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Fix v185 fwtpm complaince issue with auth entry #566

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Merged
dgarske merged 1 commit into from
Aug 10, 2026
Merged

Fix v185 fwtpm complaince issue with auth entry #566

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23 changes: 23 additions & 0 deletions src/fwtpm/fwtpm_command.c
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Original file line number Diff line number Diff line change
Expand Up @@ -16669,6 +16669,10 @@ int FWTPM_ProcessCommand(FWTPM_CTX* ctx,
cpStart = authEnd; /* cpBuffer starts after auth area */
}
}
else if (entry->authHandleCnt > 0) {
/* SESSIONS command missing its authorizationSize field. */
rc = TPM_RC_COMMAND_SIZE;
}

/* Restore position for handler (before decryption, after HMAC check) */
cmdPkt.pos = savedPos;
Expand All @@ -16681,6 +16685,25 @@ int FWTPM_ProcessCommand(FWTPM_CTX* ctx,
return TPM_RC_SUCCESS;
}

/* A SESSIONS command must supply an auth entry for each @auth handle
* (TPM 2.0 Part 1 Sec.19). */
if (entry->authHandleCnt > 0 && cmdAuthCnt < (int)entry->authHandleCnt) {
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*rspSize = FwBuildErrorResponse(rspBuf, rspCap,
TPM_ST_NO_SESSIONS, TPM_RC_AUTH_MISSING);
return TPM_RC_SUCCESS;
}

/* A trial session builds a policy digest but authorizes nothing
* (TPM 2.0 Part 1 Sec.19.3), so it cannot fill a required auth slot. */
for (pj = 0; pj < cmdAuthCnt && pj < (int)entry->authHandleCnt; pj++) {
if (cmdAuths[pj].sess != NULL &&
cmdAuths[pj].sess->sessionType == TPM_SE_TRIAL) {
*rspSize = FwBuildErrorResponse(rspBuf, rspCap,
TPM_ST_NO_SESSIONS, TPM_RC_AUTH_TYPE);
return TPM_RC_SUCCESS;
}
}

/* Policy digest validation: for policy sessions authorizing access to
* entities with an authPolicy, verify session policyDigest matches.
* Per TPM 2.0 spec Part 1, Section 19.7.1: "A policy session can only
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112 changes: 112 additions & 0 deletions tests/fwtpm_unit_tests.c
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Original file line number Diff line number Diff line change
Expand Up @@ -9099,6 +9099,114 @@ static void test_fwtpm_clear_no_sessions_returns_auth_missing(void)
fwtpm_pass("Clear NO_SESSIONS (AUTH_MISSING):", 0);
}

/* A TPM_ST_SESSIONS command that supplies no auth entry for an @auth handle
* must be rejected with TPM_RC_AUTH_MISSING (TPM 2.0 Part 1 Sec.19). */
static void test_fwtpm_sessions_empty_autharea_rejected(void)
{
FWTPM_CTX ctx;
int rc, rspSize, pos;

memset(&ctx, 0, sizeof(ctx));
AssertIntEQ(fwtpm_test_startup(&ctx), 0);

pos = 0;
PutU16BE(gCmd + pos, TPM_ST_SESSIONS); pos += 2;
PutU32BE(gCmd + pos, 0); pos += 4;
PutU32BE(gCmd + pos, TPM_CC_Clear); pos += 4;
PutU32BE(gCmd + pos, TPM_RH_PLATFORM); pos += 4;
PutU32BE(gCmd + pos, 0); pos += 4; /* authAreaSz = 0, no auth entries */
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PutU32BE(gCmd + 2, (UINT32)pos);
rspSize = 0;
rc = FWTPM_ProcessCommand(&ctx, gCmd, pos, gRsp, &rspSize, 0);
AssertIntEQ(rc, TPM_RC_SUCCESS);
AssertIntEQ(GetRspRC(gRsp), TPM_RC_AUTH_MISSING);

FWTPM_Cleanup(&ctx);
fwtpm_pass("Clear SESSIONS empty auth area (AUTH_MISSING):", 0);
}

