[PATCH v3] tpm-v2: allow algoirthm name to be configured for pcr_read and pcr_extend
Ilias Apalodimas
ilias.apalodimas at linaro.org
Sat Apr 6 18:32:33 CEST 2024
Hi Tim,
Thanks for the patch
I'll be away next week, I'll try to find time and take a closer look.
The pipeline [0] shows some TPM related failures
[0] https://source.denx.de/u-boot/custodians/u-boot-tpm/-/commit/9b4be64e41454e17269a968397933eeff300c380
Cheers
/Ilias
On Fri, 5 Apr 2024 at 03:17, 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.
>
> 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>
> ---
> 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 ++++++++++++++++++++--------
> include/tpm-v2.h | 67 ++++++++++++++++++++++++++++++++++++++-
> lib/efi_loader/efi_tcg2.c | 4 +--
> lib/tpm-v2.c | 62 +++++++++++++++++++++++-------------
> 4 files changed, 143 insertions(+), 39 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/include/tpm-v2.h b/include/tpm-v2.h
> index 33dd103767c4..263f9529e55d 100644
> --- a/include/tpm-v2.h
> +++ b/include/tpm-v2.h
> @@ -386,7 +386,54 @@ enum tpm2_algorithms {
> TPM2_ALG_SM3_256 = 0x12,
> };
>
> -extern const enum tpm2_algorithms tpm2_supported_algorithms[4];
> +/**
> + * struct digest_info - details of supported digests
> + *
> + * @hash_name: hash name
> + * @hash_alg: hash algorithm id
> + * @hash_mask: hash registry mask
> + * @hash_len: hash digest length
> + */
> +struct digest_info {
> + const char *hash_name;
> + u16 hash_alg;
> + u32 hash_mask;
> + u16 hash_len;
> +};
> +
> +/* Algorithm Registry */
> +#define TCG2_BOOT_HASH_ALG_SHA1 0x00000001
> +#define TCG2_BOOT_HASH_ALG_SHA256 0x00000002
> +#define TCG2_BOOT_HASH_ALG_SHA384 0x00000004
> +#define TCG2_BOOT_HASH_ALG_SHA512 0x00000008
> +#define TCG2_BOOT_HASH_ALG_SM3_256 0x00000010
> +
> +static const struct digest_info hash_algo_list[] = {
> + {
> + "sha1",
> + TPM2_ALG_SHA1,
> + TCG2_BOOT_HASH_ALG_SHA1,
> + TPM2_SHA1_DIGEST_SIZE,
> + },
> + {
> + "sha256",
> + TPM2_ALG_SHA256,
> + TCG2_BOOT_HASH_ALG_SHA256,
> + TPM2_SHA256_DIGEST_SIZE,
> + },
> + {
> + "sha384",
> + TPM2_ALG_SHA384,
> + TCG2_BOOT_HASH_ALG_SHA384,
> + TPM2_SHA384_DIGEST_SIZE,
> + },
> + {
> + "sha512",
> + TPM2_ALG_SHA512,
> + TCG2_BOOT_HASH_ALG_SHA512,
> + TPM2_SHA512_DIGEST_SIZE,
> + },
> +};
>
> static inline u16 tpm2_algorithm_to_len(enum tpm2_algorithms a)
> {
> @@ -965,4 +1012,22 @@ u32 tpm2_enable_nvcommits(struct udevice *dev, uint vendor_cmd,
> */
> u32 tpm2_auto_start(struct udevice *dev);
>
> +/**
> + * tpm2_name_to_algorithm() - Return an algorithm id given a supported
> + * algorithm name
> + *
> + * @name: algorithm name
> + * Return: enum tpm2_algorithms or -EINVAL
> + */
> +enum tpm2_algorithms tpm2_name_to_algorithm(const char *name);
> +
> +/**
> + * tpm2_algorithm_name() - Return an algorithm name string for a
> + * supported algorithm id
> + *
> + * @algorithm_id: algorithm defined in enum tpm2_algorithms
> + * Return: algorithm name string or ""
> + */
> +const char *tpm2_algorithm_name(enum tpm2_algorithms);
> +
> #endif /* __TPM_V2_H */
> diff --git a/lib/efi_loader/efi_tcg2.c b/lib/efi_loader/efi_tcg2.c
> index b07e0099c27e..cf5d8de018a7 100644
> --- a/lib/efi_loader/efi_tcg2.c
> +++ b/lib/efi_loader/efi_tcg2.c
> @@ -414,8 +414,8 @@ static efi_status_t tcg2_hash_pe_image(void *efi, u64 efi_size,
> }
>
> digest_list->count = 0;
> - for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); i++) {
> - u16 hash_alg = tpm2_supported_algorithms[i];
> + for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) {
> + u16 hash_alg = hash_algo_list[i].hash_alg;
>
> if (!(active & tpm2_algorithm_to_mask(hash_alg)))
> continue;
> diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
> index 68eaaa639f89..83f490c82541 100644
> --- a/lib/tpm-v2.c
> +++ b/lib/tpm-v2.c
> @@ -22,13 +22,6 @@
>
> #include "tpm-utils.h"
>
> -const enum tpm2_algorithms tpm2_supported_algorithms[4] = {
> - TPM2_ALG_SHA1,
> - TPM2_ALG_SHA256,
> - TPM2_ALG_SHA384,
> - TPM2_ALG_SHA512,
> -};
> -
> int tcg2_get_active_pcr_banks(struct udevice *dev, u32 *active_pcr_banks)
> {
> u32 supported = 0;
> @@ -82,14 +75,14 @@ int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length,
> return rc;
>
> digest_list->count = 0;
> - for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); ++i) {
