security/tpm: add TPM log format as per 2.0 spec

Used by default for all boards with TPM2 which don't specify log
format explicitly.

Change-Id: I0fac386bebab1b7104378ae3424957c6497e84e1
Ticket: https://ticket.coreboot.org/issues/422
Ticket: https://ticket.coreboot.org/issues/423
Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/68748
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

3 files changed, 258 insertions, 0 deletions

diff --git a/src/security/tpm/tspi/crtm.h b/src/security/tpm/tspi/crtm.h
index 241607757b..ffa4867594 100644
--- a/src/security/tpm/tspi/crtm.h
+++ b/src/security/tpm/tspi/crtm.h
@@ -22,6 +22,19 @@
 #  define TPM_MEASURE_ALGO VB2_HASH_SHA256
 #elif CONFIG(TPM_LOG_TPM1)
 #  define TPM_MEASURE_ALGO VB2_HASH_SHA1
+#elif CONFIG(TPM_LOG_TPM2)
+#  if CONFIG(TPM_HASH_SHA1)
+#    define TPM_MEASURE_ALGO VB2_HASH_SHA1
+#  endif
+#  if CONFIG(TPM_HASH_SHA256)
+#    define TPM_MEASURE_ALGO VB2_HASH_SHA256
+#  endif
+#  if CONFIG(TPM_HASH_SHA384)
+#    define TPM_MEASURE_ALGO VB2_HASH_SHA384
+#  endif
+#  if CONFIG(TPM_HASH_SHA512)
+#    define TPM_MEASURE_ALGO VB2_HASH_SHA512
+#  endif
 #endif
 
