diff --git a/tool/CMakeLists.txt b/tool/CMakeLists.txt
index e504838..03c1c21 100644
--- a/tool/CMakeLists.txt
+++ b/tool/CMakeLists.txt
@@ -5,10 +5,12 @@
 
 	args.cc
 	client.cc
+	server.cc
 	const.cc
 	pkcs12.cc
 	speed.cc
 	tool.cc
+	transport_common.cc
 )
 
 if (APPLE OR WIN32)
diff --git a/tool/client.cc b/tool/client.cc
index 21ea8ba..d73d408 100644
--- a/tool/client.cc
+++ b/tool/client.cc
@@ -25,23 +25,11 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 
-#if !defined(OPENSSL_WINDOWS)
-#include <arpa/inet.h>
-#include <fcntl.h>
-#include <netdb.h>
-#include <netinet/in.h>
-#include <sys/select.h>
-#include <unistd.h>
-#else
-#include <WinSock2.h>
-#include <WS2tcpip.h>
-typedef int socklen_t;
-#endif
-
 #include <openssl/err.h>
 #include <openssl/ssl.h>
 
 #include "internal.h"
+#include "transport_common.h"
 
 
 static const struct argument kArguments[] = {
@@ -58,200 +46,6 @@
     },
 };
 
-// Connect sets |*out_sock| to be a socket connected to the destination given
-// in |hostname_and_port|, which should be of the form "www.example.com:123".
-// It returns true on success and false otherwise.
-static bool Connect(int *out_sock, const std::string &hostname_and_port) {
-  const size_t colon_offset = hostname_and_port.find_last_of(':');
-  std::string hostname, port;
-
-  if (colon_offset == std::string::npos) {
-    hostname = hostname_and_port;
-    port = "443";
-  } else {
-    hostname = hostname_and_port.substr(0, colon_offset);
-    port = hostname_and_port.substr(colon_offset + 1);
-  }
-
-  struct addrinfo hint, *result;
-  memset(&hint, 0, sizeof(hint));
-  hint.ai_family = AF_UNSPEC;
-  hint.ai_socktype = SOCK_STREAM;
-
-  int ret = getaddrinfo(hostname.c_str(), port.c_str(), &hint, &result);
-  if (ret != 0) {
-    fprintf(stderr, "getaddrinfo returned: %s\n", gai_strerror(ret));
-    return false;
-  }
-
-  bool ok = false;
-  char buf[256];
-
-  *out_sock =
-      socket(result->ai_family, result->ai_socktype, result->ai_protocol);
-  if (*out_sock < 0) {
-    perror("socket");
-    goto out;
-  }
-
-  switch (result->ai_family) {
-    case AF_INET: {
-      struct sockaddr_in *sin =
-          reinterpret_cast<struct sockaddr_in *>(result->ai_addr);
-      fprintf(stderr, "Connecting to %s:%d\n",
-              inet_ntop(result->ai_family, &sin->sin_addr, buf, sizeof(buf)),
-              ntohs(sin->sin_port));
-      break;
-    }
-    case AF_INET6: {
-      struct sockaddr_in6 *sin6 =
-          reinterpret_cast<struct sockaddr_in6 *>(result->ai_addr);
-      fprintf(stderr, "Connecting to [%s]:%d\n",
-              inet_ntop(result->ai_family, &sin6->sin6_addr, buf, sizeof(buf)),
-              ntohs(sin6->sin6_port));
-      break;
-    }
-  }
-
-  if (connect(*out_sock, result->ai_addr, result->ai_addrlen) != 0) {
-    perror("connect");
-    goto out;
-  }
-  ok = true;
-
-out:
-  freeaddrinfo(result);
-  return ok;
-}
-
-static void PrintConnectionInfo(const SSL *ssl) {
-  const SSL_CIPHER *cipher = SSL_get_current_cipher(ssl);
-
-  fprintf(stderr, "  Version: %s\n", SSL_get_version(ssl));
-  fprintf(stderr, "  Cipher: %s\n", SSL_CIPHER_get_name(cipher));
