////////////////////////////////////////////////////////////////////////////////
// Copyright 2016 Google LLC.
//
// This software is licensed under the terms defined in the Widevine Master
// License Agreement. For a copy of this agreement, please contact
// widevine-licensing@google.com.
////////////////////////////////////////////////////////////////////////////////

// Unit tests for the ecb_util functions.

#include <string>

#include "testing/gmock.h"
#include "testing/gunit.h"
#include "absl/strings/escaping.h"
#include "absl/strings/string_view.h"
#include "common/ecb_util.h"

namespace widevine {
namespace crypto_util {

TEST(CryptoUtilTest, TestEncrypt3DesEcb) {
  // Test vector generated by (Python):
  // c = M2Crypto.EVP.Cipher('des_ede3_ecb', '89abcdef0123456789abcdef',
  //                         iv='', op=1, padding=False)
  // (c.update('This is a test message. ')+c.final()).encode('hex')
  // TODO(user): find some Widevine test vectors and use those
  std::string key = "0123456789abcdef";
  std::string plain = "This is a test message. ";
  std::string cipher;
  std::string decrypted;
  EXPECT_TRUE(Encrypt3DesEcb(key, plain, &cipher));
  EXPECT_EQ("ae7c7accaf99a973e7f89bb7f6dc61a9aa9e226a5ba17376",
            absl::BytesToHexString(cipher));
  EXPECT_TRUE(Decrypt3DesEcb(key, cipher, &decrypted));
  EXPECT_EQ(plain, decrypted);
}

TEST(CryptoUtilTest, TestEncrypt3DesEcbFail) {
  // Verify that 3DES fails with invalid key or data size
  std::string badkey = "0123456789abcde";              // 15 bytes
  std::string badplain = "This is a test message.";    // 23 bytes
  std::string goodkey = "0123456789abcdef";            // 16 bytes
  std::string goodplain = "This is a test message. ";  // 24 bytes

  // Encryption failure should leave 'decrypted' as empty std::string
  std::string out = "Not empty";
  EXPECT_FALSE(Encrypt3DesEcb(badkey, goodplain, &out));
  EXPECT_TRUE(out.empty());

  out = "Not empty";
  EXPECT_FALSE(Decrypt3DesEcb(goodkey, badplain, &out));
  EXPECT_TRUE(out.empty());
}

TEST(CryptoUtilTest, TestEncryptAesEcb) {
  // Test vector generated by (Python):
  // c = M2Crypto.EVP.Cipher('aes_128_ecb', key, '', 1, padding=False)
  // encrypted = c.update(data) + c.final();
  // TODO(user): find some Widevine test vectors and use those
  std::string key = "0123456789abcdef";
  std::string plaintext = "This message has 32 bytes in it.";
  std::string encrypted;
  std::string decrypted;
  EXPECT_TRUE(EncryptAesEcb(key, plaintext, &encrypted));
  EXPECT_EQ("1f6a7d63e0645de25c56c6b39ba7723d640129d65f41e96b87be812bc94ad8a9",
            absl::BytesToHexString(encrypted));
  EXPECT_TRUE(DecryptAesEcb(key, encrypted, &decrypted));
  EXPECT_EQ(plaintext, decrypted);
}

TEST(CryptoUtilTest, TestEncryptAesEcbFail) {
  // Verify that EncryptAesEcb fails with invalid key or data size
  std::string badkey = "0123456789abcde";  // 15 bytes
  std::string badplain = "This message has 31 bytes in it";
  std::string goodkey = "0123456789abcdef";  // 16 bytes
  std::string goodplain = "This message has 32 bytes in it.";

  // Encryption failure should leave 'decrypted' as empty std::string
  std::string out = "Not empty";
  EXPECT_FALSE(EncryptAesEcb(badkey, goodplain, &out));
  EXPECT_TRUE(out.empty());

  out = "Not empty";
  EXPECT_FALSE(EncryptAesEcb(goodkey, badplain, &out));
  EXPECT_TRUE(out.empty());
}

}  // namespace crypto_util
}  // namespace widevine