1 files changed, 284 insertions, 0 deletions
diff --git a/drivers/measured_boot/event_log/event_log.c b/drivers/measured_boot/event_log/event_log.c
new file mode 100644
index 000000000..1755dd95e
--- /dev/null
+++ b/drivers/measured_boot/event_log/event_log.c
@@ -0,0 +1,284 @@
+/*
+ * Copyright (c) 2020-2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+#include <arch_helpers.h>
+
+#include <common/bl_common.h>
+#include <common/debug.h>
+#include <drivers/auth/crypto_mod.h>
+#include <drivers/measured_boot/event_log/event_log.h>
+#include <mbedtls/md.h>
+
+#include <plat/common/platform.h>
+
+/* Running Event Log Pointer */
+static uint8_t *log_ptr;
+
+/* Pointer to the first byte past end of the Event Log buffer */
+static uintptr_t log_end;
+
+/* Pointer to event_log_metadata_t */
+static const event_log_metadata_t *plat_metadata_ptr;
+
+/* TCG_EfiSpecIdEvent */
+static const id_event_headers_t id_event_header = {
+	.header = {
+		.pcr_index = PCR_0,
+		.event_type = EV_NO_ACTION,
+		.digest = {0},
+		.event_size = (uint32_t)(sizeof(id_event_struct_t) +
+				(sizeof(id_event_algorithm_size_t) *
+				HASH_ALG_COUNT))
+	},
+
+	.struct_header = {
+		.signature = TCG_ID_EVENT_SIGNATURE_03,
+		.platform_class = PLATFORM_CLASS_CLIENT,
+		.spec_version_minor = TCG_SPEC_VERSION_MINOR_TPM2,
+		.spec_version_major = TCG_SPEC_VERSION_MAJOR_TPM2,
+		.spec_errata = TCG_SPEC_ERRATA_TPM2,
+		.uintn_size = (uint8_t)(sizeof(unsigned int) /
+					sizeof(uint32_t)),
+		.number_of_algorithms = HASH_ALG_COUNT
+	}
+};
+
+static const event2_header_t locality_event_header = {
+	/*
+	 * All EV_NO_ACTION events SHALL set
+	 * TCG_PCR_EVENT2.pcrIndex = 0, unless otherwise specified
+	 */
+	.pcr_index = PCR_0,
+
+	/*
+	 * All EV_NO_ACTION events SHALL set
+	 * TCG_PCR_EVENT2.eventType = 03h
+	 */
+	.event_type = EV_NO_ACTION,
+
+	/*
+	 * All EV_NO_ACTION events SHALL set TCG_PCR_EVENT2.digests to all
+	 * 0x00's for each allocated Hash algorithm
+	 */
+	.digests = {
+		.count = HASH_ALG_COUNT
+	}
+};
+
+/*
+ * Record a measurement as a TCG_PCR_EVENT2 event
+ *
+ * @param[in] hash		Pointer to hash data of TCG_DIGEST_SIZE bytes
+ * @param[in] metadata_ptr	Pointer to event_log_metadata_t structure
+ *
+ * There must be room for storing this new event into the event log buffer.
+ */
+static void event_log_record(const uint8_t *hash,
+			     const event_log_metadata_t *metadata_ptr)
+{
+	void *ptr = log_ptr;
+	uint32_t name_len;
+
+	assert(hash != NULL);
+	assert(metadata_ptr != NULL);
+	assert(metadata_ptr->name != NULL);
+	/* event_log_init() must have been called prior to this. */
+	assert(log_ptr != NULL);
+
+	name_len = (uint32_t)strlen(metadata_ptr->name) + 1U;
+
+	/* Check for space in Event Log buffer */
+	assert(((uintptr_t)ptr + (uint32_t)EVENT2_HDR_SIZE + name_len) <
+	       log_end);
+
+	/*
+	 * As per TCG specifications, firmware components that are measured
+	 * into PCR[0] must be logged in the event log using the event type
+	 * EV_POST_CODE.
