ceph/src/boost/boost/asio/ssl/context.hpp

   1 //
   2 // ssl/context.hpp
   3 // ~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2020 Christopher M. Kohlhoff (chris at kohlhoff dot com)
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
   8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   9 //
  10
  11 #ifndef BOOST_ASIO_SSL_CONTEXT_HPP
  12 #define BOOST_ASIO_SSL_CONTEXT_HPP
  13
  14 #if defined(_MSC_VER) && (_MSC_VER >= 1200)
  15 # pragma once
  16 #endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
  17
  18 #include <boost/asio/detail/config.hpp>
  19
  20 #include <string>
  21 #include <boost/asio/buffer.hpp>
  22 #include <boost/asio/io_context.hpp>
  23 #include <boost/asio/ssl/context_base.hpp>
  24 #include <boost/asio/ssl/detail/openssl_types.hpp>
  25 #include <boost/asio/ssl/detail/openssl_init.hpp>
  26 #include <boost/asio/ssl/detail/password_callback.hpp>
  27 #include <boost/asio/ssl/detail/verify_callback.hpp>
  28 #include <boost/asio/ssl/verify_mode.hpp>
  29
  30 #include <boost/asio/detail/push_options.hpp>
  31
  32 namespace boost {
  33 namespace asio {
  34 namespace ssl {
  35
  36 class context
  37   : public context_base,
  38     private noncopyable
  39 {
  40 public:
  41   /// The native handle type of the SSL context.
  42   typedef SSL_CTX* native_handle_type;
  43
  44   /// Constructor.
  45   BOOST_ASIO_DECL explicit context(method m);
  46
  47   /// Construct to take ownership of a native handle.
  48   BOOST_ASIO_DECL explicit context(native_handle_type native_handle);
  49
  50 #if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
  51   /// Move-construct a context from another.
  52   /**
  53    * This constructor moves an SSL context from one object to another.
  54    *
  55    * @param other The other context object from which the move will occur.
  56    *
  57    * @note Following the move, the following operations only are valid for the
  58    * moved-from object:
  59    * @li Destruction.
  60    * @li As a target for move-assignment.
  61    */
  62   BOOST_ASIO_DECL context(context&& other);
  63
  64   /// Move-assign a context from another.
  65   /**
  66    * This assignment operator moves an SSL context from one object to another.
  67    *
  68    * @param other The other context object from which the move will occur.
  69    *
  70    * @note Following the move, the following operations only are valid for the
  71    * moved-from object:
  72    * @li Destruction.
  73    * @li As a target for move-assignment.
  74    */
  75   BOOST_ASIO_DECL context& operator=(context&& other);
  76 #endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
  77
  78   /// Destructor.
  79   BOOST_ASIO_DECL ~context();
  80
  81   /// Get the underlying implementation in the native type.
  82   /**
  83    * This function may be used to obtain the underlying implementation of the
  84    * context. This is intended to allow access to context functionality that is
  85    * not otherwise provided.
  86    */
  87   BOOST_ASIO_DECL native_handle_type native_handle();
  88
  89   /// Clear options on the context.
  90   /**
  91    * This function may be used to configure the SSL options used by the context.
  92    *
  93    * @param o A bitmask of options. The available option values are defined in
  94    * the context_base class. The specified options, if currently enabled on the
  95    * context, are cleared.
  96    *
  97    * @throws boost::system::system_error Thrown on failure.
  98    *
  99    * @note Calls @c SSL_CTX_clear_options.
 100    */
 101   BOOST_ASIO_DECL void clear_options(options o);
 102
 103   /// Clear options on the context.
 104   /**
 105    * This function may be used to configure the SSL options used by the context.
 106    *
 107    * @param o A bitmask of options. The available option values are defined in
 108    * the context_base class. The specified options, if currently enabled on the
 109    * context, are cleared.
 110    *
 111    * @param ec Set to indicate what error occurred, if any.
 112    *
 113    * @note Calls @c SSL_CTX_clear_options.
 114    */
 115   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID clear_options(options o,
 116       boost::system::error_code& ec);
 117
 118   /// Set options on the context.
