/*

 * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#if !defined(__STDC_FORMAT_MACROS)

#define __STDC_FORMAT_MACROS

#endif

#include "packeted_bio.h"

#include <openssl/e_os2.h>

#if !defined(OPENSSL_SYS_WINDOWS)

#include <arpa/inet.h>

#include <netinet/in.h>

#include <netinet/tcp.h>

#include <signal.h>

#include <sys/socket.h>

#include <sys/time.h>

#include <unistd.h>

#else

#include <io.h>

OPENSSL_MSVC_PRAGMA(warning(push, 3))

#include <winsock2.h>

#include <ws2tcpip.h>

OPENSSL_MSVC_PRAGMA(warning(pop))

OPENSSL_MSVC_PRAGMA(comment(lib, "Ws2_32.lib"))

#endif

#include <assert.h>

#include <inttypes.h>

#include <string.h>

#include <openssl/bio.h>

#include <openssl/buffer.h>

#include <openssl/bn.h>

#include <openssl/crypto.h>

#include <openssl/dh.h>

#include <openssl/err.h>

#include <openssl/evp.h>

#include <openssl/hmac.h>

#include <openssl/objects.h>

#include <openssl/rand.h>

#include <openssl/ssl.h>

#include <openssl/x509.h>

#include <memory>

#include <string>

#include <vector>

#include "async_bio.h"

#include "test_config.h"

namespace bssl {

#if !defined(OPENSSL_SYS_WINDOWS)

static int closesocket(int sock) {

  return close(sock);

}

static void PrintSocketError(const char *func) {

  perror(func);

}

#else

static void PrintSocketError(const char *func) {

  fprintf(stderr, "%s: %d\n", func, WSAGetLastError());

}

#endif

static int Usage(const char *program) {

  fprintf(stderr, "Usage: %s [flags...]\n", program);

  return 1;

}

struct TestState {

  // async_bio is async BIO which pauses reads and writes.

  BIO *async_bio = nullptr;

  // packeted_bio is the packeted BIO which simulates read timeouts.

  BIO *packeted_bio = nullptr;

  bool cert_ready = false;

  bool handshake_done = false;

  // private_key is the underlying private key used when testing custom keys.

  bssl::UniquePtr<EVP_PKEY> private_key;

  bool got_new_session = false;

  bssl::UniquePtr<SSL_SESSION> new_session;

  bool ticket_decrypt_done = false;

  bool alpn_select_done = false;

};

static void TestStateExFree(void *parent, void *ptr, CRYPTO_EX_DATA *ad,

                            int index, long argl, void *argp) {

  delete ((TestState *)ptr);

}

static int g_config_index = 0;

static int g_state_index = 0;

static bool SetTestConfig(SSL *ssl, const TestConfig *config) {

  return SSL_set_ex_data(ssl, g_config_index, (void *)config) == 1;

}

static const TestConfig *GetTestConfig(const SSL *ssl) {

  return (const TestConfig *)SSL_get_ex_data(ssl, g_config_index);

}

static bool SetTestState(SSL *ssl, std::unique_ptr<TestState> state) {

  // |SSL_set_ex_data| takes ownership of |state| only on success.

  if (SSL_set_ex_data(ssl, g_state_index, state.get()) == 1) {

    state.release();

    return true;

  }

  return false;

}

static TestState *GetTestState(const SSL *ssl) {

  return (TestState *)SSL_get_ex_data(ssl, g_state_index);

}

static bssl::UniquePtr<X509> LoadCertificate(const std::string &file) {

  bssl::UniquePtr<BIO> bio(BIO_new(BIO_s_file()));

  if (!bio || !BIO_read_filename(bio.get(), file.c_str())) {

    return nullptr;

  }

  return bssl::UniquePtr<X509>(PEM_read_bio_X509(bio.get(), NULL, NULL, NULL));

}

static bssl::UniquePtr<EVP_PKEY> LoadPrivateKey(const std::string &file) {

  bssl::UniquePtr<BIO> bio(BIO_new(BIO_s_file()));

  if (!bio || !BIO_read_filename(bio.get(), file.c_str())) {

    return nullptr;

  }

  return bssl::UniquePtr<EVP_PKEY>(

      PEM_read_bio_PrivateKey(bio.get(), NULL, NULL, NULL));

}

template<typename T>

struct Free {

  void operator()(T *buf) {

    free(buf);

