[SeaBIOS] [RFC PATCH v1 9/9] tpm: Implement TPM 2's set_failure

[Stefan Berger]

From: Stefan Berger

Implement TPM 2's set failure.

We follow this specification:

TCG PC Client Specific Platform Firmware Profile for TPM 2.0 Systems Revision 1.0 Version 21

It can be found on this page:

http://www.trustedcomputinggroup.org/resources/specifications_in_public_revi...

Make the TPM unavailable for OS-present applications following 6.2 item 2.d.i .

Signed-off-by: Stefan Berger 
---
 src/std/tcg.h | 12 ++++++++++++
 src/tcgbios.c | 32 +++++++++++++++++++++++++++++++-
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/src/std/tcg.h b/src/std/tcg.h
index dd860e6..8466b14 100644
--- a/src/std/tcg.h
+++ b/src/std/tcg.h
@@ -372,7 +372,9 @@ struct tpm_res_sha1complete {
 #define TPM2_SU_CLEAR               0x0000
 #define TPM2_SU_STATE               0x0001

+#define TPM2_RH_OWNER               0x40000001
 #define TPM2_RS_PW                  0x40000009
+#define TPM2_RH_ENDORSEMENT         0x4000000b
 #define TPM2_RH_PLATFORM            0x4000000c

#define TPM2_ALG_SHA1               0x0004
@@ -382,6 +384,7 @@ struct tpm_res_sha1complete {
 #define TPM2_ST_SESSIONS            0x8002

/* TPM 2 commands */
+#define TPM2_CC_HierarchyControl    0x121
 #define TPM2_CC_Clear               0x126
 #define TPM2_CC_ClearControl        0x127
 #define TPM2_CC_HierarchyChangeAuth 0x129
@@ -460,4 +463,13 @@ struct tpm2_req_clear {
     struct tpm2_authblock authblock;
 } PACKED;

+struct tpm2_req_hierarchycontrol {
+    struct tpm_req_header hdr;
+    u32 authhandle;
+    u32 authblocksize;
+    struct tpm2_authblock authblock;
+    u32 enable;
+    u8 state;
+} PACKED;
+
 #endif // tcg.h
diff --git a/src/tcgbios.c b/src/tcgbios.c
index 356cef9..f1ea023 100644
--- a/src/tcgbios.c
+++ b/src/tcgbios.c
@@ -239,6 +239,35 @@ tpm_build_and_send_cmd(u8 locty, u32 ordinal, const u8 *append,
     return ret;
 }

+static int
+tpm2_hierarchycontrol(u32 hierarchy, u8 state)
+{
+    /* we will try to deactivate the TPM now - ignoring all errors */
+    struct tpm2_req_hierarchycontrol trh = {
+        .hdr.tag = cpu_to_be16(TPM2_ST_SESSIONS),
+        .hdr.totlen = cpu_to_be32(sizeof(trh)),
+        .hdr.ordinal = cpu_to_be32(TPM2_CC_HierarchyControl),
+        .authhandle = cpu_to_be32(TPM2_RH_PLATFORM),
+        .authblocksize = cpu_to_be32(sizeof(trh.authblock)),
+        .authblock = {
+            .handle = cpu_to_be32(TPM2_RS_PW),
+            .noncesize = cpu_to_be16(0),
+            .contsession = TPM2_YES,
+            .pwdsize = cpu_to_be16(0),
+        },
+        .enable = cpu_to_be32(hierarchy),
+        .state = state,
+    };
+    struct tpm_rsp_header rsp;
+    u32 resp_length = sizeof(rsp);
+    int ret = tpmhw_transmit(0, &trh.hdr, &rsp, &resp_length,
+                             TPM_DURATION_TYPE_MEDIUM);
+    if (ret || resp_length != sizeof(rsp) || rsp.errcode)
+        return -1;
+
+    return 0;
+}
+
 static void
 tpm_set_failure(void)
 {
@@ -253,7 +282,8 @@ tpm_set_failure(void)
                                NULL, 0, TPM_DURATION_TYPE_SHORT);
         break;
     case TPM_VERSION_2:
-        // FIXME: missing code
+        tpm2_hierarchycontrol(TPM2_RH_ENDORSEMENT, TPM2_NO);
+        tpm2_hierarchycontrol(TPM2_RH_OWNER, TPM2_NO);
         break;
     }