tpm: add a Sandbox TPMv2.x driver
This driver can emulate all the basic functionalities of a TPMv2.x
chip and should behave like them during regular testing.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/tpm/tpm2_tis_sandbox.c b/drivers/tpm/tpm2_tis_sandbox.c
new file mode 100644
index 0000000..3240cc5
--- /dev/null
+++ b/drivers/tpm/tpm2_tis_sandbox.c
@@ -0,0 +1,625 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2018, Bootlin
+ * Author: Miquel Raynal <miquel.raynal@bootlin.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <tpm-v2.h>
+#include <asm/state.h>
+#include <asm/unaligned.h>
+#include <linux/crc8.h>
+
+/* Hierarchies */
+enum tpm2_hierarchy {
+ TPM2_HIERARCHY_LOCKOUT = 0,
+ TPM2_HIERARCHY_ENDORSEMENT,
+ TPM2_HIERARCHY_PLATFORM,
+ TPM2_HIERARCHY_NB,
+};
+
+/* Subset of supported capabilities */
+enum tpm2_capability {
+ TPM_CAP_TPM_PROPERTIES = 0x6,
+};
+
+/* Subset of supported properties */
+#define TPM2_PROPERTIES_OFFSET 0x0000020E
+
+enum tpm2_cap_tpm_property {
+ TPM2_FAIL_COUNTER = 0,
+ TPM2_PROP_MAX_TRIES,
+ TPM2_RECOVERY_TIME,
+ TPM2_LOCKOUT_RECOVERY,
+ TPM2_PROPERTY_NB,
+};
+
+#define SANDBOX_TPM_PCR_NB 1
+
+static const u8 sandbox_extended_once_pcr[] = {
+ 0xf5, 0xa5, 0xfd, 0x42, 0xd1, 0x6a, 0x20, 0x30,
+ 0x27, 0x98, 0xef, 0x6e, 0xd3, 0x09, 0x97, 0x9b,
+ 0x43, 0x00, 0x3d, 0x23, 0x20, 0xd9, 0xf0, 0xe8,
+ 0xea, 0x98, 0x31, 0xa9, 0x27, 0x59, 0xfb, 0x4b,
+};
+
+struct sandbox_tpm2 {
+ /* TPM internal states */
+ bool init_done;
+ bool startup_done;
+ bool tests_done;
+ /* TPM password per hierarchy */
+ char pw[TPM2_HIERARCHY_NB][TPM2_DIGEST_LEN + 1];
+ int pw_sz[TPM2_HIERARCHY_NB];
+ /* TPM properties */
+ u32 properties[TPM2_PROPERTY_NB];
+ /* TPM PCRs */
+ u8 pcr[SANDBOX_TPM_PCR_NB][TPM2_DIGEST_LEN];
+ /* TPM PCR extensions */
+ u32 pcr_extensions[SANDBOX_TPM_PCR_NB];
+};
+
+/*
+ * Check the tag validity depending on the command (authentication required or
+ * not). If authentication is required, check it is valid. Update the auth
+ * pointer to point to the next chunk of data to process if needed.
+ */
+static int sandbox_tpm2_check_session(struct udevice *dev, u32 command, u16 tag,
+ const u8 **auth,
+ enum tpm2_hierarchy *hierarchy)
+{
+ struct sandbox_tpm2 *tpm = dev_get_priv(dev);
+ u32 handle, auth_sz, session_handle;
+ u16 nonce_sz, pw_sz;
+ const char *pw;
+
+ switch (command) {
+ case TPM2_CC_STARTUP:
+ case TPM2_CC_SELF_TEST:
+ case TPM2_CC_GET_CAPABILITY:
+ case TPM2_CC_PCR_READ:
+ if (tag != TPM2_ST_NO_SESSIONS) {
+ printf("No session required for command 0x%x\n",
+ command);
+ return TPM2_RC_BAD_TAG;
+ }
+
+ return 0;
+
+ case TPM2_CC_CLEAR:
+ case TPM2_CC_HIERCHANGEAUTH:
+ case TPM2_CC_DAM_RESET:
+ case TPM2_CC_DAM_PARAMETERS:
+ case TPM2_CC_PCR_EXTEND:
+ if (tag != TPM2_ST_SESSIONS) {
+ printf("Session required for command 0x%x\n", command);
+ return TPM2_RC_AUTH_CONTEXT;
+ }
+
+ handle = get_unaligned_be32(*auth);
+ *auth += sizeof(handle);
+
+ /*
+ * PCR_Extend had a different protection mechanism and does not
+ * use the same standards as other commands.
