libs/nixio/axTLS/ssl/ssl.h

   1 /*
   2  * Copyright (c) 2007, Cameron Rich
   3  *
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions are met:
   8  *
   9  * * Redistributions of source code must retain the above copyright notice,
  10  *   this list of conditions and the following disclaimer.
  11  * * Redistributions in binary form must reproduce the above copyright notice,
  12  *   this list of conditions and the following disclaimer in the documentation
  13  *   and/or other materials provided with the distribution.
  14  * * Neither the name of the axTLS project nor the names of its contributors
  15  *   may be used to endorse or promote products derived from this software
  16  *   without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  22  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  23  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  24  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  25  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  26  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  27  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  28  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 /**
  32  * @mainpage axTLS API
  33  *
  34  * @image html axolotl.jpg
  35  *
  36  * The axTLS library has features such as:
  37  * - The TLSv1 SSL client/server protocol
  38  * - No requirement to use any openssl libraries.
  39  * - A choice between AES block (128/256 bit) and RC4 (128 bit) stream ciphers.
  40  * - RSA encryption/decryption with variable sized keys (up to 4096 bits).
  41  * - Certificate chaining and peer authentication.
  42  * - Session resumption, session renegotiation.
  43  * - ASN.1, X.509, PKCS#8, PKCS#12 keys/certificates with DER/PEM encoding.
  44  * - Highly configurable compile time options.
  45  * - Portable across many platforms (written in ANSI C), and has language
  46  * bindings in C, C#, VB.NET, Java, Perl and Lua.
  47  * - Partial openssl API compatibility (via a wrapper).
  48  * - A very small footprint (around 50-60kB for the library in 'server-only'
  49  *   mode).
  50  * - No dependencies on sockets - can use serial connections for example.
  51  * - A very simple API - ~ 20 functions/methods.
  52  *
  53  * A list of these functions/methods are described below.
  54  *
  55  *  @ref c_api
  56  *
  57  *  @ref bigint_api
  58  *
  59  *  @ref csharp_api
  60  *
  61  *  @ref java_api
  62  */
  63 #ifndef HEADER_SSL_H
  64 #define HEADER_SSL_H
  65
  66 #ifdef __cplusplus
  67 extern "C" {
  68 #endif
  69
  70 #include <time.h>
  71 //#include "crypto.h"
  72
  73 /* need to predefine before ssl_lib.h gets to it */
  74 #define SSL_SESSION_ID_SIZE                     32
  75
  76 #include "tls1.h"
  77
  78 /* The optional parameters that can be given to the client/server SSL engine */
  79 #define SSL_CLIENT_AUTHENTICATION               0x00010000
  80 #define SSL_SERVER_VERIFY_LATER                 0x00020000
  81 #define SSL_NO_DEFAULT_KEY                      0x00040000
  82 #define SSL_DISPLAY_STATES                      0x00080000
  83 #define SSL_DISPLAY_BYTES                       0x00100000
  84 #define SSL_DISPLAY_CERTS                       0x00200000
  85 #define SSL_DISPLAY_RSA                         0x00400000
  86
  87 /* errors that can be generated */
  88 #define SSL_OK                                  0
  89 #define SSL_NOT_OK                              -1
  90 #define SSL_ERROR_DEAD                          -2
  91 #define SSL_ERROR_CONN_LOST                     -256
  92 #define SSL_ERROR_SOCK_SETUP_FAILURE            -258
  93 #define SSL_ERROR_INVALID_HANDSHAKE             -260
  94 #define SSL_ERROR_INVALID_PROT_MSG              -261
  95 #define SSL_ERROR_INVALID_HMAC                  -262
  96 #define SSL_ERROR_INVALID_VERSION               -263
  97 #define SSL_ERROR_INVALID_SESSION               -265
  98 #define SSL_ERROR_NO_CIPHER                     -266
  99 #define SSL_ERROR_BAD_CERTIFICATE               -268
 100 #define SSL_ERROR_INVALID_KEY                   -269
 101 #define SSL_ERROR_FINISHED_INVALID              -271
 102 #define SSL_ERROR_NO_CERT_DEFINED               -272
 103 #define SSL_ERROR_NOT_SUPPORTED                 -274