+	 */
+	/* TCG_PCR_EVENT2.PCRIndex */
+	((event2_header_t *)ptr)->pcr_index = metadata_ptr->pcr;
+
+	/* TCG_PCR_EVENT2.EventType */
+	((event2_header_t *)ptr)->event_type = EV_POST_CODE;
+
+	/* TCG_PCR_EVENT2.Digests.Count */
+	ptr = (uint8_t *)ptr + offsetof(event2_header_t, digests);
+	((tpml_digest_values *)ptr)->count = HASH_ALG_COUNT;
+
+	/* TCG_PCR_EVENT2.Digests[] */
+	ptr = (uint8_t *)((uintptr_t)ptr +
+			offsetof(tpml_digest_values, digests));
+
+	/* TCG_PCR_EVENT2.Digests[].AlgorithmId */
+	((tpmt_ha *)ptr)->algorithm_id = TPM_ALG_ID;
+
+	/* TCG_PCR_EVENT2.Digests[].Digest[] */
+	ptr = (uint8_t *)((uintptr_t)ptr + offsetof(tpmt_ha, digest));
+
+	/* Copy digest */
+	(void)memcpy(ptr, (const void *)hash, TCG_DIGEST_SIZE);
+
+	/* TCG_PCR_EVENT2.EventSize */
+	ptr = (uint8_t *)((uintptr_t)ptr + TCG_DIGEST_SIZE);
+	((event2_data_t *)ptr)->event_size = name_len;
+
+	/* Copy event data to TCG_PCR_EVENT2.Event */
+	(void)memcpy((void *)(((event2_data_t *)ptr)->event),
+			(const void *)metadata_ptr->name, name_len);
+
+	/* End of event data */
+	log_ptr = (uint8_t *)((uintptr_t)ptr +
+			offsetof(event2_data_t, event) + name_len);
+}
+
+/*
+ * Initialise Event Log global variables, used during the recording
+ * of various payload measurements into the Event Log buffer
+ *
+ * @param[in] event_log_start		Base address of Event Log buffer
+ * @param[in] event_log_finish		End address of Event Log buffer,
+ * 					it is a first byte past end of the
+ * 					buffer
+ */
+void event_log_init(uint8_t *event_log_start, uint8_t *event_log_finish)
+{
+	assert(event_log_start != NULL);
+	assert(event_log_finish > event_log_start);
+
+	log_ptr = event_log_start;
+	log_end = (uintptr_t)event_log_finish;
+
+	/* Get pointer to platform's event_log_metadata_t structure */
+	plat_metadata_ptr = plat_event_log_get_metadata();
+	assert(plat_metadata_ptr != NULL);
+}
+
+/*
+ * Initialises Event Log by writing Specification ID and
+ * Startup Locality events
+ */
+void event_log_write_header(void)
+{
+	const char locality_signature[] = TCG_STARTUP_LOCALITY_SIGNATURE;
+	void *ptr = log_ptr;
+
+	/* event_log_init() must have been called prior to this. */
+	assert(log_ptr != NULL);
+
+	/*
+	 * Add Specification ID Event first
+	 *
+	 * Copy TCG_EfiSpecIDEventStruct structure header
+	 */
+	(void)memcpy(ptr, (const void *)&id_event_header,
+			sizeof(id_event_header));
+	ptr = (uint8_t *)((uintptr_t)ptr + sizeof(id_event_header));
+
+	/* TCG_EfiSpecIdEventAlgorithmSize structure */
+	((id_event_algorithm_size_t *)ptr)->algorithm_id = TPM_ALG_ID;
+	((id_event_algorithm_size_t *)ptr)->digest_size = TCG_DIGEST_SIZE;
+	ptr = (uint8_t *)((uintptr_t)ptr + sizeof(id_event_algorithm_size_t));
+
+	/*
+	 * TCG_EfiSpecIDEventStruct.vendorInfoSize
+	 * No vendor data
+	 */
+	((id_event_struct_data_t *)ptr)->vendor_info_size = 0;
+	ptr = (uint8_t *)((uintptr_t)ptr +
+			offsetof(id_event_struct_data_t, vendor_info));
+
+	/*
+	 * The Startup Locality event should be placed in the log before
+	 * any event which extends PCR[0].
