Add tpm lite to vboot reference

firmware/stub/tpm_lite_stub.c

+/* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Stub implementations of utility functions which call their linux-specific
+ * equivalents.
+ */
+
+#define _STUB_IMPLEMENTATION_
+#include "tlcl.h"
+#include "tlcl_internal.h"
+#include "utility.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <tss/tcs.h>
+#include "tpmextras.h"
+#define TPM_DEVICE_PATH "/dev/tpm0"
+
+/* TODO: these functions should pass errors back rather than returning void */
+/* TODO: if the only callers to these are just wrappers, should just
+ * remove the wrappers and call us directly. */
+
+
+/* The file descriptor for the TPM device.
+ */
+static int tpm_fd = -1;
+
+
+/* Print |n| bytes from array |a|, with newlines.
+ */
+POSSIBLY_UNUSED static void PrintBytes(uint8_t* a, int n) {
+  int i;
+  for (i = 0; i < n; i++) {
+    VBDEBUG(("%02x ", a[i]));
+    if ((i + 1) % 16 == 0) {
+      VBDEBUG(("\n"));
+    }
+  }
+  if (i % 16 != 0) {
+    VBDEBUG(("\n"));
+  }
+}
+
+
+/* Executes a command on the TPM.
+ */
+static void TpmExecute(const uint8_t *in, const uint32_t in_len,
+                uint8_t *out, uint32_t *pout_len) {
+  uint8_t response[TPM_MAX_COMMAND_SIZE];
+  if (in_len <= 0) {
+    error("invalid command length %d\n", in_len);
+  } else if (tpm_fd < 0) {
+    error("the TPM device was not opened.  Forgot to call TlclLibInit?\n");
+  } else {
+    int n = write(tpm_fd, in, in_len);
+    if (n != in_len) {
+      error("write failure to TPM device: %s\n", strerror(errno));
+    }
+    n = read(tpm_fd, response, sizeof(response));
+    if (n == 0) {
+      error("null read from TPM device\n");
+    } else if (n < 0) {
+      error("read failure from TPM device: %s\n", strerror(errno));
+    } else {
+      if (n > *pout_len) {
+        error("TPM response too long for output buffer\n");
+      } else {
+        *pout_len = n;
+        Memcpy(out, response, n);
+      }
+    }
+  }
+}
+
+
+/* Gets the tag field of a TPM command.
+ */
+POSSIBLY_UNUSED static INLINE int TpmTag(uint8_t* buffer) {
+  uint16_t tag;
+  FromTpmUint16(buffer, &tag);
+  return (int) tag;
+}
+
+
+/* Gets the size field of a TPM command.
+ */
+POSSIBLY_UNUSED static INLINE int TpmResponseSize(const uint8_t* buffer) {
+  uint32_t size;
+  FromTpmUint32(buffer + sizeof(uint16_t), &size);
+  return (int) size;
+}
+
+
+void TlclStubInit(void) {
+  TlclOpenDevice();
+}
+
+
+void TlclCloseDevice(void) {
+  close(tpm_fd);
+  tpm_fd = -1;
+}
+
+
+void TlclOpenDevice(void) {
+  if (tpm_fd >= 0)
+    return;  /* Already open */
+
+  tpm_fd = open(TPM_DEVICE_PATH, O_RDWR);
+  if (tpm_fd < 0) {
+    error("cannot open TPM device %s: %s\n", TPM_DEVICE_PATH, strerror(errno));
+  }
+}
+
+
+void TlclStubSendReceive(uint8_t* request, int request_length,
+                         uint8_t* response, int max_length) {
+  /*
+   * In a real firmware implementation, this function should contain
+   * the equivalent API call for the firmware TPM driver which takes a
+   * raw sequence of bytes as input command and a pointer to the
+   * output buffer for putting in the results.
+   *
+   * For EFI firmwares, this can make use of the EFI TPM driver as
+   * follows (based on page 16, of TCG EFI Protocol Specs Version 1.20
+   * availaible from the TCG website):
+   *
+   * EFI_STATUS status;
+   * status = TcgProtocol->EFI_TCG_PASS_THROUGH_TO_TPM(TpmCommandSize(request),
+   *                                                   request,
+   *                                                   max_length,
+   *                                                   response);
+   * // Error checking depending on the value of the status above
+   */
+  uint32_t response_length = max_length;
+  int tag, response_tag;
+
+  struct timeval before, after;
+  gettimeofday(&before, NULL);
+  TpmExecute(request, request_length, response, &response_length);
+  gettimeofday(&after, NULL);
+
+#ifdef VBOOT_DEBUG
+  {
+    int x = request_length;
+    int y = response_length;
+    VBDEBUG(("request (%d bytes): ", x));
+    PrintBytes(request, 10);
+    PrintBytes(request + 10, x - 10);
+    VBDEBUG(("response (%d bytes): ", y));
+    PrintBytes(response, 10);
+    PrintBytes(response + 10, y - 10);
+    VBDEBUG(("execution time: %dms\n",
+            (int) ((after.tv_sec - before.tv_sec) * 1000 +
+                   (after.tv_usec - before.tv_usec) / 1000)));
+  }
+#endif
+
+  /* sanity checks */
+  tag = TpmTag(request);
+  response_tag = TpmTag(response);
+  assert(
+    (tag == TPM_TAG_RQU_COMMAND &&
+     response_tag == TPM_TAG_RSP_COMMAND) ||
+    (tag == TPM_TAG_RQU_AUTH1_COMMAND &&
+     response_tag == TPM_TAG_RSP_AUTH1_COMMAND) ||
+    (tag == TPM_TAG_RQU_AUTH2_COMMAND &&
+     response_tag == TPM_TAG_RSP_AUTH2_COMMAND));
+  assert(response_length == TpmResponseSize(response));
+}