[PATCH 2/2 v4] tpm-v2: allow algoirthm name to be configured for pcr_read and pcr_extend
Ilias Apalodimas
ilias.apalodimas at linaro.org
Wed May 22 12:34:06 CEST 2024
Hi Tim,
Minor typo on the commit message. Since there's a small change in
patch #1 please fix this as well
Reviewed-by: Ilias Apalodimas <ilias.apalodimas at linaro.org>
On Wed, 22 May 2024 at 00:38, Tim Harvey <tharvey at gateworks.com> wrote:
>
> For pcr_read and pcr_extend commands allow the digest algorithm to be
> specified by an additional argument. If not specified it will default to
> SHA256 for backwards compatibility.
>
> Additionally update test_tpm2.py for the changes in output in pcr_read
> which now shows the algo and algo length in the output.
>
> A follow-on to this could be to extend all PCR banks with the detected
> algo when the <digest_algo> argument is 'auto'.
>
> Signed-off-by: Tim Harvey <tharvey at gateworks.com>
> ---
> v4:
> - update test_tpm2.py as required by changes in pcr_read output
> - split out moving algos to an array of structs to its own patch
> and encorporate a fix for tpm2_algorithm_to_mask
> v3:
> - replace tpm2_supported_algorithms with struct and use this to
> relate hash algoirthm details
> v2:
> - use tpm2_algorithm_to_len
> - use enum tpm2_algorithms
> - make function names and parameter names more consistent with existing
> tpm-v2 functions
> - fix various spelling errors
> ---
> cmd/tpm-v2.c | 49 +++++++++++++++++++++++++++-----------
> test/py/tests/test_tpm2.py | 2 +-
> 2 files changed, 36 insertions(+), 15 deletions(-)
>
> diff --git a/cmd/tpm-v2.c b/cmd/tpm-v2.c
> index 7e479b9dfe36..2343b4d9cb9e 100644
> --- a/cmd/tpm-v2.c
> +++ b/cmd/tpm-v2.c
> @@ -99,11 +99,19 @@ static int do_tpm2_pcr_extend(struct cmd_tbl *cmdtp, int flag, int argc,
> 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 algo = TPM2_ALG_SHA256;
> + int algo_len;
> int ret;
> u32 rc;
>
> - if (argc != 3)
> + if (argc < 3 || argc > 4)
> return CMD_RET_USAGE;
> + if (argc == 4) {
> + algo = tpm2_name_to_algorithm(argv[3]);
> + if (algo < 0)
> + return CMD_RET_FAILURE;
> + }
> + algo_len = tpm2_algorithm_to_len(algo);
>
> ret = get_tpm(&dev);
> if (ret)
> @@ -116,8 +124,12 @@ static int do_tpm2_pcr_extend(struct cmd_tbl *cmdtp, int flag, int argc,
> if (index >= priv->pcr_count)
> return -EINVAL;
>
> - rc = tpm2_pcr_extend(dev, index, TPM2_ALG_SHA256, digest,
> - TPM2_DIGEST_LEN);
> + rc = tpm2_pcr_extend(dev, index, algo, digest, algo_len);
> + if (!rc) {
> + printf("PCR #%u extended with %d byte %s digest\n", index,
> + algo_len, tpm2_algorithm_name(algo));
> + print_byte_string(digest, algo_len);
> + }
>
> unmap_sysmem(digest);
>
> @@ -127,15 +139,23 @@ static int do_tpm2_pcr_extend(struct cmd_tbl *cmdtp, int flag, int argc,
> static int do_tpm_pcr_read(struct cmd_tbl *cmdtp, int flag, int argc,
> char *const argv[])
> {
> + enum tpm2_algorithms algo = TPM2_ALG_SHA256;
> struct udevice *dev;
> struct tpm_chip_priv *priv;
> u32 index, rc;
> + int algo_len;
> unsigned int updates;
> void *data;
> int ret;
>
> - if (argc != 3)
> + if (argc < 3 || argc > 4)
> return CMD_RET_USAGE;
> + if (argc == 4) {
> + algo = tpm2_name_to_algorithm(argv[3]);
> + if (algo < 0)
> + return CMD_RET_FAILURE;
> + }
> + algo_len = tpm2_algorithm_to_len(algo);
>
> ret = get_tpm(&dev);
> if (ret)
> @@ -151,11 +171,12 @@ static int do_tpm_pcr_read(struct cmd_tbl *cmdtp, int flag, int argc,
>
> data = map_sysmem(simple_strtoul(argv[2], NULL, 0), 0);
>
> - rc = tpm2_pcr_read(dev, index, priv->pcr_select_min, TPM2_ALG_SHA256,
> - data, TPM2_DIGEST_LEN, &updates);
> + rc = tpm2_pcr_read(dev, index, priv->pcr_select_min, algo,
> + data, algo_len, &updates);
> if (!rc) {
> - printf("PCR #%u content (%u known updates):\n", index, updates);
> - print_byte_string(data, TPM2_DIGEST_LEN);
> + printf("PCR #%u %s %d byte content (%u known updates):\n", index,
> + tpm2_algorithm_name(algo), algo_len, updates);
> + print_byte_string(data, algo_len);
> }
>
> unmap_sysmem(data);
> @@ -415,14 +436,14 @@ U_BOOT_CMD(tpm2, 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_extend <pcr> <digest_addr> [<digest_algo>]\n"
> +" Extend PCR #<pcr> with digest at <digest_addr> with digest_algo.\n"
> " <pcr>: index of the PCR\n"
> -" <digest_addr>: address of a 32-byte SHA256 digest\n"
> -"pcr_read <pcr> <digest_addr>\n"
> -" Read PCR #<pcr> to memory address <digest_addr>.\n"
> +" <digest_addr>: address of digest of digest_algo type (defaults to SHA256)\n"
> +"pcr_read <pcr> <digest_addr> [<digest_algo>]\n"
> +" Read PCR #<pcr> to memory address <digest_addr> with <digest_algo>.\n"
> " <pcr>: index of the PCR\n"
> -" <digest_addr>: address to store the a 32-byte SHA256 digest\n"
> +" <digest_addr>: address of digest of digest_algo type (defaults to SHA256)\n"
> "get_capability <capability> <property> <addr> <count>\n"
> " Read and display <count> entries indexed by <capability>/<property>.\n"
> " Values are 4 bytes long and are written at <addr>.\n"
> diff --git a/test/py/tests/test_tpm2.py b/test/py/tests/test_tpm2.py
> index 1d654cd4a23b..75f5d31fc675 100644
> --- a/test/py/tests/test_tpm2.py
> +++ b/test/py/tests/test_tpm2.py
> @@ -257,7 +257,7 @@ def test_tpm2_pcr_read(u_boot_console):
> updates = int(re.findall(r'\d+', str)[0])
>
> # Check the output value
> - assert 'PCR #10 content' in read_pcr
> + assert 'PCR #10 sha256 32 byte content' in read_pcr
> assert '00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00' in read_pcr
>
> @pytest.mark.buildconfigspec('cmd_tpm_v2')
> --
> 2.25.1
>
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