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

   1 //
   2 // ssl/context.hpp
   3 // ~~~~~~~~~~~~~~~
   4 //
   5 // Copyright (c) 2003-2016 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 #if defined(BOOST_ASIO_ENABLE_OLD_SSL)
  21 # include <boost/asio/ssl/basic_context.hpp>
  22 # include <boost/asio/ssl/context_service.hpp>
  23 #else // defined(BOOST_ASIO_ENABLE_OLD_SSL)
  24 # include <string>
  25 # include <boost/asio/buffer.hpp>
  26 # include <boost/asio/io_service.hpp>
  27 # include <boost/asio/ssl/context_base.hpp>
  28 # include <boost/asio/ssl/detail/openssl_types.hpp>
  29 # include <boost/asio/ssl/detail/openssl_init.hpp>
  30 # include <boost/asio/ssl/detail/password_callback.hpp>
  31 # include <boost/asio/ssl/detail/verify_callback.hpp>
  32 # include <boost/asio/ssl/verify_mode.hpp>
  33 #endif // defined(BOOST_ASIO_ENABLE_OLD_SSL)
  34
  35 #include <boost/asio/detail/push_options.hpp>
  36
  37 namespace boost {
  38 namespace asio {
  39 namespace ssl {
  40
  41 #if defined(BOOST_ASIO_ENABLE_OLD_SSL)
  42
  43 /// Typedef for the typical usage of context.
  44 typedef basic_context<context_service> context;
  45
  46 #else // defined(BOOST_ASIO_ENABLE_OLD_SSL)
  47
  48 class context
  49   : public context_base,
  50     private noncopyable
  51 {
  52 public:
  53   /// The native handle type of the SSL context.
  54   typedef SSL_CTX* native_handle_type;
  55
  56   /// (Deprecated: Use native_handle_type.) The native type of the SSL context.
  57   typedef SSL_CTX* impl_type;
  58
  59   /// Constructor.
  60   BOOST_ASIO_DECL explicit context(method m);
  61
  62   /// Deprecated constructor taking a reference to an io_service object.
  63   BOOST_ASIO_DECL context(boost::asio::io_service&, method m);
  64
  65 #if defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
  66   /// Move-construct a context from another.
  67   /**
  68    * This constructor moves an SSL context from one object to another.
  69    *
  70    * @param other The other context object from which the move will occur.
  71    *
  72    * @note Following the move, the following operations only are valid for the
  73    * moved-from object:
  74    * @li Destruction.
  75    * @li As a target for move-assignment.
  76    */
  77   BOOST_ASIO_DECL context(context&& other);
  78
  79   /// Move-assign a context from another.
  80   /**
  81    * This assignment operator moves an SSL context from one object to another.
  82    *
  83    * @param other The other context object from which the move will occur.
  84    *
  85    * @note Following the move, the following operations only are valid for the
  86    * moved-from object:
  87    * @li Destruction.
  88    * @li As a target for move-assignment.
  89    */
  90   BOOST_ASIO_DECL context& operator=(context&& other);
  91 #endif // defined(BOOST_ASIO_HAS_MOVE) || defined(GENERATING_DOCUMENTATION)
  92
  93   /// Destructor.
  94   BOOST_ASIO_DECL ~context();
  95
  96   /// Get the underlying implementation in the native type.
  97   /**
  98    * This function may be used to obtain the underlying implementation of the
  99    * context. This is intended to allow access to context functionality that is
 100    * not otherwise provided.
 101    */
 102   BOOST_ASIO_DECL native_handle_type native_handle();
 103
 104   /// (Deprecated: Use native_handle().) Get the underlying implementation in
 105   /// the native type.
 106   /**
 107    * This function may be used to obtain the underlying implementation of the
 108    * context. This is intended to allow access to context functionality that is
 109    * not otherwise provided.
 110    */
 111   BOOST_ASIO_DECL impl_type impl();
 112
 113   /// Clear options on the context.
 114   /**
 115    * This function may be used to configure the SSL options used by the context.
 116    *
 117    * @param o A bitmask of options. The available option values are defined in
 118    * the context_base class. The specified options, if currently enabled on the
 119    * context, are cleared.
 120    *
 121    * @throws boost::system::system_error Thrown on failure.
 122    *
 123    * @note Calls @c SSL_CTX_clear_options.