 #if !defined(TPM_MEASURE_ALGO)
diff --git a/src/security/tpm/tspi/log-tpm2.c b/src/security/tpm/tspi/log-tpm2.c
new file mode 100644
index 0000000000..897ccedbff
--- /dev/null
+++ b/src/security/tpm/tspi/log-tpm2.c
@@ -0,0 +1,230 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/*
+ * Unlike log.c this implements TPM log according to TPM2.0 specification
+ * rather then using coreboot-specific log format.
+ *
+ * First entry is in TPM1.2 format and serves as a header, the rest are in
+ * a newer (agile) format which supports SHA256 and multiple hashes, but we
+ * store only one hash.
+ *
+ * This is defined in "TCG EFI Protocol Specification".
+ */
+
+#include <endian.h>
+#include <console/console.h>
+#include <security/tpm/tspi.h>
+#include <security/tpm/tspi/crtm.h>
+#include <security/tpm/tspi/logs.h>
+#include <region_file.h>
+#include <string.h>
+#include <symbols.h>
+#include <cbmem.h>
+#include <vb2_sha.h>
+
+static uint16_t tpmalg_from_vb2_hash(enum vb2_hash_algorithm hash_type)
+{
+	switch (hash_type) {
+	case VB2_HASH_SHA1:
+		return TPM2_ALG_SHA1;
+	case VB2_HASH_SHA256:
+		return TPM2_ALG_SHA256;
+	case VB2_HASH_SHA384:
+		return TPM2_ALG_SHA384;
+	case VB2_HASH_SHA512:
+		return TPM2_ALG_SHA512;
+
+	default:
+		return 0xFF;
+	}
+}
+
+void *tpm2_log_cbmem_init(void)
+{
+	static struct tpm_2_log_table *tclt;
+	if (tclt)
+		return tclt;
+
+	if (cbmem_possibly_online()) {
+		size_t tpm_log_len;
+		struct tcg_efi_spec_id_event *hdr;
+
+		tclt = cbmem_find(CBMEM_ID_TPM2_TCG_LOG);
+		if (tclt)
+			return tclt;
+
+		tpm_log_len = sizeof(struct tpm_2_log_table) +
+			MAX_TPM_LOG_ENTRIES * sizeof(struct tpm_2_log_entry);
+		tclt = cbmem_add(CBMEM_ID_TPM2_TCG_LOG, tpm_log_len);
+		if (!tclt)
+			return NULL;
+
+		memset(tclt, 0, tpm_log_len);
+		hdr = &tclt->header;
+
+		hdr->event_type = htole32(EV_NO_ACTION);
+		hdr->event_size = htole32(33 + sizeof(tclt->vendor));
+		strcpy((char *)hdr->signature, TPM_20_SPEC_ID_EVENT_SIGNATURE);
+		hdr->platform_class = htole32(0x00); // client platform
+		hdr->spec_version_minor = 0x00;
+		hdr->spec_version_major = 0x02;
+		hdr->spec_errata = 0x00;
+		hdr->uintn_size = 0x02; // 64-bit UINT
+		hdr->num_of_algorithms = htole32(1);
+		hdr->digest_sizes[0].alg_id = htole16(tpmalg_from_vb2_hash(TPM_MEASURE_ALGO));
+		hdr->digest_sizes[0].digest_size = htole16(vb2_digest_size(TPM_MEASURE_ALGO));
+
+		tclt->vendor_info_size = sizeof(tclt->vendor);
+		tclt->vendor.reserved = 0;
+		tclt->vendor.version_major = TPM_20_LOG_VI_MAJOR;
+		tclt->vendor.version_minor = TPM_20_LOG_VI_MINOR;
+		tclt->vendor.magic = htole32(TPM_20_LOG_VI_MAGIC);
+		tclt->vendor.max_entries = htole16(MAX_TPM_LOG_ENTRIES);
+		tclt->vendor.num_entries = htole16(0);
+		tclt->vendor.entry_size = htole32(sizeof(struct tpm_2_log_entry));
+	}
+
+	return tclt;
+}
+
+void tpm2_log_dump(void)
+{
+	int i, j;
+	struct tpm_2_log_table *tclt;
+	int hash_size;
+	const char *alg_name;
+
+	tclt = tpm_log_init();
+	if (!tclt)
+		return;
+
+	hash_size = vb2_digest_size(TPM_MEASURE_ALGO);
+	alg_name = vb2_get_hash_algorithm_name(TPM_MEASURE_ALGO);
+
+	printk(BIOS_INFO, "coreboot TPM 2.0 measurements:\n\n");
+	for (i = 0; i < le16toh(tclt->vendor.num_entries); i++) {
+		struct tpm_2_log_entry *tce = &tclt->entries[i];
+
+		printk(BIOS_INFO, " PCR-%u ", le32toh(tce->pcr));
+
+		for (j = 0; j < hash_size; j++)
+			printk(BIOS_INFO, "%02x", tce->digest[j]);
+
+		printk(BIOS_INFO, " %s [%s]\n", alg_name, tce->data);
+	}
+	printk(BIOS_INFO, "\n");
+}
+
+void tpm2_log_add_table_entry(const char *name, const uint32_t pcr,
+			      enum vb2_hash_algorithm digest_algo,
+			      const uint8_t *digest,
+			      const size_t digest_len)
+{
+	struct tpm_2_log_table *tclt;
+	struct tpm_2_log_entry *tce;
+
+	tclt = tpm_log_init();
+	if (!tclt) {
+		printk(BIOS_WARNING, "TPM LOG: non-existent!\n");
+		return;
+	}
+
+	if (!name) {
+		printk(BIOS_WARNING, "TPM LOG: entry name not set\n");