-  fprintf(stderr, "  Secure renegotiation: %s\n",
-          SSL_get_secure_renegotiation_support(ssl) ? "yes" : "no");
-}
-
-static bool SocketSetNonBlocking(int sock, bool is_non_blocking) {
-  bool ok;
-
-#if defined(OPENSSL_WINDOWS)
-  u_long arg = is_non_blocking;
-  ok = 0 == ioctlsocket(sock, FIOBIO, &arg);
-#else
-  int flags = fcntl(sock, F_GETFL, 0);
-  if (flags < 0) {
-    return false;
-  }
-  if (is_non_blocking) {
-    flags |= O_NONBLOCK;
-  } else {
-    flags &= ~O_NONBLOCK;
-  }
-  ok = 0 == fcntl(sock, F_SETFL, flags);
-#endif
-  if (!ok) {
-    fprintf(stderr, "Failed to set socket non-blocking.\n");
-  }
-  return ok;
-}
-
-// PrintErrorCallback is a callback function from OpenSSL's
-// |ERR_print_errors_cb| that writes errors to a given |FILE*|.
-static int PrintErrorCallback(const char *str, size_t len, void *ctx) {
-  fwrite(str, len, 1, reinterpret_cast<FILE*>(ctx));
-  return 1;
-}
-
-bool TransferData(SSL *ssl, int sock) {
-  bool stdin_open = true;
-
-  fd_set read_fds;
-  FD_ZERO(&read_fds);
-
-  if (!SocketSetNonBlocking(sock, true)) {
-    return false;
-  }
-
-  for (;;) {
-    if (stdin_open) {
-      FD_SET(0, &read_fds);
-    }
-    FD_SET(sock, &read_fds);
-
-    int ret = select(sock + 1, &read_fds, NULL, NULL, NULL);
-    if (ret <= 0) {
-      perror("select");
-      return false;
-    }
-
-    if (FD_ISSET(0, &read_fds)) {
-      uint8_t buffer[512];
-      ssize_t n;
-
-      do {
-        n = read(0, buffer, sizeof(buffer));
-      } while (n == -1 && errno == EINTR);
-
-      if (n == 0) {
-        FD_CLR(0, &read_fds);
-        stdin_open = false;
-        shutdown(sock, SHUT_WR);
-        continue;
-      } else if (n < 0) {
-        perror("read from stdin");
-        return false;
-      }
-
-      if (!SocketSetNonBlocking(sock, false)) {
-        return false;
-      }
-      int ssl_ret = SSL_write(ssl, buffer, n);
-      if (!SocketSetNonBlocking(sock, true)) {
-        return false;
-      }
-
-      if (ssl_ret <= 0) {
-        int ssl_err = SSL_get_error(ssl, ssl_ret);
-        fprintf(stderr, "Error while writing: %d\n", ssl_err);
-        ERR_print_errors_cb(PrintErrorCallback, stderr);
-        return false;
-      } else if (ssl_ret != n) {
-        fprintf(stderr, "Short write from SSL_write.\n");
-        return false;
-      }
-    }
-
-    if (FD_ISSET(sock, &read_fds)) {
-      uint8_t buffer[512];
-      int ssl_ret = SSL_read(ssl, buffer, sizeof(buffer));
-
-      if (ssl_ret < 0) {
-        int ssl_err = SSL_get_error(ssl, ssl_ret);
-        if (ssl_err == SSL_ERROR_WANT_READ) {
-          continue;
-        }
-        fprintf(stderr, "Error while reading: %d\n", ssl_err);
-        ERR_print_errors_cb(PrintErrorCallback, stderr);
-        return false;
-      } else if (ssl_ret == 0) {
-        return true;
-      }
-
-      ssize_t n;
-      do {
-        n = write(1, buffer, ssl_ret);
-      } while (n == -1 && errno == EINTR);
-
-      if (n != ssl_ret) {
-        fprintf(stderr, "Short write to stderr.\n");
-        return false;
-      }
-    }
-  }
-}
-
 bool Client(const std::vector<std::string> &args) {
   std::map<std::string, std::string> args_map;
 