 119   /**
 120    * This function may be used to configure the SSL options used by the context.
 121    *
 122    * @param o A bitmask of options. The available option values are defined in
 123    * the context_base class. The options are bitwise-ored with any existing
 124    * value for the options.
 125    *
 126    * @throws boost::system::system_error Thrown on failure.
 127    *
 128    * @note Calls @c SSL_CTX_set_options.
 129    */
 130   BOOST_ASIO_DECL void set_options(options o);
 131
 132   /// Set options on the context.
 133   /**
 134    * This function may be used to configure the SSL options used by the context.
 135    *
 136    * @param o A bitmask of options. The available option values are defined in
 137    * the context_base class. The options are bitwise-ored with any existing
 138    * value for the options.
 139    *
 140    * @param ec Set to indicate what error occurred, if any.
 141    *
 142    * @note Calls @c SSL_CTX_set_options.
 143    */
 144   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID set_options(options o,
 145       boost::system::error_code& ec);
 146
 147   /// Set the peer verification mode.
 148   /**
 149    * This function may be used to configure the peer verification mode used by
 150    * the context.
 151    *
 152    * @param v A bitmask of peer verification modes. See @ref verify_mode for
 153    * available values.
 154    *
 155    * @throws boost::system::system_error Thrown on failure.
 156    *
 157    * @note Calls @c SSL_CTX_set_verify.
 158    */
 159   BOOST_ASIO_DECL void set_verify_mode(verify_mode v);
 160
 161   /// Set the peer verification mode.
 162   /**
 163    * This function may be used to configure the peer verification mode used by
 164    * the context.
 165    *
 166    * @param v A bitmask of peer verification modes. See @ref verify_mode for
 167    * available values.
 168    *
 169    * @param ec Set to indicate what error occurred, if any.
 170    *
 171    * @note Calls @c SSL_CTX_set_verify.
 172    */
 173   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID set_verify_mode(
 174       verify_mode v, boost::system::error_code& ec);
 175
 176   /// Set the peer verification depth.
 177   /**
 178    * This function may be used to configure the maximum verification depth
 179    * allowed by the context.
 180    *
 181    * @param depth Maximum depth for the certificate chain verification that
 182    * shall be allowed.
 183    *
 184    * @throws boost::system::system_error Thrown on failure.
 185    *
 186    * @note Calls @c SSL_CTX_set_verify_depth.
 187    */
 188   BOOST_ASIO_DECL void set_verify_depth(int depth);
 189
 190   /// Set the peer verification depth.
 191   /**
 192    * This function may be used to configure the maximum verification depth
 193    * allowed by the context.
 194    *
 195    * @param depth Maximum depth for the certificate chain verification that
 196    * shall be allowed.
 197    *
 198    * @param ec Set to indicate what error occurred, if any.
 199    *
 200    * @note Calls @c SSL_CTX_set_verify_depth.
 201    */
 202   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID set_verify_depth(
 203       int depth, boost::system::error_code& ec);
 204
 205   /// Set the callback used to verify peer certificates.
 206   /**
 207    * This function is used to specify a callback function that will be called
 208    * by the implementation when it needs to verify a peer certificate.
 209    *
 210    * @param callback The function object to be used for verifying a certificate.
 211    * The function signature of the handler must be:
 212    * @code bool verify_callback(
 213    *   bool preverified, // True if the certificate passed pre-verification.
 214    *   verify_context& ctx // The peer certificate and other context.
 215    * ); @endcode
 216    * The return value of the callback is true if the certificate has passed
 217    * verification, false otherwise.
 218    *
 219    * @throws boost::system::system_error Thrown on failure.
 220    *
 221    * @note Calls @c SSL_CTX_set_verify.
 222    */
 223   template <typename VerifyCallback>
 224   void set_verify_callback(VerifyCallback callback);
 225
 226   /// Set the callback used to verify peer certificates.
 227   /**
 228    * This function is used to specify a callback function that will be called
 229    * by the implementation when it needs to verify a peer certificate.
 230    *
 231    * @param callback The function object to be used for verifying a certificate.
