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-rw-r--r--src/include/antirollback.h7
-rw-r--r--src/lib/tlcl.c5
-rw-r--r--src/vendorcode/google/chromeos/vboot2/antirollback.c17
-rw-r--r--src/vendorcode/google/chromeos/vboot2/verstage.c15
4 files changed, 42 insertions, 2 deletions
diff --git a/src/include/antirollback.h b/src/include/antirollback.h
index 942793a62..5ba36f7e6 100644
--- a/src/include/antirollback.h
+++ b/src/include/antirollback.h
@@ -12,6 +12,7 @@
#include "tpm_lite/tss_constants.h"
struct vb2_context;
+enum vb2_pcr_digest;
/* TPM NVRAM location indices. */
#define FIRMWARE_NV_INDEX 0x1007
@@ -51,6 +52,12 @@ uint32_t antirollback_lock_space_firmware(void);
*/
/**
+ * Ask vboot for a digest and extend a TPM PCR with it.
+ */
+uint32_t tpm_extend_pcr(struct vb2_context *ctx, int pcr,
+ enum vb2_pcr_digest which_digest);
+
+/**
* Issue a TPM_Clear and reenable/reactivate the TPM.
*/
uint32_t tpm_clear_and_reenable(void);
diff --git a/src/lib/tlcl.c b/src/lib/tlcl.c
index c37b51a53..ccf4e8004 100644
--- a/src/lib/tlcl.c
+++ b/src/lib/tlcl.c
@@ -320,7 +320,8 @@ uint32_t tlcl_extend(int pcr_num, const uint8_t* in_digest,
if (result != TPM_SUCCESS)
return result;
- memcpy(out_digest, response + kTpmResponseHeaderLength,
- kPcrDigestLength);
+ if (out_digest)
+ memcpy(out_digest, response + kTpmResponseHeaderLength,
+ kPcrDigestLength);
return result;
}
diff --git a/src/vendorcode/google/chromeos/vboot2/antirollback.c b/src/vendorcode/google/chromeos/vboot2/antirollback.c
index f420d1611..407b19cec 100644
--- a/src/vendorcode/google/chromeos/vboot2/antirollback.c
+++ b/src/vendorcode/google/chromeos/vboot2/antirollback.c
@@ -35,6 +35,23 @@
} \
} while (0)
+
+uint32_t tpm_extend_pcr(struct vb2_context *ctx, int pcr,
+ enum vb2_pcr_digest which_digest)
+{
+ uint8_t buffer[VB2_PCR_DIGEST_RECOMMENDED_SIZE];
+ uint32_t size = sizeof(buffer);
+ int rv;
+
+ rv = vb2api_get_pcr_digest(ctx, which_digest, buffer, &size);
+ if (rv != VB2_SUCCESS)
+ return rv;
+ if (size < TPM_PCR_DIGEST)
+ return VB2_ERROR_UNKNOWN;
+
+ return tlcl_extend(pcr, buffer, NULL);
+}
+
uint32_t tpm_clear_and_reenable(void)
{
VBDEBUG("TPM: Clear and re-enable\n");
diff --git a/src/vendorcode/google/chromeos/vboot2/verstage.c b/src/vendorcode/google/chromeos/vboot2/verstage.c
index 06d76fe24..0ce4e8924 100644
--- a/src/vendorcode/google/chromeos/vboot2/verstage.c
+++ b/src/vendorcode/google/chromeos/vboot2/verstage.c
@@ -205,6 +205,12 @@ static void save_if_needed(struct vb2_context *ctx)
}
}
+static uint32_t extend_pcrs(struct vb2_context *ctx)
+{
+ return tpm_extend_pcr(ctx, 0, BOOT_MODE_PCR) ||
+ tpm_extend_pcr(ctx, 1, HWID_DIGEST_PCR);
+}
+
/**
* Verify and select the firmware in the RW image
*
@@ -248,6 +254,7 @@ void verstage_main(void)
printk(BIOS_INFO, "Recovery requested (%x)\n", rv);
/* If we need recovery mode, leave firmware selection now */
save_if_needed(&ctx);
+ extend_pcrs(&ctx); /* ignore failures */
timestamp_add_now(TS_END_VBOOT);
return;
}
@@ -284,6 +291,14 @@ void verstage_main(void)
vboot_reboot();
}
+ rv = extend_pcrs(&ctx);
+ if (rv) {
+ printk(BIOS_WARNING, "Failed to extend TPM PCRs (%#x)\n", rv);
+ vb2api_fail(&ctx, VB2_RECOVERY_RO_TPM_U_ERROR, rv);
+ save_if_needed(&ctx);
+ vboot_reboot();
+ }
+
/* Lock TPM */
rv = antirollback_lock_space_firmware();
if (rv) {