tpm: Don't call tpm_build_and_send_cmd() from tpm20_stirrandom()

Instead call tpmhw_transmit() directly.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

2 files changed, 12 insertions, 5 deletions

diff --git a/src/std/tcg.h b/src/std/tcg.h
index d5bf15a7..61a759a8 100644
--- a/src/std/tcg.h
+++ b/src/std/tcg.h
@@ -356,7 +356,8 @@ struct tpm_res_sha1complete {
 
 /* TPM 2 data structures */
 
-struct tpm2b_stir {
+struct tpm2_req_stirrandom {
+    struct tpm_req_header hdr;
     u16 size;
     u64 stir;
 } PACKED;
diff --git a/src/tcgbios.c b/src/tcgbios.c
index 5475535a..10f8ba50 100644
--- a/src/tcgbios.c
+++ b/src/tcgbios.c
@@ -591,16 +591,22 @@ tpm_extend(struct tpm_log_entry *le, int digest_len)
 static int
 tpm20_stirrandom(void)
 {
-    struct tpm2b_stir stir = {
+    struct tpm2_req_stirrandom stir = {
+        .hdr.tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
+        .hdr.totlen = cpu_to_be32(sizeof(stir)),
+        .hdr.ordinal = cpu_to_be32(TPM2_CC_StirRandom),
         .size = cpu_to_be16(sizeof(stir.stir)),
         .stir = rdtscll(),
     };
     /* set more bits to stir with */
     stir.stir += swab64(rdtscll());
 
-    int ret = tpm_build_and_send_cmd(0, TPM2_CC_StirRandom,
-                                     (u8 *)&stir, sizeof(stir),
-                                     TPM_DURATION_TYPE_SHORT);
+    struct tpm_rsp_header rsp;
+    u32 resp_length = sizeof(rsp);
+    int ret = tpmhw_transmit(0, &stir.hdr, &rsp, &resp_length,
+                             TPM_DURATION_TYPE_SHORT);
+    if (ret || resp_length != sizeof(rsp) || rsp.errcode)
+        ret = -1;
 
     dprintf(DEBUG_tcg, "TCGBIOS: Return value from sending TPM2_CC_StirRandom = 0x%08x\n",
             ret);