@@ -272,8 +66,10 @@
     SSL_CTX_set_keylog_bio(ctx, keylog_bio);
   }
 
-  if (args_map.count("-cipher") != 0) {
-    SSL_CTX_set_cipher_list(ctx, args_map["-cipher"].c_str());
+  if (args_map.count("-cipher") != 0 &&
+      !SSL_CTX_set_cipher_list(ctx, args_map["-cipher"].c_str())) {
+    fprintf(stderr, "Failed setting cipher list\n");
+    return false;
   }
 
   int sock = -1;
@@ -303,4 +99,5 @@
   return ok;
 }
 
-#endif  // !OPENSSL_WINDOWS
\ No newline at end of file
+
+#endif  // !OPENSSL_WINDOWS
diff --git a/tool/server.cc b/tool/server.cc
new file mode 100644
index 0000000..bc3739f
--- /dev/null
+++ b/tool/server.cc
@@ -0,0 +1,111 @@
+/* Copyright (c) 2014, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/base.h>
+
+// TODO(davidben): bssl client does not work on Windows.
+#if !defined(OPENSSL_WINDOWS)
+
+#include <string>
+#include <vector>
+
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/types.h>
+
+#include <openssl/err.h>
+#include <openssl/ssl.h>
+
+#include "internal.h"
+#include "transport_common.h"
+
+
+static const struct argument kArguments[] = {
+    {
+     "-accept", true,
+     "The port of the server to bind on; eg 45102",
+    },
+    {
+     "-cipher", false,
+     "An OpenSSL-style cipher suite string that configures the offered ciphers",
+    },
+    {
+      "-key", false,
+      "Private-key file to use (default is server.pem)",
+    },
+    {
+     "", false, "",
+    },
+};
+
+bool Server(const std::vector<std::string> &args) {
+  std::map<std::string, std::string> args_map;
+
+  if (!ParseKeyValueArguments(&args_map, args, kArguments)) {
+    PrintUsage(kArguments);
+    return false;
+  }
+
+  SSL_CTX *ctx = SSL_CTX_new(SSLv23_server_method());
+  SSL_CTX_set_options(ctx, SSL_OP_NO_SSLv3);
+
+  // Server authentication is required.
+  std::string key_file = "server.pem";
+  if (args_map.count("-key") != 0) {
+    key_file = args_map["-key"];
+  }
+  if (SSL_CTX_use_PrivateKey_file(ctx, key_file.c_str(), SSL_FILETYPE_PEM) <= 0) {
+    fprintf(stderr, "Failed to load private key: %s\n", key_file.c_str());
+    return false;
+  }
+  if (SSL_CTX_use_certificate_chain_file(ctx, key_file.c_str()) != 1) {
+    fprintf(stderr, "Failed to load cert chain: %s\n", key_file.c_str());
+    return false;
+  }
+
+  if (args_map.count("-cipher") != 0 &&
+      !SSL_CTX_set_cipher_list(ctx, args_map["-cipher"].c_str())) {
+    fprintf(stderr, "Failed setting cipher list\n");
+    return false;
+  }
+
+  int sock = -1;
+  if (!Accept(&sock, args_map["-accept"])) {
+    return false;
+  }
+
+  BIO *bio = BIO_new_socket(sock, BIO_CLOSE);
+  SSL *ssl = SSL_new(ctx);
+  SSL_set_bio(ssl, bio, bio);
+
+  int ret = SSL_accept(ssl);
+  if (ret != 1) {
+    int ssl_err = SSL_get_error(ssl, ret);
+    fprintf(stderr, "Error while connecting: %d\n", ssl_err);
+    ERR_print_errors_cb(PrintErrorCallback, stderr);
+    return false;
+  }
+
+  fprintf(stderr, "Connected.\n");
+  PrintConnectionInfo(ssl);
+
+  bool ok = TransferData(ssl, sock);
+
+  SSL_free(ssl);
+  SSL_CTX_free(ctx);
+  return ok;
+}
+
+
+#endif  // !OPENSSL_WINDOWS
diff --git a/tool/tool.cc b/tool/tool.cc
index f35cc7c..a57cd16 100644
--- a/tool/tool.cc
+++ b/tool/tool.cc
@@ -21,12 +21,13 @@
 