 232    * The function signature of the handler must be:
 233    * @code bool verify_callback(
 234    *   bool preverified, // True if the certificate passed pre-verification.
 235    *   verify_context& ctx // The peer certificate and other context.
 236    * ); @endcode
 237    * The return value of the callback is true if the certificate has passed
 238    * verification, false otherwise.
 239    *
 240    * @param ec Set to indicate what error occurred, if any.
 241    *
 242    * @note Calls @c SSL_CTX_set_verify.
 243    */
 244   template <typename VerifyCallback>
 245   BOOST_ASIO_SYNC_OP_VOID set_verify_callback(VerifyCallback callback,
 246       boost::system::error_code& ec);
 247
 248   /// Load a certification authority file for performing verification.
 249   /**
 250    * This function is used to load one or more trusted certification authorities
 251    * from a file.
 252    *
 253    * @param filename The name of a file containing certification authority
 254    * certificates in PEM format.
 255    *
 256    * @throws boost::system::system_error Thrown on failure.
 257    *
 258    * @note Calls @c SSL_CTX_load_verify_locations.
 259    */
 260   BOOST_ASIO_DECL void load_verify_file(const std::string& filename);
 261
 262   /// Load a certification authority file for performing verification.
 263   /**
 264    * This function is used to load the certificates for one or more trusted
 265    * certification authorities from a file.
 266    *
 267    * @param filename The name of a file containing certification authority
 268    * certificates in PEM format.
 269    *
 270    * @param ec Set to indicate what error occurred, if any.
 271    *
 272    * @note Calls @c SSL_CTX_load_verify_locations.
 273    */
 274   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID load_verify_file(
 275       const std::string& filename, boost::system::error_code& ec);
 276
 277   /// Add certification authority for performing verification.
 278   /**
 279    * This function is used to add one trusted certification authority
 280    * from a memory buffer.
 281    *
 282    * @param ca The buffer containing the certification authority certificate.
 283    * The certificate must use the PEM format.
 284    *
 285    * @throws boost::system::system_error Thrown on failure.
 286    *
 287    * @note Calls @c SSL_CTX_get_cert_store and @c X509_STORE_add_cert.
 288    */
 289   BOOST_ASIO_DECL void add_certificate_authority(const const_buffer& ca);
 290
 291   /// Add certification authority for performing verification.
 292   /**
 293    * This function is used to add one trusted certification authority
 294    * from a memory buffer.
 295    *
 296    * @param ca The buffer containing the certification authority certificate.
 297    * The certificate must use the PEM format.
 298    *
 299    * @param ec Set to indicate what error occurred, if any.
 300    *
 301    * @note Calls @c SSL_CTX_get_cert_store and @c X509_STORE_add_cert.
 302    */
 303   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID add_certificate_authority(
 304       const const_buffer& ca, boost::system::error_code& ec);
 305
 306   /// Configures the context to use the default directories for finding
 307   /// certification authority certificates.
 308   /**
 309    * This function specifies that the context should use the default,
 310    * system-dependent directories for locating certification authority
 311    * certificates.
 312    *
 313    * @throws boost::system::system_error Thrown on failure.
 314    *
 315    * @note Calls @c SSL_CTX_set_default_verify_paths.
 316    */
 317   BOOST_ASIO_DECL void set_default_verify_paths();
 318
 319   /// Configures the context to use the default directories for finding
 320   /// certification authority certificates.
 321   /**
 322    * This function specifies that the context should use the default,
 323    * system-dependent directories for locating certification authority
 324    * certificates.
 325    *
 326    * @param ec Set to indicate what error occurred, if any.
 327    *
 328    * @note Calls @c SSL_CTX_set_default_verify_paths.
 329    */
 330   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID set_default_verify_paths(
 331       boost::system::error_code& ec);
 332
 333   /// Add a directory containing certificate authority files to be used for
 334   /// performing verification.
 335   /**
 336    * This function is used to specify the name of a directory containing
 337    * certification authority certificates. Each file in the directory must
 338    * contain a single certificate. The files must be named using the subject
 339    * name's hash and an extension of ".0".
 340    *
 341    * @param path The name of a directory containing the certificates.