 124    */
 125   BOOST_ASIO_DECL void clear_options(options o);
 126
 127   /// Clear options on the context.
 128   /**
 129    * This function may be used to configure the SSL options used by the context.
 130    *
 131    * @param o A bitmask of options. The available option values are defined in
 132    * the context_base class. The specified options, if currently enabled on the
 133    * context, are cleared.
 134    *
 135    * @param ec Set to indicate what error occurred, if any.
 136    *
 137    * @note Calls @c SSL_CTX_clear_options.
 138    */
 139   BOOST_ASIO_DECL boost::system::error_code clear_options(options o,
 140       boost::system::error_code& ec);
 141
 142   /// Set options on the context.
 143   /**
 144    * This function may be used to configure the SSL options used by the context.
 145    *
 146    * @param o A bitmask of options. The available option values are defined in
 147    * the context_base class. The options are bitwise-ored with any existing
 148    * value for the options.
 149    *
 150    * @throws boost::system::system_error Thrown on failure.
 151    *
 152    * @note Calls @c SSL_CTX_set_options.
 153    */
 154   BOOST_ASIO_DECL void set_options(options o);
 155
 156   /// Set options on the context.
 157   /**
 158    * This function may be used to configure the SSL options used by the context.
 159    *
 160    * @param o A bitmask of options. The available option values are defined in
 161    * the context_base class. The options are bitwise-ored with any existing
 162    * value for the options.
 163    *
 164    * @param ec Set to indicate what error occurred, if any.
 165    *
 166    * @note Calls @c SSL_CTX_set_options.
 167    */
 168   BOOST_ASIO_DECL boost::system::error_code set_options(options o,
 169       boost::system::error_code& ec);
 170
 171   /// Set the peer verification mode.
 172   /**
 173    * This function may be used to configure the peer verification mode used by
 174    * the context.
 175    *
 176    * @param v A bitmask of peer verification modes. See @ref verify_mode for
 177    * available values.
 178    *
 179    * @throws boost::system::system_error Thrown on failure.
 180    *
 181    * @note Calls @c SSL_CTX_set_verify.
 182    */
 183   BOOST_ASIO_DECL void set_verify_mode(verify_mode v);
 184
 185   /// Set the peer verification mode.
 186   /**
 187    * This function may be used to configure the peer verification mode used by
 188    * the context.
 189    *
 190    * @param v A bitmask of peer verification modes. See @ref verify_mode for
 191    * available values.
 192    *
 193    * @param ec Set to indicate what error occurred, if any.
 194    *
 195    * @note Calls @c SSL_CTX_set_verify.
 196    */
 197   BOOST_ASIO_DECL boost::system::error_code set_verify_mode(
 198       verify_mode v, boost::system::error_code& ec);
 199
 200   /// Set the peer verification depth.
 201   /**
 202    * This function may be used to configure the maximum verification depth
 203    * allowed by the context.
 204    *
 205    * @param depth Maximum depth for the certificate chain verification that
 206    * shall be allowed.
 207    *
 208    * @throws boost::system::system_error Thrown on failure.
 209    *
 210    * @note Calls @c SSL_CTX_set_verify_depth.
 211    */
 212   BOOST_ASIO_DECL void set_verify_depth(int depth);
 213
 214   /// Set the peer verification depth.
 215   /**
 216    * This function may be used to configure the maximum verification depth
 217    * allowed by the context.
 218    *
 219    * @param depth Maximum depth for the certificate chain verification that
 220    * shall be allowed.
 221    *
 222    * @param ec Set to indicate what error occurred, if any.
 223    *
 224    * @note Calls @c SSL_CTX_set_verify_depth.
 225    */
 226   BOOST_ASIO_DECL boost::system::error_code set_verify_depth(
 227       int depth, boost::system::error_code& ec);
 228
 229   /// Set the callback used to verify peer certificates.
 230   /**
 231    * This function is used to specify a callback function that will be called
 232    * by the implementation when it needs to verify a peer certificate.
 233    *
 234    * @param callback The function object to be used for verifying a certificate.
 235    * The function signature of the handler must be:
 236    * @code bool verify_callback(
 237    *   bool preverified, // True if the certificate passed pre-verification.
 238    *   verify_context& ctx // The peer certificate and other context.
 239    * ); @endcode
 240    * The return value of the callback is true if the certificate has passed
 241    * verification, false otherwise.