+ */
+ if (command == TPM2_CC_PCR_EXTEND)
+ break;
+
+ switch (handle) {
+ case TPM2_RH_LOCKOUT:
+ *hierarchy = TPM2_HIERARCHY_LOCKOUT;
+ break;
+ case TPM2_RH_ENDORSEMENT:
+ if (command == TPM2_CC_CLEAR) {
+ printf("Endorsement hierarchy unsupported\n");
+ return TPM2_RC_AUTH_MISSING;
+ }
+ *hierarchy = TPM2_HIERARCHY_ENDORSEMENT;
+ break;
+ case TPM2_RH_PLATFORM:
+ *hierarchy = TPM2_HIERARCHY_PLATFORM;
+ break;
+ default:
+ printf("Wrong handle 0x%x\n", handle);
+ return TPM2_RC_VALUE;
+ }
+
+ break;
+
+ default:
+ printf("Command code not recognized: 0x%x\n", command);
+ return TPM2_RC_COMMAND_CODE;
+ }
+
+ auth_sz = get_unaligned_be32(*auth);
+ *auth += sizeof(auth_sz);
+
+ session_handle = get_unaligned_be32(*auth);
+ *auth += sizeof(session_handle);
+ if (session_handle != TPM2_RS_PW) {
+ printf("Wrong session handle 0x%x\n", session_handle);
+ return TPM2_RC_VALUE;
+ }
+
+ nonce_sz = get_unaligned_be16(*auth);
+ *auth += sizeof(nonce_sz);
+ if (nonce_sz) {
+ printf("Nonces not supported in Sandbox, aborting\n");
+ return TPM2_RC_HANDLE;
+ }
+
+ /* Ignore attributes */
+ *auth += sizeof(u8);
+
+ pw_sz = get_unaligned_be16(*auth);
+ *auth += sizeof(pw_sz);
+ if (auth_sz != (9 + nonce_sz + pw_sz)) {
+ printf("Authentication size (%d) do not match %d\n",
+ auth_sz, 9 + nonce_sz + pw_sz);
+ return TPM2_RC_SIZE;
+ }
+
+ /* No passwork is acceptable */
+ if (!pw_sz && !tpm->pw_sz[*hierarchy])
+ return TPM2_RC_SUCCESS;
+
+ /* Password is too long */
+ if (pw_sz > TPM2_DIGEST_LEN) {
+ printf("Password should not be more than %dB\n",
+ TPM2_DIGEST_LEN);
+ return TPM2_RC_AUTHSIZE;
+ }
+
+ pw = (const char *)*auth;
+ *auth += pw_sz;
+
+ /* Password is wrong */
+ if (pw_sz != tpm->pw_sz[*hierarchy] ||
+ strncmp(pw, tpm->pw[*hierarchy], tpm->pw_sz[*hierarchy])) {
+ printf("Authentication failed: wrong password.\n");
+ return TPM2_RC_BAD_AUTH;
+ }
+
+ return TPM2_RC_SUCCESS;
+}
+
+static int sandbox_tpm2_check_readyness(struct udevice *dev, int command)
+{
+ struct sandbox_tpm2 *tpm = dev_get_priv(dev);
+
+ switch (command) {
+ case TPM2_CC_STARTUP:
+ if (!tpm->init_done || tpm->startup_done)
+ return TPM2_RC_INITIALIZE;
+
+ break;
+ case TPM2_CC_GET_CAPABILITY:
+ if (!tpm->init_done || !tpm->startup_done)
+ return TPM2_RC_INITIALIZE;
+
+ break;
+ case TPM2_CC_SELF_TEST:
+ if (!tpm->startup_done)
+ return TPM2_RC_INITIALIZE;
+
+ break;
+ default:
+ if (!tpm->tests_done)
+ return TPM2_RC_NEEDS_TEST;
+
+ break;
+ }
+
+ return 0;
+}
+
+static int sandbox_tpm2_fill_buf(u8 **recv, size_t *recv_len, u16 tag, u32 rc)
+{
+ *recv_len = sizeof(tag) + sizeof(u32) + sizeof(rc);
+
+ /* Write tag */
+ put_unaligned_be16(tag, *recv);
+ *recv += sizeof(tag);
+
+ /* Write length */
+ put_unaligned_be32(*recv_len, *recv);
+ *recv += sizeof(u32);
+
+ /* Write return code */
+ put_unaligned_be32(rc, *recv);
+ *recv += sizeof(rc);
+
+ /* Add trailing \0 */
