/*
* (C) 2016 Philipp Weber
* (C) 2016 Daniel Neus
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include "tests.h"

#if defined(BOTAN_HAS_ECIES)
   #include <botan/ecies.h>
   #include <botan/ecdh.h>
#endif

namespace Botan_Tests {

namespace {

#if defined(BOTAN_HAS_ECIES) && defined(BOTAN_HAS_AES) && defined(BOTAN_HAS_CBC)

using Flags = Botan::ECIES_Flags;

Botan::PointGFp::Compression_Type get_compression_type(const std::string& format)
   {
   if(format == "uncompressed")
      {
      return Botan::PointGFp::UNCOMPRESSED;
      }
   else if(format == "compressed")
      {
      return Botan::PointGFp::COMPRESSED;
      }
   else if(format == "hybrid")
      {
      return Botan::PointGFp::HYBRID;
      }
   throw Botan::Invalid_Argument("invalid compression format");
   }

Flags ecies_flags(bool cofactor_mode, bool old_cofactor_mode, bool check_mode, bool single_hash_mode)
   {
   return (cofactor_mode ? Flags::COFACTOR_MODE : Flags::NONE)
          | (single_hash_mode ? Flags::SINGLE_HASH_MODE : Flags::NONE)
          | (old_cofactor_mode ? Flags::OLD_COFACTOR_MODE : Flags::NONE)
          | (check_mode ? Flags::CHECK_MODE : Flags::NONE);
   }

void check_encrypt_decrypt(Test::Result& result, const Botan::ECDH_PrivateKey& private_key,
                           const Botan::ECDH_PrivateKey& other_private_key,
                           const Botan::ECIES_System_Params& ecies_params,
                           const Botan::InitializationVector& iv, const std::string& label,
                           const std::vector<uint8_t>& plaintext, const std::vector<uint8_t>& ciphertext)
   {
   try
      {
      Botan::ECIES_Encryptor ecies_enc(private_key, ecies_params, Test::rng());
      ecies_enc.set_other_key(other_private_key.public_point());
      Botan::ECIES_Decryptor ecies_dec(other_private_key, ecies_params, Test::rng());
      if(!iv.bits_of().empty())
         {
         ecies_enc.set_initialization_vector(iv);
         ecies_dec.set_initialization_vector(iv);
         }
      if(!label.empty())
         {
         ecies_enc.set_label(label);
         ecies_dec.set_label(label);
         }

      const std::vector<uint8_t> encrypted = ecies_enc.encrypt(plaintext, Test::rng());
      if(!ciphertext.empty())
         {
         result.test_eq("encrypted data", encrypted, ciphertext);
         }
      const Botan::secure_vector<uint8_t> decrypted = ecies_dec.decrypt(encrypted);
      result.test_eq("decrypted data equals plaintext", decrypted, plaintext);

      std::vector<uint8_t> invalid_encrypted = encrypted;
      uint8_t& last_byte = invalid_encrypted[invalid_encrypted.size() - 1];
      last_byte = ~last_byte;
      result.test_throws("throw on invalid ciphertext", [&ecies_dec, &invalid_encrypted]
         {
         ecies_dec.decrypt(invalid_encrypted);
         });
      }
   catch(Botan::Lookup_Error& e)
      {
      result.test_note(std::string("Test not executed: ") + e.what());
      }
   }

void check_encrypt_decrypt(Test::Result& result, const Botan::ECDH_PrivateKey& private_key,
                           const Botan::ECDH_PrivateKey& other_private_key,
                           const Botan::ECIES_System_Params& ecies_params, size_t iv_length = 0)
   {
   const std::vector<uint8_t> plaintext { 1, 2, 3 };
   check_encrypt_decrypt(result, private_key, other_private_key, ecies_params, std::vector<uint8_t>(iv_length, 0), "",
                         plaintext, std::vector<uint8_t>());
   }

