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

On Fri, 19 Apr 2024 at 20:52, Tim Harvey tharvey@gateworks.com wrote:

On Fri, Apr 19, 2024 at 10:37 AM Ilias Apalodimas ilias.apalodimas@linaro.org wrote:

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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@linaro.org wrote:

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Hi Tim,

On Fri, 19 Apr 2024 at 20:13, Tim Harvey tharvey@gateworks.com wrote:

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On Sat, Apr 6, 2024 at 9:33 AM Ilias Apalodimas ilias.apalodimas@linaro.org wrote:

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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/9b4be64e41454e1...

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

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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

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Cheers /Ilias

On Fri, 5 Apr 2024 at 03:17, Tim Harvey tharvey@gateworks.com wrote:

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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@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

Cheers /Ilias

Best Regards,

Tim

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Cheers /Ilias

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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))