 342    *
 343    * @throws boost::system::system_error Thrown on failure.
 344    *
 345    * @note Calls @c SSL_CTX_load_verify_locations.
 346    */
 347   BOOST_ASIO_DECL void add_verify_path(const std::string& path);
 348
 349   /// Add a directory containing certificate authority files to be used for
 350   /// performing verification.
 351   /**
 352    * This function is used to specify the name of a directory containing
 353    * certification authority certificates. Each file in the directory must
 354    * contain a single certificate. The files must be named using the subject
 355    * name's hash and an extension of ".0".
 356    *
 357    * @param path The name of a directory containing the certificates.
 358    *
 359    * @param ec Set to indicate what error occurred, if any.
 360    *
 361    * @note Calls @c SSL_CTX_load_verify_locations.
 362    */
 363   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID add_verify_path(
 364       const std::string& path, boost::system::error_code& ec);
 365
 366   /// Use a certificate from a memory buffer.
 367   /**
 368    * This function is used to load a certificate into the context from a buffer.
 369    *
 370    * @param certificate The buffer containing the certificate.
 371    *
 372    * @param format The certificate format (ASN.1 or PEM).
 373    *
 374    * @throws boost::system::system_error Thrown on failure.
 375    *
 376    * @note Calls @c SSL_CTX_use_certificate or SSL_CTX_use_certificate_ASN1.
 377    */
 378   BOOST_ASIO_DECL void use_certificate(
 379       const const_buffer& certificate, file_format format);
 380
 381   /// Use a certificate from a memory buffer.
 382   /**
 383    * This function is used to load a certificate into the context from a buffer.
 384    *
 385    * @param certificate The buffer containing the certificate.
 386    *
 387    * @param format The certificate format (ASN.1 or PEM).
 388    *
 389    * @param ec Set to indicate what error occurred, if any.
 390    *
 391    * @note Calls @c SSL_CTX_use_certificate or SSL_CTX_use_certificate_ASN1.
 392    */
 393   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID use_certificate(
 394       const const_buffer& certificate, file_format format,
 395       boost::system::error_code& ec);
 396
 397   /// Use a certificate from a file.
 398   /**
 399    * This function is used to load a certificate into the context from a file.
 400    *
 401    * @param filename The name of the file containing the certificate.
 402    *
 403    * @param format The file format (ASN.1 or PEM).
 404    *
 405    * @throws boost::system::system_error Thrown on failure.
 406    *
 407    * @note Calls @c SSL_CTX_use_certificate_file.
 408    */
 409   BOOST_ASIO_DECL void use_certificate_file(
 410       const std::string& filename, file_format format);
 411
 412   /// Use a certificate from a file.
 413   /**
 414    * This function is used to load a certificate into the context from a file.
 415    *
 416    * @param filename The name of the file containing the certificate.
 417    *
 418    * @param format The file format (ASN.1 or PEM).
 419    *
 420    * @param ec Set to indicate what error occurred, if any.
 421    *
 422    * @note Calls @c SSL_CTX_use_certificate_file.
 423    */
 424   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID use_certificate_file(
 425       const std::string& filename, file_format format,
 426       boost::system::error_code& ec);
 427
 428   /// Use a certificate chain from a memory buffer.
 429   /**
 430    * This function is used to load a certificate chain into the context from a
 431    * buffer.
 432    *
 433    * @param chain The buffer containing the certificate chain. The certificate
 434    * chain must use the PEM format.
 435    *
 436    * @throws boost::system::system_error Thrown on failure.
 437    *
 438    * @note Calls @c SSL_CTX_use_certificate and SSL_CTX_add_extra_chain_cert.
 439    */
 440   BOOST_ASIO_DECL void use_certificate_chain(const const_buffer& chain);
 441
 442   /// Use a certificate chain from a memory buffer.
 443   /**
 444    * This function is used to load a certificate chain into the context from a
 445    * buffer.
 446    *
 447    * @param chain The buffer containing the certificate chain. The certificate
 448    * chain must use the PEM format.
 449    *
 450    * @param ec Set to indicate what error occurred, if any.