  }

};

static bool GetCertificate(SSL *ssl, bssl::UniquePtr<X509> *out_x509,

                           bssl::UniquePtr<EVP_PKEY> *out_pkey) {

  const TestConfig *config = GetTestConfig(ssl);

  if (!config->key_file.empty()) {

    *out_pkey = LoadPrivateKey(config->key_file.c_str());

    if (!*out_pkey) {

      return false;

    }

  }

  if (!config->cert_file.empty()) {

    *out_x509 = LoadCertificate(config->cert_file.c_str());

    if (!*out_x509) {

      return false;

    }

  }

  return true;

}

static bool InstallCertificate(SSL *ssl) {

  bssl::UniquePtr<X509> x509;

  bssl::UniquePtr<EVP_PKEY> pkey;

  if (!GetCertificate(ssl, &x509, &pkey)) {

    return false;

  }

  if (pkey && !SSL_use_PrivateKey(ssl, pkey.get())) {

    return false;

  }

  if (x509 && !SSL_use_certificate(ssl, x509.get())) {

    return false;

  }

  return true;

}

static int ClientCertCallback(SSL *ssl, X509 **out_x509, EVP_PKEY **out_pkey) {

  if (GetTestConfig(ssl)->async && !GetTestState(ssl)->cert_ready) {

    return -1;

  }

  bssl::UniquePtr<X509> x509;

  bssl::UniquePtr<EVP_PKEY> pkey;

  if (!GetCertificate(ssl, &x509, &pkey)) {

    return -1;

  }

  // Return zero for no certificate.

  if (!x509) {

    return 0;

  }

  // Asynchronous private keys are not supported with client_cert_cb.

  *out_x509 = x509.release();

  *out_pkey = pkey.release();

  return 1;

}

static int VerifySucceed(X509_STORE_CTX *store_ctx, void *arg) {

  return 1;

}

static int VerifyFail(X509_STORE_CTX *store_ctx, void *arg) {

  X509_STORE_CTX_set_error(store_ctx, X509_V_ERR_APPLICATION_VERIFICATION);

  return 0;

}

static int NextProtosAdvertisedCallback(SSL *ssl, const uint8_t **out,

                                        unsigned int *out_len, void *arg) {

  const TestConfig *config = GetTestConfig(ssl);

  if (config->advertise_npn.empty()) {

    return SSL_TLSEXT_ERR_NOACK;

  }

  *out = (const uint8_t*)config->advertise_npn.data();

  *out_len = config->advertise_npn.size();

  return SSL_TLSEXT_ERR_OK;

}

static int NextProtoSelectCallback(SSL* ssl, uint8_t** out, uint8_t* outlen,

                                   const uint8_t* in, unsigned inlen, void* arg) {

  const TestConfig *config = GetTestConfig(ssl);

  if (config->select_next_proto.empty()) {

    return SSL_TLSEXT_ERR_NOACK;

  }

  *out = (uint8_t*)config->select_next_proto.data();

  *outlen = config->select_next_proto.size();

  return SSL_TLSEXT_ERR_OK;

}

static int AlpnSelectCallback(SSL* ssl, const uint8_t** out, uint8_t* outlen,

                              const uint8_t* in, unsigned inlen, void* arg) {

  if (GetTestState(ssl)->alpn_select_done) {

    fprintf(stderr, "AlpnSelectCallback called after completion.\n");

    exit(1);

  }

  GetTestState(ssl)->alpn_select_done = true;

  const TestConfig *config = GetTestConfig(ssl);

  if (config->decline_alpn) {

    return SSL_TLSEXT_ERR_NOACK;

  }

  if (!config->expected_advertised_alpn.empty() &&

      (config->expected_advertised_alpn.size() != inlen ||

       memcmp(config->expected_advertised_alpn.data(),

              in, inlen) != 0)) {

    fprintf(stderr, "bad ALPN select callback inputs\n");

    exit(1);

  }

  *out = (const uint8_t*)config->select_alpn.data();

  *outlen = config->select_alpn.size();

  return SSL_TLSEXT_ERR_OK;

}

static unsigned PskClientCallback(SSL *ssl, const char *hint,

                                  char *out_identity,

                                  unsigned max_identity_len,

                                  uint8_t *out_psk, unsigned max_psk_len) {

  const TestConfig *config = GetTestConfig(ssl);

  if (config->psk_identity.empty()) {

    if (hint != nullptr) {

      fprintf(stderr, "Server PSK hint was non-null.\n");

      return 0;

