1 files changed, 294 insertions, 0 deletions
diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h
new file mode 100644
index 000000000..7d68a5cc5
--- /dev/null
+++ b/include/linux/tpm_eventlog.h
@@ -0,0 +1,294 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __LINUX_TPM_EVENTLOG_H__
+#define __LINUX_TPM_EVENTLOG_H__
+
+#include <linux/tpm.h>
+
+#define TCG_EVENT_NAME_LEN_MAX	255
+#define MAX_TEXT_EVENT		1000	/* Max event string length */
+#define ACPI_TCPA_SIG		"TCPA"	/* 0x41504354 /'TCPA' */
+
+#define EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2 0x1
+#define EFI_TCG2_EVENT_LOG_FORMAT_TCG_2   0x2
+
+#ifdef CONFIG_PPC64
+#define do_endian_conversion(x) be32_to_cpu(x)
+#else
+#define do_endian_conversion(x) x
+#endif
+
+enum bios_platform_class {
+	BIOS_CLIENT = 0x00,
+	BIOS_SERVER = 0x01,
+};
+
+struct tcpa_event {
+	u32 pcr_index;
+	u32 event_type;
+	u8 pcr_value[20];	/* SHA1 */
+	u32 event_size;
+	u8 event_data[];
+};
+
+enum tcpa_event_types {
+	PREBOOT = 0,
+	POST_CODE,
+	UNUSED,
+	NO_ACTION,
+	SEPARATOR,
+	ACTION,
+	EVENT_TAG,
+	SCRTM_CONTENTS,
+	SCRTM_VERSION,
+	CPU_MICROCODE,
+	PLATFORM_CONFIG_FLAGS,
+	TABLE_OF_DEVICES,
+	COMPACT_HASH,
+	IPL,
+	IPL_PARTITION_DATA,
+	NONHOST_CODE,
+	NONHOST_CONFIG,
+	NONHOST_INFO,
+};
+
+struct tcpa_pc_event {
+	u32 event_id;
+	u32 event_size;
+	u8 event_data[];
+};
+
+enum tcpa_pc_event_ids {
+	SMBIOS = 1,
+	BIS_CERT,
+	POST_BIOS_ROM,
+	ESCD,
+	CMOS,
+	NVRAM,
+	OPTION_ROM_EXEC,
+	OPTION_ROM_CONFIG,
+	OPTION_ROM_MICROCODE = 10,
+	S_CRTM_VERSION,
+	S_CRTM_CONTENTS,
+	POST_CONTENTS,
+	HOST_TABLE_OF_DEVICES,
+};
+
+/* http://www.trustedcomputinggroup.org/tcg-efi-protocol-specification/ */
+
+struct tcg_efi_specid_event_algs {
+	u16 alg_id;
+	u16 digest_size;
+} __packed;
+
+#define TCG_SPECID_SIG "Spec ID Event03"
+
+struct tcg_efi_specid_event_head {
+	u8 signature[16];
+	u32 platform_class;
+	u8 spec_version_minor;
+	u8 spec_version_major;
+	u8 spec_errata;
+	u8 uintnsize;
+	u32 num_algs;
+	struct tcg_efi_specid_event_algs digest_sizes[];
+} __packed;
+
+struct tcg_pcr_event {
+	u32 pcr_idx;
+	u32 event_type;
+	u8 digest[20];
+	u32 event_size;
+	u8 event[];
+} __packed;
+
+struct tcg_event_field {
+	u32 event_size;
+	u8 event[];
+} __packed;
+
+struct tcg_pcr_event2_head {
+	u32 pcr_idx;
+	u32 event_type;
+	u32 count;
+	struct tpm_digest digests[];
+} __packed;
+
+struct tcg_algorithm_size {
+	u16 algorithm_id;
+	u16 algorithm_size;
+};
+
+struct tcg_algorithm_info {
+	u8 signature[16];
+	u32 platform_class;
+	u8 spec_version_minor;
+	u8 spec_version_major;
+	u8 spec_errata;
+	u8 uintn_size;
+	u32 number_of_algorithms;
+	struct tcg_algorithm_size digest_sizes[];
+};
+
+#ifndef TPM_MEMREMAP
+#define TPM_MEMREMAP(start, size) NULL
+#endif
+
+#ifndef TPM_MEMUNMAP
+#define TPM_MEMUNMAP(start, size) do{} while(0)
+#endif
+
+/**
+ * __calc_tpm2_event_size - calculate the size of a TPM2 event log entry
+ * @event:        Pointer to the event whose size should be calculated
+ * @event_header: Pointer to the initial event containing the digest lengths
+ * @do_mapping:   Whether or not the event needs to be mapped
+ *
+ * The TPM2 event log format can contain multiple digests corresponding to
+ * separate PCR banks, and also contains a variable length of the data that
+ * was measured. This requires knowledge of how long each digest type is,
+ * and this information is contained within the first event in the log.
