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authorVadim Bendebury <vbendeb@chromium.org>2016-07-03 22:20:17 -0700
committerMartin Roth <martinroth@google.com>2016-07-14 00:00:30 +0200
commitf5ef699f40ca36815069e9c1df72af6385e600f0 (patch)
tree7cbc40acafedef812c0d04d611ccaeb625fc454c /src/lib/tpm2_tlcl_structures.h
parent4c0851cc37f42ed88d62b876357b71cfdaac480f (diff)
downloadcoreboot-f5ef699f40ca36815069e9c1df72af6385e600f0.tar.xz
tpm2: implement and use pcr_extend command
TPM PCRs are used in Chrome OS for two purposes: to communicate crucial information from RO firmware and to protect FW and kernel rollback counters from being deleted. As implemented in a TPM1 compatible way, the PCR extension command requires a prebuilt digest to calculate a new PCR value. TPM2 specification introduces a PCR_Event command, where the TPM itself calculates the digest of an arbitrary length string, and then uses the calculated digest for PCR extension. PCR_Event could be a better option for Chrome OS, this needs to be investigated separately. BRANCH=none BUG=chrome-os-partner:50645 TEST=verified that the two PCRs are successfully extended before the RW firmware is called. Change-Id: I38fc88172de8ec8bef56fec026f83058480c8010 Signed-off-by: Martin Roth <martinroth@chromium.org> Original-Commit-Id: 73388139db3ffaf61a3d9027522c5ebecb3ad051 Original-Change-Id: I1a9bab7396fdb652e2e3bc8529b828ea3423d851 Original-Signed-off-by: Vadim Bendebury <vbendeb@chromium.org> Original-Reviewed-on: https://chromium-review.googlesource.com/358098 Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org> Original-Reviewed-by: Darren Krahn <dkrahn@chromium.org> Reviewed-on: https://review.coreboot.org/15639 Tested-by: build bot (Jenkins) Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@googlemail.com>
Diffstat (limited to 'src/lib/tpm2_tlcl_structures.h')
-rw-r--r--src/lib/tpm2_tlcl_structures.h30
1 files changed, 29 insertions, 1 deletions
diff --git a/src/lib/tpm2_tlcl_structures.h b/src/lib/tpm2_tlcl_structures.h
index 1e7fcf05fa..36a3e8b253 100644
--- a/src/lib/tpm2_tlcl_structures.h
+++ b/src/lib/tpm2_tlcl_structures.h
@@ -25,11 +25,12 @@ typedef uint32_t TPM_CC;
typedef uint32_t TPM_HANDLE;
typedef uint32_t TPM_RC;
typedef uint8_t TPMI_YES_NO;
+typedef TPM_ALG_ID TPMI_ALG_HASH;
+typedef TPM_HANDLE TPMI_DH_PCR;
typedef TPM_HANDLE TPMI_RH_NV_INDEX;
typedef TPM_HANDLE TPMI_RH_PROVISION;
typedef TPM_HANDLE TPMI_SH_AUTH_SESSION;
typedef TPM_HANDLE TPM_RH;
-typedef TPM_ALG_ID TPMI_ALG_HASH;
/* Some hardcoded algorithm values. */
#define TPM_ALG_HMAC ((TPM_ALG_ID)0x0005)
@@ -37,6 +38,8 @@ typedef TPM_ALG_ID TPMI_ALG_HASH;
#define TPM_ALG_SHA1 ((TPM_ALG_ID)0x0004)
#define TPM_ALG_SHA256 ((TPM_ALG_ID)0x000b)
+#define SHA256_DIGEST_SIZE 32
+
/* Some hardcoded hierarchies. */
#define TPM_RH_NULL 0x40000007
#define TPM_RS_PW 0x40000009
@@ -64,11 +67,13 @@ struct tpm_header {
#define TPM2_Startup ((TPM_CC)0x00000144)
#define TPM2_NV_Read ((TPM_CC)0x0000014E)
#define TPM2_GetCapability ((TPM_CC)0x0000017A)
+#define TPM2_PCR_Extend ((TPM_CC)0x00000182)
/* Startup values. */
#define TPM_SU_CLEAR 0
#define TPM_SU_STATE 1
+#define TPM_HT_PCR 0x00
#define TPM_HT_NV_INDEX 0x01
#define TPM_HT_HMAC_SESSION 0x02
#define TPM_HT_POLICY_SESSION 0x03
@@ -241,6 +246,24 @@ typedef union {
TPM2B b;
} TPM2B_MAX_NV_BUFFER;
+/*
+ * This is a union, but as of now we support just one digest - sha256, so
+ * there is just one element.
+ */
+typedef union {
+ uint8_t sha256[SHA256_DIGEST_SIZE];
+} TPMU_HA;
+
+typedef struct {
+ TPMI_ALG_HASH hashAlg;
+ TPMU_HA digest;
+} TPMT_HA;
+
+typedef struct {
+ uint32_t count;
+ TPMT_HA digests[1]; /* Limit max number of hashes to 1. */
+} TPML_DIGEST_VALUES;
+
struct nv_read_response {
uint32_t params_size;
TPM2B_MAX_NV_BUFFER buffer;
@@ -306,4 +329,9 @@ struct tpm2_nv_write_lock_cmd {
TPMI_RH_NV_INDEX nvIndex;
};
+struct tpm2_pcr_extend_cmd {
+ TPMI_DH_PCR pcrHandle;
+ TPML_DIGEST_VALUES digests;
+};
+
#endif // __SRC_LIB_TPM2_TLCL_STRUCTURES_H