 242    *
 243    * @throws boost::system::system_error Thrown on failure.
 244    *
 245    * @note Calls @c SSL_CTX_set_verify.
 246    */
 247   template <typename VerifyCallback>
 248   void set_verify_callback(VerifyCallback callback);
 249
 250   /// Set the callback used to verify peer certificates.
 251   /**
 252    * This function is used to specify a callback function that will be called
 253    * by the implementation when it needs to verify a peer certificate.
 254    *
 255    * @param callback The function object to be used for verifying a certificate.
 256    * The function signature of the handler must be:
 257    * @code bool verify_callback(
 258    *   bool preverified, // True if the certificate passed pre-verification.
 259    *   verify_context& ctx // The peer certificate and other context.
 260    * ); @endcode
 261    * The return value of the callback is true if the certificate has passed
 262    * verification, false otherwise.
 263    *
 264    * @param ec Set to indicate what error occurred, if any.
 265    *
 266    * @note Calls @c SSL_CTX_set_verify.
 267    */
 268   template <typename VerifyCallback>
 269   boost::system::error_code set_verify_callback(VerifyCallback callback,
 270       boost::system::error_code& ec);
 271
 272   /// Load a certification authority file for performing verification.
 273   /**
 274    * This function is used to load one or more trusted certification authorities
 275    * from a file.
 276    *
 277    * @param filename The name of a file containing certification authority
 278    * certificates in PEM format.
 279    *
 280    * @throws boost::system::system_error Thrown on failure.
 281    *
 282    * @note Calls @c SSL_CTX_load_verify_locations.
 283    */
 284   BOOST_ASIO_DECL void load_verify_file(const std::string& filename);
 285
 286   /// Load a certification authority file for performing verification.
 287   /**
 288    * This function is used to load the certificates for one or more trusted
 289    * certification authorities from a file.
 290    *
 291    * @param filename The name of a file containing certification authority
 292    * certificates in PEM format.
 293    *
 294    * @param ec Set to indicate what error occurred, if any.
 295    *
 296    * @note Calls @c SSL_CTX_load_verify_locations.
 297    */
 298   BOOST_ASIO_DECL boost::system::error_code load_verify_file(
 299       const std::string& filename, boost::system::error_code& ec);
 300
 301   /// Add certification authority for performing verification.
 302   /**
 303    * This function is used to add one trusted certification authority
 304    * from a memory buffer.
 305    *
 306    * @param ca The buffer containing the certification authority certificate.
 307    * The certificate must use the PEM format.
 308    *
 309    * @throws boost::system::system_error Thrown on failure.
 310    *
 311    * @note Calls @c SSL_CTX_get_cert_store and @c X509_STORE_add_cert.
 312    */
 313   BOOST_ASIO_DECL void add_certificate_authority(const const_buffer& ca);
 314
 315   /// Add certification authority for performing verification.
 316   /**
 317    * This function is used to add one trusted certification authority
 318    * from a memory buffer.
 319    *
 320    * @param ca The buffer containing the certification authority certificate.
 321    * The certificate must use the PEM format.
 322    *
 323    * @param ec Set to indicate what error occurred, if any.
 324    *
 325    * @note Calls @c SSL_CTX_get_cert_store and @c X509_STORE_add_cert.
 326    */
 327   BOOST_ASIO_DECL boost::system::error_code add_certificate_authority(
 328       const const_buffer& ca, boost::system::error_code& ec);
 329
 330   /// Configures the context to use the default directories for finding
 331   /// certification authority certificates.
 332   /**
 333    * This function specifies that the context should use the default,
 334    * system-dependent directories for locating certification authority
 335    * certificates.
 336    *
 337    * @throws boost::system::system_error Thrown on failure.
 338    *
 339    * @note Calls @c SSL_CTX_set_default_verify_paths.
 340    */
 341   BOOST_ASIO_DECL void set_default_verify_paths();
 342
 343   /// Configures the context to use the default directories for finding
 344   /// certification authority certificates.
 345   /**
 346    * This function specifies that the context should use the default,
 347    * system-dependent directories for locating certification authority
 348    * certificates.
 349    *
 350    * @param ec Set to indicate what error occurred, if any.
 351    *
 352    * @note Calls @c SSL_CTX_set_default_verify_paths.
 353    */
 354   BOOST_ASIO_DECL boost::system::error_code set_default_verify_paths(
 355       boost::system::error_code& ec);
 356
 357   /// Add a directory containing certificate authority files to be used for
 358   /// performing verification.
 359   /**
 360    * This function is used to specify the name of a directory containing
 361    * certification authority certificates. Each file in the directory must
 362    * contain a single certificate. The files must be named using the subject
 363    * name's hash and an extension of ".0".
 364    *
 365    * @param path The name of a directory containing the certificates.
 366    *
 367    * @throws boost::system::system_error Thrown on failure.
 368    *
 369    * @note Calls @c SSL_CTX_load_verify_locations.
 370    */
 371   BOOST_ASIO_DECL void add_verify_path(const std::string& path);
 372
 373   /// Add a directory containing certificate authority files to be used for
 374   /// performing verification.
 375   /**
 376    * This function is used to specify the name of a directory containing
 377    * certification authority certificates. Each file in the directory must
 378    * contain a single certificate. The files must be named using the subject
 379    * name's hash and an extension of ".0".
 380    *
 381    * @param path The name of a directory containing the certificates.
 382    *
 383    * @param ec Set to indicate what error occurred, if any.
 384    *
 385    * @note Calls @c SSL_CTX_load_verify_locations.
 386    */
 387   BOOST_ASIO_DECL boost::system::error_code add_verify_path(
 388       const std::string& path, boost::system::error_code& ec);
 389
 390   /// Use a certificate from a memory buffer.
 391   /**
 392    * This function is used to load a certificate into the context from a buffer.
 393    *
 394    * @param certificate The buffer containing the certificate.
 395    *
 396    * @param format The certificate format (ASN.1 or PEM).
 397    *
 398    * @throws boost::system::system_error Thrown on failure.
 399    *
 400    * @note Calls @c SSL_CTX_use_certificate or SSL_CTX_use_certificate_ASN1.
 401    */
 402   BOOST_ASIO_DECL void use_certificate(
 403       const const_buffer& certificate, file_format format);
 404
 405   /// Use a certificate from a memory buffer.
 406   /**
 407    * This function is used to load a certificate into the context from a buffer.
 408    *
 409    * @param certificate The buffer containing the certificate.
 410    *
 411    * @param format The certificate format (ASN.1 or PEM).
 412    *
 413    * @param ec Set to indicate what error occurred, if any.
 414    *
 415    * @note Calls @c SSL_CTX_use_certificate or SSL_CTX_use_certificate_ASN1.
 416    */
 417   BOOST_ASIO_DECL boost::system::error_code use_certificate(
 418       const const_buffer& certificate, file_format format,
 419       boost::system::error_code& ec);
 420
 421   /// Use a certificate from a file.
 422   /**
 423    * This function is used to load a certificate into the context from a file.
 424    *
 425    * @param filename The name of the file containing the certificate.
 426    *
 427    * @param format The file format (ASN.1 or PEM).
 428    *
 429    * @throws boost::system::system_error Thrown on failure.
 430    *
 431    * @note Calls @c SSL_CTX_use_certificate_file.
 432    */
 433   BOOST_ASIO_DECL void use_certificate_file(
 434       const std::string& filename, file_format format);
 435
 436   /// Use a certificate from a file.
 437   /**
 438    * This function is used to load a certificate into the context from a file.
 439    *
 440    * @param filename The name of the file containing the certificate.
 441    *
 442    * @param format The file format (ASN.1 or PEM).
 443    *
 444    * @param ec Set to indicate what error occurred, if any.
 445    *
 446    * @note Calls @c SSL_CTX_use_certificate_file.
 447    */
 448   BOOST_ASIO_DECL boost::system::error_code use_certificate_file(
 449       const std::string& filename, file_format format,
 450       boost::system::error_code& ec);
 451
 452   /// Use a certificate chain from a memory buffer.
 453   /**
 454    * This function is used to load a certificate chain into the context from a
 455    * buffer.
 456    *
 457    * @param chain The buffer containing the certificate chain. The certificate
 458    * chain must use the PEM format.
 459    *
 460    * @throws boost::system::system_error Thrown on failure.
 461    *
 462    * @note Calls @c SSL_CTX_use_certificate and SSL_CTX_add_extra_chain_cert.
 463    */
 464   BOOST_ASIO_DECL void use_certificate_chain(const const_buffer& chain);
 465
 466   /// Use a certificate chain from a memory buffer.
