From 4d2af9df7cc1aab4a48ddf0f06c3f92e6580f6fa Mon Sep 17 00:00:00 2001 From: Philipp Deppenwiese Date: Tue, 14 Aug 2018 09:46:55 -0700 Subject: [PATCH] security/tpm: Fix TPM 1.2 state machine issues * Fix ACPI resume path compilation for TPM ramstage driver * Move enabling of the TPM prior activation and remove reboot return status from TPM enable. More information can be found via the TCG specification v1.2 Tested=Elgon Change-Id: Ided110e0c1889b302e29acac6d8d2341f97eb10b Signed-off-by: Philipp Deppenwiese Reviewed-on: https://review.coreboot.org/28085 Reviewed-by: Patrick Rudolph Reviewed-by: Philipp Deppenwiese Tested-by: build bot (Jenkins) --- src/drivers/tpm/tpm.c | 6 ++++-- src/security/tpm/tspi/tspi.c | 31 ++++++++++++++----------------- 2 files changed, 18 insertions(+), 19 deletions(-) diff --git a/src/drivers/tpm/tpm.c b/src/drivers/tpm/tpm.c index e4a81c3da4..77d3a8e81e 100644 --- a/src/drivers/tpm/tpm.c +++ b/src/drivers/tpm/tpm.c @@ -18,16 +18,18 @@ #include #include -#if IS_ENABLED(CONFIG_ARCH_X86) +#if IS_ENABLED(CONFIG_HAVE_ACPI_RESUME) #include #endif static void init_tpm_dev(void *unused) { -#if IS_ENABLED(CONFIG_ARCH_X86) +#if IS_ENABLED(CONFIG_HAVE_ACPI_RESUME) int s3resume = acpi_is_wakeup_s3(); tpm_setup(s3resume); #else + /* This can lead to PCR reset attacks but currently there + is no generic way to detect resume on other platforms. */ tpm_setup(false); #endif } diff --git a/src/security/tpm/tspi/tspi.c b/src/security/tpm/tspi/tspi.c index 950e930133..fccf224519 100644 --- a/src/security/tpm/tspi/tspi.c +++ b/src/security/tpm/tspi/tspi.c @@ -25,17 +25,27 @@ #if IS_ENABLED(CONFIG_TPM1) static uint32_t tpm1_invoke_state_machine(void) { - uint8_t disable; + uint8_t disabled; uint8_t deactivated; uint32_t result = TPM_SUCCESS; /* Check that the TPM is enabled and activated. */ - result = tlcl_get_flags(&disable, &deactivated, NULL); + result = tlcl_get_flags(&disabled, &deactivated, NULL); if (result != TPM_SUCCESS) { printk(BIOS_ERR, "TPM: Can't read capabilities.\n"); return result; } + if (disabled) { + printk(BIOS_INFO, "TPM: is disabled. Enabling...\n"); + + result = tlcl_set_enable(); + if (result != TPM_SUCCESS) { + printk(BIOS_ERR, "TPM: Can't set enabled state.\n"); + return result; + } + } + if (!!deactivated != IS_ENABLED(CONFIG_TPM_DEACTIVATE)) { printk(BIOS_INFO, "TPM: Unexpected TPM deactivated state. Toggling...\n"); @@ -50,19 +60,6 @@ static uint32_t tpm1_invoke_state_machine(void) result = TPM_E_MUST_REBOOT; } - if (disable && !deactivated) { - printk(BIOS_INFO, "TPM: disabled (%d). Enabling...\n", disable); - - result = tlcl_set_enable(); - if (result != TPM_SUCCESS) { - printk(BIOS_ERR, "TPM: Can't set enabled state.\n"); - return result; - } - - printk(BIOS_INFO, "TPM: Must reboot to re-enable\n"); - result = TPM_E_MUST_REBOOT; - } - return result; } #endif @@ -122,8 +119,8 @@ uint32_t tpm_setup(int s3flag) result = tlcl_physical_presence_cmd_enable(); if (result != TPM_SUCCESS) { printk( - BIOS_ERR, - "TPM: Can't enable physical presence command.\n"); + BIOS_ERR, + "TPM: Can't enable physical presence command.\n"); goto out; }