+		return;
+	}
+
+	if (digest_algo != TPM_MEASURE_ALGO) {
+		printk(BIOS_WARNING, "TPM LOG: digest is of unsupported type: %s\n",
+		       vb2_get_hash_algorithm_name(digest_algo));
+		return;
+	}
+
+	if (digest_len != vb2_digest_size(TPM_MEASURE_ALGO)) {
+		printk(BIOS_WARNING, "TPM LOG: digest has invalid length: %d\n",
+		       (int)digest_len);
+		return;
+	}
+
+	if (le16toh(tclt->vendor.num_entries) >= le16toh(tclt->vendor.max_entries)) {
+		printk(BIOS_WARNING, "TPM LOG: log table is full\n");
+		return;
+	}
+
+	tce = &tclt->entries[le16toh(tclt->vendor.num_entries)];
+	tclt->vendor.num_entries = htole16(le16toh(tclt->vendor.num_entries) + 1);
+
+	tce->pcr = htole32(pcr);
+	tce->event_type = htole32(EV_ACTION);
+
+	tce->digest_count = htole32(1);
+	tce->digest_type = htole16(tpmalg_from_vb2_hash(TPM_MEASURE_ALGO));
+	memcpy(tce->digest, digest, vb2_digest_size(TPM_MEASURE_ALGO));
+
+	tce->data_length = htole32(sizeof(tce->data));
+	strncpy((char *)tce->data, name, sizeof(tce->data) - 1);
+	tce->data[sizeof(tce->data) - 1] = '\0';
+}
+
+int tpm2_log_get(int entry_idx, int *pcr, const uint8_t **digest_data,
+		 enum vb2_hash_algorithm *digest_algo, const char **event_name)
+{
+	struct tpm_2_log_table *tclt;
+	struct tpm_2_log_entry *tce;
+
+	tclt = tpm_log_init();
+	if (!tclt)
+		return 1;
+
+	if (entry_idx < 0 || entry_idx >= le16toh(tclt->vendor.num_entries))
+		return 1;
+
+	tce = &tclt->entries[entry_idx];
+
+	*pcr = le32toh(tce->pcr);
+	*digest_data = tce->digest;
+	*digest_algo = TPM_MEASURE_ALGO; /* We validate algorithm on addition */
+	*event_name = (char *)tce->data;
+	return 0;
+}
+
+uint16_t tpm2_log_get_size(const void *log_table)
+{
+	const struct tpm_2_log_table *tclt = log_table;
+	return le16toh(tclt->vendor.num_entries);
+}
+
+void tpm2_preram_log_clear(void)
+{
+	printk(BIOS_INFO, "TPM LOG: clearing the log\n");
+	/*
+	 * Pre-RAM log is only for internal use and isn't exported anywhere, hence it's header
+	 * is not initialized.
+	 */
+	struct tpm_2_log_table *tclt = (struct tpm_2_log_table *)_tpm_log;
+	tclt->vendor.max_entries = htole16(MAX_TPM_LOG_ENTRIES);
+	tclt->vendor.num_entries = htole16(0);
+}
+
+void tpm2_log_copy_entries(const void *from, void *to)
+{
+	const struct tpm_2_log_table *from_log = from;
+	struct tpm_2_log_table *to_log = to;
+	int i;
+
+	for (i = 0; i < le16toh(from_log->vendor.num_entries); i++) {
+		struct tpm_2_log_entry *tce =
+			&to_log->entries[le16toh(to_log->vendor.num_entries)];
+		to_log->vendor.num_entries = htole16(le16toh(to_log->vendor.num_entries) + 1);
+
+		tce->pcr = from_log->entries[i].pcr;
+		tce->event_type = from_log->entries[i].event_type;
+
+		tce->digest_count = from_log->entries[i].digest_count;
+		tce->digest_type = from_log->entries[i].digest_type;
+		memcpy(tce->digest, from_log->entries[i].digest, sizeof(tce->digest));
+
+		tce->data_length = from_log->entries[i].data_length;
+		memcpy(tce->data, from_log->entries[i].data, sizeof(tce->data));
+	}
+}
diff --git a/src/security/tpm/tspi/logs.h b/src/security/tpm/tspi/logs.h
index 417017628e..2d802f0bc5 100644
--- a/src/security/tpm/tspi/logs.h
+++ b/src/security/tpm/tspi/logs.h
@@ -36,4 +36,19 @@ void tpm1_log_add_table_entry(const char *name, const uint32_t pcr,
 			      const size_t digest_len);
 void tpm1_log_dump(void);
 
+/* TPM 2.0 log format */
+
+void *tpm2_log_init(void);
+void *tpm2_log_cbmem_init(void);
+void tpm2_preram_log_clear(void);
+uint16_t tpm2_log_get_size(const void *log_table);
+void tpm2_log_copy_entries(const void *from, void *to);
+int tpm2_log_get(int entry_idx, int *pcr, const uint8_t **digest_data,
+		 enum vb2_hash_algorithm *digest_algo, const char **event_name);
+void tpm2_log_add_table_entry(const char *name, const uint32_t pcr,
+			      enum vb2_hash_algorithm digest_algo,
+			      const uint8_t *digest,
+			      const size_t digest_len);
+void tpm2_log_dump(void);
+
 #endif /* LOGS_H_ */