/*

* (C) 2015,2016 Jack Lloyd

*

* Botan is released under the Simplified BSD License (see license.txt)

*/

#include "fuzzers.h"

#include <botan/data_src.h>

#include <botan/hex.h>

#include <botan/pkcs8.h>

#include <botan/tls_server.h>

#include <botan/tls_session_manager_noop.h>

#include <memory>

namespace {

const char* const fixed_ecdsa_key =

   "-----BEGIN PRIVATE KEY-----"

   "MIGHAgEAMBMGByqGSM49AgEGCCqGSM49AwEHBG0wawIBAQQgfUjnfxgvrIyrqa5N"

   "47X1W50cVStDPbASwRcY6zqehjyhRANCAAQTNF0poMBM4tuCY50NrDJU8za/SK45"

   "erOdFpGK7KRWtBE9zNj6J0f1UB+K8GdekFD2me+iL63v+uBqo/PHRPT9"

   "-----END PRIVATE KEY-----";

const char* const fixed_ecdsa_cert =

   "-----BEGIN CERTIFICATE-----"

   "MIIB3zCCAYWgAwIBAgIRAPFi6dun9OY7YLuZHqKzdEMwCgYIKoZIzj0EAwIwOTEa"

   "MBgGA1UEAwwRSXQncyBGdXp6aW5nIFRpbWUxCzAJBgNVBAYTAlZUMQ4wDAYDVQQK"

   "EwVCb3RhbjAeFw0yNTAxMjAxMzI0MjdaFw0zODAxMTgxMzI0MjdaMDkxGjAYBgNV"

   "BAMMEUl0J3MgRnV6emluZyBUaW1lMQswCQYDVQQGEwJWVDEOMAwGA1UEChMFQm90"

   "YW4wWTATBgcqhkjOPQIBBggqhkjOPQMBBwNCAAQTNF0poMBM4tuCY50NrDJU8za/"

   "SK45erOdFpGK7KRWtBE9zNj6J0f1UB+K8GdekFD2me+iL63v+uBqo/PHRPT9o24w"

   "bDAhBgNVHQ4EGgQYevp/SCkZVWPKNAUSez17HTOyneXEWwpEMBQGA1UdEQQNMAuC"

   "CWxvY2FsaG9zdDAMBgNVHRMBAf8EAjAAMCMGA1UdIwQcMBqAGHr6f0gpGVVjyjQF"

   "Ens9ex0zsp3lxFsKRDAKBggqhkjOPQQDAgNIADBFAiEApqVCYhySxK/8GLq8wlPh"

   "MeBg8CwKO83s1h/GYQZD4CUCID5Mzh5mwrkkAuSENjLXAD4dtiu91Zsoye5J0uuU"

   "60v7"

   "-----END CERTIFICATE-----";

class Fuzzer_TLS_Server_Creds : public Botan::Credentials_Manager {

   public:

      Fuzzer_TLS_Server_Creds() {

         Botan::DataSource_Memory cert_in(fixed_ecdsa_cert);

         m_ecdsa_cert = std::make_unique<Botan::X509_Certificate>(cert_in);

         Botan::DataSource_Memory key_in(fixed_ecdsa_key);

         m_ecdsa_key.reset(Botan::PKCS8::load_key(key_in).release());

      }

      std::vector<Botan::X509_Certificate> cert_chain(

         const std::vector<std::string>& algos,

         const std::vector<Botan::AlgorithmIdentifier>& /*signature_schemes*/,

         const std::string& /*type*/,

         const std::string& /*hostname*/) override {

         std::vector<Botan::X509_Certificate> v;

         for(const auto& algo : algos) {

            if(algo == "ECDSA") {

               v.push_back(*m_ecdsa_cert);

               break;

            }

         }

         return v;

      }

      std::shared_ptr<Botan::Private_Key> private_key_for(const Botan::X509_Certificate& /*cert*/,

                                                          const std::string& type,

                                                          const std::string& /*context*/) override {

         if(type == "ECDSA") {

            return m_ecdsa_key;

