mdw@git.distorted.org.uk Git - tripe/blob - tripe.h

   1 /* -*-c-*-
   2  *
   3  * $Id: tripe.h,v 1.20 2004/04/18 18:08:11 mdw Exp $
   4  *
   5  * Main header file for TrIPE
   6  *
   7  * (c) 2001 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Trivial IP Encryption (TrIPE).
  13  *
  14  * TrIPE is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * TrIPE is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with TrIPE; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 #ifndef TRIPE_H
  30 #define TRIPE_H
  31
  32 #ifdef __cplusplus
  33   extern "C" {
  34 #endif
  35
  36 /*----- Header files ------------------------------------------------------*/
  37
  38 #include "config.h"
  39
  40 #include <assert.h>
  41 #include <ctype.h>
  42 #include <errno.h>
  43 #include <signal.h>
  44 #include <stdarg.h>
  45 #include <stddef.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <time.h>
  50
  51 #include <sys/types.h>
  52 #include <sys/time.h>
  53 #include <unistd.h>
  54 #include <fcntl.h>
  55 #include <sys/stat.h>
  56
  57 #include <sys/socket.h>
  58 #include <sys/un.h>
  59 #include <netinet/in.h>
  60 #include <arpa/inet.h>
  61 #include <netdb.h>
  62
  63 #include <pwd.h>
  64 #include <grp.h>
  65
  66 #include <mLib/alloc.h>
  67 #include <mLib/arena.h>
  68 #include <mLib/bres.h>
  69 #include <mLib/dstr.h>
  70 #include <mLib/env.h>
  71 #include <mLib/fdflags.h>
  72 #include <mLib/fwatch.h>
  73 #include <mLib/mdwopt.h>
  74 #include <mLib/quis.h>
  75 #include <mLib/report.h>
  76 #include <mLib/sel.h>
  77 #include <mLib/selbuf.h>
  78 #include <mLib/sig.h>
  79 #include <mLib/str.h>
  80 #include <mLib/sub.h>
  81 #include <mLib/trace.h>
  82
  83 #include <catacomb/buf.h>
  84
  85 #include <catacomb/gcipher.h>
  86 #include <catacomb/gmac.h>
  87 #include <catacomb/grand.h>
  88 #include <catacomb/key.h>
  89 #include <catacomb/paranoia.h>
  90
  91 #include <catacomb/noise.h>
  92 #include <catacomb/rand.h>
  93
  94 #include <catacomb/mp.h>
  95 #include <catacomb/mprand.h>
  96 #include <catacomb/dh.h>
  97 #include <catacomb/ec.h>
  98 #include <catacomb/ec-keys.h>
  99 #include <catacomb/group.h>
 100
 101 #include "tripe-protocol.h"
 102 #include "util.h"
 103
 104 #undef sun
 105
 106 /*----- Magic numbers -----------------------------------------------------*/
 107
 108 /* --- Tunnel types --- */
 109
 110 #define TUN_NOTDEF 0
 111 #define TUN_UNET 1
 112 #define TUN_BSD 2
 113 #define TUN_LINUX 3
 114
 115 /* --- Trace flags --- */
 116
 117 #define T_TUNNEL 1u
 118 #define T_PEER 2u
 119 #define T_PACKET 4u
 120 #define T_ADMIN 8u
 121 #define T_CRYPTO 16u
 122 #define T_KEYSET 32u
 123 #define T_KEYEXCH 64u
 124 #define T_KEYMGMT 128u
 125
 126 #define T_ALL 255u
 127
 128 /* --- Units --- */
 129
 130 #define SEC(n) (n##u)
 131 #define MIN(n) (n##u * 60u)
 132 #define MEG(n) (n##ul * 1024ul * 1024ul)
 133
 134 /* --- Other things --- */
 135
 136 #define PKBUFSZ 65536
 137
 138 /*----- Cipher selections -------------------------------------------------*/
 139
 140 typedef struct algswitch {
 141   const gccipher *c;                    /* Symmetric encryption scheme */
 142   const gccipher *mgf;                  /* Mask-generation function */
 143   const gchash *h;                      /* Hash function */
 144   const gcmac *m;                       /* Message authentication code */
 145   size_t hashsz;                        /* Hash output size */
 146   size_t tagsz;                         /* Length to truncate MAC tags */
 147   size_t cksz, mksz;                    /* Key lengths for @c@ and @m@ */
 148 } algswitch;
 149
 150 extern algswitch algs;
 151
 152 #define MAXHASHSZ 64                    /* Largest possible hash size */
 153
 154 #define HASH_STRING(h, s) GH_HASH((h), (s), sizeof(s))
 155
 156 /*----- Data structures ---------------------------------------------------*/
 157
 158 /* --- Socket addresses --- *
 159  *
 160  * A magic union of supported socket addresses.