/* A trial session authorizes nothing, so naming one in a required auth slot
* must be rejected with TPM_RC_AUTH_TYPE. */
static void test_fwtpm_sessions_trial_in_auth_slot_rejected(void)
{
FWTPM_CTX ctx;
int rspSize, pos;
UINT32 trialH;

memset(&ctx, 0, sizeof(ctx));
AssertIntEQ(fwtpm_test_startup(&ctx), 0);
trialH = StartSessionHelper(&ctx, TPM_SE_TRIAL);
AssertIntNE(trialH, 0);

pos = 0;
PutU16BE(gCmd + pos, TPM_ST_SESSIONS); pos += 2;
PutU32BE(gCmd + pos, 0); pos += 4;
PutU32BE(gCmd + pos, TPM_CC_Clear); pos += 4;
PutU32BE(gCmd + pos, TPM_RH_PLATFORM); pos += 4;
PutU32BE(gCmd + pos, 9); pos += 4; /* authAreaSz */
PutU32BE(gCmd + pos, trialH); pos += 4; /* sessionHandle */
PutU16BE(gCmd + pos, 0); pos += 2; /* nonceSize */
gCmd[pos++] = 0; /* attributes */
PutU16BE(gCmd + pos, 0); pos += 2; /* hmacSize */
PutU32BE(gCmd + 2, (UINT32)pos);
rspSize = 0;
FWTPM_ProcessCommand(&ctx, gCmd, pos, gRsp, &rspSize, 0);
AssertIntEQ(GetRspRC(gRsp), TPM_RC_AUTH_TYPE);

FWTPM_Cleanup(&ctx);
fwtpm_pass("Clear SESSIONS trial session (AUTH_TYPE):", 0);
}

/* A command with two @auth handles that supplies only one auth entry must be
* rejected with TPM_RC_AUTH_MISSING. */
static void test_fwtpm_sessions_short_authcount_rejected(void)
{
FWTPM_CTX ctx;
int rspSize, pos;

memset(&ctx, 0, sizeof(ctx));
AssertIntEQ(fwtpm_test_startup(&ctx), 0);

pos = 0;
PutU16BE(gCmd + pos, TPM_ST_SESSIONS); pos += 2;
PutU32BE(gCmd + pos, 0); pos += 4;
PutU32BE(gCmd + pos, TPM_CC_EventSequenceComplete); pos += 4;
PutU32BE(gCmd + pos, 0x80000000); pos += 4; /* handle 1 */
PutU32BE(gCmd + pos, TPM_RH_PLATFORM); pos += 4; /* handle 2 */
pos = AppendPwAuth(gCmd, pos, NULL, 0); /* single auth entry */
PutU32BE(gCmd + 2, (UINT32)pos);
rspSize = 0;
FWTPM_ProcessCommand(&ctx, gCmd, pos, gRsp, &rspSize, 0);
AssertIntEQ(GetRspRC(gRsp), TPM_RC_AUTH_MISSING);

FWTPM_Cleanup(&ctx);
fwtpm_pass("SESSIONS two-auth one-entry (AUTH_MISSING):", 0);
}

/* A SESSIONS command that ends before its authorizationSize field is malformed
* and must be reported as TPM_RC_COMMAND_SIZE, not an auth error. */
static void test_fwtpm_sessions_missing_authsize_command_size(void)
{
FWTPM_CTX ctx;
int rspSize, pos;

memset(&ctx, 0, sizeof(ctx));
AssertIntEQ(fwtpm_test_startup(&ctx), 0);

pos = 0;
PutU16BE(gCmd + pos, TPM_ST_SESSIONS); pos += 2;
PutU32BE(gCmd + pos, 0); pos += 4;
PutU32BE(gCmd + pos, TPM_CC_Clear); pos += 4;
PutU32BE(gCmd + pos, TPM_RH_PLATFORM); pos += 4; /* no authorizationSize */
PutU32BE(gCmd + 2, (UINT32)pos);
rspSize = 0;
FWTPM_ProcessCommand(&ctx, gCmd, pos, gRsp, &rspSize, 0);
AssertIntEQ(GetRspRC(gRsp), TPM_RC_COMMAND_SIZE);

FWTPM_Cleanup(&ctx);
fwtpm_pass("SESSIONS missing authSize (COMMAND_SIZE):", 0);
}

static void test_fwtpm_change_eps(void)
{
FWTPM_CTX ctx;
Expand Down Expand Up @@ -11361,6 +11469,10 @@ int fwtpm_unit_tests(int argc, char *argv[])
test_fwtpm_change_eps();
test_fwtpm_change_pps();
test_fwtpm_clear_no_sessions_returns_auth_missing();
test_fwtpm_sessions_empty_autharea_rejected();
test_fwtpm_sessions_trial_in_auth_slot_rejected();
test_fwtpm_sessions_short_authcount_rejected();
test_fwtpm_sessions_missing_authsize_command_size();
test_fwtpm_clear();

printf("\nAll fwTPM unit tests passed!\n");
Expand Down
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