    }

  } else if (hint == nullptr ||

             strcmp(hint, config->psk_identity.c_str()) != 0) {

    fprintf(stderr, "Server PSK hint did not match.\n");

    return 0;

  }

  // Account for the trailing '\0' for the identity.

  if (config->psk_identity.size() >= max_identity_len ||

      config->psk.size() > max_psk_len) {

    fprintf(stderr, "PSK buffers too small\n");

    return 0;

  }

  BUF_strlcpy(out_identity, config->psk_identity.c_str(),

              max_identity_len);

  memcpy(out_psk, config->psk.data(), config->psk.size());

  return config->psk.size();

}

static unsigned PskServerCallback(SSL *ssl, const char *identity,

                                  uint8_t *out_psk, unsigned max_psk_len) {

  const TestConfig *config = GetTestConfig(ssl);

  if (strcmp(identity, config->psk_identity.c_str()) != 0) {

    fprintf(stderr, "Client PSK identity did not match.\n");

    return 0;

  }

  if (config->psk.size() > max_psk_len) {

    fprintf(stderr, "PSK buffers too small\n");

    return 0;

  }

  memcpy(out_psk, config->psk.data(), config->psk.size());

  return config->psk.size();

}

static int CertCallback(SSL *ssl, void *arg) {

  const TestConfig *config = GetTestConfig(ssl);

  // Check the CertificateRequest metadata is as expected.

  //

  // TODO(davidben): Test |SSL_get_client_CA_list|.

  if (!SSL_is_server(ssl) &&

      !config->expected_certificate_types.empty()) {

    const uint8_t *certificate_types;

    size_t certificate_types_len =

        SSL_get0_certificate_types(ssl, &certificate_types);

    if (certificate_types_len != config->expected_certificate_types.size() ||

        memcmp(certificate_types,

               config->expected_certificate_types.data(),

               certificate_types_len) != 0) {

      fprintf(stderr, "certificate types mismatch\n");

      return 0;

    }

  }

  // The certificate will be installed via other means.

  if (!config->async ||

      config->use_old_client_cert_callback) {

    return 1;

  }

  if (!GetTestState(ssl)->cert_ready) {

    return -1;

  }

  if (!InstallCertificate(ssl)) {

    return 0;

  }

  return 1;

}

static void InfoCallback(const SSL *ssl, int type, int val) {

  if (type == SSL_CB_HANDSHAKE_DONE) {

    if (GetTestConfig(ssl)->handshake_never_done) {

      fprintf(stderr, "Handshake unexpectedly completed.\n");

      // Abort before any expected error code is printed, to ensure the overall

      // test fails.

      abort();

    }

    GetTestState(ssl)->handshake_done = true;

    // Callbacks may be called again on a new handshake.

    GetTestState(ssl)->ticket_decrypt_done = false;

    GetTestState(ssl)->alpn_select_done = false;

  }

}

static int NewSessionCallback(SSL *ssl, SSL_SESSION *session) {

  GetTestState(ssl)->got_new_session = true;

  GetTestState(ssl)->new_session.reset(session);

  return 1;

}

static int TicketKeyCallback(SSL *ssl, uint8_t *key_name, uint8_t *iv,

                             EVP_CIPHER_CTX *ctx, HMAC_CTX *hmac_ctx,

                             int encrypt) {

  if (!encrypt) {

    if (GetTestState(ssl)->ticket_decrypt_done) {

      fprintf(stderr, "TicketKeyCallback called after completion.\n");

      return -1;

    }

    GetTestState(ssl)->ticket_decrypt_done = true;

  }

  // This is just test code, so use the all-zeros key.

  static const uint8_t kZeros[16] = {0};

  if (encrypt) {

    memcpy(key_name, kZeros, sizeof(kZeros));

    RAND_bytes(iv, 16);

  } else if (memcmp(key_name, kZeros, 16) != 0) {

    return 0;

  }

  if (!HMAC_Init_ex(hmac_ctx, kZeros, sizeof(kZeros), EVP_sha256(), NULL) ||

      !EVP_CipherInit_ex(ctx, EVP_aes_128_cbc(), NULL, kZeros, iv, encrypt)) {

    return -1;

  }

  if (!encrypt) {

    return GetTestConfig(ssl)->renew_ticket ? 2 : 1;

  }

  return 1;