 161  */
 162
 163 typedef union addr {
 164   struct sockaddr sa;
 165   struct sockaddr_in sin;
 166 } addr;
 167
 168 /* --- A symmetric keyset --- *
 169  *
 170  * A keyset contains a set of symmetric keys for encrypting and decrypting
 171  * packets.  Keysets are stored in a list, sorted in reverse order of
 172  * creation, so that the most recent keyset (the one most likely to be used)
 173  * is first.
 174  *
 175  * Each keyset has a time limit and a data limit.  The keyset is destroyed
 176  * when either it has existed for too long, or it has been used to encrypt
 177  * too much data.  New key exchanges are triggered when keys are close to
 178  * expiry.
 179  */
 180
 181 typedef struct keyset {
 182   struct keyset *next;                  /* Next active keyset in the list */
 183   unsigned ref;                         /* Reference count for keyset */
 184   struct peer *p;                       /* Pointer to peer structure */
 185   time_t t_exp;                         /* Expiry time for this keyset */
 186   unsigned long sz_exp;                 /* Data limit for the keyset */
 187   T( unsigned seq; )                    /* Sequence number for tracing */
 188   unsigned f;                           /* Various useful flags */
 189   gcipher *cin, *cout;                  /* Keyset ciphers for encryption */
 190   size_t tagsz;                         /* Length to truncate MAC tags */
 191   gmac *min, *mout;                     /* Keyset MACs for integrity */
 192   uint32 oseq;                          /* Outbound sequence number */
 193   uint32 iseq, iwin;                    /* Inbound sequence number */
 194 } keyset;
 195
 196 #define KS_SEQWINSZ 32                  /* Bits in sequence number window */
 197
 198 #define KSF_LISTEN 1u                   /* Don't encrypt packets yet */
 199 #define KSF_LINK 2u                     /* Key is in a linked list */
 200
 201 /* --- Key exchange --- *
 202  *
 203  * TrIPE uses the Wrestlers Protocol for its key exchange.  The Wrestlers
 204  * Protocol has a number of desirable features (e.g., perfect forward
 205  * secrecy, and zero-knowledge authentication) which make it attractive for
 206  * use in TrIPE.  The Wrestlers Protocol was designed by Mark Wooding and
 207  * Clive Jones.
 208  */
 209
 210 #define KX_NCHAL 16u
 211 #define KX_THRESH 4u
 212
 213 typedef struct kxchal {
 214   struct keyexch *kx;                   /* Pointer back to key exchange */
 215   ge *c;                                /* Responder's challenge */
 216   ge *r;                                /* My reply to the challenge */
 217   keyset *ks;                           /* Pointer to temporary keyset */
 218   unsigned f;                           /* Various useful flags */
 219   sel_timer t;                          /* Response timer for challenge */
 220   octet hc[MAXHASHSZ];                  /* Hash of his challenge */
 221   mp *ck;                               /* The check value */
 222   octet hswrq_in[MAXHASHSZ];            /* Inbound switch request message */
 223   octet hswok_in[MAXHASHSZ];            /* Inbound switch confirmation */
 224   octet hswrq_out[MAXHASHSZ];           /* Outbound switch request message */
 225   octet hswok_out[MAXHASHSZ];           /* Outbound switch confirmation */
 226 } kxchal;
 227
 228 typedef struct keyexch {
 229   struct peer *p;                       /* Pointer back to the peer */
 230   keyset **ks;                          /* Peer's list of keysets */
 231   unsigned f;                           /* Various useful flags */
 232   unsigned s;                           /* Current state in exchange */
 233   sel_timer t;                          /* Timer for next exchange */
 234   ge *kpub;                             /* Peer's public key */
 235   time_t texp_kpub;                     /* Expiry time for public key */
 236   mp *alpha;                            /* My temporary secret */
 237   ge *c;                                /* My challenge */
 238   ge *rx;                               /* The expected response */
 239   unsigned nr;                          /* Number of extant responses */
 240   time_t t_valid;                       /* When this exchange goes bad */
 241   octet hc[MAXHASHSZ];                  /* Hash of my challenge */
 242   kxchal *r[KX_NCHAL];                  /* Array of challenges */
 243 } keyexch;
 244
 245 #define KXF_TIMER 1u                    /* Waiting for a timer to go off */
 246 #define KXF_DEAD 2u                     /* The key-exchanger isn't up */
 247 #define KXF_PUBKEY 4u                   /* Key exchanger has a public key */
 248
 249 enum {
 250   KXS_DEAD,                             /* Uninitialized state (magical) */
 251   KXS_CHAL,                             /* Main answer-challenges state */
 252   KXS_COMMIT,                           /* