/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nss.h"
#include "pk11pub.h"
#include <memory>

#include "gtest/gtest.h"

namespace nss_test {

const size_t kPmsSize = 48;
const size_t kMasterSecretSize = 48;
const size_t kPrfSeedSizeSha256 = 32;
const size_t kPrfSeedSizeTlsPrf = 36;

// This is not the right size for anything
const size_t kIncorrectSize = 17;

const uint8_t kPmsData[] = {
  0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
  0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,
  0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
  0x18,0x19,0x1a,0x1b,0x1c,0x1d,0x1e,0x1f,
  0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,
  0x28,0x29,0x2a,0x2b,0x2c,0x2d,0x2e,0x2f
};

const uint8_t kPrfSeed[] = {
  0xf0,0xf1,0xf2,0xf3,0xf4,0xf5,0xf6,0xf7,
  0xf8,0xf9,0xfa,0xfb,0xfc,0xfd,0xfe,0xff,
  0xe0,0xe1,0xe2,0xe3,0xe4,0xe5,0xe6,0xe7,
  0xe8,0xe9,0xea,0xeb,0xec,0xed,0xee,0xef,
  0xd0,0xd1,0xd2,0xd3
};

const uint8_t kExpectedOutputEmsSha256[] = {
  0x75,0xa7,0xa5,0x98,0xef,0xab,0x90,0xe7,
  0x7c,0x67,0x80,0xde,0xab,0x3a,0x11,0xf3,
  0x5d,0xb2,0xf8,0x47,0xff,0x09,0x01,0xec,
  0xf8,0x93,0x89,0xfc,0x98,0x2e,0x6e,0xf9,
  0x2c,0xf5,0x9b,0x04,0x04,0x6f,0xd7,0x28,
  0x6e,0xea,0xe3,0x83,0xc4,0x4a,0xff,0x03
};

const uint8_t kExpectedOutputEmsTlsPrf[] = {
  0x06,0xbf,0x29,0x86,0x5d,0xf3,0x3e,0x38,
  0xfd,0xfa,0x91,0x10,0x2a,0x20,0xff,0xd6,
  0xb9,0xd5,0x72,0x5a,0x6d,0x42,0x20,0x16,
  0xde,0xa4,0xa0,0x51,0xe5,0x53,0xc1,0x28,
  0x04,0x99,0xbc,0xb1,0x2c,0x9d,0xe8,0x0b,
  0x18,0xa2,0x0e,0x48,0x52,0x8d,0x61,0x13
};

static unsigned char* toUcharPtr(const uint8_t* v) {
  return const_cast<unsigned char*>(
    static_cast<const unsigned char *>(v));
}

class TlsPrfTest : public ::testing::Test {
 public:
  TlsPrfTest()
    : params_({siBuffer, nullptr, 0})
    , pms_item_({siBuffer, toUcharPtr(kPmsData), kPmsSize})
    , key_mech_(0)
    , slot_(nullptr)
    , pms_(nullptr)
    , ms_(nullptr)
    , pms_version_({0, 0}) {}

  ~TlsPrfTest() {
    if (slot_) { PK11_FreeSlot(slot_); }
    ClearTempVars();
  }

  void ClearTempVars() {
    if (pms_) { PK11_FreeSymKey(pms_); }
    if (ms_)  { PK11_FreeSymKey(ms_);  }
  }

  void Init() {
    params_.type = siBuffer;

    pms_item_.type = siBuffer;
    pms_item_.data = const_cast<unsigned char*>(
                        static_cast<const unsigned char *>(kPmsData));

    slot_ = PK11_GetInternalSlot();
    ASSERT_NE(nullptr, slot_);
  }

  void CheckForError(CK_MECHANISM_TYPE hash_mech,
                     size_t seed_len,
                     size_t pms_len,
                     size_t output_len) {
    // Error tests don't depend on the derivation mechansim
    Inner(CKM_NSS_TLS_EXTENDED_MASTER_KEY_DERIVE, hash_mech,
          seed_len, pms_len, output_len, nullptr, nullptr);
  }

  void ComputeAndVerifyMs(CK_MECHANISM_TYPE derive_mech,
                          CK_MECHANISM_TYPE hash_mech,
                          CK_VERSION* version,
                          const uint8_t* expected) {
    // Infer seed length from mechanism
    int seed_len = 0;
    switch (hash_mech) {
      case CKM_TLS_PRF: seed_len = kPrfSeedSizeTlsPrf; break;
      case CKM_SHA256:  seed_len = kPrfSeedSizeSha256; break;
      default:          ASSERT_TRUE(false);
    }

    Inner(derive_mech, hash_mech, seed_len,
          kPmsSize, 0, version, expected);
  }


  // Set output == nullptr to test when errors occur
  void Inner(
      CK_MECHANISM_TYPE derive_mech,
      CK_MECHANISM_TYPE hash_mech,
      size_t seed_len,
      size_t pms_len,
      size_t output_len,
      CK_VERSION* version,
      const uint8_t* expected) {
    ClearTempVars();

    // Infer the key mechanism from the hash type
    switch (hash_mech) {
      case CKM_TLS_PRF: key_mech_ = CKM_TLS_KEY_AND_MAC_DERIVE; break;
      case CKM_SHA256:  key_mech_ = CKM_NSS_TLS_KEY_AND_MAC_DERIVE_SHA256; break;
      default:          ASSERT_TRUE(false);
    }

    // Import the params
    CK_NSS_TLS_EXTENDED_MASTER_KEY_DERIVE_PARAMS master_params = {
      hash_mech,
      toUcharPtr(kPrfSeed),
      static_cast<CK_ULONG>(seed_len),
      version
    };
    params_.data = reinterpret_cast<unsigned char*>(&master_params);
    params_.len = sizeof(master_params);

    // Import the PMS
    pms_item_.len = pms_len;
    pms_ = PK11_ImportSymKey(slot_, derive_mech, PK11_OriginUnwrap,
                            CKA_DERIVE, &pms_item_, NULL);
    ASSERT_NE(nullptr, pms_);


    // Compute the EMS
    ms_ = PK11_DeriveWithFlags(pms_, derive_mech, &params_, key_mech_,
        CKA_DERIVE, output_len, CKF_SIGN | CKF_VERIFY);

    // Verify the EMS has the expected value (null or otherwise)
    if (!expected) {
      EXPECT_EQ(nullptr, ms_);
    } else {
      ASSERT_NE(nullptr, ms_);

      SECStatus rv = PK11_ExtractKeyValue(ms_);
      ASSERT_EQ(SECSuccess, rv);

      SECItem *msData = PK11_GetKeyData(ms_);
      ASSERT_NE(nullptr, msData);

      ASSERT_EQ(kMasterSecretSize, msData->len);
      EXPECT_EQ(0,
                memcmp(msData->data, expected, kMasterSecretSize));
    }
  }

 protected:
  SECItem params_;
  SECItem pms_item_;
  CK_MECHANISM_TYPE key_mech_;
  PK11SlotInfo *slot_;
  PK11SymKey *pms_;
  PK11SymKey *ms_;
  CK_VERSION pms_version_;
};

TEST_F(TlsPrfTest, ExtendedMsParamErr) {
  Init();

  // This should fail; it's the correct set from which the below are derived
  // CheckForError(CKM_NSS_TLS_EXTENDED_MASTER_KEY_DERIVE, CKM_TLS_PRF, kPrfSeedSizeTlsPrf, kPmsSize, 0);

  // Output key size != 0, SSL3_MASTER_SECRET_LENGTH
  CheckForError(CKM_TLS_PRF, kPrfSeedSizeTlsPrf, kPmsSize, kIncorrectSize);

  // not-DH && pms size != SSL3_PMS_LENGTH
  CheckForError(CKM_TLS_PRF, kPrfSeedSizeTlsPrf, kIncorrectSize, 0);

  // CKM_TLS_PRF && seed length != MD5_LENGTH + SHA1_LENGTH
  CheckForError(CKM_TLS_PRF, kIncorrectSize, kPmsSize, 0);

  // !CKM_TLS_PRF && seed length != hash output length
  CheckForError(CKM_SHA256, kIncorrectSize, kPmsSize, 0);
}

// Test matrix:
//
//            DH  RSA
//  TLS_PRF   1   2
//  SHA256    3   4
TEST_F(TlsPrfTest, ExtendedMsDhTlsPrf) {
  Init();
  ComputeAndVerifyMs(CKM_NSS_TLS_EXTENDED_MASTER_KEY_DERIVE_DH,
                     CKM_TLS_PRF,
                     nullptr,
                     kExpectedOutputEmsTlsPrf);
}

TEST_F(TlsPrfTest, ExtendedMsRsaTlsPrf) {
  Init();
  ComputeAndVerifyMs(CKM_NSS_TLS_EXTENDED_MASTER_KEY_DERIVE,
                     CKM_TLS_PRF,
                     &pms_version_,
                     kExpectedOutputEmsTlsPrf);
  EXPECT_EQ(0, pms_version_.major);
  EXPECT_EQ(1, pms_version_.minor);
}


TEST_F(TlsPrfTest, ExtendedMsDhSha256) {
  Init();
  ComputeAndVerifyMs(CKM_NSS_TLS_EXTENDED_MASTER_KEY_DERIVE_DH,
                     CKM_SHA256,
                     nullptr,
                     kExpectedOutputEmsSha256);
}

TEST_F(TlsPrfTest, ExtendedMsRsaSha256) {
  Init();
  ComputeAndVerifyMs(CKM_NSS_TLS_EXTENDED_MASTER_KEY_DERIVE,
                     CKM_SHA256,
                     &pms_version_,
                     kExpectedOutputEmsSha256);
  EXPECT_EQ(0, pms_version_.major);
  EXPECT_EQ(1, pms_version_.minor);
}

}  // namespace nss_test