[coreboot-gerrit] New patch to review for coreboot: TPM: WIP - Add TCPA Log support

[Philipp Deppenwiese]

Philipp Deppenwiese ([e-mail]) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/14137

-gerrit

commit f6bd58f46c21e186cb224dc8222a1409bcbf15b7
Author: Philipp Deppenwiese 
Date:   Fri Mar 18 04:22:20 2016 +0100

TPM: WIP - Add TCPA Log support

Change-Id: Ia36817c9840b9ebe59265d641691276edc9c9e06
    Signed-off-by: Philipp Deppenwiese 
---
 src/include/tpm/tss_constants.h | 15 ++++++++
 src/lib/tpm/tspi.c              | 76 +++++++++++++++++++++++++++++++++++++++--
 2 files changed, 88 insertions(+), 3 deletions(-)

diff --git a/src/include/tpm/tss_constants.h b/src/include/tpm/tss_constants.h
index afd2593..3f2092d 100644
--- a/src/include/tpm/tss_constants.h
+++ b/src/include/tpm/tss_constants.h
@@ -15,6 +15,7 @@
 #define TPM_LARGE_ENOUGH_COMMAND_SIZE 256  /* saves space in the firmware */
 #define TPM_PUBEK_SIZE 256
 #define TPM_PCR_DIGEST 20
+#define TPM_EVENT_DATA_SIZE 25

#define TPM_E_NON_FATAL 0x800

@@ -60,6 +61,8 @@

typedef uint8_t TSS_BOOL;
 typedef uint16_t TPM_STRUCTURE_TAG;
+typedef uint32_t TSS_EVENTTYPE;
+typedef uint32_t TSS_PCRINDEX;

typedef struct tdTPM_PERMANENT_FLAGS {
    TPM_STRUCTURE_TAG tag;
@@ -94,4 +97,16 @@ typedef struct tdTPM_STCLEAR_FLAGS {
    TSS_BOOL bGlobalLock;
 } TPM_STCLEAR_FLAGS;

+typedef struct tdTPM_DIGEST {
+	uint8_t	digest[TPM_PCR_DIGEST];
+} TPM_DIGEST;
+
+typedef struct tdTPM_PCR_EVENT {
+	TSS_PCRINDEX PCRIndex; //PCRIndex event extended to
+	TSS_EVENTTYPE EventType; //See Table 7-1, below
+	TPM_DIGEST Digest; //Value extended into PCRIndex
+	uint32_t EventSize; //Size of the event data
+	uint8_t Event[TPM_EVENT_DATA_SIZE]; //The event data
+} TPM_PCR_EVENT;
+
 #endif /* TPM_TSS_CONSTANTS_H */
diff --git a/src/lib/tpm/tspi.c b/src/lib/tpm/tspi.c
index bd3025b..7cd2224 100644
--- a/src/lib/tpm/tspi.c
+++ b/src/lib/tpm/tspi.c
@@ -17,10 +17,15 @@
 #include <console/cbmem_console.h>
 #include <console/console.h>
 #include <reset.h>
+#include <string.h>

#include <tpm/tss.h>
 #include <tpm/tspi.h>

+#include <cbmem.h>
+
+#define MAX_EVENT_STRUCT_SIZE 100
+
 static inline void _debug_init_pcrs(void)
 {
    uint32_t result;
@@ -125,11 +130,72 @@ void init_tpm(int s3resume)
    }
 }

+static inline int tcpa_log(uint32_t pcr, const unsigned char *digest, const char *log_message) {
+	const struct cbmem_entry *ce;
+	TPM_PCR_EVENT tcpa_event;
+	TPM_DIGEST pcr_digest;
+	size_t size;
+  void *lasa;
+	uint8_t lasa_old[MAX_EVENT_STRUCT_SIZE];
+	size_t log_message_len;
+
+	if(log_message == NULL) {
+		return -1;
+	} else {
+		log_message_len = strlen(log_message);
+
+		if(log_message_len >= TPM_EVENT_DATA_SIZE) {
+			return -2;
+		}
+	}
+
+	memcpy(pcr_digest.digest, digest, TPM_PCR_DIGEST);
+
+	tcpa_event.PCRIndex = pcr;
+	tcpa_event.EventType = 5; // ACTION type for linux kernel.
+	tcpa_event.Digest = pcr_digest;
+	tcpa_event.EventSize = TPM_EVENT_DATA_SIZE;
+
+	memset(tcpa_event.Event, 0, TPM_EVENT_DATA_SIZE);
+	memcpy(tcpa_event.Event, log_message, log_message_len);
+
+	ce = cbmem_entry_find(CBMEM_ID_TCPA_LOG);
+  if (ce) {
+		lasa = cbmem_entry_start(ce);
+    size = cbmem_entry_size(ce);
+
+		memcpy(lasa_old, lasa, size);
+
+		if(cbmem_entry_remove(ce) != 0) {
+			return -3;
+		}
+
+		lasa = cbmem_add(CBMEM_ID_TCPA_LOG, sizeof(TPM_PCR_EVENT) + size);
+		if (!lasa) {
+			printk(BIOS_ERR, "TCPA log creation failed\n");
+			return -4;
+		}
+
+		memcpy(lasa, lasa_old, size);
+		lasa += size;
+	} else {
+		lasa = cbmem_add(CBMEM_ID_TCPA_LOG, sizeof(TPM_PCR_EVENT));
+		if (!lasa) {
+			printk(BIOS_ERR, "TCPA log creation failed\n");
+			return -4;
+		}
+	}
+
+	memcpy(lasa, &tcpa_event, sizeof(TPM_PCR_EVENT));
+
+	return 0;
+}
+
 void measure_thing(const uint8_t * data, size_t size, int pcr,
    	const char *thing_name)
 {
    uint8_t digest[SHA1_DIGEST_LENGTH];
-	
+
    sha1(data, size, digest);

printk(BIOS_DEBUG, "TPM: Digest for "%s": ",
@@ -143,13 +209,17 @@ void measure_thing(const uint8_t * data, size_t size, int pcr,

if (tlcl_extend(pcr, digest, digest) == TPM_SUCCESS) {
    	printk(BIOS_DEBUG, "TPM: PCR[%i] after extension: ", pcr);
-	
+
    	for(size = 0; size < SHA1_DIGEST_LENGTH; ++size) {
    		printk(BIOS_SPEW, "%02x%c",
    				digest[size],
    				size < SHA1_DIGEST_LENGTH - 1 ?
    				':' : '\n');
    	}
+
+		if(tcpa_log(pcr, digest, thing_name) < 0) {
+			printk(BIOS_SPEW, "TCPA logging failed!");
+		}
    }
 }

@@ -160,7 +230,7 @@ void measure_prog(struct prog *program, int pcr, const char *prog_name) {
    start = prog_start(program);
    size = prog_size(program);

-	printk(BIOS_DEBUG, "TPM: Measuring program "%s" at %p (%lx bytes)\n",
+	printk(BIOS_DEBUG, "TPM: Measuring program "%s" at %p (%u bytes)\n",
    		prog_name, start, size);

return measure_thing(start, size, pcr, prog_name);