> + for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
> u32 mask =
> - tpm2_algorithm_to_mask(tpm2_supported_algorithms[i]);
> + tpm2_algorithm_to_mask(hash_algo_list[i].hash_alg);
>
> if (!(active & mask))
> continue;
>
> - switch (tpm2_supported_algorithms[i]) {
> + switch (hash_algo_list[i].hash_alg) {
> case TPM2_ALG_SHA1:
> sha1_starts(&ctx);
> sha1_update(&ctx, input, length);
> @@ -116,12 +109,12 @@ int tcg2_create_digest(struct udevice *dev, const u8 *input, u32 length,
> break;
> default:
> printf("%s: unsupported algorithm %x\n", __func__,
> - tpm2_supported_algorithms[i]);
> + hash_algo_list[i].hash_alg);
> continue;
> }
>
> digest_list->digests[digest_list->count].hash_alg =
> - tpm2_supported_algorithms[i];
> + hash_algo_list[i].hash_alg;
> memcpy(&digest_list->digests[digest_list->count].digest, final,
> len);
> digest_list->count++;
> @@ -208,13 +201,13 @@ static int tcg2_log_init(struct udevice *dev, struct tcg2_event_log *elog)
> return rc;
>
> event_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes);
> - for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); ++i) {
> - mask = tpm2_algorithm_to_mask(tpm2_supported_algorithms[i]);
> + for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
> + mask = tpm2_algorithm_to_mask(hash_algo_list[i].hash_alg);
>
> if (!(active & mask))
> continue;
>
> - switch (tpm2_supported_algorithms[i]) {
> + switch (hash_algo_list[i].hash_alg) {
> case TPM2_ALG_SHA1:
> case TPM2_ALG_SHA256:
> case TPM2_ALG_SHA384:
> @@ -253,17 +246,17 @@ static int tcg2_log_init(struct udevice *dev, struct tcg2_event_log *elog)
> put_unaligned_le32(count, &ev->number_of_algorithms);
>
> count = 0;
> - for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); ++i) {
> - mask = tpm2_algorithm_to_mask(tpm2_supported_algorithms[i]);
> + for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
> + mask = tpm2_algorithm_to_mask(hash_algo_list[i].hash_alg);
>
> if (!(active & mask))
> continue;
>
> - len = tpm2_algorithm_to_len(tpm2_supported_algorithms[i]);
> + len = hash_algo_list[i].hash_len;
> if (!len)
> continue;
>
> - put_unaligned_le16(tpm2_supported_algorithms[i],
> + put_unaligned_le16(hash_algo_list[i].hash_alg,
> &ev->digest_sizes[count].algorithm_id);
> put_unaligned_le16(len, &ev->digest_sizes[count].digest_size);
> count++;
> @@ -304,7 +297,7 @@ static int tcg2_replay_eventlog(struct tcg2_event_log *elog,
> pos = offsetof(struct tcg_pcr_event2, digests) +
> offsetof(struct tpml_digest_values, count);
> count = get_unaligned_le32(log + pos);
> - if (count > ARRAY_SIZE(tpm2_supported_algorithms) ||
> + if (count > ARRAY_SIZE(hash_algo_list) ||
> (digest_list->count && digest_list->count != count))
> return 0;
>
> @@ -407,7 +400,7 @@ static int tcg2_log_parse(struct udevice *dev, struct tcg2_event_log *elog)
> return 0;
>
> count = get_unaligned_le32(&event->number_of_algorithms);
> - if (count > ARRAY_SIZE(tpm2_supported_algorithms))
> + if (count > ARRAY_SIZE(hash_algo_list))
> return 0;
>
> calc_size = offsetof(struct tcg_efi_spec_id_event, digest_sizes) +
> @@ -1110,7 +1103,7 @@ int tpm2_get_pcr_info(struct udevice *dev, u32 *supported_pcr, u32 *active_pcr,
> * We only support 5 algorithms for now so check against that
> * instead of TPM2_NUM_PCR_BANKS
> */
> - if (pcrs.count > ARRAY_SIZE(tpm2_supported_algorithms) ||
> + if (pcrs.count > ARRAY_SIZE(hash_algo_list) ||
> pcrs.count < 1) {
> printf("%s: too many pcrs: %u\n", __func__, pcrs.count);
> return -EMSGSIZE;
> @@ -1555,3 +1548,28 @@ u32 tpm2_enable_nvcommits(struct udevice *dev, uint vendor_cmd,
>
> return 0;
> }
> +
> +enum tpm2_algorithms tpm2_name_to_algorithm(const char *name)
> +{
> + size_t i;
> +
> + for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
> + if (!strcasecmp(name, hash_algo_list[i].hash_name))
> + return hash_algo_list[i].hash_alg;
> + }
> + printf("%s: unsupported algorithm %s\n", __func__, name);
> +
> + return -EINVAL;
> +}
> +
> +const char *tpm2_algorithm_name(enum tpm2_algorithms algo)
> +{
> + size_t i;
> +
> + for (i = 0; i < ARRAY_SIZE(hash_algo_list); ++i) {
> + if (hash_algo_list[i].hash_alg == algo)
> + return hash_algo_list[i].hash_name;
> + }
> +
> + return "";
> +}
> --
> 2.25.1
>
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