 104 #define SSL_X509_OFFSET                         -512
 105 #define SSL_X509_ERROR(A)                       (SSL_X509_OFFSET+A)
 106
 107 /* these are all the alerts that are recognized */
 108 #define SSL_ALERT_CLOSE_NOTIFY                  0
 109 #define SSL_ALERT_UNEXPECTED_MESSAGE            10
 110 #define SSL_ALERT_BAD_RECORD_MAC                20
 111 #define SSL_ALERT_HANDSHAKE_FAILURE             40
 112 #define SSL_ALERT_BAD_CERTIFICATE               42
 113 #define SSL_ALERT_ILLEGAL_PARAMETER             47
 114 #define SSL_ALERT_DECODE_ERROR                  50
 115 #define SSL_ALERT_DECRYPT_ERROR                 51
 116 #define SSL_ALERT_INVALID_VERSION               70
 117
 118 /* The ciphers that are supported */
 119 #define SSL_AES128_SHA                          0x2f
 120 #define SSL_AES256_SHA                          0x35
 121 #define SSL_RC4_128_SHA                         0x05
 122 #define SSL_RC4_128_MD5                         0x04
 123
 124 /* build mode ids' */
 125 #define SSL_BUILD_SKELETON_MODE                 0x01
 126 #define SSL_BUILD_SERVER_ONLY                   0x02
 127 #define SSL_BUILD_ENABLE_VERIFICATION           0x03
 128 #define SSL_BUILD_ENABLE_CLIENT                 0x04
 129 #define SSL_BUILD_FULL_MODE                     0x05
 130
 131 /* offsets to retrieve configuration information */
 132 #define SSL_BUILD_MODE                          0
 133 #define SSL_MAX_CERT_CFG_OFFSET                 1
 134 #define SSL_MAX_CA_CERT_CFG_OFFSET              2
 135 #define SSL_HAS_PEM                             3
 136
 137 /* default session sizes */
 138 #define SSL_DEFAULT_SVR_SESS                    5
 139 #define SSL_DEFAULT_CLNT_SESS                   1
 140
 141 /* X.509/X.520 distinguished name types */
 142 #define SSL_X509_CERT_COMMON_NAME               0
 143 #define SSL_X509_CERT_ORGANIZATION              1
 144 #define SSL_X509_CERT_ORGANIZATIONAL_NAME       2
 145 #define SSL_X509_CA_CERT_COMMON_NAME            3
 146 #define SSL_X509_CA_CERT_ORGANIZATION           4
 147 #define SSL_X509_CA_CERT_ORGANIZATIONAL_NAME    5
 148
 149 /* SSL object loader types */
 150 #define SSL_OBJ_X509_CERT                       1
 151 #define SSL_OBJ_X509_CACERT                     2
 152 #define SSL_OBJ_RSA_KEY                         3
 153 #define SSL_OBJ_PKCS8                           4
 154 #define SSL_OBJ_PKCS12                          5
 155
 156 /**
 157  * @defgroup c_api Standard C API
 158  * @brief The standard interface in C.
 159  * @{
 160  */
 161
 162 /**
 163  * @brief Establish a new client/server context.
 164  *
 165  * This function is called before any client/server SSL connections are made.
 166  *
 167  * Each new connection will use the this context's private key and
 168  * certificate chain. If a different certificate chain is required, then a
 169  * different context needs to be be used.
 170  *
 171  * There are two threading models supported - a single thread with one
 172  * SSL_CTX can support any number of SSL connections - and multiple threads can
 173  * support one SSL_CTX object each (the default). But if a single SSL_CTX
 174  * object uses many SSL objects in individual threads, then the
 175  * CONFIG_SSL_CTX_MUTEXING option needs to be configured.
 176  *
 177  * @param options [in]  Any particular options. At present the options
 178  * supported are:
 179  * - SSL_SERVER_VERIFY_LATER (client only): Don't stop a handshake if the server
 180  * authentication fails. The certificate can be authenticated later with a
 181  * call to ssl_verify_cert().
 182  * - SSL_CLIENT_AUTHENTICATION (server only): Enforce client authentication
 183  * i.e. each handshake will include a "certificate request" message from the
 184  * server. Only available if verification has been enabled.
 185  * - SSL_DISPLAY_BYTES (full mode build only): Display the byte sequences
 186  * during the handshake.
 187  * - SSL_DISPLAY_STATES (full mode build only): Display the state changes
 188  * during the handshake.
 189  * - SSL_DISPLAY_CERTS (full mode build only): Display the certificates that
 190  * are passed during a handshake.
 191  * - SSL_DISPLAY_RSA (full mode build only): Display the RSA key details that
 192  * are passed during a handshake.