#if defined(BOTAN_HAS_KDF1_18033) && defined(BOTAN_HAS_SHA1)

class ECIES_ISO_Tests final : public Text_Based_Test
   {
   public:
      ECIES_ISO_Tests() : Text_Based_Test(
            "pubkey/ecies-18033.vec",
            "format,p,a,b,mu,nu,gx,gy,hx,hy,x,r,C0,K") {}

      Test::Result run_one_test(const std::string&, const VarMap& vars) override
         {
         Test::Result result("ECIES-ISO");

         // get test vectors defined by ISO 18033
         const Botan::PointGFp::Compression_Type compression_type = get_compression_type(vars.get_req_str("format"));
         const Botan::BigInt p = vars.get_req_bn("p");
         const Botan::BigInt a = vars.get_req_bn("a");
         const Botan::BigInt b = vars.get_req_bn("b");
         const Botan::BigInt mu = vars.get_req_bn("mu");   // order
         const Botan::BigInt nu = vars.get_req_bn("nu");   // cofactor
         const Botan::BigInt gx = vars.get_req_bn("gx");   // base point x
         const Botan::BigInt gy = vars.get_req_bn("gy");   // base point y
         const Botan::BigInt hx = vars.get_req_bn("hx");   // x of public point of bob
         const Botan::BigInt hy = vars.get_req_bn("hy");   // y of public point of bob
         const Botan::BigInt x = vars.get_req_bn("x");   // private key of bob
         const Botan::BigInt r = vars.get_req_bn("r");   // (ephemeral) private key of alice
         const std::vector<uint8_t> c0 = vars.get_req_bin("C0");   // expected encoded (ephemeral) public key
         const std::vector<uint8_t> k = vars.get_req_bin("K");   // expected derived secret

         const Botan::EC_Group domain(p, a, b, gx, gy, mu, nu);

         // keys of bob
         const Botan::ECDH_PrivateKey other_private_key(Test::rng(), domain, x);
         const Botan::PointGFp other_public_key_point = domain.point(hx, hy);
         const Botan::ECDH_PublicKey other_public_key(domain, other_public_key_point);

         // (ephemeral) keys of alice
         const Botan::ECDH_PrivateKey eph_private_key(Test::rng(), domain, r);
         const Botan::PointGFp eph_public_key_point = eph_private_key.public_point();
         const std::vector<uint8_t> eph_public_key_bin = eph_public_key_point.encode(compression_type);
         result.test_eq("encoded (ephemeral) public key", eph_public_key_bin, c0);

         // test secret derivation: ISO 18033 test vectors use KDF1 from ISO 18033
         // no cofactor-/oldcofactor-/singlehash-/check-mode and 128 byte secret length
         Botan::ECIES_KA_Params ka_params(eph_private_key.domain(), "KDF1-18033(SHA-1)", 128, compression_type, Flags::NONE);
         const Botan::ECIES_KA_Operation ka(eph_private_key, ka_params, true, Test::rng());
         const Botan::SymmetricKey secret_key = ka.derive_secret(eph_public_key_bin, other_public_key_point);
         result.test_eq("derived secret key", secret_key.bits_of(), k);

         // test encryption / decryption

         for(auto comp_type : { Botan::PointGFp::UNCOMPRESSED, Botan::PointGFp::COMPRESSED, Botan::PointGFp::HYBRID })
            {
            for(bool cofactor_mode : { true, false })
               {
               for(bool single_hash_mode : { true, false })
                  {
                  for(bool old_cofactor_mode : { true, false })
                     {
                     for(bool check_mode : { true, false })
                        {
                        Flags flags = ecies_flags(cofactor_mode, old_cofactor_mode, check_mode, single_hash_mode);

                        if(size_t(cofactor_mode) + size_t(check_mode) + size_t(old_cofactor_mode) > 1)
                           {
                           auto onThrow =  [&]()
                              {
                              Botan::ECIES_System_Params(eph_private_key.domain(),
                                 "KDF2(SHA-1)", "AES-256/CBC", 32, "HMAC(SHA-1)", 20,
                                 comp_type, flags);
                              };
                           result.test_throws("throw on invalid ECIES_Flags", onThrow);
                           continue;
                           }

                        Botan::ECIES_System_Params ecies_params(eph_private_key.domain(), "KDF2(SHA-1)", "AES-256/CBC",
                                                                32, "HMAC(SHA-1)", 20, comp_type, flags);
                        check_encrypt_decrypt(result, eph_private_key, other_private_key, ecies_params, 16);
                        }
                     }
                  }
               }
            }

         return result;
         }
   };

BOTAN_REGISTER_TEST("ecies_iso", ECIES_ISO_Tests);

#endif

class ECIES_Tests final : public Text_Based_Test
   {
   public:
      ECIES_Tests()
         : Text_Based_Test(
              "pubkey/ecies.vec",
              "Curve,PrivateKey,OtherPrivateKey,Kdf,Dem,DemKeyLen,Iv,Mac,MacKeyLen,Format,"
              "CofactorMode,OldCofactorMode,CheckMode,SingleHashMode,Label,Plaintext,Ciphertext") {}

      Test::Result run_one_test(const std::string&, const VarMap& vars) override
         {
         Test::Result result("ECIES");

         const std::string curve = vars.get_req_str("Curve");
         const Botan::BigInt private_key_value = vars.get_req_bn("PrivateKey");
         const Botan::BigInt other_private_key_value = vars.get_req_bn("OtherPrivateKey");
         const std::string kdf = vars.get_req_str("Kdf");
         const std::string dem = vars.get_req_str("Dem");
         const size_t dem_key_len = vars.get_req_sz("DemKeyLen");
         const std::vector<uint8_t> iv = vars.get_req_bin("Iv");
         const std::string mac = vars.get_req_str("Mac");
         const size_t mac_key_len = vars.get_req_sz("MacKeyLen");
         const Botan::PointGFp::Compression_Type compression_type = get_compression_type(vars.get_req_str("Format"));
         const bool cofactor_mode = vars.get_req_sz("CofactorMode") != 0;
         const bool old_cofactor_mode = vars.get_req_sz("OldCofactorMode") != 0;
         const bool check_mode = vars.get_req_sz("CheckMode") != 0;
         const bool single_hash_mode = vars.get_req_sz("SingleHashMode") != 0;
         const std::string label = vars.get_req_str("Label");
         const std::vector<uint8_t> plaintext = vars.get_req_bin("Plaintext");
         const std::vector<uint8_t> ciphertext = vars.get_req_bin("Ciphertext");

         const Flags flags = ecies_flags(cofactor_mode, old_cofactor_mode, check_mode, single_hash_mode);
         const Botan::EC_Group domain(curve);
         const Botan::ECDH_PrivateKey private_key(Test::rng(), domain, private_key_value);
         const Botan::ECDH_PrivateKey other_private_key(Test::rng(), domain, other_private_key_value);

         const Botan::ECIES_System_Params ecies_params(private_key.domain(), kdf, dem, dem_key_len, mac, mac_key_len,
               compression_type, flags);
         check_encrypt_decrypt(result, private_key, other_private_key, ecies_params, iv, label, plaintext, ciphertext);

         return result;
         }

   };

BOTAN_REGISTER_TEST("ecies", ECIES_Tests);

#if defined(BOTAN_HAS_KDF1_18033) && defined(BOTAN_HAS_HMAC) && defined(BOTAN_HAS_AES) && defined(BOTAN_HAS_SHA2_64)

Test::Result test_other_key_not_set()
   {
   Test::Result result("ECIES other key not set");

   const Flags flags = ecies_flags(false, false, false, true);
   const Botan::EC_Group domain("secp521r1");
   const Botan::BigInt private_key_value("405029866705438137604064977397053031159826489755682166267763407"
                                         "5002761777100287880684822948852132235484464537021197213998300006"
                                         "547176718172344447619746779823");

   const Botan::ECDH_PrivateKey private_key(Test::rng(), domain, private_key_value);
   const Botan::ECIES_System_Params ecies_params(private_key.domain(), "KDF1-18033(SHA-512)", "AES-256/CBC", 32,
         "HMAC(SHA-512)", 20, Botan::PointGFp::Compression_Type::COMPRESSED,
         flags);

   Botan::ECIES_Encryptor ecies_enc(private_key, ecies_params, Test::rng());

   result.test_throws("encrypt not possible without setting other public key", [ &ecies_enc ]()
      {
      ecies_enc.encrypt(std::vector<uint8_t>(8), Test::rng());
      });

   return result;
   }

Test::Result test_kdf_not_found()
   {
   Test::Result result("ECIES kdf not found");

   const Flags flags = ecies_flags(false, false, false, true);
   const Botan::EC_Group domain("secp521r1");
   const Botan::BigInt private_key_value("405029866705438137604064977397053031159826489755682166267763407"
                                         "5002761777100287880684822948852132235484464537021197213998300006"
                                         "547176718172344447619746779823");

   const Botan::ECDH_PrivateKey private_key(Test::rng(), domain, private_key_value);
   const Botan::ECIES_System_Params ecies_params(private_key.domain(), "KDF-XYZ(SHA-512)", "AES-256/CBC", 32,
         "HMAC(SHA-512)", 20, Botan::PointGFp::Compression_Type::COMPRESSED,
         flags);

   result.test_throws("kdf not found", [&]()
      {
      Botan::ECIES_Encryptor ecies_enc(private_key, ecies_params, Test::rng());
      ecies_enc.encrypt(std::vector<uint8_t>(8), Test::rng());
      });

   return result;
   }

Test::Result test_mac_not_found()
   {
   Test::Result result("ECIES mac not found");

   const Flags flags = ecies_flags(false, false, false, true);
   const Botan::EC_Group domain("secp521r1");
   const Botan::BigInt private_key_value("405029866705438137604064977397053031159826489755682166267763407"
                                         "5002761777100287880684822948852132235484464537021197213998300006"
                                         "547176718172344447619746779823");

   const Botan::ECDH_PrivateKey private_key(Test::rng(), domain, private_key_value);
   const Botan::ECIES_System_Params ecies_params(private_key.domain(), "KDF1-18033(SHA-512)", "AES-256/CBC", 32,
         "XYZMAC(SHA-512)", 20, Botan::PointGFp::Compression_Type::COMPRESSED,
         flags);

   result.test_throws("mac not found", [&]()
      {
      Botan::ECIES_Encryptor ecies_enc(private_key, ecies_params, Test::rng());
      ecies_enc.encrypt(std::vector<uint8_t>(8), Test::rng());
      });

   return result;
   }

Test::Result test_cipher_not_found()
   {
   Test::Result result("ECIES cipher not found");

   const Flags flags = ecies_flags(false, false, false, true);
   const Botan::EC_Group domain("secp521r1");
   const Botan::BigInt private_key_value("405029866705438137604064977397053031159826489755682166267763407"
                                         "5002761777100287880684822948852132235484464537021197213998300006"
                                         "547176718172344447619746779823");

   const Botan::ECDH_PrivateKey private_key(Test::rng(), domain, private_key_value);
   const Botan::ECIES_System_Params ecies_params(private_key.domain(), "KDF1-18033(SHA-512)", "AES-XYZ-256/CBC", 32,
         "HMAC(SHA-512)", 20, Botan::PointGFp::Compression_Type::COMPRESSED,
         flags);

   result.test_throws("cipher not found", [&]()
      {
      Botan::ECIES_Encryptor ecies_enc(private_key, ecies_params, Test::rng());
      ecies_enc.encrypt(std::vector<uint8_t>(8), Test::rng());
      });

   return result;
   }

Test::Result test_system_params_short_ctor()
   {
   Test::Result result("ECIES short system params ctor");

   const Botan::EC_Group domain("secp521r1");
   const Botan::BigInt private_key_value("405029866705438137604064977397053031159826489755682166267763407"
                                         "5002761777100287880684822948852132235484464537021197213998300006"
                                         "547176718172344447619746779823");

   const Botan::BigInt other_private_key_value("2294226772740614508941417891614236736606752960073669253551166842"
         "5866095315090327914760325168219669828915074071456176066304457448"
         "25404691681749451640151380153");

   const Botan::ECDH_PrivateKey private_key(Test::rng(), domain, private_key_value);
   const Botan::ECDH_PrivateKey other_private_key(Test::rng(), domain, other_private_key_value);

   const Botan::ECIES_System_Params ecies_params(private_key.domain(), "KDF1-18033(SHA-512)", "AES-256/CBC", 32,
         "HMAC(SHA-512)", 16);

   const Botan::InitializationVector iv("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF");
   const std::string label = "Test";

   const std::vector<uint8_t> plaintext = Botan::hex_decode("000102030405060708090A0B0C0D0E0F");

   // generated with botan
   const std::vector<uint8_t> ciphertext = Botan::hex_decode("0401519EAA0489FF9D51E98E4C22349463E2001CD06F8CE47D81D4007A"
                                           "79ACF98E92C814686477CEA666EFC277DC84E15FC95E38AFF8E16D478A"
                                           "44CD5C5F1517F8B1F300000591317F261C3D04A7207F01EAE3EC70F2360"
                                           "0F82C53CC0B85BE7AC9F6CE79EF2AB416E5934D61BA9D346385D7545C57F"
                                           "77C7EA7C58E18C70CBFB0A24AE1B9943EC5A8D0657522CCDF30BA95674D81"
                                           "B397635D215178CD13BD9504AE957A9888F4128FFC0F0D3F1CEC646AEC8CE"
                                           "3F2463D233B22A7A12B679F4C06501F584D4DEFF6D26592A8D873398BD892"
                                           "B477B3468813C053DA43C4F3D49009F7A12D6EF7");

   check_encrypt_decrypt(result, private_key, other_private_key, ecies_params, iv, label, plaintext, ciphertext);

   return result;
   }

Test::Result test_ciphertext_too_short()
   {
   Test::Result result("ECIES ciphertext too short");

   const Botan::EC_Group domain("secp521r1");
   const Botan::BigInt private_key_value("405029866705438137604064977397053031159826489755682166267763407"
                                         "5002761777100287880684822948852132235484464537021197213998300006"
                                         "547176718172344447619746779823");

   const Botan::BigInt other_private_key_value("2294226772740614508941417891614236736606752960073669253551166842"
         "5866095315090327914760325168219669828915074071456176066304457448"
         "25404691681749451640151380153");

   const Botan::ECDH_PrivateKey private_key(Test::rng(), domain, private_key_value);
   const Botan::ECDH_PrivateKey other_private_key(Test::rng(), domain, other_private_key_value);

   const Botan::ECIES_System_Params ecies_params(private_key.domain(), "KDF1-18033(SHA-512)", "AES-256/CBC", 32,
         "HMAC(SHA-512)", 16);

   Botan::ECIES_Decryptor ecies_dec(other_private_key, ecies_params, Test::rng());

   result.test_throws("ciphertext too short", [ &ecies_dec ]()
      {
      ecies_dec.decrypt(Botan::hex_decode("0401519EAA0489FF9D51E98E4C22349A"));
      });

   return result;
   }

class ECIES_Unit_Tests final : public Test
   {
   public:
      std::vector<Test::Result> run() override
         {
         std::vector<Test::Result> results;

         std::vector<std::function<Test::Result()>> fns =
            {
            test_other_key_not_set,
            test_kdf_not_found,
            test_mac_not_found,
            test_cipher_not_found,
            test_system_params_short_ctor,
            test_ciphertext_too_short
            };

         for(size_t i = 0; i != fns.size(); ++i)
            {
            try
               {
               results.emplace_back(fns[ i ]());
               }
            catch(std::exception& e)
               {
               results.emplace_back(Test::Result::Failure("ECIES unit tests " + std::to_string(i), e.what()));
               }
            }

         return results;
         }
   };

BOTAN_REGISTER_TEST("ecies_unit", ECIES_Unit_Tests);

#endif

#endif

}

}