From 4c0851cc37f42ed88d62b876357b71cfdaac480f Mon Sep 17 00:00:00 2001 From: Vadim Bendebury Date: Sun, 3 Jul 2016 17:08:10 -0700 Subject: tpm2: implement locking firmware rollback counter TPM1.2 is using the somewhat misnamed tlcl_set_global_lock() command function to lock the hardware rollback counter. For TPM2 let's implement and use the TPM2 command to lock an NV Ram location (TPM2_NV_WriteLock). BRANCH=none BUG=chrome-os-partner:50645 TEST=verified that TPM2_NV_WriteLock command is invoked before RO firmware starts RW, and succeeds. Change-Id: I52aa8db95b908488ec4cf0843afeb6310dc7f38b Signed-off-by: Martin Roth Original-Commit-Id: 2f859335dfccfeea900f15bbb8c6cb3fd5ec8c77 Original-Change-Id: I62f22b9991522d4309cccc44180a5ebd4dca488d Original-Signed-off-by: Vadim Bendebury Original-Reviewed-on: https://chromium-review.googlesource.com/358097 Original-Reviewed-by: Aaron Durbin Original-Reviewed-by: Darren Krahn Reviewed-on: https://review.coreboot.org/15638 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi --- src/include/tpm_lite/tlcl.h | 5 ++++ src/lib/tpm2_marshaling.c | 14 +++++++++++ src/lib/tpm2_tlcl.c | 27 ++++++++++++---------- src/lib/tpm2_tlcl_structures.h | 5 ++++ .../google/chromeos/vboot2/antirollback.c | 15 ++++++++---- 5 files changed, 49 insertions(+), 17 deletions(-) (limited to 'src') diff --git a/src/include/tpm_lite/tlcl.h b/src/include/tpm_lite/tlcl.h index 1a4f63865d..8ea5564ecb 100644 --- a/src/include/tpm_lite/tlcl.h +++ b/src/include/tpm_lite/tlcl.h @@ -135,6 +135,11 @@ uint32_t tlcl_get_flags(uint8_t *disable, uint8_t *deactivated, */ uint32_t tlcl_set_global_lock(void); +/** + * Make an NV Ram location read_only. The TPM error code is returned. + */ +uint32_t tlcl_lock_nv_write(uint32_t index); + /** * Perform a TPM_Extend. */ diff --git a/src/lib/tpm2_marshaling.c b/src/lib/tpm2_marshaling.c index 9565aeab94..00c8f7d9f9 100644 --- a/src/lib/tpm2_marshaling.c +++ b/src/lib/tpm2_marshaling.c @@ -303,6 +303,15 @@ static void marshal_nv_write(void **buffer, marshal_u16(buffer, command_body->offset, buffer_space); } +static void marshal_nv_write_lock(void **buffer, + struct tpm2_nv_write_lock_cmd *command_body, + size_t *buffer_space) +{ + uint32_t handles[] = { TPM_RH_PLATFORM, command_body->nvIndex }; + marshal_common_session_header(buffer, handles, + ARRAY_SIZE(handles), buffer_space); +} + static void marshal_nv_read(void **buffer, struct tpm2_nv_read_cmd *command_body, size_t *buffer_space) @@ -364,6 +373,10 @@ int tpm_marshal_command(TPM_CC command, void *tpm_command_body, marshal_nv_write(&cmd_body, tpm_command_body, &body_size); break; + case TPM2_NV_WriteLock: + marshal_nv_write_lock(&cmd_body, tpm_command_body, &body_size); + break; + case TPM2_SelfTest: marshal_selftest(&cmd_body, tpm_command_body, &body_size); break; @@ -533,6 +546,7 @@ struct tpm2_response *tpm_unmarshal_response(TPM_CC command, case TPM2_Clear: case TPM2_NV_DefineSpace: case TPM2_NV_Write: + case TPM2_NV_WriteLock: /* Session data included in response can be safely ignored. */ cr_size = 0; break; diff --git a/src/lib/tpm2_tlcl.c b/src/lib/tpm2_tlcl.c index 312fe36414..3003400033 100644 --- a/src/lib/tpm2_tlcl.c +++ b/src/lib/tpm2_tlcl.c @@ -201,19 +201,22 @@ uint32_t tlcl_set_enable(void) return TPM_SUCCESS; } -uint32_t tlcl_set_global_lock(void) +uint32_t tlcl_lock_nv_write(uint32_t index) { - /* - * This is where the locking of the RO NVram index is supposed to - * happen. The most likely way to achieve it is to extend PCR used for - * policy when defining this space. - */ - printk(BIOS_INFO, "%s:%s:%d\n", __FILE__, __func__, __LINE__); - return TPM_SUCCESS; -} -uint32_t tlcl_set_nv_locked(void) -{ - printk(BIOS_INFO, "%s:%s:%d\n", __FILE__, __func__, __LINE__); + struct tpm2_response *response; + /* TPM Wll reject attempts to write at non-defined index. */ + struct tpm2_nv_write_lock_cmd nv_wl = { + .nvIndex = HR_NV_INDEX + index, + }; + + response = tpm_process_command(TPM2_NV_WriteLock, &nv_wl); + + printk(BIOS_INFO, "%s: response is %x\n", + __func__, response ? response->hdr.tpm_code : -1); + + if (!response || response->hdr.tpm_code) + return TPM_E_IOERROR; + return TPM_SUCCESS; } diff --git a/src/lib/tpm2_tlcl_structures.h b/src/lib/tpm2_tlcl_structures.h index 8e518583bc..1e7fcf05fa 100644 --- a/src/lib/tpm2_tlcl_structures.h +++ b/src/lib/tpm2_tlcl_structures.h @@ -59,6 +59,7 @@ struct tpm_header { #define TPM2_Clear ((TPM_CC)0x00000126) #define TPM2_NV_DefineSpace ((TPM_CC)0x0000012A) #define TPM2_NV_Write ((TPM_CC)0x00000137) +#define TPM2_NV_WriteLock ((TPM_CC)0x00000138) #define TPM2_SelfTest ((TPM_CC)0x00000143) #define TPM2_Startup ((TPM_CC)0x00000144) #define TPM2_NV_Read ((TPM_CC)0x0000014E) @@ -301,4 +302,8 @@ struct tpm2_nv_read_cmd { uint16_t offset; }; +struct tpm2_nv_write_lock_cmd { + TPMI_RH_NV_INDEX nvIndex; +}; + #endif // __SRC_LIB_TPM2_TLCL_STRUCTURES_H diff --git a/src/vendorcode/google/chromeos/vboot2/antirollback.c b/src/vendorcode/google/chromeos/vboot2/antirollback.c index 5b738c4897..a51e5d6d55 100644 --- a/src/vendorcode/google/chromeos/vboot2/antirollback.c +++ b/src/vendorcode/google/chromeos/vboot2/antirollback.c @@ -157,6 +157,11 @@ uint32_t tpm_clear_and_reenable(void) return TPM_SUCCESS; } +uint32_t antirollback_lock_space_firmware(void) +{ + return tlcl_lock_nv_write(FIRMWARE_NV_INDEX); +} + #else uint32_t tpm_clear_and_reenable(void) @@ -263,6 +268,11 @@ static uint32_t _factory_initialize_tpm(struct vb2_context *ctx) VB2_SECDATA_SIZE)); return TPM_SUCCESS; } + +uint32_t antirollback_lock_space_firmware(void) +{ + return tlcl_set_global_lock(); +} #endif uint32_t factory_initialize_tpm(struct vb2_context *ctx) @@ -424,8 +434,3 @@ uint32_t antirollback_write_space_firmware(struct vb2_context *ctx) { return write_secdata(FIRMWARE_NV_INDEX, ctx->secdata, VB2_SECDATA_SIZE); } - -uint32_t antirollback_lock_space_firmware() -{ - return tlcl_set_global_lock(); -} -- cgit v1.2.3