diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/tpm-v2.h | 59 |
1 files changed, 43 insertions, 16 deletions
diff --git a/include/tpm-v2.h b/include/tpm-v2.h index aedf2c0f4f5..4fd19c52fd7 100644 --- a/include/tpm-v2.h +++ b/include/tpm-v2.h @@ -278,48 +278,40 @@ struct digest_info { #define TCG2_BOOT_HASH_ALG_SM3_256 0x00000010 static const struct digest_info hash_algo_list[] = { +#if IS_ENABLED(CONFIG_SHA1) { "sha1", TPM2_ALG_SHA1, TCG2_BOOT_HASH_ALG_SHA1, TPM2_SHA1_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA256) { "sha256", TPM2_ALG_SHA256, TCG2_BOOT_HASH_ALG_SHA256, TPM2_SHA256_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA384) { "sha384", TPM2_ALG_SHA384, TCG2_BOOT_HASH_ALG_SHA384, TPM2_SHA384_DIGEST_SIZE, }, +#endif +#if IS_ENABLED(CONFIG_SHA512) { "sha512", TPM2_ALG_SHA512, TCG2_BOOT_HASH_ALG_SHA512, TPM2_SHA512_DIGEST_SIZE, }, +#endif }; -static inline u16 tpm2_algorithm_to_len(enum tpm2_algorithms a) -{ - switch (a) { - case TPM2_ALG_SHA1: - return TPM2_SHA1_DIGEST_SIZE; - case TPM2_ALG_SHA256: - return TPM2_SHA256_DIGEST_SIZE; - case TPM2_ALG_SHA384: - return TPM2_SHA384_DIGEST_SIZE; - case TPM2_ALG_SHA512: - return TPM2_SHA512_DIGEST_SIZE; - default: - return 0; - } -} - /* NV index attributes */ enum tpm_index_attrs { TPMA_NV_PPWRITE = 1UL << 0, @@ -713,6 +705,41 @@ enum tpm2_algorithms tpm2_name_to_algorithm(const char *name); const char *tpm2_algorithm_name(enum tpm2_algorithms); /** + * tpm2_algorithm_to_len() - Return an algorithm length for supported algorithm id + * + * @algorithm_id: algorithm defined in enum tpm2_algorithms + * Return: len or 0 if not supported + */ +u16 tpm2_algorithm_to_len(enum tpm2_algorithms algo); + +/* + * When measured boot is enabled via EFI or bootX commands all the algorithms + * above are selected by our Kconfigs. Due to U-Boots nature of being small there + * are cases where we need some functionality from the TPM -- e.g storage or RNG + * but we don't want to support measurements. + * + * The choice of hash algorithms are determined by the platform and the TPM + * configuration. Failing to cap a PCR in a bank which the platform left + * active is a security vulnerability. It permits the unsealing of secrets + * if an attacker can replay a good set of measurements into an unused bank. + * + * On top of that a previous stage bootloader (e.g TF-A), migh pass an eventlog + * since it doesn't have a TPM driver, which U-Boot needs to replace. The algorit h + * choice is a compile time option in that case and we need to make sure we conform. + * + * Add a variable here that sums the supported algorithms U-Boot was compiled + * with so we can refuse to do measurements if we don't support all of them + */ + +/** + * tpm2_allow_extend() - Check if extending PCRs is allowed and safe + * + * @dev: TPM device + * Return: true if allowed + */ +bool tpm2_allow_extend(struct udevice *dev); + +/** * tpm2_is_active_pcr() - check the pcr_select. If at least one of the PCRs * supports the algorithm add it on the active ones * |