 193  *
 194  * @param num_sessions [in] The number of sessions to be used for session
 195  * caching. If this value is 0, then there is no session caching. This option
 196  * is not used in skeleton mode.
 197  * @return A client/server context.
 198  */
 199 EXP_FUNC SSL_CTX * STDCALL ssl_ctx_new(uint32_t options, int num_sessions);
 200
 201 /**
 202  * @brief Remove a client/server context.
 203  *
 204  * Frees any used resources used by this context. Each connection will be
 205  * sent a "Close Notify" alert (if possible).
 206  * @param ssl_ctx [in] The client/server context.
 207  */
 208 EXP_FUNC void STDCALL ssl_ctx_free(SSL_CTX *ssl_ctx);
 209
 210 /**
 211  * @brief (server only) Establish a new SSL connection to an SSL client.
 212  *
 213  * It is up to the application to establish the logical connection (whether it
 214  * is  a socket, serial connection etc).
 215  * @param ssl_ctx [in] The server context.
 216  * @param client_fd [in] The client's file descriptor.
 217  * @return An SSL object reference.
 218  */
 219 EXP_FUNC SSL * STDCALL ssl_server_new(SSL_CTX *ssl_ctx, int client_fd);
 220
 221 /**
 222  * @brief (client only) Establish a new SSL connection to an SSL server.
 223  *
 224  * It is up to the application to establish the initial logical connection
 225  * (whether it is  a socket, serial connection etc).
 226  *
 227  * This is a blocking call - it will finish when the handshake is complete (or
 228  * has failed).
 229  * @param ssl_ctx [in] The client context.
 230  * @param client_fd [in] The client's file descriptor.
 231  * @param session_id [in] A 32 byte session id for session resumption. This
 232  * can be null if no session resumption is being used or required. This option
 233  * is not used in skeleton mode.
 234  * @param sess_id_size The size of the session id (max 32)
 235  * @return An SSL object reference. Use ssl_handshake_status() to check
 236  * if a handshake succeeded.
 237  */
 238 EXP_FUNC SSL * STDCALL ssl_client_new(SSL_CTX *ssl_ctx, int client_fd, const uint8_t *session_id, uint8_t sess_id_size);
 239
 240 /**
 241  * @brief Free any used resources on this connection.
 242
 243  * A "Close Notify" message is sent on this connection (if possible). It is up
 244  * to the application to close the socket or file descriptor.
 245  * @param ssl [in] The ssl object reference.
 246  */
 247 EXP_FUNC void STDCALL ssl_free(SSL *ssl);
 248
 249 /**
 250  * @brief Read the SSL data stream.
 251  * The socket must be in blocking mode.
 252  * @param ssl [in] An SSL object reference.
 253  * @param in_data [out] If the read was successful, a pointer to the read
 254  * buffer will be here. Do NOT ever free this memory as this buffer is used in
 255  * sucessive calls. If the call was unsuccessful, this value will be null.
 256  * @return The number of decrypted bytes:
 257  * - if > 0, then the handshaking is complete and we are returning the number
 258  *   of decrypted bytes.
 259  * - SSL_OK if the handshaking stage is successful (but not yet complete).
 260  * - < 0 if an error.
 261  * @see ssl.h for the error code list.
 262  * @note Use in_data before doing any successive ssl calls.
 263  */
 264 EXP_FUNC int STDCALL ssl_read(SSL *ssl, uint8_t **in_data);
 265
 266 /**
 267  * @brief Write to the SSL data stream.
 268  * The socket must be in blocking mode.
 269  * @param ssl [in] An SSL obect reference.
 270  * @param out_data [in] The data to be written
 271  * @param out_len [in] The number of bytes to be written.
 272  * @return The number of bytes sent, or if < 0 if an error.
 273  * @see ssl.h for the error code list.
 274  */
 275 EXP_FUNC int STDCALL ssl_write(SSL *ssl, const uint8_t *out_data, int out_len);
 276
 277 /**
 278  * @brief Find an ssl object based on a file descriptor.
 279  *
 280  * Goes through the list of SSL objects maintained in a client/server context
 281  * to look for a file descriptor match.
 282  * @param ssl_ctx [in] The client/server context.
 283  * @param client_fd [in]  The file descriptor.
 284  * @return A reference to the SSL object. Returns null if the object could not
 285  * be found.
 286  */
 287 EXP_FUNC SSL * STDCALL ssl_find(SSL_CTX *ssl_ctx, int client_fd);
 288
 289 /**
 290  * @brief Get the session id for a handshake.
 291  *
 292  * This will be a 32 byte sequence and is available after the first
 293  * handshaking messages are sent.
 294  * @param ssl [in] An SSL object reference.
 295  * @return The session id as a 32 byte sequence.
 296  * @note A SSLv23 handshake may have only 16 valid bytes.
 297  */
 298 EXP_FUNC const uint8_t * STDCALL ssl_get_session_id(const SSL *ssl);
 299
 300 /**
 301  * @brief Get the session id size for a handshake.
 302  *
 303  * This will normally be 32 but could be 0 (no session id) or something else.
 304  * @param ssl [in] An SSL object reference.
 305  * @return The size of the session id.
 306  */
 307 EXP_FUNC uint8_t STDCALL ssl_get_session_id_size(const SSL *ssl);
 308
 309 /**
 310  * @brief Return the cipher id (in the SSL form).
 311  * @param ssl [in] An SSL object reference.
 312  * @return The cipher id. This will be one of the following:
 313  * - SSL_AES128_SHA (0x2f)
 314  * - SSL_AES256_SHA (0x35)
 315  * - SSL_RC4_128_SHA (0x05)
 316  * - SSL_RC4_128_MD5 (0x04)
 317  */
 318 EXP_FUNC uint8_t STDCALL ssl_get_cipher_id(const SSL *ssl);
 319
 320 /**
 321  * @brief Return the status of the handshake.
 322  * @param ssl [in] An SSL object reference.
 323  * @return SSL_OK if the handshake is complete and ok.
 324  * @see ssl.h for the error code list.
 325  */
 326 EXP_FUNC int STDCALL ssl_handshake_status(const SSL *ssl);
 327
 328 /**
 329  * @brief Retrieve various parameters about the axTLS engine.
 330  * @param offset [in] The configuration offset. It will be one of the following:
 331  * - SSL_BUILD_MODE The build mode. This will be one of the following:
 332  *   - SSL_BUILD_SERVER_ONLY            (basic server mode)
 333  *   - SSL_BUILD_ENABLE_VERIFICATION    (server can do client authentication)
 334  *   - SSL_BUILD_ENABLE_CLIENT          (client/server capabilties)
 335  *   - SSL_BUILD_FULL_MODE              (client/server with diagnostics)
 336  *   - SSL_BUILD_SKELETON_MODE          (skeleton mode)
 337  * - SSL_MAX_CERT_CFG_OFFSET The maximum number of certificates allowed.
 338  * - SSL_MAX_CA_CERT_CFG_OFFSET The maximum number of CA certificates allowed.
 339  * - SSL_HAS_PEM                        1 if supported
 340  * @return The value of the requested parameter.
 341  */
 342 EXP_FUNC int STDCALL ssl_get_config(int offset);
 343
 344 /**
 345  * @brief Display why the handshake failed.
 346  *
 347  * This call is only useful in a 'full mode' build. The output is to stdout.
 348  * @param error_code [in] An error code.
 349  * @see ssl.h for the error code list.
 350  */
 351 EXP_FUNC void STDCALL ssl_display_error(int error_code);
 352
 353 /**
 354  * @brief Authenticate a received certificate.
 355  *
 356  * This call is usually made by a client after a handshake is complete and the
 357  * context is in SSL_SERVER_VERIFY_LATER mode.
 358  * @param ssl [in] An SSL object reference.
 359  * @return SSL_OK if the certificate is verified.
 360  */
 361 EXP_FUNC int STDCALL ssl_verify_cert(const SSL *ssl);
 362
 363 /**
 364  * @brief Retrieve an X.509 distinguished name component.
 365  *
 366  * When a handshake is complete and a certificate has been exchanged, then the
 367  * details of the remote certificate can be retrieved.
 368  *
 369  * This will usually be used by a client to check that the server's common
 370  * name matches the URL.
 371  *
 372  * A full handshake needs to occur for this call to work properly.
 373  *
 374  * @param ssl [in] An SSL object reference.
 375  * @param component [in] one of:
 376  * - SSL_X509_CERT_COMMON_NAME
 377  * - SSL_X509_CERT_ORGANIZATION
 378  * - SSL_X509_CERT_ORGANIZATIONAL_NAME
 379  * - SSL_X509_CA_CERT_COMMON_NAME
 380  * - SSL_X509_CA_CERT_ORGANIZATION
 381  * - SSL_X509_CA_CERT_ORGANIZATIONAL_NAME
 382  * @return The appropriate string (or null if not defined)
 383  * @note Verification build mode must be enabled.
