From a557d258c6be49ec1253947a227189de149971df Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Tue, 30 Aug 2022 21:05:32 -0600 Subject: [PATCH] tpm: Require a digest source when extending the PCR This feature is used for measured boot, so we can add a log entry to the TCPA with some information about where the digest comes from. It is not currently supported in the TPM drivers, but add it to the API so that code which expects it can signal its request. Signed-off-by: Simon Glass Reviewed-by: Ilias Apalodimas Signed-off-by: Ilias Apalodimas --- cmd/tpm-v1.c | 3 ++- cmd/tpm_test.c | 5 +++-- include/tpm_api.h | 8 +++++--- lib/tpm-v2.c | 2 ++ lib/tpm_api.c | 10 ++++++---- 5 files changed, 18 insertions(+), 10 deletions(-) diff --git a/cmd/tpm-v1.c b/cmd/tpm-v1.c index bf238a9f2e..0efb079b0a 100644 --- a/cmd/tpm-v1.c +++ b/cmd/tpm-v1.c @@ -131,7 +131,8 @@ static int do_tpm_extend(struct cmd_tbl *cmdtp, int flag, int argc, return CMD_RET_FAILURE; } - rc = tpm_pcr_extend(dev, index, in_digest, out_digest); + rc = tpm_pcr_extend(dev, index, in_digest, sizeof(in_digest), + out_digest, "cmd"); if (!rc) { puts("PCR value after execution of the command:\n"); print_byte_string(out_digest, sizeof(out_digest)); diff --git a/cmd/tpm_test.c b/cmd/tpm_test.c index a3ccb12f53..b35eae81dc 100644 --- a/cmd/tpm_test.c +++ b/cmd/tpm_test.c @@ -91,7 +91,8 @@ static int test_early_extend(struct udevice *dev) tpm_init(dev); TPM_CHECK(tpm_startup(dev, TPM_ST_CLEAR)); TPM_CHECK(tpm_continue_self_test(dev)); - TPM_CHECK(tpm_pcr_extend(dev, 1, value_in, value_out)); + TPM_CHECK(tpm_pcr_extend(dev, 1, value_in, sizeof(value_in), value_out, + "test")); printf("done\n"); return 0; } @@ -438,7 +439,7 @@ static int test_timing(struct udevice *dev) 100); TTPM_CHECK(tpm_nv_read_value(dev, INDEX0, (uint8_t *)&x, sizeof(x)), 100); - TTPM_CHECK(tpm_pcr_extend(dev, 0, in, out), 200); + TTPM_CHECK(tpm_pcr_extend(dev, 0, in, sizeof(in), out, "test"), 200); TTPM_CHECK(tpm_set_global_lock(dev), 50); TTPM_CHECK(tpm_tsc_physical_presence(dev, PHYS_PRESENCE), 100); printf("done\n"); diff --git a/include/tpm_api.h b/include/tpm_api.h index 11aa14eb79..8979d9d6df 100644 --- a/include/tpm_api.h +++ b/include/tpm_api.h @@ -81,14 +81,16 @@ u32 tpm_nv_write_value(struct udevice *dev, u32 index, const void *data, * * @param dev TPM device * @param index index of the PCR - * @param in_digest 160-bit value representing the event to be + * @param in_digest 160/256-bit value representing the event to be * recorded - * @param out_digest 160-bit PCR value after execution of the + * @param size size of digest in bytes + * @param out_digest 160/256-bit PCR value after execution of the * command + * @param name digest source, used for log output * Return: return code of the operation */ u32 tpm_pcr_extend(struct udevice *dev, u32 index, const void *in_digest, - void *out_digest); + uint size, void *out_digest, const char *name); /** * Issue a TPM_PCRRead command. diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index 1bf627853a..6058f2e1e4 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -157,6 +157,8 @@ u32 tpm2_pcr_extend(struct udevice *dev, u32 index, u32 algorithm, }; int ret; + if (!digest) + return -EINVAL; /* * Fill the command structure starting from the first buffer: * - the digest diff --git a/lib/tpm_api.c b/lib/tpm_api.c index 032f383ca0..7e8df8795e 100644 --- a/lib/tpm_api.c +++ b/lib/tpm_api.c @@ -140,15 +140,17 @@ u32 tpm_write_lock(struct udevice *dev, u32 index) } u32 tpm_pcr_extend(struct udevice *dev, u32 index, const void *in_digest, - void *out_digest) + uint size, void *out_digest, const char *name) { - if (tpm_is_v1(dev)) + if (tpm_is_v1(dev)) { return tpm1_extend(dev, index, in_digest, out_digest); - else if (tpm_is_v2(dev)) + } else if (tpm_is_v2(dev)) { return tpm2_pcr_extend(dev, index, TPM2_ALG_SHA256, in_digest, TPM2_DIGEST_LEN); - else + /* @name is ignored as we do not support the TPM log here */ + } else { return -ENOSYS; + } } u32 tpm_pcr_read(struct udevice *dev, u32 index, void *data, size_t count)