diff --git a/src/shared/tpm2-util.c b/src/shared/tpm2-util.c index 6214aff7d9..49e4ea12ef 100644 --- a/src/shared/tpm2-util.c +++ b/src/shared/tpm2-util.c @@ -53,6 +53,7 @@ static TSS2_RC (*sym_Esys_ReadPublic)(ESYS_CONTEXT *esysContext, ESYS_TR objectH static 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; static TSS2_RC (*sym_Esys_Startup)(ESYS_CONTEXT *esysContext, TPM2_SU startupType) = NULL; static TSS2_RC (*sym_Esys_TestParms)(ESYS_CONTEXT *esysContext, ESYS_TR shandle1, ESYS_TR shandle2, ESYS_TR shandle3, const TPMT_PUBLIC_PARMS *parameters) = NULL; +static TSS2_RC (*sym_Esys_TR_Close)(ESYS_CONTEXT *esys_context, ESYS_TR *rsrc_handle) = NULL; static TSS2_RC (*sym_Esys_TR_Deserialize)(ESYS_CONTEXT *esys_context, uint8_t const *buffer, size_t buffer_size, ESYS_TR *esys_handle) = NULL; static TSS2_RC (*sym_Esys_TR_FromTPMPublic)(ESYS_CONTEXT *esysContext, TPM2_HANDLE tpm_handle, ESYS_TR optionalSession1, ESYS_TR optionalSession2, ESYS_TR optionalSession3, ESYS_TR *object) = NULL; static TSS2_RC (*sym_Esys_TR_GetName)(ESYS_CONTEXT *esysContext, ESYS_TR handle, TPM2B_NAME **name) = NULL; @@ -100,6 +101,7 @@ int dlopen_tpm2(void) { DLSYM_ARG(Esys_StartAuthSession), DLSYM_ARG(Esys_Startup), DLSYM_ARG(Esys_TestParms), + DLSYM_ARG(Esys_TR_Close), DLSYM_ARG(Esys_TR_Deserialize), DLSYM_ARG(Esys_TR_FromTPMPublic), DLSYM_ARG(Esys_TR_GetName), @@ -255,6 +257,84 @@ int tpm2_supports_alg(Tpm2Context *c, TPM2_ALG_ID alg) { return tpm2_get_capability_alg(c, alg, NULL); } +/* Query the TPM for populated handles. + * + * This provides an array of handle indexes populated in the TPM, starting at the requested handle. The array will + * contain only populated handle addresses (which might not include the requested handle). The number of + * handles will be no more than the 'max' number requested. This will not search past the end of the handle + * range (i.e. handle & 0xff000000). + * + * Returns 0 if all populated handles in the range (starting at the requested handle) were provided (or no + * handles were in the range), or 1 if there are more populated handles in the range, or < 0 on any error. */ +static int tpm2_get_capability_handles( + Tpm2Context *c, + TPM2_HANDLE start, + size_t max, + TPM2_HANDLE **ret_handles, + size_t *ret_n_handles) { + + _cleanup_free_ TPM2_HANDLE *handles = NULL; + size_t n_handles = 0; + TPM2_HANDLE current = start; + int r = 0; + + assert(c); + assert(ret_handles); + assert(ret_n_handles); + + while (max > 0) { + TPMU_CAPABILITIES capability; + r = tpm2_get_capability(c, TPM2_CAP_HANDLES, current, (uint32_t) max, &capability); + if (r < 0) + return r; + + TPML_HANDLE handle_list = capability.handles; + if (handle_list.count == 0) + break; + + assert(handle_list.count <= max); + + if (n_handles > SIZE_MAX - handle_list.count) + return log_oom(); + + if (!GREEDY_REALLOC(handles, n_handles + handle_list.count)) + return log_oom(); + + memcpy_safe(&handles[n_handles], handle_list.handle, sizeof(handles[0]) * handle_list.count); + + max -= handle_list.count; + n_handles += handle_list.count; + + /* Update current to the handle index after the last handle in the list. */ + current = handles[n_handles - 1] + 1; + + if (r == 0) + /* No more