diff options
Diffstat (limited to 'src/shared/tpm2-util.c')
| -rw-r--r-- | src/shared/tpm2-util.c | 81 |
1 files changed, 76 insertions, 5 deletions
diff --git a/src/shared/tpm2-util.c b/src/shared/tpm2-util.c index 70a2929432..44fe899acd 100644 --- a/src/shared/tpm2-util.c +++ b/src/shared/tpm2-util.c @@ -14,6 +14,7 @@ #include "hexdecoct.h" #include "memory-util.h" #include "random-util.h" +#include "sha256.h" #include "time-util.h" static void *libtss2_esys_dl = NULL; @@ -30,10 +31,12 @@ TSS2_RC (*sym_Esys_GetRandom)(ESYS_CONTEXT *esysContext, ESYS_TR shandle1, ESYS_ TSS2_RC (*sym_Esys_Initialize)(ESYS_CONTEXT **esys_context, TSS2_TCTI_CONTEXT *tcti, TSS2_ABI_VERSION *abiVersion) = NULL; TSS2_RC (*sym_Esys_Load)(ESYS_CONTEXT *esysContext, ESYS_TR parentHandle, ESYS_TR shandle1, ESYS_TR shandle2, ESYS_TR shandle3, const TPM2B_PRIVATE *inPrivate, const TPM2B_PUBLIC *inPublic, ESYS_TR *objectHandle) = NULL; TSS2_RC (*sym_Esys_PCR_Read)(ESYS_CONTEXT *esysContext, ESYS_TR shandle1,ESYS_TR shandle2, ESYS_TR shandle3, const TPML_PCR_SELECTION *pcrSelectionIn, UINT32 *pcrUpdateCounter, TPML_PCR_SELECTION **pcrSelectionOut, TPML_DIGEST **pcrValues); +TSS2_RC (*sym_Esys_PolicyAuthValue)(ESYS_CONTEXT *esysContext, ESYS_TR policySession, ESYS_TR shandle1, ESYS_TR shandle2, ESYS_TR shandle3) = NULL; TSS2_RC (*sym_Esys_PolicyGetDigest)(ESYS_CONTEXT *esysContext, ESYS_TR policySession, ESYS_TR shandle1, ESYS_TR shandle2, ESYS_TR shandle3, TPM2B_DIGEST **policyDigest) = NULL; TSS2_RC (*sym_Esys_PolicyPCR)(ESYS_CONTEXT *esysContext, ESYS_TR policySession, ESYS_TR shandle1, ESYS_TR shandle2, ESYS_TR shandle3, const TPM2B_DIGEST *pcrDigest, const TPML_PCR_SELECTION *pcrs) = NULL; TSS2_RC (*sym_Esys_StartAuthSession)(ESYS_CONTEXT *esysContext, ESYS_TR tpmKey, ESYS_TR bind, ESYS_TR shandle1, ESYS_TR shandle2, ESYS_TR shandle3, const TPM2B_NONCE *nonceCaller, TPM2_SE sessionType, const TPMT_SYM_DEF *symmetric, TPMI_ALG_HASH authHash, ESYS_TR *sessionHandle) = NULL; TSS2_RC (*sym_Esys_Startup)(ESYS_CONTEXT *esysContext, TPM2_SU startupType) = NULL; +TSS2_RC (*sym_Esys_TR_SetAuth)(ESYS_CONTEXT *esysContext, ESYS_TR handle, TPM2B_AUTH const *authValue) = NULL; TSS2_RC (*sym_Esys_Unseal)(ESYS_CONTEXT *esysContext, ESYS_TR itemHandle, ESYS_TR shandle1, ESYS_TR shandle2, ESYS_TR shandle3, TPM2B_SENSITIVE_DATA **outData) = NULL; const char* (*sym_Tss2_RC_Decode)(TSS2_RC rc) = NULL; @@ -58,10 +61,12 @@ int dlopen_tpm2(void) { DLSYM_ARG(Esys_Initialize), DLSYM_ARG(Esys_Load), DLSYM_ARG(Esys_PCR_Read), + DLSYM_ARG(Esys_PolicyAuthValue), DLSYM_ARG(Esys_PolicyGetDigest), DLSYM_ARG(Esys_PolicyPCR), DLSYM_ARG(Esys_StartAuthSession), DLSYM_ARG(Esys_Startup), + DLSYM_ARG(Esys_TR_SetAuth), DLSYM_ARG(Esys_Unseal)); if (r < 0) return r; @@ -594,6 +599,7 @@ static int tpm2_make_pcr_session( ESYS_CONTEXT *c, uint32_t pcr_mask, uint16_t pcr_bank, /* If UINT16_MAX, pick best bank automatically, otherwise specify bank explicitly. */ + bool use_pin, ESYS_TR *ret_session, TPM2B_DIGEST **ret_policy_digest, TPMI_ALG_HASH *ret_pcr_bank) { @@ -669,6 +675,21 @@ static int tpm2_make_pcr_session( goto finish; } + if (use_pin) { + rc = sym_Esys_PolicyAuthValue( + c, + session, + ESYS_TR_NONE, + ESYS_TR_NONE, + ESYS_TR_NONE); + if (rc != TSS2_RC_SUCCESS) { + r = log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), + "Failed to add authValue policy to TPM: %s", + sym_Tss2_RC_Decode(rc)); + goto finish; + } + } + if (DEBUG_LOGGING || ret_policy_digest) { log_debug("Acquiring policy digest."); @@ -717,9 +738,22 @@ finish: return r; } +static void hash_pin(const char *pin, size_t len, uint8_t ret_digest[static SHA256_DIGEST_SIZE]) { + struct