}

// kCustomExtensionValue is the extension value that the custom extension

// callbacks will add.

static const uint16_t kCustomExtensionValue = 1234;

static void *const kCustomExtensionAddArg =

    reinterpret_cast<void *>(kCustomExtensionValue);

static void *const kCustomExtensionParseArg =

    reinterpret_cast<void *>(kCustomExtensionValue + 1);

static const char kCustomExtensionContents[] = "custom extension";

static int CustomExtensionAddCallback(SSL *ssl, unsigned extension_value,

                                      const uint8_t **out, size_t *out_len,

                                      int *out_alert_value, void *add_arg) {

  if (extension_value != kCustomExtensionValue ||

      add_arg != kCustomExtensionAddArg) {

    abort();

  }

  if (GetTestConfig(ssl)->custom_extension_skip) {

    return 0;

  }

  if (GetTestConfig(ssl)->custom_extension_fail_add) {

    return -1;

  }

  *out = reinterpret_cast<const uint8_t*>(kCustomExtensionContents);

  *out_len = sizeof(kCustomExtensionContents) - 1;

  return 1;

}

static void CustomExtensionFreeCallback(SSL *ssl, unsigned extension_value,

                                        const uint8_t *out, void *add_arg) {

  if (extension_value != kCustomExtensionValue ||

      add_arg != kCustomExtensionAddArg ||

      out != reinterpret_cast<const uint8_t *>(kCustomExtensionContents)) {

    abort();

  }

}

static int CustomExtensionParseCallback(SSL *ssl, unsigned extension_value,

                                        const uint8_t *contents,

                                        size_t contents_len,

                                        int *out_alert_value, void *parse_arg) {

  if (extension_value != kCustomExtensionValue ||

      parse_arg != kCustomExtensionParseArg) {

    abort();

  }

  if (contents_len != sizeof(kCustomExtensionContents) - 1 ||

      memcmp(contents, kCustomExtensionContents, contents_len) != 0) {

    *out_alert_value = SSL_AD_DECODE_ERROR;

    return 0;

  }

  return 1;

}

static int ServerNameCallback(SSL *ssl, int *out_alert, void *arg) {

  // SNI must be accessible from the SNI callback.

  const TestConfig *config = GetTestConfig(ssl);

  const char *server_name = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name);

  if (server_name == nullptr ||

      std::string(server_name) != config->expected_server_name) {

    fprintf(stderr, "servername mismatch (got %s; want %s)\n", server_name,

            config->expected_server_name.c_str());

    return SSL_TLSEXT_ERR_ALERT_FATAL;

  }

  return SSL_TLSEXT_ERR_OK;

}

// Connect returns a new socket connected to localhost on |port| or -1 on

// error.

static int Connect(uint16_t port) {

  int sock = socket(AF_INET, SOCK_STREAM, 0);

  if (sock == -1) {

    PrintSocketError("socket");

    return -1;

  }

  int nodelay = 1;

  if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,

          reinterpret_cast<const char*>(&nodelay), sizeof(nodelay)) != 0) {

    PrintSocketError("setsockopt");

    closesocket(sock);

    return -1;

  }

  sockaddr_in sin;

  memset(&sin, 0, sizeof(sin));

  sin.sin_family = AF_INET;

  sin.sin_port = htons(port);

  if (!inet_pton(AF_INET, "127.0.0.1", &sin.sin_addr)) {

    PrintSocketError("inet_pton");

    closesocket(sock);

    return -1;

  }

  if (connect(sock, reinterpret_cast<const sockaddr*>(&sin),

              sizeof(sin)) != 0) {

    PrintSocketError("connect");

    closesocket(sock);

    return -1;

  }

  return sock;

}

class SocketCloser {

 public:

  explicit SocketCloser(int sock) : sock_(sock) {}

  ~SocketCloser() {

    // Half-close and drain the socket before releasing it. This seems to be

    // necessary for graceful shutdown on Windows. It will also avoid write

    // failures in the test runner.