 451    *
 452    * @note Calls @c SSL_CTX_use_certificate and SSL_CTX_add_extra_chain_cert.
 453    */
 454   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID use_certificate_chain(
 455       const const_buffer& chain, boost::system::error_code& ec);
 456
 457   /// Use a certificate chain from a file.
 458   /**
 459    * This function is used to load a certificate chain into the context from a
 460    * file.
 461    *
 462    * @param filename The name of the file containing the certificate. The file
 463    * must use the PEM format.
 464    *
 465    * @throws boost::system::system_error Thrown on failure.
 466    *
 467    * @note Calls @c SSL_CTX_use_certificate_chain_file.
 468    */
 469   BOOST_ASIO_DECL void use_certificate_chain_file(const std::string& filename);
 470
 471   /// Use a certificate chain from a file.
 472   /**
 473    * This function is used to load a certificate chain into the context from a
 474    * file.
 475    *
 476    * @param filename The name of the file containing the certificate. The file
 477    * must use the PEM format.
 478    *
 479    * @param ec Set to indicate what error occurred, if any.
 480    *
 481    * @note Calls @c SSL_CTX_use_certificate_chain_file.
 482    */
 483   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID use_certificate_chain_file(
 484       const std::string& filename, boost::system::error_code& ec);
 485
 486   /// Use a private key from a memory buffer.
 487   /**
 488    * This function is used to load a private key into the context from a buffer.
 489    *
 490    * @param private_key The buffer containing the private key.
 491    *
 492    * @param format The private key format (ASN.1 or PEM).
 493    *
 494    * @throws boost::system::system_error Thrown on failure.
 495    *
 496    * @note Calls @c SSL_CTX_use_PrivateKey or SSL_CTX_use_PrivateKey_ASN1.
 497    */
 498   BOOST_ASIO_DECL void use_private_key(
 499       const const_buffer& private_key, file_format format);
 500
 501   /// Use a private key from a memory buffer.
 502   /**
 503    * This function is used to load a private key into the context from a buffer.
 504    *
 505    * @param private_key The buffer containing the private key.
 506    *
 507    * @param format The private key format (ASN.1 or PEM).
 508    *
 509    * @param ec Set to indicate what error occurred, if any.
 510    *
 511    * @note Calls @c SSL_CTX_use_PrivateKey or SSL_CTX_use_PrivateKey_ASN1.
 512    */
 513   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID use_private_key(
 514       const const_buffer& private_key, file_format format,
 515       boost::system::error_code& ec);
 516
 517   /// Use a private key from a file.
 518   /**
 519    * This function is used to load a private key into the context from a file.
 520    *
 521    * @param filename The name of the file containing the private key.
 522    *
 523    * @param format The file format (ASN.1 or PEM).
 524    *
 525    * @throws boost::system::system_error Thrown on failure.
 526    *
 527    * @note Calls @c SSL_CTX_use_PrivateKey_file.
 528    */
 529   BOOST_ASIO_DECL void use_private_key_file(
 530       const std::string& filename, file_format format);
 531
 532   /// Use a private key from a file.
 533   /**
 534    * This function is used to load a private key into the context from a file.
 535    *
 536    * @param filename The name of the file containing the private key.
 537    *
 538    * @param format The file format (ASN.1 or PEM).
 539    *
 540    * @param ec Set to indicate what error occurred, if any.
 541    *
 542    * @note Calls @c SSL_CTX_use_PrivateKey_file.
 543    */
 544   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID use_private_key_file(
 545       const std::string& filename, file_format format,
 546       boost::system::error_code& ec);
 547
 548   /// Use an RSA private key from a memory buffer.
 549   /**
 550    * This function is used to load an RSA private key into the context from a
 551    * buffer.
 552    *
 553    * @param private_key The buffer containing the RSA private key.
 554    *
 555    * @param format The private key format (ASN.1 or PEM).
 556    *
 557    * @throws boost::system::system_error Thrown on failure.
 558    *
 559    * @note Calls @c SSL_CTX_use_RSAPrivateKey or SSL_CTX_use_RSAPrivateKey_ASN1.
