diff options
Diffstat (limited to 'src/security/vboot/mrc_cache_hash_tpm.c')
| -rw-r--r-- | src/security/vboot/mrc_cache_hash_tpm.c | 40 |
1 files changed, 11 insertions, 29 deletions
diff --git a/src/security/vboot/mrc_cache_hash_tpm.c b/src/security/vboot/mrc_cache_hash_tpm.c index 77c23f63e4..f67eae48cb 100644 --- a/src/security/vboot/mrc_cache_hash_tpm.c +++ b/src/security/vboot/mrc_cache_hash_tpm.c @@ -2,27 +2,16 @@ #include <security/vboot/antirollback.h> #include <program_loading.h> -#include <security/vboot/vboot_common.h> #include <vb2_api.h> #include <security/tpm/tss.h> +#include <security/vboot/misc.h> #include <security/vboot/mrc_cache_hash_tpm.h> #include <console/console.h> #include <string.h> void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size) { - uint8_t data_hash[VB2_SHA256_DIGEST_SIZE]; - static const uint8_t dead_hash[VB2_SHA256_DIGEST_SIZE] = { - 0xba, 0xad, 0xda, 0x1a, /* BAADDA1A */ - 0xde, 0xad, 0xde, 0xad, /* DEADDEAD */ - 0xde, 0xad, 0xda, 0x1a, /* DEADDA1A */ - 0xba, 0xad, 0xba, 0xad, /* BAADBAAD */ - 0xba, 0xad, 0xda, 0x1a, /* BAADDA1A */ - 0xde, 0xad, 0xde, 0xad, /* DEADDEAD */ - 0xde, 0xad, 0xda, 0x1a, /* DEADDA1A */ - 0xba, 0xad, 0xba, 0xad, /* BAADBAAD */ - }; - const uint8_t *hash_ptr = data_hash; + struct vb2_hash hash; /* Initialize TPM driver. */ if (tlcl_lib_init() != VB2_SUCCESS) { @@ -31,8 +20,8 @@ void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size) } /* Calculate hash of data generated by MRC. */ - if (vb2_digest_buffer(data, size, VB2_HASH_SHA256, data_hash, - sizeof(data_hash))) { + if (vb2_hash_calculate(vboot_hwcrypto_allowed(), data, size, + VB2_HASH_SHA256, &hash)) { printk(BIOS_ERR, "MRC: SHA-256 calculation failed for data. " "Not updating TPM hash space.\n"); /* @@ -40,13 +29,13 @@ void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size) * currently stored in TPM hash space is no longer * valid. If we are not able to calculate hash of the * data being updated, reset all the bits in TPM hash - * space to pre-defined hash pattern. + * space to zero to invalidate it. */ - hash_ptr = dead_hash; + memset(hash.raw, 0, VB2_SHA256_DIGEST_SIZE); } /* Write hash of data to TPM space. */ - if (antirollback_write_space_mrc_hash(index, hash_ptr, VB2_SHA256_DIGEST_SIZE) + if (antirollback_write_space_mrc_hash(index, hash.sha256, sizeof(hash.sha256)) != TPM_SUCCESS) { printk(BIOS_ERR, "MRC: Could not save hash to TPM.\n"); return; @@ -57,15 +46,7 @@ void mrc_cache_update_hash(uint32_t index, const uint8_t *data, size_t size) int mrc_cache_verify_hash(uint32_t index, const uint8_t *data, size_t size) { - uint8_t data_hash[VB2_SHA256_DIGEST_SIZE]; - uint8_t tpm_hash[VB2_SHA256_DIGEST_SIZE]; - - /* Calculate hash of data read from MRC_CACHE. */ - if (vb2_digest_buffer(data, size, VB2_HASH_SHA256, data_hash, - sizeof(data_hash))) { - printk(BIOS_ERR, "MRC: SHA-256 calculation failed for data.\n"); - return 0; - } + struct vb2_hash tpm_hash = { .algo = VB2_HASH_SHA256 }; /* Initialize TPM driver. */ if (tlcl_lib_init() != VB2_SUCCESS) { @@ -74,13 +55,14 @@ int mrc_cache_verify_hash(uint32_t index, const uint8_t *data, size_t size) } /* Read hash of MRC data saved in TPM. */ - if (antirollback_read_space_mrc_hash(index, tpm_hash, sizeof(tpm_hash)) + if (antirollback_read_space_mrc_hash(index, tpm_hash.sha256, sizeof(tpm_hash.sha256)) != TPM_SUCCESS) { printk(BIOS_ERR, "MRC: Could not read hash from TPM.\n"); return 0; } - if (memcmp(tpm_hash, data_hash, sizeof(tpm_hash))) { + /* Calculate hash of data read from MRC_CACHE and compare. */ + if (vb2_hash_verify(vboot_hwcrypto_allowed(), data, size, &tpm_hash)) { printk(BIOS_ERR, "MRC: Hash comparison failed.\n"); return 0; } |