 467   /**
 468    * This function is used to load a certificate chain into the context from a
 469    * buffer.
 470    *
 471    * @param chain The buffer containing the certificate chain. The certificate
 472    * chain must use the PEM format.
 473    *
 474    * @param ec Set to indicate what error occurred, if any.
 475    *
 476    * @note Calls @c SSL_CTX_use_certificate and SSL_CTX_add_extra_chain_cert.
 477    */
 478   BOOST_ASIO_DECL boost::system::error_code use_certificate_chain(
 479       const const_buffer& chain, boost::system::error_code& ec);
 480
 481   /// Use a certificate chain from a file.
 482   /**
 483    * This function is used to load a certificate chain into the context from a
 484    * file.
 485    *
 486    * @param filename The name of the file containing the certificate. The file
 487    * must use the PEM format.
 488    *
 489    * @throws boost::system::system_error Thrown on failure.
 490    *
 491    * @note Calls @c SSL_CTX_use_certificate_chain_file.
 492    */
 493   BOOST_ASIO_DECL void use_certificate_chain_file(const std::string& filename);
 494
 495   /// Use a certificate chain from a file.
 496   /**
 497    * This function is used to load a certificate chain into the context from a
 498    * file.
 499    *
 500    * @param filename The name of the file containing the certificate. The file
 501    * must use the PEM format.
 502    *
 503    * @param ec Set to indicate what error occurred, if any.
 504    *
 505    * @note Calls @c SSL_CTX_use_certificate_chain_file.
 506    */
 507   BOOST_ASIO_DECL boost::system::error_code use_certificate_chain_file(
 508       const std::string& filename, boost::system::error_code& ec);
 509
 510   /// Use a private key from a memory buffer.
 511   /**
 512    * This function is used to load a private key into the context from a buffer.
 513    *
 514    * @param private_key The buffer containing the private key.
 515    *
 516    * @param format The private key format (ASN.1 or PEM).
 517    *
 518    * @throws boost::system::system_error Thrown on failure.
 519    *
 520    * @note Calls @c SSL_CTX_use_PrivateKey or SSL_CTX_use_PrivateKey_ASN1.
 521    */
 522   BOOST_ASIO_DECL void use_private_key(
 523       const const_buffer& private_key, file_format format);
 524
 525   /// Use a private key from a memory buffer.
 526   /**
 527    * This function is used to load a private key into the context from a buffer.
 528    *
 529    * @param private_key The buffer containing the private key.
 530    *
 531    * @param format The private key format (ASN.1 or PEM).
 532    *
 533    * @param ec Set to indicate what error occurred, if any.
 534    *
 535    * @note Calls @c SSL_CTX_use_PrivateKey or SSL_CTX_use_PrivateKey_ASN1.
 536    */
 537   BOOST_ASIO_DECL boost::system::error_code use_private_key(
 538       const const_buffer& private_key, file_format format,
 539       boost::system::error_code& ec);
 540
 541   /// Use a private key from a file.
 542   /**
 543    * This function is used to load a private key into the context from a file.
 544    *
 545    * @param filename The name of the file containing the private key.
 546    *
 547    * @param format The file format (ASN.1 or PEM).
 548    *
 549    * @throws boost::system::system_error Thrown on failure.
 550    *
 551    * @note Calls @c SSL_CTX_use_PrivateKey_file.
 552    */
 553   BOOST_ASIO_DECL void use_private_key_file(
 554       const std::string& filename, file_format format);
 555
 556   /// Use a private key from a file.
 557   /**
 558    * This function is used to load a private key into the context from a file.
 559    *
 560    * @param filename The name of the file containing the private key.
 561    *
 562    * @param format The file format (ASN.1 or PEM).
 563    *
 564    * @param ec Set to indicate what error occurred, if any.
 565    *
 566    * @note Calls @c SSL_CTX_use_PrivateKey_file.
 567    */
 568   BOOST_ASIO_DECL boost::system::error_code use_private_key_file(
 569       const std::string& filename, file_format format,
 570       boost::system::error_code& ec);
 571
 572   /// Use an RSA private key from a memory buffer.
 573   /**
 574    * This function is used to load an RSA private key into the context from a
 575    * buffer.
 576    *
 577    * @param private_key The buffer containing the RSA private key.
 578    *
 579    * @param format The private key format (ASN.1 or PEM).
