg, struct argp_state *state)
return EINVAL;
}
args->tpm2_tpm2key = 1;
args->tpm2_tpm2key = true;
args->args |= PROTECT_ARG_TPM2_TPM2KEY;
break;
case PROTECT_OPT_TPM2_NVINDEX:
if (args->args & PROTECT_ARG_TPM2_NVINDEX)
{
fprintf (stderr, N_("--tpm2-nvindex can only be specified once.\n"));
return EINVAL;
}
err = grub_tpm2_protector_parse_tpm_handle (arg, &args->tpm2_nvindex);
if (err != GRUB_ERR_NONE)
{
if (grub_errno != GRUB_ERR_NONE)
grub_print_error ();
return EINVAL;
}
args->args |= PROTECT_ARG_TPM2_NVINDEX;
break;
default:
return ARGP_ERR_UNKNOWN;
}