 560    */
 561   BOOST_ASIO_DECL void use_rsa_private_key(
 562       const const_buffer& private_key, file_format format);
 563
 564   /// Use an RSA private key from a memory buffer.
 565   /**
 566    * This function is used to load an RSA private key into the context from a
 567    * buffer.
 568    *
 569    * @param private_key The buffer containing the RSA private key.
 570    *
 571    * @param format The private key format (ASN.1 or PEM).
 572    *
 573    * @param ec Set to indicate what error occurred, if any.
 574    *
 575    * @note Calls @c SSL_CTX_use_RSAPrivateKey or SSL_CTX_use_RSAPrivateKey_ASN1.
 576    */
 577   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID use_rsa_private_key(
 578       const const_buffer& private_key, file_format format,
 579       boost::system::error_code& ec);
 580
 581   /// Use an RSA private key from a file.
 582   /**
 583    * This function is used to load an RSA private key into the context from a
 584    * file.
 585    *
 586    * @param filename The name of the file containing the RSA private key.
 587    *
 588    * @param format The file format (ASN.1 or PEM).
 589    *
 590    * @throws boost::system::system_error Thrown on failure.
 591    *
 592    * @note Calls @c SSL_CTX_use_RSAPrivateKey_file.
 593    */
 594   BOOST_ASIO_DECL void use_rsa_private_key_file(
 595       const std::string& filename, file_format format);
 596
 597   /// Use an RSA private key from a file.
 598   /**
 599    * This function is used to load an RSA private key into the context from a
 600    * file.
 601    *
 602    * @param filename The name of the file containing the RSA private key.
 603    *
 604    * @param format The file format (ASN.1 or PEM).
 605    *
 606    * @param ec Set to indicate what error occurred, if any.
 607    *
 608    * @note Calls @c SSL_CTX_use_RSAPrivateKey_file.
 609    */
 610   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID use_rsa_private_key_file(
 611       const std::string& filename, file_format format,
 612       boost::system::error_code& ec);
 613
 614   /// Use the specified memory buffer to obtain the temporary Diffie-Hellman
 615   /// parameters.
 616   /**
 617    * This function is used to load Diffie-Hellman parameters into the context
 618    * from a buffer.
 619    *
 620    * @param dh The memory buffer containing the Diffie-Hellman parameters. The
 621    * buffer must use the PEM format.
 622    *
 623    * @throws boost::system::system_error Thrown on failure.
 624    *
 625    * @note Calls @c SSL_CTX_set_tmp_dh.
 626    */
 627   BOOST_ASIO_DECL void use_tmp_dh(const const_buffer& dh);
 628
 629   /// Use the specified memory buffer to obtain the temporary Diffie-Hellman
 630   /// parameters.
 631   /**
 632    * This function is used to load Diffie-Hellman parameters into the context
 633    * from a buffer.
 634    *
 635    * @param dh The memory buffer containing the Diffie-Hellman parameters. The
 636    * buffer must use the PEM format.
 637    *
 638    * @param ec Set to indicate what error occurred, if any.
 639    *
 640    * @note Calls @c SSL_CTX_set_tmp_dh.
 641    */
 642   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID use_tmp_dh(
 643       const const_buffer& dh, boost::system::error_code& ec);
 644
 645   /// Use the specified file to obtain the temporary Diffie-Hellman parameters.
 646   /**
 647    * This function is used to load Diffie-Hellman parameters into the context
 648    * from a file.
 649    *
 650    * @param filename The name of the file containing the Diffie-Hellman
 651    * parameters. The file must use the PEM format.
 652    *
 653    * @throws boost::system::system_error Thrown on failure.
 654    *
 655    * @note Calls @c SSL_CTX_set_tmp_dh.
 656    */
 657   BOOST_ASIO_DECL void use_tmp_dh_file(const std::string& filename);
 658
 659   /// Use the specified file to obtain the temporary Diffie-Hellman parameters.
 660   /**
 661    * This function is used to load Diffie-Hellman parameters into the context
 662    * from a file.
 663    *
 664    * @param filename The name of the file containing the Diffie-Hellman
 665    * parameters. The file must use the PEM format.
