diff options
| -rw-r--r-- | libstb/tss2/eventlog.c | 126 | ||||
| -rw-r--r-- | libstb/tss2/eventlog.h | 30 |
2 files changed, 156 insertions, 0 deletions
diff --git a/libstb/tss2/eventlog.c b/libstb/tss2/eventlog.c new file mode 100644 index 0000000..f69db4b --- /dev/null +++ b/libstb/tss2/eventlog.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later +/* Copyright 2020 IBM Corp. */ + +#include <skiboot.h> + +#include <eventlog.h> +#include <eventlib.h> +#include <ibmtss/tssmarshal.h> + + +int load_eventlog(TpmLogMgr *logmgr, uint8_t *eventlog_ptr, + uint32_t eventlog_size) +{ + TCG_PCR_EVENT2 *event2 = NULL; + TCG_PCR_EVENT *event = NULL; + uint8_t *log_ptr, *ptr; + uint32_t size; + int rc = 0; + + event = zalloc(sizeof(TCG_PCR_EVENT)); + if(!event){ + rc = 1; + goto cleanup; + } + + event2 = zalloc(sizeof(TCG_PCR_EVENT2)); + if(!event2){ + rc = 1; + goto cleanup; + } + + logmgr->logMaxSize = eventlog_size; + logmgr->eventLogInMem = eventlog_ptr; + logmgr->logSize = 0; + + log_ptr = logmgr->eventLogInMem; + size = sizeof(TCG_PCR_EVENT); + + //first event in the log is a header + rc = TSS_EVENT_Line_LE_Unmarshal(event, &log_ptr, &size); + if(rc) + { + prlog(PR_INFO, "Couldn't read event log header event, rc=%d", + rc); + rc = 1; + goto cleanup; + } + //now iterate through all events + ptr = log_ptr; + do { + size = sizeof(TCG_PCR_EVENT2); + rc = TSS_EVENT2_Line_LE_Unmarshal(event2, &ptr, &size); + /* something went wrong in parsing (invalid values) or + * digest.count is 0 - which doesn't make sense - we stop. + */ + if (rc || event2->digests.count == 0 ) + break; + log_ptr = ptr; + } while(1); + logmgr->logSize = log_ptr - logmgr->eventLogInMem; + logmgr->newEventPtr = log_ptr; + +cleanup: + free(event); + free(event2); + return rc; +} + +int add_to_eventlog(TpmLogMgr *logmgr, TCG_PCR_EVENT2 *event) +{ + uint32_t size = sizeof(TCG_PCR_EVENT2), rc = 0; + uint16_t written = 0, ev_size =0; + + /* Calling Marshal function with a NULL buffer to obtain the event size. + * It's a well known and safe pattern used in TSS code. + * Then check if an event that larger will fit in evenlog buffer, and + * only after success here marshal it to eventlog buffer pointed by + * logmgr->newEventPtr. + */ + TSS_EVENT2_Line_LE_Marshal(event, &ev_size, NULL, &size); + if(logmgr->logSize + ev_size > logmgr->logMaxSize){ + return 1; + } + rc = TSS_EVENT2_Line_LE_Marshal(event, &written, + &(logmgr->newEventPtr), &size); + if(rc) + return rc; + logmgr->logSize += ev_size; + + return rc; +} + +int build_event(TCG_PCR_EVENT2 *event, TPMI_DH_PCR pcrHandle, + TPMI_ALG_HASH *hashes, uint8_t hashes_len, + const uint8_t **digests, uint32_t event_type, + const char* logmsg, uint32_t logmsg_len) +{ + uint16_t alg_digest_size; + uint32_t size; + + memset(event, 0, sizeof(TCG_PCR_EVENT2)); + event->pcrIndex = pcrHandle; + event->eventType = event_type; + event->digests.count = hashes_len; + + size = sizeof(TPMI_ALG_HASH); + for (int i=0; i < event->digests.count; i++){ + event->digests.digests[i].hashAlg = hashes[i]; + + TSS_TPMI_ALG_HASH_Marshalu(hashes+i, &alg_digest_size, NULL, &size); + + if (alg_digest_size == 0) + return 1; + memcpy(&(event->digests.digests[i].digest), digests[i], + strlen(digests[i]) > alg_digest_size ? + strlen(digests[i]) : alg_digest_size); + + } + + event->eventSize = logmsg_len; + memset(&(event->event), 0, sizeof(event->event)); + memcpy(&(event->event), logmsg, + event->eventSize > TCG_EVENT_LEN_MAX ? + TCG_EVENT_LEN_MAX - 1: event->eventSize); + return 0; +} diff --git a/libstb/tss2/eventlog.h b/libstb/tss2/eventlog.h new file mode 100644 index 0000000..dd4a1d7 --- /dev/null +++ b/libstb/tss2/eventlog.h @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later +/* Copyright 2020 IBM Corp. */ + +#ifndef __EVENTLOG_H +#define __EVENTLOG_H + +#include <ibmtss/TPM_Types.h> +#include <eventlib.h> + +#define MAX_TPM_LOG_MSG 128 +#define MAX_VENDOR_INFO_LEN 255 + +struct _TpmLogMgr +{ + uint32_t logSize; + uint32_t logMaxSize; + uint8_t* newEventPtr; + uint8_t* eventLogInMem; +}; +typedef struct _TpmLogMgr TpmLogMgr; + + +int load_eventlog(TpmLogMgr *logmgr, uint8_t* eventlog_ptr, + uint32_t eventlog_size); +int add_to_eventlog(TpmLogMgr *logmgr, TCG_PCR_EVENT2 *event); +int build_event(TCG_PCR_EVENT2 *event, TPMI_DH_PCR pcrHandle, + TPMI_ALG_HASH *hashes, uint8_t hashes_len, + const uint8_t **digests, uint32_t event_type, + const char* logmsg, uint32_t logmsg_len); +#endif //__EVENTLOG_H |