 #if !defined(OPENSSL_WINDOWS)
 bool Client(const std::vector<std::string> &args);
+bool Server(const std::vector<std::string> &args);
 #endif
 bool DoPKCS12(const std::vector<std::string> &args);
 bool Speed(const std::vector<std::string> &args);
 
 static void usage(const char *name) {
-  printf("Usage: %s [speed|client|pkcs12]\n", name);
+  printf("Usage: %s [speed|client|server|pkcs12]\n", name);
 }
 
 int main(int argc, char **argv) {
@@ -47,6 +48,8 @@
 #if !defined(OPENSSL_WINDOWS)
   } else if (tool == "s_client" || tool == "client") {
     return !Client(args);
+  } else if (tool == "s_server" || tool == "server") {
+    return !Server(args);
 #endif
   } else if (tool == "pkcs12") {
     return !DoPKCS12(args);
diff --git a/tool/transport_common.cc b/tool/transport_common.cc
new file mode 100644
index 0000000..528dd3e
--- /dev/null
+++ b/tool/transport_common.cc
@@ -0,0 +1,276 @@
+/* Copyright (c) 2014, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/base.h>
+
+// TODO(davidben): bssl client does not work on Windows.
+#if !defined(OPENSSL_WINDOWS)
+
+#include <string>
+#include <vector>
+
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#if !defined(OPENSSL_WINDOWS)
+#include <arpa/inet.h>
+#include <fcntl.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <sys/select.h>
+#include <unistd.h>
+#else
+#include <WinSock2.h>
+#include <WS2tcpip.h>
+typedef int socklen_t;
+#endif
+
+#include <openssl/err.h>
+#include <openssl/ssl.h>
+
+#include "internal.h"
+
+
+// Connect sets |*out_sock| to be a socket connected to the destination given
+// in |hostname_and_port|, which should be of the form "www.example.com:123".
+// It returns true on success and false otherwise.
+bool Connect(int *out_sock, const std::string &hostname_and_port) {
+  const size_t colon_offset = hostname_and_port.find_last_of(':');
+  std::string hostname, port;
+
+  if (colon_offset == std::string::npos) {
+    hostname = hostname_and_port;
+    port = "443";
+  } else {
+    hostname = hostname_and_port.substr(0, colon_offset);
+    port = hostname_and_port.substr(colon_offset + 1);
+  }
+
+  struct addrinfo hint, *result;
+  memset(&hint, 0, sizeof(hint));
+  hint.ai_family = AF_UNSPEC;
+  hint.ai_socktype = SOCK_STREAM;
+
+  int ret = getaddrinfo(hostname.c_str(), port.c_str(), &hint, &result);
+  if (ret != 0) {
+    fprintf(stderr, "getaddrinfo returned: %s\n", gai_strerror(ret));
+    return false;
+  }
+
+  bool ok = false;
+  char buf[256];
+
+  *out_sock =
+      socket(result->ai_family, result->ai_socktype, result->ai_protocol);
+  if (*out_sock < 0) {
+    perror("socket");
+    goto out;
+  }
+
+  switch (result->ai_family) {
+    case AF_INET: {
+      struct sockaddr_in *sin =
+          reinterpret_cast<struct sockaddr_in *>(result->ai_addr);
+      fprintf(stderr, "Connecting to %s:%d\n",
+              inet_ntop(result->ai_family, &sin->sin_addr, buf, sizeof(buf)),