#if defined(OPENSSL_SYS_WINDOWS)

    shutdown(sock_, SD_SEND);

#else

    shutdown(sock_, SHUT_WR);

#endif

    while (true) {

      char buf[1024];

      if (recv(sock_, buf, sizeof(buf), 0) <= 0) {

        break;

      }

    }

    closesocket(sock_);

  }

 private:

  const int sock_;

};

static bssl::UniquePtr<SSL_CTX> SetupCtx(const TestConfig *config) {

  const char sess_id_ctx[] = "ossl_shim";

  bssl::UniquePtr<SSL_CTX> ssl_ctx(SSL_CTX_new(

      config->is_dtls ? DTLS_method() : TLS_method()));

  if (!ssl_ctx) {

    return nullptr;

  }

  SSL_CTX_set_security_level(ssl_ctx.get(), 0);

#if 0

  /* Disabled for now until we have some TLS1.3 support */

  // Enable TLS 1.3 for tests.

  if (!config->is_dtls &&

      !SSL_CTX_set_max_proto_version(ssl_ctx.get(), TLS1_3_VERSION)) {

    return nullptr;

  }

#else

  /* Ensure we don't negotiate TLSv1.3 until we can handle it */

  if (!config->is_dtls &&

      !SSL_CTX_set_max_proto_version(ssl_ctx.get(), TLS1_2_VERSION)) {

    return nullptr;

  }

#endif

  std::string cipher_list = "ALL";

  if (!config->cipher.empty()) {

    cipher_list = config->cipher;

    SSL_CTX_set_options(ssl_ctx.get(), SSL_OP_CIPHER_SERVER_PREFERENCE);

  }

  if (!SSL_CTX_set_cipher_list(ssl_ctx.get(), cipher_list.c_str())) {

    return nullptr;

  }

  DH *tmpdh;

  if (config->use_sparse_dh_prime) {

    BIGNUM *p, *g;

    p = BN_new();

    g = BN_new();

    tmpdh = DH_new();

    if (p == NULL || g == NULL || tmpdh == NULL) {

        BN_free(p);

        BN_free(g);

        DH_free(tmpdh);

        return nullptr;

    }

    // This prime number is 2^1024 + 643 – a value just above a power of two.

    // Because of its form, values modulo it are essentially certain to be one

    // byte shorter. This is used to test padding of these values.

    if (BN_hex2bn(

            &p,

            "1000000000000000000000000000000000000000000000000000000000000000"

            "0000000000000000000000000000000000000000000000000000000000000000"

            "0000000000000000000000000000000000000000000000000000000000000000"

            "0000000000000000000000000000000000000000000000000000000000000028"

            "3") == 0 ||

        !BN_set_word(g, 2)) {

      BN_free(p);

      BN_free(g);

      DH_free(tmpdh);

      return nullptr;

    }

    DH_set0_pqg(tmpdh, p, NULL, g);

  } else {

      tmpdh = DH_get_2048_256();

  }

  bssl::UniquePtr<DH> dh(tmpdh);

  if (!dh || !SSL_CTX_set_tmp_dh(ssl_ctx.get(), dh.get())) {

    return nullptr;

  }

  SSL_CTX_set_session_cache_mode(ssl_ctx.get(), SSL_SESS_CACHE_BOTH);

  if (config->use_old_client_cert_callback) {

    SSL_CTX_set_client_cert_cb(ssl_ctx.get(), ClientCertCallback);

  }

  SSL_CTX_set_npn_advertised_cb(

      ssl_ctx.get(), NextProtosAdvertisedCallback, NULL);

  if (!config->select_next_proto.empty()) {

    SSL_CTX_set_next_proto_select_cb(ssl_ctx.get(), NextProtoSelectCallback,

                                     NULL);

  }

  if (!config->select_alpn.empty() || config->decline_alpn) {

    SSL_CTX_set_alpn_select_cb(ssl_ctx.get(), AlpnSelectCallback, NULL);

  }

  SSL_CTX_set_info_callback(ssl_ctx.get(), InfoCallback);

  SSL_CTX_sess_set_new_cb(ssl_ctx.get(), NewSessionCallback);

  if (config->use_ticket_callback) {

    SSL_CTX_set_tlsext_ticket_key_cb(ssl_ctx.get(), TicketKeyCallback);

  }

  if (config->enable_client_custom_extension &&

      !SSL_CTX_add_client_custom_ext(

          ssl_ctx.get(), kCustomExtensionValue, CustomExtensionAddCallback,

          CustomExtensionFreeCallback, kCustomExtensionAddArg,

          CustomExtensionParseCallback, kCustomExtensionParseArg)) {

    return nullptr;

