diff options
Diffstat (limited to 'security/integrity/ima/ima_init.c')
| -rw-r--r-- | security/integrity/ima/ima_init.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 567468188a61..4902fe7bd570 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -19,13 +19,13 @@ #include "ima.h" /* name for boot aggregate entry */ -static const char boot_aggregate_name[] = "boot_aggregate"; +const char boot_aggregate_name[] = "boot_aggregate"; struct tpm_chip *ima_tpm_chip; /* Add the boot aggregate to the IMA measurement list and extend * the PCR register. * - * Calculate the boot aggregate, a SHA1 over tpm registers 0-7, + * Calculate the boot aggregate, a hash over tpm registers 0-7, * assuming a TPM chip exists, and zeroes if the TPM chip does not * exist. Add the boot aggregate measurement to the measurement * list and extend the PCR register. @@ -49,15 +49,27 @@ static int __init ima_add_boot_aggregate(void) int violation = 0; struct { struct ima_digest_data hdr; - char digest[TPM_DIGEST_SIZE]; + char digest[TPM_MAX_DIGEST_SIZE]; } hash; memset(iint, 0, sizeof(*iint)); memset(&hash, 0, sizeof(hash)); iint->ima_hash = &hash.hdr; - iint->ima_hash->algo = HASH_ALGO_SHA1; - iint->ima_hash->length = SHA1_DIGEST_SIZE; - + iint->ima_hash->algo = ima_hash_algo; + iint->ima_hash->length = hash_digest_size[ima_hash_algo]; + + /* + * With TPM 2.0 hash agility, TPM chips could support multiple TPM + * PCR banks, allowing firmware to configure and enable different + * banks. The SHA1 bank is not necessarily enabled. + * + * Use the same hash algorithm for reading the TPM PCRs as for + * calculating the boot aggregate digest. Preference is given to + * the configured IMA default hash algorithm. Otherwise, use the + * TCG required banks - SHA256 for TPM 2.0, SHA1 for TPM 1.2. + * Ultimately select SHA1 also for TPM 2.0 if the SHA256 PCR bank + * is not found. + */ if (ima_tpm_chip) { result = ima_calc_boot_aggregate(&hash.hdr); if (result < 0) { |