From 1c6608bd92acfa3a4c269ccdcb92905a4e512813 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Sun, 18 Jul 2021 14:18:06 -0600 Subject: sandbox: tpm: Support extending a PCR multiple times It is fairly easy to handle this case and it makes the emulator more useful, since PCRs are commonly extended several times. Add support for this, using U-Boot's sha256 support. For now sandbox only supports a single PCR, but that is enough for the tests that currently exist. Signed-off-by: Simon Glass --- drivers/tpm/tpm2_tis_sandbox.c | 24 ++++++++++-------------- 1 file changed, 10 insertions(+), 14 deletions(-) (limited to 'drivers/tpm') diff --git a/drivers/tpm/tpm2_tis_sandbox.c b/drivers/tpm/tpm2_tis_sandbox.c index 3c4bbcdf2e..ac6eb14353 100644 --- a/drivers/tpm/tpm2_tis_sandbox.c +++ b/drivers/tpm/tpm2_tis_sandbox.c @@ -11,6 +11,7 @@ #include #include #include +#include #include "sandbox_common.h" /* Hierarchies */ @@ -39,13 +40,6 @@ enum tpm2_cap_tpm_property { #define SANDBOX_TPM_PCR_NB 1 -static const u8 sandbox_extended_once_pcr[] = { - 0xf5, 0xa5, 0xfd, 0x42, 0xd1, 0x6a, 0x20, 0x30, - 0x27, 0x98, 0xef, 0x6e, 0xd3, 0x09, 0x97, 0x9b, - 0x43, 0x00, 0x3d, 0x23, 0x20, 0xd9, 0xf0, 0xe8, - 0xea, 0x98, 0x31, 0xa9, 0x27, 0x59, 0xfb, 0x4b, -}; - /* * Information about our TPM emulation. This is preserved in the sandbox * state file if enabled. @@ -407,15 +401,17 @@ static int sandbox_tpm2_extend(struct udevice *dev, int pcr_index, const u8 *extension) { struct sandbox_tpm2 *tpm = dev_get_priv(dev); - int i; + sha256_context ctx; + + /* Zero the PCR if this is the first use */ + if (!tpm->pcr_extensions[pcr_index]) + memset(tpm->pcr[pcr_index], '\0', TPM2_DIGEST_LEN); - /* Only simulate the first extensions from all '0' with only '0' */ - for (i = 0; i < TPM2_DIGEST_LEN; i++) - if (tpm->pcr[pcr_index][i] || extension[i]) - return TPM2_RC_FAILURE; + sha256_starts(&ctx); + sha256_update(&ctx, tpm->pcr[pcr_index], TPM2_DIGEST_LEN); + sha256_update(&ctx, extension, TPM2_DIGEST_LEN); + sha256_finish(&ctx, tpm->pcr[pcr_index]); - memcpy(tpm->pcr[pcr_index], sandbox_extended_once_pcr, - TPM2_DIGEST_LEN); tpm->pcr_extensions[pcr_index]++; return 0; -- cgit v1.2.3