Vboot Reference: Add functions to verify signed kernel images.

src/platform/vboot_reference/tests/kernel_image_tests.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.
+ *
+ * Tests for kernel image library.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "file_keys.h"
+#include "kernel_image.h"
+#include "rsa_utility.h"
+#include "sha_utility.h"
+#include "utility.h"
+
+/* ANSI Color coding sequences. */
+#define COL_GREEN "\e[1;32m"
+#define COL_RED "\e[0;31m"
+#define COL_STOP "\e[m"
+
+int TEST_EQ(int result, int expected_result, char* testname) {
+  if (result == expected_result) {
+    fprintf(stderr, "%s Test " COL_GREEN " PASSED\n" COL_STOP, testname);
+    return 1;
+  }
+  else {
+    fprintf(stderr, "%s Test " COL_RED " FAILED\n" COL_STOP, testname);
+    return 0;
+  }
+}
+
+KernelImage* GenerateTestKernelImage(int firmware_sign_algorithm,
+                                     int kernel_sign_algorithm,
+                                     uint8_t* kernel_sign_key,
+                                     int kernel_key_version,
+                                     int kernel_version,
+                                     int kernel_len) {
+  KernelImage* image = KernelImageNew();
+  uint8_t* header_checksum;
+  DigestContext ctx;
+
+  Memcpy(image->magic, KERNEL_MAGIC, KERNEL_MAGIC_SIZE);
+  image->header_version = 1;
+  image->firmware_sign_algorithm = firmware_sign_algorithm;
+  image->kernel_sign_algorithm = kernel_sign_algorithm;
+  image->kernel_key_version = kernel_key_version;
+  image->kernel_sign_key = (uint8_t*) Malloc(
+      RSAProcessedKeySize(image->kernel_sign_algorithm));
+  Memcpy(image->kernel_sign_key, kernel_sign_key,
+         RSAProcessedKeySize(image->kernel_sign_algorithm));
+
+  /* Update correct header length. */
+  image->header_len = (sizeof(image->header_version) +
+                       sizeof(image->header_len) +
+                       sizeof(image->firmware_sign_algorithm) +
+                       sizeof(image->kernel_sign_algorithm) +
+                       RSAProcessedKeySize(image->kernel_sign_algorithm) +
+                       sizeof(image->kernel_key_version) +
+                       sizeof(image->header_checksum));
+
+  /* Calculate SHA-512 digest on header and populate header_checksum. */
+  DigestInit(&ctx, SHA512_DIGEST_ALGORITHM);
+  DigestUpdate(&ctx, (uint8_t*) &image->header_version,
+               sizeof(image->header_version));
+  DigestUpdate(&ctx, (uint8_t*) &image->header_len,
+               sizeof(image->header_len));
+  DigestUpdate(&ctx, (uint8_t*) &image->firmware_sign_algorithm,
+               sizeof(image->firmware_sign_algorithm));
+  DigestUpdate(&ctx, (uint8_t*) &image->kernel_sign_algorithm,
+               sizeof(image->kernel_sign_algorithm));
+  DigestUpdate(&ctx, (uint8_t*) &image->kernel_key_version,
+               sizeof(image->kernel_key_version));
+  DigestUpdate(&ctx, image->kernel_sign_key,
+               RSAProcessedKeySize(image->kernel_sign_algorithm));
+  header_checksum = DigestFinal(&ctx);
+  Memcpy(image->header_checksum, header_checksum, SHA512_DIGEST_SIZE);
+  Free(header_checksum);
+
+  /* Populate kernel options and data with dummy data. */
+  image->kernel_version = kernel_version;
+  image->options.version[0] = 1;
+  image->options.version[1] = 1;
+  image->options.kernel_len = kernel_len;
+  image->options.kernel_load_addr = 0;
+  image->options.kernel_entry_addr = 0;
+  image->kernel_key_signature = image->kernel_signature = NULL;
+  image->kernel_data = Malloc(kernel_len);
+  Memset(image->kernel_data, 'F', kernel_len);
+
+  return image;
+}
+
+#define DEV_MODE_ENABLED 1
+#define DEV_MODE_DISABLED 0
+
+/* Normal Kernel Blob Verification Tests. */
+int VerifyKernelTest(uint8_t* kernel_blob, uint8_t* firmware_key_blob) {
+  int success = 1;
+  if (!TEST_EQ(VerifyKernel(firmware_key_blob, kernel_blob, DEV_MODE_ENABLED),
+               VERIFY_KERNEL_SUCCESS,
+               "Normal Kernel Blob Verification (Dev Mode)"))
+    success = 0;
+
+  if (!TEST_EQ(VerifyKernel(firmware_key_blob, kernel_blob, DEV_MODE_DISABLED),
+               VERIFY_KERNEL_SUCCESS,
+               "Normal Kernel Blob Verification (Trusted)"))
+    success = 0;
+  return success;
+}
+
+
+/* Normal KernelImage Verification Tests. */
+int VerifyKernelImageTest(KernelImage* image,
+                          RSAPublicKey* firmware_key) {
+  int success = 1;
+  if (!TEST_EQ(VerifyKernelImage(firmware_key, image, DEV_MODE_ENABLED),
+               VERIFY_KERNEL_SUCCESS,
+               "Normal KernelImage Verification (Dev Mode)"))
+    success = 0;
+
+  if (!TEST_EQ(VerifyKernelImage(firmware_key, image, DEV_MODE_DISABLED),
+               VERIFY_KERNEL_SUCCESS,