+              ntohs(sin->sin_port));
+      break;
+    }
+    case AF_INET6: {
+      struct sockaddr_in6 *sin6 =
+          reinterpret_cast<struct sockaddr_in6 *>(result->ai_addr);
+      fprintf(stderr, "Connecting to [%s]:%d\n",
+              inet_ntop(result->ai_family, &sin6->sin6_addr, buf, sizeof(buf)),
+              ntohs(sin6->sin6_port));
+      break;
+    }
+  }
+
+  if (connect(*out_sock, result->ai_addr, result->ai_addrlen) != 0) {
+    perror("connect");
+    goto out;
+  }
+  ok = true;
+
+out:
+  freeaddrinfo(result);
+  return ok;
+}
+
+bool Accept(int *out_sock, const std::string &port) {
+  struct sockaddr_in addr, cli_addr;
+  socklen_t cli_addr_len = sizeof(cli_addr);
+  memset(&addr, 0, sizeof(addr));
+
+  addr.sin_family = AF_INET;
+  addr.sin_addr.s_addr = INADDR_ANY;
+  addr.sin_port = htons(atoi(port.c_str()));
+
+  bool ok = false;
+  int server_sock = -1;
+
+  server_sock =
+      socket(addr.sin_family, SOCK_STREAM, 0);
+  if (server_sock < 0) {
+    perror("socket");
+    goto out;
+  }
+
+  if (bind(server_sock, (struct sockaddr*)&addr, sizeof(addr)) != 0) {
+    perror("connect");
+    goto out;
+  }
+  listen(server_sock, 1);
+  *out_sock = accept(server_sock, (struct sockaddr*)&cli_addr, &cli_addr_len);
+
+  ok = true;
+
+out:
+  close(server_sock);
+  return ok;
+}
+
+void PrintConnectionInfo(const SSL *ssl) {
+  const SSL_CIPHER *cipher = SSL_get_current_cipher(ssl);
+
+  fprintf(stderr, "  Version: %s\n", SSL_get_version(ssl));
+  fprintf(stderr, "  Cipher: %s\n", SSL_CIPHER_get_name(cipher));
+  fprintf(stderr, "  Secure renegotiation: %s\n",
+          SSL_get_secure_renegotiation_support(ssl) ? "yes" : "no");
+}
+
+bool SocketSetNonBlocking(int sock, bool is_non_blocking) {
+  bool ok;
+
+#if defined(OPENSSL_WINDOWS)
+  u_long arg = is_non_blocking;
+  ok = 0 == ioctlsocket(sock, FIOBIO, &arg);
+#else
+  int flags = fcntl(sock, F_GETFL, 0);
+  if (flags < 0) {
+    return false;
+  }
+  if (is_non_blocking) {
+    flags |= O_NONBLOCK;
+  } else {
+    flags &= ~O_NONBLOCK;
+  }
+  ok = 0 == fcntl(sock, F_SETFL, flags);
+#endif
+  if (!ok) {
+    fprintf(stderr, "Failed to set socket non-blocking.\n");
+  }
+  return ok;
+}
+
+// PrintErrorCallback is a callback function from OpenSSL's
+// |ERR_print_errors_cb| that writes errors to a given |FILE*|.
+int PrintErrorCallback(const char *str, size_t len, void *ctx) {
+  fwrite(str, len, 1, reinterpret_cast<FILE*>(ctx));
+  return 1;
+}
+
+bool TransferData(SSL *ssl, int sock) {
+  bool stdin_open = true;
+
+  fd_set read_fds;
+  FD_ZERO(&read_fds);
+
+  if (!SocketSetNonBlocking(sock, true)) {
+    return false;
+  }
+
+  for (;;) {
+    if (stdin_open) {
+      FD_SET(0, &read_fds);
+    }
+    FD_SET(sock, &read_fds);
+
+    int ret = select(sock + 1, &read_fds, NULL, NULL, NULL);
+    if (ret <= 0) {
+      perror("select");
+      return false;
+    }
+
