diff options
| -rw-r--r-- | src/include/antirollback.h | 3 | ||||
| -rw-r--r-- | src/vendorcode/google/chromeos/antirollback.c | 61 |
2 files changed, 49 insertions, 15 deletions
diff --git a/src/include/antirollback.h b/src/include/antirollback.h index 0473e2446c..06ad9f786b 100644 --- a/src/include/antirollback.h +++ b/src/include/antirollback.h @@ -15,6 +15,9 @@ /* TPM NVRAM location indices. */ #define FIRMWARE_NV_INDEX 0x1007 +#define KERNEL_NV_INDEX 0x1008 +/* This is just an opaque space for backup purposes */ +#define BACKUP_NV_INDEX 0x1009 /* Structure definitions for TPM spaces */ diff --git a/src/vendorcode/google/chromeos/antirollback.c b/src/vendorcode/google/chromeos/antirollback.c index 020a06abb2..bb547b51bc 100644 --- a/src/vendorcode/google/chromeos/antirollback.c +++ b/src/vendorcode/google/chromeos/antirollback.c @@ -34,7 +34,6 @@ } \ } while (0) - uint32_t tpm_clear_and_reenable(void) { VBDEBUG("TPM: Clear and re-enable\n"); @@ -85,30 +84,36 @@ static uint32_t read_space_firmware(struct vb2_context *ctx) return TPM_E_CORRUPTED_STATE; } -static uint32_t write_space_firmware(struct vb2_context *ctx) +static uint32_t write_secdata(uint32_t index, + const uint8_t *secdata, + uint32_t len) { - uint8_t secdata[VB2_SECDATA_SIZE]; - uint32_t r; + uint8_t sd[32]; + uint32_t rv; int attempts = 3; - memcpy(secdata, ctx->secdata, VB2_SECDATA_SIZE); + if (len > sizeof(sd)) { + VBDEBUG("TPM: %s() - data is too large\n", __func__); + return TPM_E_WRITE_FAILURE; + } + while (attempts--) { - r = safe_write(FIRMWARE_NV_INDEX, secdata, VB2_SECDATA_SIZE); + rv = safe_write(index, secdata, len); /* Can't write, not gonna try again */ - if (r != TPM_SUCCESS) - return r; + if (rv != TPM_SUCCESS) + return rv; /* Read it back to be sure it got the right values. */ - r = read_space_firmware(ctx); - if (r == TPM_SUCCESS && memcmp(secdata, ctx->secdata, - VB2_SECDATA_SIZE) == 0) - return r; + rv = tlcl_read(index, sd, len); + if (rv == TPM_SUCCESS && memcmp(secdata, sd, len) == 0) + return rv; - VBDEBUG("TPM: %s() failed\n", __func__); + VBDEBUG("TPM: %s() failed. trying again\n", __func__); /* Try writing it again. Maybe it was garbled on the way out. */ } VBDEBUG("TPM: %s() - too many failures, giving up\n", __func__); + return TPM_E_CORRUPTED_STATE; } @@ -116,6 +121,15 @@ uint32_t factory_initialize_tpm(struct vb2_context *ctx) { TPM_PERMANENT_FLAGS pflags; uint32_t result; + /* this is derived from rollback_index.h of vboot_reference. see struct + * RollbackSpaceKernel for details. */ + static const uint8_t secdata_kernel[] = { + 0x02, + 0x4C, 0x57, 0x52, 0x47, + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, + 0xE8, + }; VBDEBUG("TPM: factory initialization\n"); @@ -161,13 +175,30 @@ uint32_t factory_initialize_tpm(struct vb2_context *ctx) VBDEBUG("TPM: Clearing owner\n"); RETURN_ON_FAILURE(tpm_clear_and_reenable()); + /* Define the backup space. No need to initialize it, though. */ + RETURN_ON_FAILURE(safe_define_space(BACKUP_NV_INDEX, + TPM_NV_PER_PPWRITE, + VB2_NVDATA_SIZE)); + + /* Define and initialize the kernel space */ + RETURN_ON_FAILURE(safe_define_space(KERNEL_NV_INDEX, + TPM_NV_PER_PPWRITE, + sizeof(secdata_kernel))); + RETURN_ON_FAILURE(write_secdata(KERNEL_NV_INDEX, + secdata_kernel, + sizeof(secdata_kernel))); + /* Defines and sets vb2 secdata space */ vb2api_secdata_create(ctx); RETURN_ON_FAILURE(safe_define_space(FIRMWARE_NV_INDEX, TPM_NV_PER_GLOBALLOCK | TPM_NV_PER_PPWRITE, VB2_SECDATA_SIZE)); - RETURN_ON_FAILURE(write_space_firmware(ctx)); + RETURN_ON_FAILURE(write_secdata(FIRMWARE_NV_INDEX, + ctx->secdata, + VB2_SECDATA_SIZE)); + + VBDEBUG("TPM: factory initialization successful\n"); return TPM_SUCCESS; } @@ -289,7 +320,7 @@ uint32_t antirollback_read_space_firmware(struct vb2_context *ctx) uint32_t antirollback_write_space_firmware(struct vb2_context *ctx) { - return write_space_firmware(ctx); + return write_secdata(FIRMWARE_NV_INDEX, ctx->secdata, VB2_SECDATA_SIZE); } uint32_t antirollback_lock_space_firmware() |