+               "Normal KernelImage Verification (Trusted)"))
+    success = 0;
+  return success;
+}
+
+/* Tampered KernelImage Verification Tests. */
+int VerifyKernelImageTamperTest(KernelImage* image,
+                                RSAPublicKey* firmware_key) {
+  int success = 1;
+  fprintf(stderr, "[[Tampering with kernel config....]]\n");
+  image->options.kernel_load_addr = 0xFFFF;
+  if (!TEST_EQ(VerifyKernelImage(firmware_key, image, DEV_MODE_ENABLED),
+               VERIFY_KERNEL_CONFIG_SIGNATURE_FAILED,
+               "KernelImage Config Tamper Verification (Dev Mode)"))
+    success = 0;
+  if (!TEST_EQ(VerifyKernelImage(firmware_key, image, DEV_MODE_DISABLED),
+               VERIFY_KERNEL_CONFIG_SIGNATURE_FAILED,
+               "KernelImage Config Tamper Verification (Trusted)"))
+    success = 0;
+  image->options.kernel_load_addr = 0;
+
+  image->kernel_data[0] = 'T';
+  if (!TEST_EQ(VerifyKernelImage(firmware_key, image, DEV_MODE_ENABLED),
+               VERIFY_KERNEL_SIGNATURE_FAILED,
+               "KernelImage Tamper Verification (Dev Mode)"))
+    success = 0;
+  if (!TEST_EQ(VerifyKernelImage(firmware_key, image, DEV_MODE_DISABLED),
+               VERIFY_KERNEL_SIGNATURE_FAILED,
+               "KernelImage Tamper Verification (Trusted)"))
+    success = 0;
+  image->kernel_data[0] = 'F';
+
+
+  fprintf(stderr, "[[Tampering with kernel key signature...]]\n");
+  image->kernel_key_signature[0] = 0xFF;
+  image->kernel_key_signature[1] = 0x00;
+  if (!TEST_EQ(VerifyKernelImage(firmware_key, image, DEV_MODE_ENABLED),
+               VERIFY_KERNEL_SUCCESS,
+               "KernelImage Key Signature Tamper Verification (Dev Mode)"))
+    success = 0;
+  if (!TEST_EQ(VerifyKernelImage(firmware_key, image, DEV_MODE_DISABLED),
+               VERIFY_KERNEL_KEY_SIGNATURE_FAILED,
+               "KernelImage Key Signature Tamper Verification (Trusted)"))
+    success = 0;
+
+  return success;
+}
+
+int main(int argc, char* argv[]) {
+  uint32_t len;
+  uint8_t* kernel_sign_key_buf = NULL;
+  uint8_t* firmware_key_blob = NULL;
+  uint8_t* kernel_blob = NULL;
+  KernelImage* image = NULL;
+  RSAPublicKey* firmware_key = NULL;
+  int error_code = 1;
+  char* tmp_kernelblob_file = ".tmpKernelBlob";
+
+  if(argc != 7) {
+    fprintf(stderr, "Usage: %s <firmware signing algorithm> "  /* argv[1] */
+            "<kernel signing algorithm> "  /* argv[2] */
+            "<firmware key> "  /* argv[3] */
+            "<processed firmware pubkey> "  /* argv[4] */
+            "<kernel signing key> "  /* argv[5] */
+            "<processed kernel signing key>\n",  /* argv[6] */
+            argv[0]);
+    return -1;
+  }
+
+  /* Read verification keys and create a test image. */
+  firmware_key = RSAPublicKeyFromFile(argv[4]);
+  firmware_key_blob = BufferFromFile(argv[4], &len);
+  kernel_sign_key_buf = BufferFromFile(argv[6], &len);
+  if (!firmware_key || !kernel_sign_key_buf || !kernel_sign_key_buf) {
+    error_code = 1;
+    goto failure;
+  }
+
+  image = GenerateTestKernelImage(atoi(argv[1]),
+                                  atoi(argv[2]),
+                                  kernel_sign_key_buf,
+                                  1,  /* Kernel Key Version */
+                                  1,  /* Kernel Version */
+                                  1000);  /* Kernel Size */
+  if (!image) {
+    error_code = 1;
+    goto failure;
+  }
+
+  /* Generate and populate signatures. */
+  if (!AddKernelKeySignature(image, argv[3])) {
+    fprintf(stderr, "Couldn't create key signature.\n");
+    error_code = 1;
+    goto failure;
+  }
+
+  if (!AddKernelSignature(image, argv[5], image->kernel_sign_algorithm)) {
+    fprintf(stderr, "Couldn't create firmware and preamble signature.\n");
+    error_code = 1;
+    goto failure;
+  }
+
+  /* Generate a firmware binary blob from image.
+   *
+   * TODO(gauravsh): Add a function to directly generate a binary
+   * blob buffer from a KernelImage instead of indirectly writing to a file
+   * and reading it into a buffer.
+   */
+  if (!WriteKernelImage(tmp_kernelblob_file, image)) {
+    fprintf(stderr, "Couldn't create a temporary kernel blob file.\n");
+    error_code = 1;
+    goto failure;
+  }
+  kernel_blob = BufferFromFile(tmp_kernelblob_file, &len);
+
+  /* Test Kernel blob verify operations. */
+  if (!VerifyKernelTest(kernel_blob, firmware_key_blob))
+    error_code = 255;
+
+  /* Test KernelImage verify operations. */
+  if (!VerifyKernelImageTest(image, firmware_key))
+    error_code = 255;
+  if (!VerifyKernelImageTamperTest(image, firmware_key))
+    error_code = 255;
+
+failure:
+  Free(kernel_blob);
+  KernelImageFree(image);
+  Free(kernel_sign_key_buf);
+  Free(firmware_key_blob);
+  Free(firmware_key);
+
+  return error_code;
+}