         }

         return nullptr;

      }

      Botan::secure_vector<uint8_t> session_ticket_key() override {

         return Botan::hex_decode_locked("AABBCCDDEEFF00112233445566778899");

      }

      Botan::secure_vector<uint8_t> dtls_cookie_secret() override {

         return Botan::hex_decode_locked("AABBCCDDEEFF00112233445566778899");

      }

      std::string psk_identity_hint(const std::string&, const std::string&) override { return "psk_hint"; }

      std::string psk_identity(const std::string&, const std::string&, const std::string&) override { return "psk_id"; }

      std::vector<Botan::TLS::ExternalPSK> find_preshared_keys(

         std::string_view host,

         Botan::TLS::Connection_Side whoami,

         const std::vector<std::string>& identities = {},

         const std::optional<std::string>& prf = std::nullopt) override {

         if(!identities.empty() && std::find(identities.begin(), identities.end(), "psk_id") == identities.end()) {

            return Botan::Credentials_Manager::find_preshared_keys(host, whoami, identities, prf);

         }

         std::vector<Botan::TLS::ExternalPSK> psks;

         psks.emplace_back("psk_id", "SHA-256", Botan::hex_decode_locked("AABBCCDDEEFF00112233445566778899"));

         return psks;

      }

   private:

      std::unique_ptr<Botan::X509_Certificate> m_ecdsa_cert;

      std::shared_ptr<Botan::Private_Key> m_ecdsa_key;

};

class Fuzzer_TLS_Policy : public Botan::TLS::Policy {

   public:

      std::vector<uint16_t> ciphersuite_list(Botan::TLS::Protocol_Version) const override {

         std::vector<uint16_t> ciphersuites;

         for(auto&& suite : Botan::TLS::Ciphersuite::all_known_ciphersuites()) {

            if(suite.valid()) {

               ciphersuites.push_back(suite.ciphersuite_code());

            }

         }

         return ciphersuites;

      }

};

class Fuzzer_TLS_Server_Callbacks : public Botan::TLS::Callbacks {

   public:

      void tls_emit_data(std::span<const uint8_t>) override {

         // discard

      }

      void tls_record_received(uint64_t, std::span<const uint8_t>) override {

         // ignore peer data

      }

      void tls_alert(Botan::TLS::Alert) override {

         // ignore alert

      }

      std::string tls_server_choose_app_protocol(const std::vector<std::string>& client_protos) override {

         if(client_protos.size() > 1) {

            return client_protos[0];

         } else {

            return "fuzzy";

         }

      }

      void tls_verify_cert_chain(const std::vector<Botan::X509_Certificate>& cert_chain,

                                 const std::vector<std::optional<Botan::OCSP::Response>>& ocsp_responses,

                                 const std::vector<Botan::Certificate_Store*>& trusted_roots,

                                 Botan::Usage_Type usage,

                                 std::string_view hostname,

                                 const Botan::TLS::Policy& policy) override {

         try {

            // try to validate to exercise those code paths

            Botan::TLS::Callbacks::tls_verify_cert_chain(

               cert_chain, ocsp_responses, trusted_roots, usage, hostname, policy);

         } catch(...) {

            // ignore validation result

         }

      }

};

}  // namespace

void fuzz(std::span<const uint8_t> in) {

   if(in.size() <= 1) {

      return;

   }

   auto session_manager = std::make_shared<Botan::TLS::Session_Manager_Noop>();

   auto policy = std::make_shared<Fuzzer_TLS_Policy>();

   Botan::TLS::Server_Information info("server.name", 443);

   auto creds = std::make_shared<Fuzzer_TLS_Server_Creds>();

   auto callbacks = std::make_shared<Fuzzer_TLS_Server_Callbacks>();

   const bool is_datagram = in[0] & 1;

   Botan::TLS::Server server(callbacks, session_manager, creds, policy, fuzzer_rng_as_shared(), is_datagram);

   try {

      server.received_data(in.subspan(1, in.size() - 1));

   } catch(std::exception& e) {}

}