 580    *
 581    * @throws boost::system::system_error Thrown on failure.
 582    *
 583    * @note Calls @c SSL_CTX_use_RSAPrivateKey or SSL_CTX_use_RSAPrivateKey_ASN1.
 584    */
 585   BOOST_ASIO_DECL void use_rsa_private_key(
 586       const const_buffer& private_key, file_format format);
 587
 588   /// Use an RSA private key from a memory buffer.
 589   /**
 590    * This function is used to load an RSA private key into the context from a
 591    * buffer.
 592    *
 593    * @param private_key The buffer containing the RSA private key.
 594    *
 595    * @param format The private key format (ASN.1 or PEM).
 596    *
 597    * @param ec Set to indicate what error occurred, if any.
 598    *
 599    * @note Calls @c SSL_CTX_use_RSAPrivateKey or SSL_CTX_use_RSAPrivateKey_ASN1.
 600    */
 601   BOOST_ASIO_DECL boost::system::error_code use_rsa_private_key(
 602       const const_buffer& private_key, file_format format,
 603       boost::system::error_code& ec);
 604
 605   /// Use an RSA private key from a file.
 606   /**
 607    * This function is used to load an RSA private key into the context from a
 608    * file.
 609    *
 610    * @param filename The name of the file containing the RSA private key.
 611    *
 612    * @param format The file format (ASN.1 or PEM).
 613    *
 614    * @throws boost::system::system_error Thrown on failure.
 615    *
 616    * @note Calls @c SSL_CTX_use_RSAPrivateKey_file.
 617    */
 618   BOOST_ASIO_DECL void use_rsa_private_key_file(
 619       const std::string& filename, file_format format);
 620
 621   /// Use an RSA private key from a file.
 622   /**
 623    * This function is used to load an RSA private key into the context from a
 624    * file.
 625    *
 626    * @param filename The name of the file containing the RSA private key.
 627    *
 628    * @param format The file format (ASN.1 or PEM).
 629    *
 630    * @param ec Set to indicate what error occurred, if any.
 631    *
 632    * @note Calls @c SSL_CTX_use_RSAPrivateKey_file.
 633    */
 634   BOOST_ASIO_DECL boost::system::error_code use_rsa_private_key_file(
 635       const std::string& filename, file_format format,
 636       boost::system::error_code& ec);
 637
 638   /// Use the specified memory buffer to obtain the temporary Diffie-Hellman
 639   /// parameters.
 640   /**
 641    * This function is used to load Diffie-Hellman parameters into the context
 642    * from a buffer.
 643    *
 644    * @param dh The memory buffer containing the Diffie-Hellman parameters. The
 645    * buffer must use the PEM format.
 646    *
 647    * @throws boost::system::system_error Thrown on failure.
 648    *
 649    * @note Calls @c SSL_CTX_set_tmp_dh.
 650    */
 651   BOOST_ASIO_DECL void use_tmp_dh(const const_buffer& dh);
 652
 653   /// Use the specified memory buffer to obtain the temporary Diffie-Hellman
 654   /// parameters.
 655   /**
 656    * This function is used to load Diffie-Hellman parameters into the context
 657    * from a buffer.
 658    *
 659    * @param dh The memory buffer containing the Diffie-Hellman parameters. The
 660    * buffer must use the PEM format.
 661    *
 662    * @param ec Set to indicate what error occurred, if any.
 663    *
 664    * @note Calls @c SSL_CTX_set_tmp_dh.
 665    */
 666   BOOST_ASIO_DECL boost::system::error_code use_tmp_dh(
 667       const const_buffer& dh, boost::system::error_code& ec);
 668
 669   /// Use the specified file to obtain the temporary Diffie-Hellman parameters.
 670   /**
 671    * This function is used to load Diffie-Hellman parameters into the context
 672    * from a file.
 673    *
 674    * @param filename The name of the file containing the Diffie-Hellman
 675    * parameters. The file must use the PEM format.
 676    *
 677    * @throws boost::system::system_error Thrown on failure.
 678    *
 679    * @note Calls @c SSL_CTX_set_tmp_dh.
 680    */
 681   BOOST_ASIO_DECL void use_tmp_dh_file(const std::string& filename);
 682
 683   /// Use the specified file to obtain the temporary Diffie-Hellman parameters.
 684   /**
 685    * This function is used to load Diffie-Hellman parameters into the context
 686    * from a file.