+ *recv = '\0';
+
+ return 0;
+}
+
+static int sandbox_tpm2_extend(struct udevice *dev, int pcr_index,
+ const u8 *extension)
+{
+ struct sandbox_tpm2 *tpm = dev_get_priv(dev);
+ int i;
+
+ /* Only simulate the first extensions from all '0' with only '0' */
+ for (i = 0; i < TPM2_DIGEST_LEN; i++)
+ if (tpm->pcr[pcr_index][i] || extension[i])
+ return TPM2_RC_FAILURE;
+
+ memcpy(tpm->pcr[pcr_index], sandbox_extended_once_pcr,
+ TPM2_DIGEST_LEN);
+ tpm->pcr_extensions[pcr_index]++;
+
+ return 0;
+};
+
+static int sandbox_tpm2_xfer(struct udevice *dev, const u8 *sendbuf,
+ size_t send_size, u8 *recvbuf,
+ size_t *recv_len)
+{
+ struct sandbox_tpm2 *tpm = dev_get_priv(dev);
+ enum tpm2_hierarchy hierarchy = 0;
+ const u8 *sent = sendbuf;
+ u8 *recv = recvbuf;
+ u32 length, command, rc = 0;
+ u16 tag, mode, new_pw_sz;
+ u8 yes_no;
+ int i, j;
+
+ /* TPM2_GetProperty */
+ u32 capability, property, property_count;
+
+ /* TPM2_PCR_Read/Extend variables */
+ int pcr_index;
+ u64 pcr_map = 0;
+ u32 selections, pcr_nb;
+ u16 alg;
+ u8 pcr_array_sz;
+
+ tag = get_unaligned_be16(sent);
+ sent += sizeof(tag);
+
+ length = get_unaligned_be32(sent);
+ sent += sizeof(length);
+ if (length != send_size) {
+ printf("TPM2: Unmatching length, received: %ld, expected: %d\n",
+ send_size, length);
+ rc = TPM2_RC_SIZE;
+ sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ return 0;
+ }
+
+ command = get_unaligned_be32(sent);
+ sent += sizeof(command);
+ rc = sandbox_tpm2_check_readyness(dev, command);
+ if (rc) {
+ sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ return 0;
+ }
+
+ rc = sandbox_tpm2_check_session(dev, command, tag, &sent, &hierarchy);
+ if (rc) {
+ sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ return 0;
+ }
+
+ switch (command) {
+ case TPM2_CC_STARTUP:
+ mode = get_unaligned_be16(sent);
+ sent += sizeof(mode);
+ switch (mode) {
+ case TPM2_SU_CLEAR:
+ case TPM2_SU_STATE:
+ break;
+ default:
+ rc = TPM2_RC_VALUE;
+ }
+
+ tpm->startup_done = true;
+
+ sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ break;
+
+ case TPM2_CC_SELF_TEST:
+ yes_no = *sent;
+ sent += sizeof(yes_no);
+ switch (yes_no) {
+ case TPMI_YES:
+ case TPMI_NO:
+ break;
+ default:
+ rc = TPM2_RC_VALUE;
+ }
+
+ tpm->tests_done = true;
+
+ sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ break;
+
+ case TPM2_CC_CLEAR:
+ /* Reset this hierarchy password */
+ tpm->pw_sz[hierarchy] = 0;
+
+ /* Reset all password if thisis the PLATFORM hierarchy */
+ if (hierarchy == TPM2_HIERARCHY_PLATFORM)
+ for (i = 0; i < TPM2_HIERARCHY_NB; i++)
+ tpm->pw_sz[i] = 0;
+
+ /* Reset the properties */
+ for (i = 0; i < TPM2_PROPERTY_NB; i++)
+ tpm->properties[i] = 0;
+
+ /* Reset the PCRs and their number of extensions */
+ for (i = 0; i < SANDBOX_TPM_PCR_NB; i++) {
+ tpm->pcr_extensions[i] = 0;
+ for (j = 0; j < TPM2_DIGEST_LEN; j++)
+ tpm->pcr[i][j] = 0;
+ }
