[PATCH v3] tpm-v2: allow algoirthm name to be configured for pcr_read and pcr_extend
Tim Harvey
tharvey at gateworks.com
Thu May 16 02:28:40 CEST 2024
On Fri, Apr 19, 2024 at 1:04 PM Ilias Apalodimas
<ilias.apalodimas at linaro.org> wrote:
>
> On Fri, 19 Apr 2024 at 20:52, Tim Harvey <tharvey at gateworks.com> wrote:
> >
> > On Fri, Apr 19, 2024 at 10:37 AM Ilias Apalodimas
> > <ilias.apalodimas at linaro.org> wrote:
> > >
> > > Also quickly looking at this, you need a new function for
> > > tpm2_algorithm_to_mask() (look below)
> > >
> > > On Fri, 19 Apr 2024 at 20:20, Ilias Apalodimas
> > > <ilias.apalodimas at linaro.org> wrote:
> > > >
> > > > 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_SHA384,
> > > > > > > - TPM2_ALG_SHA512,
> > > > > > > -};
> > >
> > > The current tpm2_algorithm_to_mask() operates on those values and bits
> > > shifts based on the enum. Since you remove the enum above, you must
> > > also change the function implementation and return
> > > hash_algo_list.hash_mask
> > >
> >
> > That's already taken care of as the calls to tpm2_algorithm_to_mask()
> > in my patch were adjusted from:
> > tpm2_algorithm_to_mask(tpm2_supported_algorithms[i])
> > to
> > tpm2_algorithm_to_mask(hash_algo_list[i].hash_alg)
> >
> > The hash_alg is the value from the previous enum.
>
> The previous enums were defining TPM2_ALG_SHA1=1, TPM2_ALG_SHA256=2 etc
> The current values are different. On top of that the .hash_mask entry
> of digest_info is never used. So you need to change
> tpm2_algorithm_to_mask() and directly return the hash_mask
>
Hi Ilias,
Just getting back to this. I don't agree with your assessment.
The previous enum:
-const enum tpm2_algorithms tpm2_supported_algorithms[4] = {
- TPM2_ALG_SHA1,
- TPM2_ALG_SHA256,
- TPM2_ALG_SHA384,
- TPM2_ALG_SHA512,
-};
is defining 4 values which equate to 0x04, 0x0B, 0x0C, 0x0D (not 1, 2,
3, 4 as you say) which is what I'm putting in the hash_alg field. The
tpm2_algorithm_to_mask macro shifts those values (not the index into
the enum).
So with the current code:
for (i = 0; i < ARRAY_SIZE(tpm2_supported_algorithms); i++) {
int alg = tpm2_supported_algorithms[i];
printf("alg:0x%02x mask=0x%02x\n", alg, tpm2_algorithm_to_mask(alg));
}
alg:0x04 mask=0x10
alg:0x0b mask=0x800
alg:0x0c mask=0x1000
alg:0x0d mask=0x2000
With this proposed patch:
for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) {
int alg = hash_algo_list[i].hash_alg;
printf("alg:0x%02x mask=0x%02x %s\n", alg,
tpm2_algorithm_to_mask(alg), tpm2_algorithm_name(alg));
}
alg:0x04 mask=0x10 sha1
alg:0x0b mask=0x800 sha256
alg:0x0c mask=0x1000 sha384
alg:0x0d mask=0x2000 sha512
Am I misunderstanding something else you are pointing out?
Maybe it would be easier to compare if I named the new struct
tpm2_supported_algorithms?
Best Regards,
Tim
> Cheers
> /Ilias
> >
> > Best Regards,
> >
> > Tim
> >
> > > Cheers
> > > /Ilias
> > >
> > >
> > >
> > > > > > > -
> > > > > > > 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))
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