handles in this range. */ + break; + } + + *ret_handles = TAKE_PTR(handles); + *ret_n_handles = n_handles; + + return r; +} + +#define TPM2_HANDLE_RANGE(h) ((TPM2_HANDLE)((h) & TPM2_HR_RANGE_MASK)) +#define TPM2_HANDLE_TYPE(h) ((TPM2_HT)(TPM2_HANDLE_RANGE(h) >> TPM2_HR_SHIFT)) + +/* Returns 1 if the handle is populated in the TPM, 0 if not, and < 0 on any error. */ +static int tpm2_get_capability_handle(Tpm2Context *c, TPM2_HANDLE handle) { + _cleanup_free_ TPM2_HANDLE *handles = NULL; + size_t n_handles = 0; + int r; + + r = tpm2_get_capability_handles(c, handle, 1, &handles, &n_handles); + if (r < 0) + return r; + + return n_handles == 0 ? false : handles[0] == handle; +} + /* Returns 1 if the TPM supports the parms, or 0 if the TPM does not support the parms. */ bool tpm2_test_parms(Tpm2Context *c, TPMI_ALG_PUBLIC alg, const TPMU_PUBLIC_PARMS *parms) { TSS2_RC rc; @@ -457,17 +537,25 @@ int tpm2_context_new(const char *device, Tpm2Context **ret_context) { return 0; } -static void tpm2_handle_flush(ESYS_CONTEXT *esys_context, ESYS_TR esys_handle) { +static void tpm2_handle_cleanup(ESYS_CONTEXT *esys_context, ESYS_TR esys_handle, bool flush) { + TSS2_RC rc; + if (!esys_context || esys_handle == ESYS_TR_NONE) return; - TSS2_RC rc = sym_Esys_FlushContext(esys_context, esys_handle); + /* Closing the handle removes its reference from the esys_context, but leaves the corresponding + * handle in the actual TPM. Flushing the handle removes its reference from the esys_context as well + * as removing its corresponding handle from the actual TPM. */ + if (flush) + rc = sym_Esys_FlushContext(esys_context, esys_handle); + else + rc = sym_Esys_TR_Close(esys_context, &esys_handle); if (rc != TSS2_RC_SUCCESS) /* We ignore failures here (besides debug logging), since this is called * in error paths, where we cannot do anything about failures anymore. And * when it is called in successful codepaths by this time we already did * what we wanted to do, and got the results we wanted so there's no * reason to make this fail more loudly than necessary. */ - log_debug("Failed to flush TPM handle, ignoring: %s", sym_Tss2_RC_Decode(rc)); + log_debug("Failed to %s TPM handle, ignoring: %s", flush ? "flush" : "close", sym_Tss2_RC_Decode(rc)); } Tpm2Handle *tpm2_handle_free(Tpm2Handle *handle) { @@ -475,8 +563,8 @@ Tpm2Handle *tpm2_handle_free(Tpm2Handle *handle) { return NULL; _cleanup_(tpm2_context_unrefp) Tpm2Context *context = (Tpm2Context*)handle->tpm2_context; - if (context && !handle->keep) - tpm2_handle_flush(context->esys_context, handle->esys_handle); + if (context) + tpm2_handle_cleanup(context->esys_context, handle->esys_handle, handle->flush); return mfree(handle); } @@ -493,6 +581,7 @@ int tpm2_handle_new(Tpm2Context *context, Tpm2Handle **ret_handle) { *handle = (Tpm2Handle) { .tpm2_context = tpm2_context_ref(context), .esys_handle = ESYS_TR_NONE, + .flush = true, }; *ret_handle = TAKE_PTR(handle); @@ -500,6 +589,81 @@ int tpm2_handle_new(Tpm2Context *context, Tpm2Handle **ret_handle) { return 0; } +/* Create a Tpm2Handle object that references a pre-existing handle in the TPM, at the TPM2_HANDLE address + * provided. This should be used only for persistent, transient, or