[PATCH v4 4/6] tpm: sandbox: Update for needed TPM2 capabilities

Eddie James
2023-01-25T17:20:51Z

The driver needs to support getting the PCRs in the capabilities
command. Fix various other things and support the max number
of PCRs for TPM2.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
drivers/tpm/tpm2_tis_sandbox.c | 100 ++++++++++++++++++++++++---------
1 file changed, 72 insertions(+), 28 deletions(-)

diff --git a/drivers/tpm/tpm2_tis_sandbox.c b/drivers/tpm/tpm2_tis_sandbox.c
index dd94bdc31f..ea7fb5e3cb 100644
--- a/drivers/tpm/tpm2_tis_sandbox.c
+++ b/drivers/tpm/tpm2_tis_sandbox.c
@@ -22,11 +22,6 @@ enum tpm2_hierarchy {
TPM2_HIERARCHY_NB,
};

-/* Subset of supported capabilities */
-enum tpm2_capability {
- TPM_CAP_TPM_PROPERTIES = 0x6,
-};
-
/* Subset of supported properties */
#define TPM2_PROPERTIES_OFFSET 0x0000020E

@@ -38,7 +33,8 @@ enum tpm2_cap_tpm_property {
TPM2_PROPERTY_NB,
};

-#define SANDBOX_TPM_PCR_NB 1
+#define SANDBOX_TPM_PCR_NB TPM2_MAX_PCRS
+#define SANDBOX_TPM_PCR_SELECT_MAX ((SANDBOX_TPM_PCR_NB + 7) / 8)

/*
* Information about our TPM emulation. This is preserved in the sandbox
@@ -433,7 +429,7 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
int i, j;

/* TPM2_GetProperty */
- u32 capability, property, property_count;
+ u32 capability, property, property_count, val;

/* TPM2_PCR_Read/Extend variables */
int pcr_index = 0;
@@ -542,19 +538,32 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
case TPM2_CC_GET_CAPABILITY:
capability = get_unaligned_be32(sent);
sent += sizeof(capability);
- if (capability != TPM_CAP_TPM_PROPERTIES) {
- printf("Sandbox TPM only support TPM_CAPABILITIES\n");
- return TPM2_RC_HANDLE;
- }
-
property = get_unaligned_be32(sent);
sent += sizeof(property);
- property -= TPM2_PROPERTIES_OFFSET;
-
property_count = get_unaligned_be32(sent);
sent += sizeof(property_count);
- if (!property_count ||
- property + property_count > TPM2_PROPERTY_NB) {
+
+ switch (capability) {
+ case TPM2_CAP_PCRS:
+ break;
+ case TPM2_CAP_TPM_PROPERTIES:
+ if (!property_count) {
+ rc = TPM2_RC_HANDLE;
+ return sandbox_tpm2_fill_buf(recv, recv_len,
+ tag, rc);
+ }
+
+ if (property > TPM2_PROPERTIES_OFFSET &&
+ ((property - TPM2_PROPERTIES_OFFSET) +
+ property_count > TPM2_PROPERTY_NB)) {
+ rc = TPM2_RC_HANDLE;
+ return sandbox_tpm2_fill_buf(recv, recv_len,
+ tag, rc);
+ }
+ break;
+ default:
+ printf("Sandbox TPM2 only supports TPM2_CAP_PCRS or "
+ "TPM2_CAP_TPM_PROPERTIES\n");
rc = TPM2_RC_HANDLE;
return sandbox_tpm2_fill_buf(recv, recv_len, tag, rc);
}
@@ -578,18 +587,53 @@ static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
put_unaligned_be32(capability, recv);
recv += sizeof(capability);

- /* Give the number of properties that follow */
- put_unaligned_be32(property_count, recv);
- recv += sizeof(property_count);
-
- /* Fill with the properties */
- for (i = 0; i < property_count; i++) {
- put_unaligned_be32(TPM2_PROPERTIES_OFFSET + property +
- i, recv);
- recv += sizeof(property);
- put_unaligned_be32(tpm->properties[property + i],
- recv);
- recv += sizeof(property);
+ switch (capability) {
+ case TPM2_CAP_PCRS:
+ /* Give the number of algorithms supported - just SHA256 */
+ put_unaligned_be32(1, recv);
+ recv += sizeof(u32);
+
+ /* Give SHA256 algorithm */
+ put_unaligned_be16(TPM2_ALG_SHA256, recv);
+ recv += sizeof(u16);
+
+ /* Select the PCRs supported */
+ *recv = SANDBOX_TPM_PCR_SELECT_MAX;
+ recv++;
+
+ /* Activate all the PCR bits */
+ for (i = 0; i < SANDBOX_TPM_PCR_SELECT_MAX; ++i) {
+ *recv = 0xff;
+ recv++;
+ }
+ break;
+ case TPM2_CAP_TPM_PROPERTIES:
+ /* Give the number of properties that follow */
+ put_unaligned_be32(property_count, recv);
+ recv += sizeof(property_count);
+
+ /* Fill with the properties */
+ for (i = 0; i < property_count; i++) {
+ put_unaligned_be32(property + i, recv);
+ recv += sizeof(property);
+ if (property > TPM2_PROPERTIES_OFFSET) {
+ val = tpm->properties[(property -
+ TPM2_PROPERTIES_OFFSET) + i];
+ } else {
+ switch (property) {
+ case TPM2_PT_PCR_COUNT:
+ val = SANDBOX_TPM_PCR_NB;
+ break;
+ default:
+ val = 0xffffffff;
+ break;
+ }
+ }
+
+ put_unaligned_be32(val, recv);
+ recv += sizeof(property);
+ }
+ break;
}

/* Add trailing \0 */
--
2.31.1