 687    *
 688    * @param filename The name of the file containing the Diffie-Hellman
 689    * parameters. The file must use the PEM format.
 690    *
 691    * @param ec Set to indicate what error occurred, if any.
 692    *
 693    * @note Calls @c SSL_CTX_set_tmp_dh.
 694    */
 695   BOOST_ASIO_DECL boost::system::error_code use_tmp_dh_file(
 696       const std::string& filename, boost::system::error_code& ec);
 697
 698   /// Set the password callback.
 699   /**
 700    * This function is used to specify a callback function to obtain password
 701    * information about an encrypted key in PEM format.
 702    *
 703    * @param callback The function object to be used for obtaining the password.
 704    * The function signature of the handler must be:
 705    * @code std::string password_callback(
 706    *   std::size_t max_length,  // The maximum size for a password.
 707    *   password_purpose purpose // Whether password is for reading or writing.
 708    * ); @endcode
 709    * The return value of the callback is a string containing the password.
 710    *
 711    * @throws boost::system::system_error Thrown on failure.
 712    *
 713    * @note Calls @c SSL_CTX_set_default_passwd_cb.
 714    */
 715   template <typename PasswordCallback>
 716   void set_password_callback(PasswordCallback callback);
 717
 718   /// Set the password callback.
 719   /**
 720    * This function is used to specify a callback function to obtain password
 721    * information about an encrypted key in PEM format.
 722    *
 723    * @param callback The function object to be used for obtaining the password.
 724    * The function signature of the handler must be:
 725    * @code std::string password_callback(
 726    *   std::size_t max_length,  // The maximum size for a password.
 727    *   password_purpose purpose // Whether password is for reading or writing.
 728    * ); @endcode
 729    * The return value of the callback is a string containing the password.
 730    *
 731    * @param ec Set to indicate what error occurred, if any.
 732    *
 733    * @note Calls @c SSL_CTX_set_default_passwd_cb.
 734    */
 735   template <typename PasswordCallback>
 736   boost::system::error_code set_password_callback(PasswordCallback callback,
 737       boost::system::error_code& ec);
 738
 739 private:
 740   struct bio_cleanup;
 741   struct x509_cleanup;
 742   struct evp_pkey_cleanup;
 743   struct rsa_cleanup;
 744   struct dh_cleanup;
 745
 746   // Helper function used to set a peer certificate verification callback.
 747   BOOST_ASIO_DECL boost::system::error_code do_set_verify_callback(
 748       detail::verify_callback_base* callback, boost::system::error_code& ec);
 749
 750   // Callback used when the SSL implementation wants to verify a certificate.
 751   BOOST_ASIO_DECL static int verify_callback_function(
 752       int preverified, X509_STORE_CTX* ctx);
 753
 754   // Helper function used to set a password callback.
 755   BOOST_ASIO_DECL boost::system::error_code do_set_password_callback(
 756       detail::password_callback_base* callback, boost::system::error_code& ec);
 757
 758   // Callback used when the SSL implementation wants a password.
 759   BOOST_ASIO_DECL static int password_callback_function(
 760       char* buf, int size, int purpose, void* data);
 761
 762   // Helper function to set the temporary Diffie-Hellman parameters from a BIO.
 763   BOOST_ASIO_DECL boost::system::error_code do_use_tmp_dh(
 764       BIO* bio, boost::system::error_code& ec);
 765
 766   // Helper function to make a BIO from a memory buffer.
 767   BOOST_ASIO_DECL BIO* make_buffer_bio(const const_buffer& b);
 768
 769   // The underlying native implementation.
 770   native_handle_type handle_;
 771
 772   // Ensure openssl is initialised.
 773   boost::asio::ssl::detail::openssl_init<> init_;
 774 };
 775
 776 #endif // defined(BOOST_ASIO_ENABLE_OLD_SSL)
 777
 778 } // namespace ssl
 779 } // namespace asio
 780 } // namespace boost
 781
 782 #include <boost/asio/detail/pop_options.hpp>
 783
 784 #include <boost/asio/ssl/impl/context.hpp>
 785 #if defined(BOOST_ASIO_HEADER_ONLY)
 786 # include <boost/asio/ssl/impl/context.ipp>
 787 #endif // defined(BOOST_ASIO_HEADER_ONLY)
 788
 789 #endif // BOOST_ASIO_SSL_CONTEXT_HPP