+    if (FD_ISSET(0, &read_fds)) {
+      uint8_t buffer[512];
+      ssize_t n;
+
+      do {
+        n = read(0, buffer, sizeof(buffer));
+      } while (n == -1 && errno == EINTR);
+
+      if (n == 0) {
+        FD_CLR(0, &read_fds);
+        stdin_open = false;
+        shutdown(sock, SHUT_WR);
+        continue;
+      } else if (n < 0) {
+        perror("read from stdin");
+        return false;
+      }
+
+      if (!SocketSetNonBlocking(sock, false)) {
+        return false;
+      }
+      int ssl_ret = SSL_write(ssl, buffer, n);
+      if (!SocketSetNonBlocking(sock, true)) {
+        return false;
+      }
+
+      if (ssl_ret <= 0) {
+        int ssl_err = SSL_get_error(ssl, ssl_ret);
+        fprintf(stderr, "Error while writing: %d\n", ssl_err);
+        ERR_print_errors_cb(PrintErrorCallback, stderr);
+        return false;
+      } else if (ssl_ret != n) {
+        fprintf(stderr, "Short write from SSL_write.\n");
+        return false;
+      }
+    }
+
+    if (FD_ISSET(sock, &read_fds)) {
+      uint8_t buffer[512];
+      int ssl_ret = SSL_read(ssl, buffer, sizeof(buffer));
+
+      if (ssl_ret < 0) {
+        int ssl_err = SSL_get_error(ssl, ssl_ret);
+        if (ssl_err == SSL_ERROR_WANT_READ) {
+          continue;
+        }
+        fprintf(stderr, "Error while reading: %d\n", ssl_err);
+        ERR_print_errors_cb(PrintErrorCallback, stderr);
+        return false;
+      } else if (ssl_ret == 0) {
+        return true;
+      }
+
+      ssize_t n;
+      do {
+        n = write(1, buffer, ssl_ret);
+      } while (n == -1 && errno == EINTR);
+
+      if (n != ssl_ret) {
+        fprintf(stderr, "Short write to stderr.\n");
+        return false;
+      }
+    }
+  }
+}
+
+
+#endif  // !OPENSSL_WINDOWS
diff --git a/tool/transport_common.h b/tool/transport_common.h
new file mode 100644
index 0000000..6b96659
--- /dev/null
+++ b/tool/transport_common.h
@@ -0,0 +1,41 @@
+/* Copyright (c) 2014, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#ifndef OPENSSL_HEADER_TOOL_TRANSPORT_COMMON_H
+#define OPENSSL_HEADER_TOOL_TRANSPORT_COMMON_H
+
+#include <openssl/ssl.h>
+#include <string.h>
+
+
+// Connect sets |*out_sock| to be a socket connected to the destination given
+// in |hostname_and_port|, which should be of the form "www.example.com:123".
+// It returns true on success and false otherwise.
+bool Connect(int *out_sock, const std::string &hostname_and_port);
+
+// Accept sets |*out_sock| to be a socket connected to the port given
+// in |port|, which should be of the form "123".
+// It returns true on success and false otherwise.
+bool Accept(int *out_sock, const std::string &port);
+
+void PrintConnectionInfo(const SSL *ssl);
+
+bool SocketSetNonBlocking(int sock, bool is_non_blocking);
+
+int PrintErrorCallback(const char *str, size_t len, void *ctx);
+
+bool TransferData(SSL *ssl, int sock);
+
+
+#endif  /* !OPENSSL_HEADER_TOOL_TRANSPORT_COMMON_H */