+	 *
+	 * Ref. TCG PC Client Platform Firmware Profile 9.4.5.3
+	 */
+
+	/* Copy Startup Locality Event Header */
+	(void)memcpy(ptr, (const void *)&locality_event_header,
+			sizeof(locality_event_header));
+	ptr = (uint8_t *)((uintptr_t)ptr + sizeof(locality_event_header));
+
+	/* TCG_PCR_EVENT2.Digests[].AlgorithmId */
+	((tpmt_ha *)ptr)->algorithm_id = TPM_ALG_ID;
+
+	/* TCG_PCR_EVENT2.Digests[].Digest[] */
+	(void)memset(&((tpmt_ha *)ptr)->digest, 0, TPM_ALG_ID);
+	ptr = (uint8_t *)((uintptr_t)ptr +
+			offsetof(tpmt_ha, digest) + TCG_DIGEST_SIZE);
+
+	/* TCG_PCR_EVENT2.EventSize */
+	((event2_data_t *)ptr)->event_size =
+		(uint32_t)sizeof(startup_locality_event_t);
+	ptr = (uint8_t *)((uintptr_t)ptr + offsetof(event2_data_t, event));
+
+	/* TCG_EfiStartupLocalityEvent.Signature */
+	(void)memcpy(ptr, (const void *)locality_signature,
+		sizeof(TCG_STARTUP_LOCALITY_SIGNATURE));
+
+	/*
+	 * TCG_EfiStartupLocalityEvent.StartupLocality = 0:
+	 * the platform's boot firmware
+	 */
+	((startup_locality_event_t *)ptr)->startup_locality = 0U;
+	log_ptr = (uint8_t *)((uintptr_t)ptr + sizeof(startup_locality_event_t));
+}
+
+/*
+ * Calculate and write hash of image, configuration data, etc.
+ * to Event Log.
+ *
+ * @param[in] data_base		Address of data
+ * @param[in] data_size		Size of data
+ * @param[in] data_id		Data ID
+ * @return:
+ *	0 = success
+ *    < 0 = error
+ */
+int event_log_measure_and_record(uintptr_t data_base, uint32_t data_size,
+				 uint32_t data_id)
+{
+	unsigned char hash_data[MBEDTLS_MD_MAX_SIZE];
+	int rc;
+	const event_log_metadata_t *metadata_ptr = plat_metadata_ptr;
+
+	/* Get the metadata associated with this image. */
+	while ((metadata_ptr->id != INVALID_ID) &&
+		(metadata_ptr->id != data_id)) {
+		metadata_ptr++;
+	}
+	assert(metadata_ptr->id != INVALID_ID);
+
+	/* Calculate hash */
+	rc = crypto_mod_calc_hash((unsigned int)MBEDTLS_MD_ID,
+				(void *)data_base, data_size, hash_data);
+	if (rc != 0) {
+		return rc;
+	}
+
+	event_log_record(hash_data, metadata_ptr);
+
+	return 0;
+}
+
+/*
+ * Get current Event Log buffer size i.e. used space of Event Log buffer
+ *
+ * @param[in]  event_log_start		Base Pointer to Event Log buffer
+ *
+ * @return: current Size of Event Log buffer
+ */
+size_t event_log_get_cur_size(uint8_t *event_log_start)
+{
+	assert(event_log_start != NULL);
+	assert(log_ptr >= event_log_start);
+
+	return (size_t)((uintptr_t)log_ptr - (uintptr_t)event_log_start);
+}