Add function for generating validation signatures.

src/trusted/validator/caching/validation_caching_test.cc

+/*
+ * Copyright (c) 2012 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gtest/gtest.h"
+
+#include <openssl/crypto/sha/sha.h>
+#include "native_client/src/trusted/validator/caching/hashing_interface.h"
+#include "native_client/src/trusted/validator/caching/validation_signature.h"
+
+void * TestHashCreate(const unsigned char *key, const unsigned int length) {

[bsy, 2012/02/22 01:43:35]

either "void* TestHashCreate" or "void *TestHashCreate" so it doesn't look like
multiplication.

[Nick Bray (chromium), 2012/02/22 03:07:28]

Done.

+  SHA256_CTX * ctx = (SHA256_CTX *) malloc(sizeof(SHA256_CTX));
+  SHA256_Init(ctx);
+  // Peturb the hash with the key - unique keys ensure unique signatures.
+  // TODO(ncbray) full HMAC
+  SHA256_Update(ctx, key, length);
+  return ctx;
+}
+
+void TestHashUpdate(void *ctx, const unsigned char *data,
+                     const unsigned int length) {
+  SHA256_Update((SHA256_CTX *) ctx, data, length);
+}
+
+void TestHashEnd(void *ctx, unsigned char *data, unsigned int *length,
+                  const unsigned int max_length) {
+  unsigned char buffer[SHA256_DIGEST_LENGTH];
+  unsigned int actual_length = SHA256_DIGEST_LENGTH;
+  if (max_length < actual_length)
+    actual_length = max_length;
+  SHA256_Final(buffer, (SHA256_CTX *) ctx);
+  memcpy(data, buffer, actual_length);
+  *length = actual_length;
+  free((SHA256_CTX *) ctx);
+}
+
+void InitTestHashingInterface(HashingInterface *hashing) {
+  hashing->create = &TestHashCreate;
+  hashing->update = &TestHashUpdate;
+  hashing->end = &TestHashEnd;
+}
+
+const unsigned char *code = (const unsigned char*) "foo bar!";
+const unsigned char *code_alt = (const unsigned char*) "barred!!";
+unsigned int code_length = 8;
+
+class ValidationCachingTests : public ::testing::Test {
+ protected:
+  HashingInterface hashing;
+  ValidationInfo info1;
+  ValidationInfo info2;
+  NaClCPUFeatures cpu_features1;
+  NaClCPUFeatures cpu_features2;
+  ValidationSignature sig1;
+  ValidationSignature sig2;
+
+  void SetUp() {
+    InitTestHashingInterface(&hashing);
+    initInfo(&info1, &cpu_features1);
+    initInfo(&info2, &cpu_features2);
+    memset(&sig1, 0, sizeof(ValidationSignature));
+    memset(&sig2, 0, sizeof(ValidationSignature));
+  }
+
+  void initInfo(ValidationInfo *info, NaClCPUFeatures *cpu_features) {
+    info->key = (unsigned char *) "a man a plan a canal panama";
+    info->key_length = 27;
+    info->isa = "x86-32";
+    info->version = "hello";
+    info->cpu_features = cpu_features;
+    NaClSetAllCPUFeatures(cpu_features);
+  }
+
+  void GetSig(ValidationInfo *info, const unsigned char *code,
+              unsigned int code_length, ValidationSignature *sig) {
+    GetValidationSignature(&hashing, info, code, code_length, sig);
+  }
+
+  // For debugging.
+  void printSig(ValidationSignature *sig) {
+    for (unsigned int i = 0; i < sig->length; i++) {
+      printf("%2.2x ", sig->data[i]);
+    }
+    printf("\n");
+  }
+
+  void checkSanity(ValidationSignature *sig1, ValidationSignature *sig2) {
+    // printSig(sig1);
+    // printSig(sig2);
+    EXPECT_GE(sig1->length, (unsigned int) 16);
+    EXPECT_LE(sig1->length, (unsigned int) VALIDATION_SIGNATURE_MAX_LENGTH);
+    ASSERT_EQ(sig1->length, sig2->length);
+  }
+
+  void expectDifferent(ValidationSignature *sig1, ValidationSignature *sig2) {
+    checkSanity(sig1, sig2);
+    ASSERT_NE(0, memcmp(sig1->data, sig2->data, sig1->length));
+  }
+
+  void expectSame(ValidationSignature *sig1, ValidationSignature *sig2) {
+    checkSanity(sig1, sig2);
+    ASSERT_EQ(0, memcmp(sig1->data, sig2->data, sig1->length));
+  }
+};
+
+TEST_F(ValidationCachingTests, SetupSanity) {
+  ASSERT_EQ(0, memcmp(&sig1, &sig2, sizeof(ValidationSignature)));
+}
+
+// Make sure the signature is repeatable.
+TEST_F(ValidationCachingTests, Identical) {
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code, code_length, &sig2);
+  expectSame(&sig1, &sig2);
+}
+
+// Make sure every byte of the signature is written.
+TEST_F(ValidationCachingTests, TotalOverwrite) {
+  memset(&sig1, 0x33, sizeof(ValidationSignature));
+  memset(&sig2, 0x55, sizeof(ValidationSignature));
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code, code_length, &sig2);
+  expectSame(&sig1, &sig2);
+}
+
+// Make sure the signature generation obeys null termination for strings.
+TEST_F(ValidationCachingTests, VersionStringTermination) {
+  info1.version = "a\0b";
+  info2.version = "a\0c";
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code, code_length, &sig2);
+  expectSame(&sig1, &sig2);
+}
+
+// Make sure changing a single input byte changes the signature.
+TEST_F(ValidationCachingTests, PeturbVersion) {
+  info2.version = "hell!";
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code, code_length, &sig2);
+  expectDifferent(&sig1, &sig2);
+
+  info2.version = "yello";
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code, code_length, &sig2);
+  expectDifferent(&sig1, &sig2);
+}
+
+TEST_F(ValidationCachingTests, PeturbISA) {
+  info2.isa = "x86-64";
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code, code_length, &sig2);
+  expectDifferent(&sig1, &sig2);
+}
+
+TEST_F(ValidationCachingTests, PeturbCode) {
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code_alt, code_length, &sig2);
+  expectDifferent(&sig1, &sig2);
+}
+
+TEST_F(ValidationCachingTests, PeturbCodeLength) {
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code, code_length-1, &sig2);
+  expectDifferent(&sig1, &sig2);
+}
+
+TEST_F(ValidationCachingTests, PeturbKey) {
+  info2.key = (unsigned char *) "xxxxxxxxxxxxxxxxxxxxxxxxxxx";
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code, code_length, &sig2);
+  expectDifferent(&sig1, &sig2);
+}
+
+TEST_F(ValidationCachingTests, PeturbKeyLength) {
+  info2.key_length -= 1;
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code, code_length, &sig2);
+  expectDifferent(&sig1, &sig2);
+}
+
+TEST_F(ValidationCachingTests, PeturbCPUFeatures) {
+  NaClClearCPUFeatures(info2.cpu_features);
+  GetSig(&info1, code, code_length, &sig1);
+  GetSig(&info2, code, code_length, &sig2);
+  expectDifferent(&sig1, &sig2);
+}
+
+// Test driver function.
+int main(int argc, char *argv[]) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}