Merge pull request #608 from aidangarske/fenrir-fixes-14014-14015-14068-14072-14073-14074-14087

Fix fwTPM SPDM and TPM transport security findings

src/fwtpm/fwtpm_command.c

@@ -6375,7 +6375,7 @@ static TPM_RC FwCmd_Create(FWTPM_CTX* ctx, TPM2_Packet* cmd,
                 if (rc == 0) {
                     inPublic->publicArea.unique.keyedHash.size = (UINT16)
                         FwComputeUniqueHash(inPublic->publicArea.nameAlg,
-                            privKeyDer, keySz,
+                            privKeyDer, privKeyDerSz,
                             inPublic->publicArea.unique.keyedHash.buffer);
                 }
                 break;
@@ -7995,6 +7995,10 @@ static TPM_RC FwCmd_Rewrap(FWTPM_CTX* ctx, TPM2_Packet* cmd,
     FWTPM_ALLOC_BUF(plainSens, FWTPM_MAX_SENSITIVE_SIZE);
     FWTPM_ALLOC_BUF(encSeedBuf, FWTPM_MAX_PUB_BUF);
 
+    /* The dispatcher leaves the command packet overflow flag as-is, so clear it
+     * before parsing to measure only this command's reads. */
+    cmd->overflow = 0;
+
     /* Parse handles */
     TPM2_Packet_ParseU32(cmd, &oldParentH);
     TPM2_Packet_ParseU32(cmd, &newParentH);
@@ -8031,6 +8035,12 @@ static TPM_RC FwCmd_Rewrap(FWTPM_CTX* ctx, TPM2_Packet* cmd,
         TPM2_Packet_ParseBytes(cmd, symSeedBuf, symSeedSz);
     }
 
+    /* Reject a command that declared more bytes than it carried; the missing
+     * duplicate suffix would otherwise be re-wrapped and disclosed. */
+    if (rc == 0 && cmd->overflow) {
+        rc = TPM_RC_SIZE;
+    }
+
     /* Look up oldParent (TPM_RH_NULL means no outer protection) */
     if (rc == 0 && oldParentH != TPM_RH_NULL) {
         oldParent = FwFindObject(ctx, oldParentH);
@@ -19539,12 +19549,11 @@ int FWTPM_ProcessCommand(FWTPM_CTX* ctx,
                 }
             }
             else if (authPolicy != NULL && authPolicy->size == 0 &&
-                    cmdAuths[pj].cmdHmacSize == 0) {
-                /* Per TPM 2.0 Part 1 Sec.19.7, a policy session can only
-                 * authorize an entity whose authPolicy is non-empty.
-                 * When the entity has no authPolicy AND the session
-                 * supplied no HMAC, every downstream auth check would
-                 * be skipped — reject up front. */
+                    (cmdAuths[pj].cmdHmacSize == 0 ||
+                     (!pSess->isPasswordPolicy && !pSess->isAuthValuePolicy))) {
+                /* A policy session authorizes an empty-authPolicy entity only
+                 * via PolicyPassword or PolicyAuthValue; otherwise the entity
+                 * auth is excluded and an unbound/empty HMAC would authorize. */
             #ifdef DEBUG_WOLFTPM
                 printf("fwTPM: Policy session empty-HMAC rejected for "
                     "handle 0x%x without authPolicy (CC=0x%x)\n",

src/tpm2.c

@@ -590,6 +590,15 @@ static TPM_RC TPM2_TransmitCommand(TPM2_CTX* ctx, TPM2_Packet* packet,
     /* parse response header and extract the TPM response code */
     rc = TPM2_Packet_Parse(rc, packet);
 
+    /* Wipe request-tail bytes a shorter response did not overwrite, so
+     * plaintext auth values do not linger in the shared command buffer. Only
+     * on success: the command must survive a transport error for inspection. */
+    if (rc == TPM_RC_SUCCESS && packet->size >= 0 &&
+            (UINT32)packet->size < cmdSz) {
+        TPM2_ForceZero(packet->buf + packet->size,
+            cmdSz - (UINT32)packet->size);
+    }
+
     return rc;
 }
 #else
@@ -630,6 +639,16 @@ static TPM_RC TPM2_TransmitCommand(TPM2_CTX* ctx, TPM2_Packet* packet,
         break;
     }
 
+    /* Wipe request-tail bytes a shorter response did not overwrite, so
+     * plaintext auth values do not linger in the shared command buffer. Only
+     * after the final attempt, and only on success so the command survives a
+     * transport error for retry and inspection. */
+    if (rc == TPM_RC_SUCCESS && packet->size >= 0 &&
+            (UINT32)packet->size < cmdSz) {
+        TPM2_ForceZero(packet->buf + packet->size,
+            cmdSz - (UINT32)packet->size);
+    }
+
     return rc;
 }
 #endif /* WOLFTPM_NO_RETRY */
@@ -7648,8 +7667,14 @@ int TPM2_ParsePublic(TPM2B_PUBLIC* pub, byte* buf, word32 size, int* sizeUsed)
     packet.buf = buf;
     packet.pos = 0;
     packet.size = (int)size;
+    packet.overflow = 0;
 
     TPM2_Packet_ParsePublic(&packet, pub);
+
+    if (packet.overflow) {
+        *sizeUsed = 0;
+        return TPM_RC_SIZE;
+    }
     *sizeUsed = packet.pos;
 
     return TPM_RC_SUCCESS;

src/tpm2_tis.c

@@ -335,6 +335,7 @@ int TPM2_TIS_RequestLocalityEx(TPM2_CTX* ctx, int locality, int timeout)
 
 int TPM2_TIS_RequestLocality(TPM2_CTX* ctx, int timeout)
 {
+    int rc;
     int locality = WOLFTPM_LOCALITY_DEFAULT;
 #ifdef WOLFTPM_TIS_RESET_STALE_LOCALITY
     int l;
@@ -359,7 +360,12 @@ int TPM2_TIS_RequestLocality(TPM2_CTX* ctx, int timeout)
     }
 #endif /* WOLFTPM_TIS_RESET_STALE_LOCALITY */
 
-    return TPM2_TIS_RequestLocalityEx(ctx, locality, timeout);
+    rc = TPM2_TIS_RequestLocalityEx(ctx, locality, timeout);
+    /* RequestLocalityEx returns the granted locality (0-4) on success; status
+     * callers expect TPM_RC_SUCCESS, so map any granted locality onto it. */
+    if (rc >= 0 && rc <= WOLFTPM_LOCALITY_MAX)
+        rc = TPM_RC_SUCCESS;
+    return rc;
 }
 
 int TPM2_TIS_ReleaseLocality(TPM2_CTX* ctx, int locality)