From 926160f00356c562eea2d87bb88c1cd3febe0655 Mon Sep 17 00:00:00 2001 From: Dan Streetman Date: Mon, 27 Feb 2023 06:44:13 -0500 Subject: [PATCH] tpm2: add TPM2_PCR_VALID() (cherry picked from commit aa07a4fa353d758562c4bec8c7d3b1d44b55e573) Related: RHEL-16182 --- .../cryptsetup-token-systemd-tpm2.c | 2 +- src/cryptsetup/cryptsetup.c | 2 +- src/shared/tpm2-util.c | 2 +- src/shared/tpm2-util.h | 18 ++++++++++++------ 4 files changed, 15 insertions(+), 9 deletions(-) diff --git a/src/cryptsetup/cryptsetup-tokens/cryptsetup-token-systemd-tpm2.c b/src/cryptsetup/cryptsetup-tokens/cryptsetup-token-systemd-tpm2.c index 319b0ca64d..e8bc091191 100644 --- a/src/cryptsetup/cryptsetup-tokens/cryptsetup-token-systemd-tpm2.c +++ b/src/cryptsetup/cryptsetup-tokens/cryptsetup-token-systemd-tpm2.c @@ -271,7 +271,7 @@ _public_ int cryptsetup_token_validate( } u = json_variant_unsigned(e); - if (u >= TPM2_PCRS_MAX) { + if (!TPM2_PCR_VALID(u)) { crypt_log_debug(cd, "TPM2 PCR number out of range."); return 1; } diff --git a/src/cryptsetup/cryptsetup.c b/src/cryptsetup/cryptsetup.c index d5ce252e57..d46a88c9fb 100644 --- a/src/cryptsetup/cryptsetup.c +++ b/src/cryptsetup/cryptsetup.c @@ -438,7 +438,7 @@ static int parse_one_option(const char *option) { } pcr = r ? TPM_PCR_INDEX_VOLUME_KEY : UINT_MAX; - } else if (pcr >= TPM2_PCRS_MAX) { + } else if (!TPM2_PCR_VALID(pcr)) { log_error("Selected TPM index for measurement %u outside of allowed range 0…%u, ignoring.", pcr, TPM2_PCRS_MAX-1); return 0; } diff --git a/src/shared/tpm2-util.c b/src/shared/tpm2-util.c index b5eabb8159..0cbb32f819 100644 --- a/src/shared/tpm2-util.c +++ b/src/shared/tpm2-util.c @@ -462,7 +462,7 @@ void tpm2_pcr_mask_to_selection(uint32_t mask, uint16_t bank, TPML_PCR_SELECTION assert(ret); /* We only do 24bit here, as that's what PC TPMs are supposed to support */ - assert(mask <= 0xFFFFFFU); + assert(TPM2_PCR_MASK_VALID(mask)); *ret = (TPML_PCR_SELECTION) { .count = 1, diff --git a/src/shared/tpm2-util.h b/src/shared/tpm2-util.h index d26a945a90..07a8a89800 100644 --- a/src/shared/tpm2-util.h +++ b/src/shared/tpm2-util.h @@ -11,6 +11,18 @@ typedef enum TPM2Flags { TPM2_FLAGS_USE_PIN = 1 << 0, } TPM2Flags; + +/* As per https://trustedcomputinggroup.org/wp-content/uploads/TCG_PCClient_PFP_r1p05_v23_pub.pdf a + * TPM2 on a Client PC must have at least 24 PCRs. This hardcodes our expectation of 24. */ +#define TPM2_PCRS_MAX 24U +#define TPM2_PCRS_MASK ((UINT32_C(1) << TPM2_PCRS_MAX) - 1) +static inline bool TPM2_PCR_VALID(unsigned pcr) { + return pcr < TPM2_PCRS_MAX; +} +static inline bool TPM2_PCR_MASK_VALID(uint32_t pcr_mask) { + return pcr_mask <= TPM2_PCRS_MASK; +} + #if HAVE_TPM2 #include @@ -108,12 +120,6 @@ int tpm2_parse_pcr_json_array(JsonVariant *v, uint32_t *ret); int tpm2_make_luks2_json(int keyslot, uint32_t hash_pcr_mask, uint16_t pcr_bank, const void *pubkey, size_t pubkey_size, uint32_t pubkey_pcr_mask, uint16_t primary_alg, const void *blob, size_t blob_size, const void *policy_hash, size_t policy_hash_size, const void *salt, size_t salt_size, TPM2Flags flags, JsonVariant **ret); int tpm2_parse_luks2_json(JsonVariant *v, int *ret_keyslot, uint32_t *ret_hash_pcr_mask, uint16_t *ret_pcr_bank, void **ret_pubkey, size_t *ret_pubkey_size, uint32_t *ret_pubkey_pcr_mask, uint16_t *ret_primary_alg, void **ret_blob, size_t *ret_blob_size, void **ret_policy_hash, size_t *ret_policy_hash_size, void **ret_salt, size_t *ret_salt_size, TPM2Flags *ret_flags); -#define TPM2_PCRS_MAX 24U - -static inline bool TPM2_PCR_MASK_VALID(uint64_t pcr_mask) { - return pcr_mask < (UINT64_C(1) << TPM2_PCRS_MAX); /* Support 24 PCR banks */ -} - /* Default to PCR 7 only */ #define TPM2_PCR_MASK_DEFAULT (UINT32_C(1) << 7)