NV handles. Returns 1 on success, 0 if + * the requested handle is not present in the TPM, or < 0 on error. */ +static int tpm2_esys_handle_from_tpm_handle( + Tpm2Context *c, + const Tpm2Handle *session, + TPM2_HANDLE tpm_handle, + Tpm2Handle **ret_handle) { + + TSS2_RC rc; + int r; + + assert(c); + assert(tpm_handle > 0); + assert(ret_handle); + + /* Let's restrict this, at least for now, to allow only some handle types. */ + switch (TPM2_HANDLE_TYPE(tpm_handle)) { + case TPM2_HT_PERSISTENT: + case TPM2_HT_NV_INDEX: + case TPM2_HT_TRANSIENT: + break; + case TPM2_HT_PCR: + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Refusing to create ESYS handle for PCR handle 0x%08" PRIx32 ".", + tpm_handle); + case TPM2_HT_HMAC_SESSION: + case TPM2_HT_POLICY_SESSION: + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Refusing to create ESYS handle for session handle 0x%08" PRIx32 ".", + tpm_handle); + case TPM2_HT_PERMANENT: /* Permanent handles are defined, e.g. ESYS_TR_RH_OWNER. */ + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Refusing to create ESYS handle for permanent handle 0x%08" PRIx32 ".", + tpm_handle); + default: + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Refusing to create ESYS handle for unknown handle 0x%08" PRIx32 ".", + tpm_handle); + } + + r = tpm2_get_capability_handle(c, tpm_handle); + if (r < 0) + return r; + if (r == 0) { + log_debug("TPM handle 0x%08" PRIx32 " not populated.", tpm_handle); + *ret_handle = NULL; + return 0; + } + + _cleanup_(tpm2_handle_freep) Tpm2Handle *handle = NULL; + r = tpm2_handle_new(c, &handle); + if (r < 0) + return r; + + /* Since we didn't create this handle in the TPM (this is only creating an ESYS_TR handle for the + * pre-existing TPM handle), we shouldn't flush (or evict) it on cleanup. */ + handle->flush = false; + + rc = sym_Esys_TR_FromTPMPublic( + c->esys_context, + tpm_handle, + session ? session->esys_handle : ESYS_TR_NONE, + ESYS_TR_NONE, + ESYS_TR_NONE, + &handle->esys_handle); + if (rc != TSS2_RC_SUCCESS) + return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), + "Failed to read public info: %s", sym_Tss2_RC_Decode(rc)); + + *ret_handle = TAKE_PTR(handle); + + return 1; +} + #define TPM2_CREDIT_RANDOM_FLAG_PATH "/run/systemd/tpm-rng-credited" static int tpm2_credit_random(Tpm2Context *c) { @@ -663,60 +827,32 @@ const TPM2B_PUBLIC *tpm2_get_primary_template(Tpm2SRKTemplateFlags flags) { */ static int tpm2_get_srk( Tpm2Context *c, + const Tpm2Handle *session, TPMI_ALG_PUBLIC *ret_alg, - Tpm2Handle *ret_primary) { + Tpm2Handle **ret_handle) { - TPMI_YES_NO more_data; - ESYS_TR primary_tr = ESYS_TR_NONE; - _cleanup_(Esys_Freep) TPMS_CAPABILITY_DATA *cap_data = NULL; + int r; assert(c); - assert(ret_primary); - - TSS2_RC rc = sym_Esys_GetCapability(c->esys_context, - ESYS_TR_NONE, - ESYS_TR_NONE, - ESYS_TR_NONE, - TPM2_CAP_HANDLES, - SRK_HANDLE, - 1, - &more_data, - &cap_data); - if (rc != TSS2_RC_SUCCESS) - return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), - "Failed to enumerate handles searching for SRK: %s", - sym_Tss2_RC_Decode(rc)); - - /* Did Not find SRK, indicate this by returning 0 */ - if (cap_data->data.handles.count == 0 || cap_data->data.handles.handle[0] != SRK_HANDLE) { - ret_primary->esys_handle = ESYS_TR_NONE; + _cleanup_(tpm2_handle_freep) Tpm2Handle *handle = NULL; + r = tpm2_esys_handle_from_tpm_handle(c, session, SRK_HANDLE, &handle); + if (r < 0) + return r; + if (r == 0) { /* SRK not found */ if (ret_alg) - *ret_alg = 0; + *ret_alg = TPM2_ALG_ERROR; + if (ret_handle) + *ret_handle = NULL; return 0; } - log_debug("Found SRK on TPM."); - - /* convert the raw handle to an ESYS_TR */ - TPM2_HANDLE handle = cap_data->data.handles.handle[0]; - rc = sym_Esys_TR_FromTPMPublic(c->esys_context, - handle, - ESYS_TR_NONE, - ESYS_TR_NONE, - ESYS_TR_NONE, - &primary_tr); - if (rc != TSS2_RC_SUCCESS) - return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), - "Failed to convert ray handle to ESYS_TR for SRK: %s", - sym_Tss2_RC_Decode(rc)); - /* Get the algorithm if the caller wants it */ _cleanup_(Esys_Freep) TPM2B_PUBLIC *out_public = NULL; if (ret_alg) { - rc = sym_Esys_ReadPublic( + TSS2_RC rc = sym_Esys_ReadPublic( c->esys_context, - primary_tr, + handle->esys_handle, ESYS_TR_NONE, ESYS_TR_NONE, ESYS_TR_NONE, @@ -729,7 +865,8 @@ static int tpm2_get_srk( sym_Tss2_RC_Decode(rc)); } - ret_primary->esys_handle = primary_tr; + if (ret_handle) + *ret_handle = TAKE_PTR(handle); if (ret_alg) *ret_alg = out_public->publicArea.type; @@ -762,9 +899,6 @@ static int tpm2_make_primary( ts = now(CLOCK_MONOTONIC); _cleanup_(tpm2_handle_freep) Tpm2Handle *primary = NULL; - r = tpm2_handle_new(c, &primary); - if (r < 0) - return r; /* we only need the SRK lock when making the SRK since its not atomic, transient * primary creations don't even matter if they stomp on each other, the TPM will @@ -779,7 +913,7 @@ static int tpm2_make_primary( /* Find existing SRK and use it if present */ if (use_srk_model) { TPMI_ALG_PUBLIC got_alg = TPM2_ALG_NULL; - r = tpm2_get_srk(c, &got_alg, primary); + r = tpm2_get_srk(c, NULL, &got_alg, &primary); if (r < 0) return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to establish if SRK is present"); @@ -799,6 +933,10 @@ static int tpm2_make_primary( log_debug("Did not find SRK, generating..."); } + r = tpm2_handle_new(c, &primary); + if (r < 0) + return r; + if (IN_SET(alg, 0, TPM2_ALG_ECC)) { primary_template = tpm2_get_primary_template(base_flags | TPM2_SRK_TEMPLATE_ECC); @@ -869,7 +1007,7 @@ static int tpm2_make_primary( if (rc != TSS2_RC_SUCCESS) return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to persist SRK within TPM: %s", sym_Tss2_RC_Decode(rc)); - primary->keep = true; + primary->flush = false; } if (ret_primary) @@ -2853,7 +2991,7 @@ int tpm2_unseal(const char *device, if (r < 0) return r; - primary->keep = true; + primary->flush = false; log_debug("Found existing SRK key to use, deserializing ESYS_TR"); rc = sym_Esys_TR_Deserialize( diff --git a/src/shared/tpm2-util.h b/src/shared/tpm2-util.h index 043be9b190..015514e4bf 100644 --- a/src/shared/tpm2-util.h +++ b/src/shared/tpm2-util.h @@ -80,7 +80,8 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(Tpm2Context*, tpm2_context_unref); typedef struct { Tpm2Context *tpm2_context; ESYS_TR esys_handle; - bool keep; + + bool flush; } Tpm2Handle; #define _tpm2_handle(c, h) { .tpm2_context = (c), .esys_handle = (h), }