+
+ sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ break;
+
+ case TPM2_CC_HIERCHANGEAUTH:
+ new_pw_sz = get_unaligned_be16(sent);
+ sent += sizeof(new_pw_sz);
+ if (new_pw_sz > TPM2_DIGEST_LEN) {
+ rc = TPM2_RC_SIZE;
+ } else if (new_pw_sz) {
+ tpm->pw_sz[hierarchy] = new_pw_sz;
+ memcpy(tpm->pw[hierarchy], sent, new_pw_sz);
+ sent += new_pw_sz;
+ }
+
+ sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ break;
+
+ 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) {
+ rc = TPM2_RC_HANDLE;
+ return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ }
+
+ /* Write tag */
+ put_unaligned_be16(tag, recv);
+ recv += sizeof(tag);
+
+ /* Ignore length for now */
+ recv += sizeof(u32);
+
+ /* Write return code */
+ put_unaligned_be32(rc, recv);
+ recv += sizeof(rc);
+
+ /* Tell there is more data to read */
+ *recv = TPMI_YES;
+ recv += sizeof(yes_no);
+
+ /* Repeat the capability */
+ 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);
+ }
+
+ /* Add trailing \0 */
+ *recv = '\0';
+
+ /* Write response length */
+ *recv_len = recv - recvbuf;
+ put_unaligned_be32(*recv_len, recvbuf + sizeof(tag));
+
+ break;
+
+ case TPM2_CC_DAM_PARAMETERS:
+ tpm->properties[TPM2_PROP_MAX_TRIES] = get_unaligned_be32(sent);
+ sent += sizeof(*tpm->properties);
+ tpm->properties[TPM2_RECOVERY_TIME] = get_unaligned_be32(sent);
+ sent += sizeof(*tpm->properties);
+ tpm->properties[TPM2_LOCKOUT_RECOVERY] = get_unaligned_be32(sent);
+ sent += sizeof(*tpm->properties);
+
+ sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ break;
+
+ case TPM2_CC_PCR_READ:
+ selections = get_unaligned_be32(sent);
+ sent += sizeof(selections);
+ if (selections != 1) {
+ printf("Sandbox cannot handle more than one PCR\n");
+ rc = TPM2_RC_VALUE;
+ return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ }
+
+ alg = get_unaligned_be16(sent);
+ sent += sizeof(alg);
+ if (alg != TPM2_ALG_SHA256) {
+ printf("Sandbox TPM only handle SHA256 algorithm\n");
+ rc = TPM2_RC_VALUE;
+ return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ }
+
+ pcr_array_sz = *sent;
+ sent += sizeof(pcr_array_sz);
+ if (!pcr_array_sz || pcr_array_sz > 8) {
+ printf("Sandbox TPM cannot handle so much PCRs\n");
+ rc = TPM2_RC_VALUE;
+ return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ }
+
+ for (i = 0; i < pcr_array_sz; i++)
+ pcr_map += (u64)sent[i] << (i * 8);
+
+ if (pcr_map >> SANDBOX_TPM_PCR_NB) {
+ printf("Sandbox TPM handles up to %d PCR(s)\n",
+ SANDBOX_TPM_PCR_NB);
+ rc = TPM2_RC_VALUE;
+ return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ }
+
+ if (pcr_map >> SANDBOX_TPM_PCR_NB) {
+ printf("Wrong PCR map.\n");
+ rc = TPM2_RC_VALUE;
+ return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ }
+
+ for (i = 0; i < SANDBOX_TPM_PCR_NB; i++)
+ if (pcr_map & BIT(i))
+ pcr_index = i;
+
+ /* Write tag */
+ put_unaligned_be16(tag, recv);
+ recv += sizeof(tag);
