[PATCH v3] tpm-v2: allow algoirthm name to be configured for pcr_read and pcr_extend

Ilias Apalodimas ilias.apalodimas at linaro.org
Fri Apr 19 19:20:23 CEST 2024


Hi Tim,

On Fri, 19 Apr 2024 at 20:13, Tim Harvey <tharvey at gateworks.com> wrote:
>
> On Sat, Apr 6, 2024 at 9:33 AM Ilias Apalodimas
> <ilias.apalodimas at linaro.org> wrote:
> >
> > 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
> >
>
> Hi Ilias,
>
> I changed the output of 'tpm pcr_read' so that it shows the algo and
> size causing the test in test/py/tests/test_tpm2.py to fail:
> @@ -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);
>         }
>
> failure:
> E   AssertionError: assert 'PCR #10 content' in 'PCR #10 sha256 32
> byte content (723 known updates):\r\r\n 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00\r\r\n 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00'
>
> So I suppose I need to update test/py/tests/test_tpm2.py as well.

Yes

>
> Would I update test/py/tests/test_tpm2.py in the same patch as the one
> that causes the failure?

Yes please, I'd like patches merged that won't break the CI

>
> How do I go about running the tests manually to make sure I've addressed it?

You can send a PR against U-Boots repo (in github)

Cheers
/Ilias
>
> Best Regards,
>
> Tim
>
> > 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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