 384  */
 385 EXP_FUNC const char * STDCALL ssl_get_cert_dn(const SSL *ssl, int component);
 386
 387 /**
 388  * @brief Force the client to perform its handshake again.
 389  *
 390  * For a client this involves sending another "client hello" message.
 391  * For the server is means sending a "hello request" message.
 392  *
 393  * This is a blocking call on the client (until the handshake completes).
 394  *
 395  * @param ssl [in] An SSL object reference.
 396  * @return SSL_OK if renegotiation instantiation was ok
 397  */
 398 EXP_FUNC int STDCALL ssl_renegotiate(SSL *ssl);
 399
 400 /**
 401  * @brief Process a file that is in binary DER or ASCII PEM format.
 402  *
 403  * These are temporary objects that are used to load private keys,
 404  * certificates etc into memory.
 405  * @param ssl_ctx [in] The client/server context.
 406  * @param obj_type [in] The format of the file. Can be one of:
 407  * - SSL_OBJ_X509_CERT (no password required)
 408  * - SSL_OBJ_X509_CACERT (no password required)
 409  * - SSL_OBJ_RSA_KEY (AES128/AES256 PEM encryption supported)
 410  * - SSL_OBJ_PKCS8 (RC4-128 encrypted data supported)
 411  * - SSL_OBJ_PKCS12 (RC4-128 encrypted data supported)
 412  *
 413  * PEM files are automatically detected (if supported). The object type is
 414  * also detected, and so is not relevant for these types of files.
 415  * @param filename [in] The location of a file in DER/PEM format.
 416  * @param password [in] The password used. Can be null if not required.
 417  * @return SSL_OK if all ok
 418  * @note Not available in skeleton build mode.
 419  */
 420 EXP_FUNC int STDCALL ssl_obj_load(SSL_CTX *ssl_ctx, int obj_type, const char *filename, const char *password);
 421
 422 /**
 423  * @brief Process binary data.
 424  *
 425  * These are temporary objects that are used to load private keys,
 426  * certificates etc into memory.
 427  * @param ssl_ctx [in] The client/server context.
 428  * @param obj_type [in] The format of the memory data.
 429  * @param data [in] The binary data to be loaded.
 430  * @param len [in] The amount of data to be loaded.
 431  * @param password [in] The password used. Can be null if not required.
 432  * @return SSL_OK if all ok
 433  * @see ssl_obj_load for more details on obj_type.
 434  */
 435 EXP_FUNC int STDCALL ssl_obj_memory_load(SSL_CTX *ssl_ctx, int obj_type, const uint8_t *data, int len, const char *password);
 436
 437 #ifdef CONFIG_SSL_GENERATE_X509_CERT
 438 /**
 439  * @brief Create an X.509 certificate.
 440  *
 441  * This certificate is a self-signed v1 cert with a fixed start/stop validity
 442  * times. It is signed with an internal private key in ssl_ctx.
 443  *
 444  * @param ssl_ctx [in] The client/server context.
 445  * @param options [in] Not used yet.
 446  * @param dn [in] An array of distinguished name strings. The array is defined
 447  * by:
 448  * - SSL_X509_CERT_COMMON_NAME (0)
 449  *      - If SSL_X509_CERT_COMMON_NAME is empty or not defined, then the
 450  *        hostname will be used.
 451  * - SSL_X509_CERT_ORGANIZATION (1)
 452  *      - If SSL_X509_CERT_ORGANIZATION is empty or not defined, then $USERNAME
 453  *        will be used.
 454  * - SSL_X509_CERT_ORGANIZATIONAL_NAME (2)
 455  *      - SSL_X509_CERT_ORGANIZATIONAL_NAME is optional.
 456  * @param cert_data [out] The certificate as a sequence of bytes.
 457  * @return < 0 if an error, or the size of the certificate in bytes.
 458  * @note cert_data must be freed when there is no more need for it.
 459  */
 460 EXP_FUNC int STDCALL ssl_x509_create(SSL_CTX *ssl_ctx, uint32_t options, const char * dn[], uint8_t **cert_data);
 461 #endif
 462
 463 /**
 464  * @brief Return the axTLS library version as a string.
 465  */
 466 EXP_FUNC const char * STDCALL ssl_version(void);
 467
 468 /** @} */
 469
 470 #ifdef __cplusplus
 471 }
 472 #endif
 473
 474 #endif