sha256_ctx hash; + + assert(pin); + + sha256_init_ctx(&hash); + sha256_process_bytes(pin, len, &hash); + sha256_finish_ctx(&hash, ret_digest); + + explicit_bzero_safe(&hash, sizeof(hash)); +} + int tpm2_seal( const char *device, uint32_t pcr_mask, + const char *pin, void **ret_secret, size_t *ret_secret_size, void **ret_blob, @@ -782,7 +816,8 @@ int tpm2_seal( if (r < 0) return r; - r = tpm2_make_pcr_session(c.esys_context, pcr_mask, UINT16_MAX, NULL, &policy_digest, &pcr_bank); + r = tpm2_make_pcr_session(c.esys_context, pcr_mask, UINT16_MAX, !!pin, NULL, &policy_digest, + &pcr_bank); if (r < 0) goto finish; @@ -813,6 +848,10 @@ int tpm2_seal( .size = sizeof(hmac_sensitive.sensitive), .sensitive.data.size = 32, }; + if (pin) { + hash_pin(pin, strlen(pin), hmac_sensitive.sensitive.userAuth.buffer); + hmac_sensitive.sensitive.userAuth.size = SHA256_DIGEST_SIZE; + } assert(sizeof(hmac_sensitive.sensitive.data.buffer) >= hmac_sensitive.sensitive.data.size); (void) tpm2_credit_random(c.esys_context); @@ -910,6 +949,7 @@ int tpm2_seal( r = 0; finish: + explicit_bzero_safe(&hmac_sensitive, sizeof(hmac_sensitive)); primary = flush_context_verbose(c.esys_context, primary); return r; } @@ -923,6 +963,7 @@ int tpm2_unseal( size_t blob_size, const void *known_policy_hash, size_t known_policy_hash_size, + const char *pin, void **ret_secret, size_t *ret_secret_size) { @@ -978,7 +1019,7 @@ int tpm2_unseal( if (r < 0) return r; - r = tpm2_make_pcr_session(c.esys_context, pcr_mask, pcr_bank, &session, &policy_digest, NULL); + r = tpm2_make_pcr_session(c.esys_context, pcr_mask, pcr_bank, !!pin, &session, &policy_digest, NULL); if (r < 0) goto finish; @@ -1005,11 +1046,38 @@ int tpm2_unseal( &public, &hmac_key); if (rc != TSS2_RC_SUCCESS) { - r = log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), - "Failed to load HMAC key in TPM: %s", sym_Tss2_RC_Decode(rc)); + /* If we're in dictionary attack lockout mode, we should see a lockout error here, which we + * need to translate for the caller. */ + if (rc == TPM2_RC_LOCKOUT) + r = log_error_errno( + SYNTHETIC_ERRNO(ENOLCK), + "TPM2 device is in dictionary attack lockout mode."); + else + r = log_error_errno( + SYNTHETIC_ERRNO(ENOTRECOVERABLE), + "Failed to load HMAC key in TPM: %s", + sym_Tss2_RC_Decode(rc)); goto finish; } + if (pin) { + TPM2B_AUTH auth = { + .size = SHA256_DIGEST_SIZE + }; + + hash_pin(pin, strlen(pin), auth.buffer); + + rc = sym_Esys_TR_SetAuth(c.esys_context, hmac_key, &auth); + explicit_bzero_safe(&auth, sizeof(auth)); + if (rc != TSS2_RC_SUCCESS) { + r = log_error_errno( + SYNTHETIC_ERRNO(ENOTRECOVERABLE), + "Failed to load PIN in TPM: %s", + sym_Tss2_RC_Decode(rc)); + goto finish; + } + } + log_debug("Unsealing HMAC key."); rc = sym_Esys_Unseal( @@ -1223,6 +1291,7 @@ int tpm2_make_luks2_json( size_t blob_size, const void *policy_hash, size_t policy_hash_size, + TPM2Flags flags, JsonVariant **ret) { _cleanup_(json_variant_unrefp) JsonVariant *v = NULL, *a = NULL; @@ -1263,7 +1332,9 @@ int tpm2_make_luks2_json( JSON_BUILD_PAIR("tpm2-pcrs", JSON_BUILD_VARIANT(a)), JSON_BUILD_PAIR_CONDITION(!!tpm2_pcr_bank_to_string(pcr_bank), "tpm2-pcr-bank", JSON_BUILD_STRING(tpm2_pcr_bank_to_string(pcr_bank))), JSON_BUILD_PAIR_CONDITION(!!tpm2_primary_alg_to_string(primary_alg), "tpm2-primary-alg", JSON_BUILD_STRING(tpm2_primary_alg_to_string(primary_alg))), - JSON_BUILD_PAIR("tpm2-policy-hash", JSON_BUILD_HEX(policy_hash, policy_hash_size)))); + JSON_BUILD_PAIR("tpm2-policy-hash", JSON_BUILD_HEX(policy_hash, policy_hash_size)), + JSON_BUILD_PAIR("tpm2-pin", JSON_BUILD_BOOLEAN(flags & TPM2_FLAGS_USE_PIN))) + ); if (r < 0) return r; |