  }

  if (config->enable_server_custom_extension &&

      !SSL_CTX_add_server_custom_ext(

          ssl_ctx.get(), kCustomExtensionValue, CustomExtensionAddCallback,

          CustomExtensionFreeCallback, kCustomExtensionAddArg,

          CustomExtensionParseCallback, kCustomExtensionParseArg)) {

    return nullptr;

  }

  if (config->verify_fail) {

    SSL_CTX_set_cert_verify_callback(ssl_ctx.get(), VerifyFail, NULL);

  } else {

    SSL_CTX_set_cert_verify_callback(ssl_ctx.get(), VerifySucceed, NULL);

  }

  if (config->use_null_client_ca_list) {

    SSL_CTX_set_client_CA_list(ssl_ctx.get(), nullptr);

  }

  if (!SSL_CTX_set_session_id_context(ssl_ctx.get(),

                                      (const unsigned char *)sess_id_ctx,

                                      sizeof(sess_id_ctx) - 1))

    return nullptr;

  if (!config->expected_server_name.empty()) {

    SSL_CTX_set_tlsext_servername_callback(ssl_ctx.get(), ServerNameCallback);

  }

  return ssl_ctx;

}

// RetryAsync is called after a failed operation on |ssl| with return code

// |ret|. If the operation should be retried, it simulates one asynchronous

// event and returns true. Otherwise it returns false.

static bool RetryAsync(SSL *ssl, int ret) {

  // No error; don't retry.

  if (ret >= 0) {

    return false;

  }

  TestState *test_state = GetTestState(ssl);

  assert(GetTestConfig(ssl)->async);

  if (test_state->packeted_bio != nullptr &&

      PacketedBioAdvanceClock(test_state->packeted_bio)) {

    // The DTLS retransmit logic silently ignores write failures. So the test

    // may progress, allow writes through synchronously.

    AsyncBioEnforceWriteQuota(test_state->async_bio, false);

    int timeout_ret = DTLSv1_handle_timeout(ssl);

    AsyncBioEnforceWriteQuota(test_state->async_bio, true);

    if (timeout_ret < 0) {

      fprintf(stderr, "Error retransmitting.\n");

      return false;

    }

    return true;

  }

  // See if we needed to read or write more. If so, allow one byte through on

  // the appropriate end to maximally stress the state machine.

  switch (SSL_get_error(ssl, ret)) {

    case SSL_ERROR_WANT_READ:

      AsyncBioAllowRead(test_state->async_bio, 1);

      return true;

    case SSL_ERROR_WANT_WRITE:

      AsyncBioAllowWrite(test_state->async_bio, 1);

      return true;

    case SSL_ERROR_WANT_X509_LOOKUP:

      test_state->cert_ready = true;

      return true;

    default:

      return false;

  }

}

// DoRead reads from |ssl|, resolving any asynchronous operations. It returns

// the result value of the final |SSL_read| call.

static int DoRead(SSL *ssl, uint8_t *out, size_t max_out) {

  const TestConfig *config = GetTestConfig(ssl);

  TestState *test_state = GetTestState(ssl);

  int ret;

  do {

    if (config->async) {

      // The DTLS retransmit logic silently ignores write failures. So the test

      // may progress, allow writes through synchronously. |SSL_read| may

      // trigger a retransmit, so disconnect the write quota.

      AsyncBioEnforceWriteQuota(test_state->async_bio, false);

    }

    ret = config->peek_then_read ? SSL_peek(ssl, out, max_out)

                                 : SSL_read(ssl, out, max_out);

    if (config->async) {

      AsyncBioEnforceWriteQuota(test_state->async_bio, true);

    }

  } while (config->async && RetryAsync(ssl, ret));

  if (config->peek_then_read && ret > 0) {

    std::unique_ptr<uint8_t[]> buf(new uint8_t[static_cast<size_t>(ret)]);

    // SSL_peek should synchronously return the same data.

    int ret2 = SSL_peek(ssl, buf.get(), ret);

    if (ret2 != ret ||

        memcmp(buf.get(), out, ret) != 0) {

      fprintf(stderr, "First and second SSL_peek did not match.\n");

      return -1;

    }

    // SSL_read should synchronously return the same data and consume it.

    ret2 = SSL_read(ssl, buf.get(), ret);

    if (ret2 != ret ||

        memcmp(buf.get(), out, ret) != 0) {

      fprintf(stderr, "SSL_peek and SSL_read did not match.\n");

      return -1;

    }

  }

  return ret;