 666    *
 667    * @param ec Set to indicate what error occurred, if any.
 668    *
 669    * @note Calls @c SSL_CTX_set_tmp_dh.
 670    */
 671   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID use_tmp_dh_file(
 672       const std::string& filename, boost::system::error_code& ec);
 673
 674   /// Set the password callback.
 675   /**
 676    * This function is used to specify a callback function to obtain password
 677    * information about an encrypted key in PEM format.
 678    *
 679    * @param callback The function object to be used for obtaining the password.
 680    * The function signature of the handler must be:
 681    * @code std::string password_callback(
 682    *   std::size_t max_length,  // The maximum size for a password.
 683    *   password_purpose purpose // Whether password is for reading or writing.
 684    * ); @endcode
 685    * The return value of the callback is a string containing the password.
 686    *
 687    * @throws boost::system::system_error Thrown on failure.
 688    *
 689    * @note Calls @c SSL_CTX_set_default_passwd_cb.
 690    */
 691   template <typename PasswordCallback>
 692   void set_password_callback(PasswordCallback callback);
 693
 694   /// Set the password callback.
 695   /**
 696    * This function is used to specify a callback function to obtain password
 697    * information about an encrypted key in PEM format.
 698    *
 699    * @param callback The function object to be used for obtaining the password.
 700    * The function signature of the handler must be:
 701    * @code std::string password_callback(
 702    *   std::size_t max_length,  // The maximum size for a password.
 703    *   password_purpose purpose // Whether password is for reading or writing.
 704    * ); @endcode
 705    * The return value of the callback is a string containing the password.
 706    *
 707    * @param ec Set to indicate what error occurred, if any.
 708    *
 709    * @note Calls @c SSL_CTX_set_default_passwd_cb.
 710    */
 711   template <typename PasswordCallback>
 712   BOOST_ASIO_SYNC_OP_VOID set_password_callback(PasswordCallback callback,
 713       boost::system::error_code& ec);
 714
 715 private:
 716   struct bio_cleanup;
 717   struct x509_cleanup;
 718   struct evp_pkey_cleanup;
 719   struct rsa_cleanup;
 720   struct dh_cleanup;
 721
 722   // Helper function used to set a peer certificate verification callback.
 723   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID do_set_verify_callback(
 724       detail::verify_callback_base* callback, boost::system::error_code& ec);
 725
 726   // Callback used when the SSL implementation wants to verify a certificate.
 727   BOOST_ASIO_DECL static int verify_callback_function(
 728       int preverified, X509_STORE_CTX* ctx);
 729
 730   // Helper function used to set a password callback.
 731   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID do_set_password_callback(
 732       detail::password_callback_base* callback, boost::system::error_code& ec);
 733
 734   // Callback used when the SSL implementation wants a password.
 735   BOOST_ASIO_DECL static int password_callback_function(
 736       char* buf, int size, int purpose, void* data);
 737
 738   // Helper function to set the temporary Diffie-Hellman parameters from a BIO.
 739   BOOST_ASIO_DECL BOOST_ASIO_SYNC_OP_VOID do_use_tmp_dh(
 740       BIO* bio, boost::system::error_code& ec);
 741
 742   // Helper function to make a BIO from a memory buffer.
 743   BOOST_ASIO_DECL BIO* make_buffer_bio(const const_buffer& b);
 744
 745   // The underlying native implementation.
 746   native_handle_type handle_;
 747
 748   // Ensure openssl is initialised.
 749   boost::asio::ssl::detail::openssl_init<> init_;
 750 };
 751
 752 } // namespace ssl
 753 } // namespace asio
 754 } // namespace boost
 755
 756 #include <boost/asio/detail/pop_options.hpp>
 757
 758 #include <boost/asio/ssl/impl/context.hpp>
 759 #if defined(BOOST_ASIO_HEADER_ONLY)
 760 # include <boost/asio/ssl/impl/context.ipp>
 761 #endif // defined(BOOST_ASIO_HEADER_ONLY)
 762
 763 #endif // BOOST_ASIO_SSL_CONTEXT_HPP