+
+ /* Ignore length for now */
+ recv += sizeof(u32);
+
+ /* Write return code */
+ put_unaligned_be32(rc, recv);
+ recv += sizeof(rc);
+
+ /* Number of extensions */
+ put_unaligned_be32(tpm->pcr_extensions[pcr_index], recv);
+ recv += sizeof(u32);
+
+ /* Copy the PCR */
+ memcpy(recv, tpm->pcr[pcr_index], TPM2_DIGEST_LEN);
+ recv += TPM2_DIGEST_LEN;
+
+ /* Add trailing \0 */
+ *recv = '\0';
+
+ /* Write response length */
+ *recv_len = recv - recvbuf;
+ put_unaligned_be32(*recv_len, recvbuf + sizeof(tag));
+
+ break;
+
+ case TPM2_CC_PCR_EXTEND:
+ /* Get the PCR index */
+ pcr_index = get_unaligned_be32(sendbuf + sizeof(tag) +
+ sizeof(length) +
+ sizeof(command));
+ if (pcr_index > SANDBOX_TPM_PCR_NB) {
+ printf("Sandbox TPM handles up to %d PCR(s)\n",
+ SANDBOX_TPM_PCR_NB);
+ rc = TPM2_RC_VALUE;
+ }
+
+ /* Check the number of hashes */
+ pcr_nb = get_unaligned_be32(sent);
+ sent += sizeof(pcr_nb);
+ if (pcr_nb != 1) {
+ printf("Sandbox cannot handle more than one PCR\n");
+ rc = TPM2_RC_VALUE;
+ return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ }
+
+ /* Check the hash algorithm */
+ alg = get_unaligned_be16(sent);
+ sent += sizeof(alg);
+ if (alg != TPM2_ALG_SHA256) {
+ printf("Sandbox TPM only handle SHA256 algorithm\n");
+ rc = TPM2_RC_VALUE;
+ return sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ }
+
+ /* Extend the PCR */
+ rc = sandbox_tpm2_extend(dev, pcr_index, sent);
+
+ sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ break;
+
+ default:
+ printf("TPM2 command %02x unknown in Sandbox\n", command);
+ rc = TPM2_RC_COMMAND_CODE;
+ sandbox_tpm2_fill_buf(&recv, recv_len, tag, rc);
+ }
+
+ return 0;
+}
+
+static int sandbox_tpm2_get_desc(struct udevice *dev, char *buf, int size)
+{
+ if (size < 15)
+ return -ENOSPC;
+
+ return snprintf(buf, size, "Sandbox TPM2.x");
+}
+
+static int sandbox_tpm2_open(struct udevice *dev)
+{
+ struct sandbox_tpm2 *tpm = dev_get_priv(dev);
+
+ if (tpm->init_done)
+ return -EIO;
+
+ tpm->init_done = true;
+
+ return 0;
+}
+
+static int sandbox_tpm2_probe(struct udevice *dev)
+{
+ struct sandbox_tpm2 *tpm = dev_get_priv(dev);
+ struct tpm_chip_priv *priv = dev_get_uclass_priv(dev);
+
+ memset(tpm, 0, sizeof(*tpm));
+
+ priv->pcr_count = 32;
+ priv->pcr_select_min = 2;
+
+ return 0;
+}
+
+static int sandbox_tpm2_close(struct udevice *dev)
+{
+ return 0;
+}
+
+static const struct tpm_ops sandbox_tpm2_ops = {
+ .open = sandbox_tpm2_open,
+ .close = sandbox_tpm2_close,
+ .get_desc = sandbox_tpm2_get_desc,
+ .xfer = sandbox_tpm2_xfer,
+};
+
+static const struct udevice_id sandbox_tpm2_ids[] = {
+ { .compatible = "sandbox,tpm2" },
+ { }
+};
+
+U_BOOT_DRIVER(sandbox_tpm2) = {
+ .name = "sandbox_tpm2",
+ .id = UCLASS_TPM,
+ .of_match = sandbox_tpm2_ids,
+ .ops = &sandbox_tpm2_ops,
+ .probe = sandbox_tpm2_probe,
+ .priv_auto_alloc_size = sizeof(struct sandbox_tpm2),
+};