}

// WriteAll writes |in_len| bytes from |in| to |ssl|, resolving any asynchronous

// operations. It returns the result of the final |SSL_write| call.

static int WriteAll(SSL *ssl, const uint8_t *in, size_t in_len) {

  const TestConfig *config = GetTestConfig(ssl);

  int ret;

  do {

    ret = SSL_write(ssl, in, in_len);

    if (ret > 0) {

      in += ret;

      in_len -= ret;

    }

  } while ((config->async && RetryAsync(ssl, ret)) || (ret > 0 && in_len > 0));

  return ret;

}

// DoShutdown calls |SSL_shutdown|, resolving any asynchronous operations. It

// returns the result of the final |SSL_shutdown| call.

static int DoShutdown(SSL *ssl) {

  const TestConfig *config = GetTestConfig(ssl);

  int ret;

  do {

    ret = SSL_shutdown(ssl);

  } while (config->async && RetryAsync(ssl, ret));

  return ret;

}

static uint16_t GetProtocolVersion(const SSL *ssl) {

  uint16_t version = SSL_version(ssl);

  if (!SSL_is_dtls(ssl)) {

    return version;

  }

  return 0x0201 + ~version;

}

// CheckHandshakeProperties checks, immediately after |ssl| completes its

// initial handshake (or False Starts), whether all the properties are

// consistent with the test configuration and invariants.

static bool CheckHandshakeProperties(SSL *ssl, bool is_resume) {

  const TestConfig *config = GetTestConfig(ssl);

  if (SSL_get_current_cipher(ssl) == nullptr) {

    fprintf(stderr, "null cipher after handshake\n");

    return false;

  }

  if (is_resume &&

      (!!SSL_session_reused(ssl) == config->expect_session_miss)) {

    fprintf(stderr, "session was%s reused\n",

            SSL_session_reused(ssl) ? "" : " not");

    return false;

  }

  if (!GetTestState(ssl)->handshake_done) {

    fprintf(stderr, "handshake was not completed\n");

    return false;

  }

  if (!config->is_server) {

    bool expect_new_session =

        !config->expect_no_session &&

        (!SSL_session_reused(ssl) || config->expect_ticket_renewal) &&

        // Session tickets are sent post-handshake in TLS 1.3.

        GetProtocolVersion(ssl) < TLS1_3_VERSION;

    if (expect_new_session != GetTestState(ssl)->got_new_session) {

      fprintf(stderr,

              "new session was%s cached, but we expected the opposite\n",

              GetTestState(ssl)->got_new_session ? "" : " not");

      return false;

    }

  }

  if (!config->expected_server_name.empty()) {

    const char *server_name =

        SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name);

    if (server_name == nullptr ||

            std::string(server_name) != config->expected_server_name) {

      fprintf(stderr, "servername mismatch (got %s; want %s)\n",

              server_name, config->expected_server_name.c_str());

      return false;

    }

  }

  if (!config->expected_next_proto.empty()) {

    const uint8_t *next_proto;

    unsigned next_proto_len;

    SSL_get0_next_proto_negotiated(ssl, &next_proto, &next_proto_len);

    if (next_proto_len != config->expected_next_proto.size() ||

        memcmp(next_proto, config->expected_next_proto.data(),

               next_proto_len) != 0) {

      fprintf(stderr, "negotiated next proto mismatch\n");

      return false;

    }

  }

  if (!config->expected_alpn.empty()) {

    const uint8_t *alpn_proto;

    unsigned alpn_proto_len;

    SSL_get0_alpn_selected(ssl, &alpn_proto, &alpn_proto_len);

    if (alpn_proto_len != config->expected_alpn.size() ||

        memcmp(alpn_proto, config->expected_alpn.data(),

               alpn_proto_len) != 0) {

      fprintf(stderr, "negotiated alpn proto mismatch\n");

      return false;

    }

  }

  if (config->expect_extended_master_secret) {

    if (!SSL_get_extms_support(ssl)) {

      fprintf(stderr, "No EMS for connection when expected");

      return false;

    }

  }

  if (config->expect_verify_result) {

    int expected_verify_result = config->verify_fail ?

      X509_V_ERR_APPLICATION_VERIFICATION :

      X509_V_OK;

    if (SSL_get_verify_result(ssl) != expected_verify_result) {

      fprintf(stderr, "Wrong certificate verification result\n");

      return false;

    }

  }

  if (!config->psk.empty()) {