+ *
+ * We calculate the length by examining the number of events, and then looking
+ * at each event in turn to determine how much space is used for events in
+ * total. Once we've done this we know the offset of the data length field,
+ * and can calculate the total size of the event.
+ *
+ * Return: size of the event on success, 0 on failure
+ */
+
+static __always_inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event,
+					 struct tcg_pcr_event *event_header,
+					 bool do_mapping)
+{
+	struct tcg_efi_specid_event_head *efispecid;
+	struct tcg_event_field *event_field;
+	void *mapping = NULL;
+	int mapping_size;
+	void *marker;
+	void *marker_start;
+	u32 halg_size;
+	size_t size;
+	u16 halg;
+	int i;
+	int j;
+	u32 count, event_type;
+	const u8 zero_digest[sizeof(event_header->digest)] = {0};
+
+	marker = event;
+	marker_start = marker;
+	marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type)
+		+ sizeof(event->count);
+
+	/* Map the event header */
+	if (do_mapping) {
+		mapping_size = marker - marker_start;
+		mapping = TPM_MEMREMAP((unsigned long)marker_start,
+				       mapping_size);
+		if (!mapping) {
+			size = 0;
+			goto out;
+		}
+	} else {
+		mapping = marker_start;
+	}
+
+	event = (struct tcg_pcr_event2_head *)mapping;
+	/*
+	 * The loop below will unmap these fields if the log is larger than
+	 * one page, so save them here for reference:
+	 */
+	count = event->count;
+	event_type = event->event_type;
+
+	/* Verify that it's the log header */
+	if (event_header->pcr_idx != 0 ||
+	    event_header->event_type != NO_ACTION ||
+	    memcmp(event_header->digest, zero_digest, sizeof(zero_digest))) {
+		size = 0;
+		goto out;
+	}
+
+	efispecid = (struct tcg_efi_specid_event_head *)event_header->event;
+
+	/*
+	 * Perform validation of the event in order to identify malformed
+	 * events. This function may be asked to parse arbitrary byte sequences
+	 * immediately following a valid event log. The caller expects this
+	 * function to recognize that the byte sequence is not a valid event
+	 * and to return an event size of 0.
+	 */
+	if (memcmp(efispecid->signature, TCG_SPECID_SIG,
+		   sizeof(TCG_SPECID_SIG)) ||
+	    !efispecid->num_algs || count != efispecid->num_algs) {
+		size = 0;
+		goto out;
+	}
+
+	for (i = 0; i < count; i++) {
+		halg_size = sizeof(event->digests[i].alg_id);
+
+		/* Map the digest's algorithm identifier */
+		if (do_mapping) {
+			TPM_MEMUNMAP(mapping, mapping_size);
+			mapping_size = halg_size;
+			mapping = TPM_MEMREMAP((unsigned long)marker,
+					     mapping_size);
+			if (!mapping) {
+				size = 0;
+				goto out;
+			}
+		} else {
+			mapping = marker;
+		}
+
+		memcpy(&halg, mapping, halg_size);
+		marker = marker + halg_size;
+
+		for (j = 0; j < efispecid->num_algs; j++) {
+			if (halg == efispecid->digest_sizes[j].alg_id) {
+				marker +=
+					efispecid->digest_sizes[j].digest_size;
+				break;
+			}
+		}
+		/* Algorithm without known length. Such event is unparseable. */
+		if (j == efispecid->num_algs) {
+			size = 0;
+			goto out;
+		}
+	}
+
+	/*
+	 * Map the event size - we don't read from the event itself, so
+	 * we don't need to map it
+	 */
+	if (do_mapping) {
+		TPM_MEMUNMAP(mapping, mapping_size);
+		mapping_size += sizeof(event_field->event_size);
+		mapping = TPM_MEMREMAP((unsigned long)marker,
+				       mapping_size);
+		if (!mapping) {
+			size = 0;
+			goto out;
+		}
+	} else {
+		mapping = marker;
+	}
+
+	event_field = (struct tcg_event_field *)mapping;
+
+	marker = marker + sizeof(event_field->event_size)
+		+ event_field->event_size;
+	size = marker - marker_start;
+
+	if (event_type == 0 && event_field->event_size == 0)
+		size = 0;
+
+out:
+	if (do_mapping)
+		TPM_MEMUNMAP(mapping, mapping_size);
+	return size;
+}
+
+#endif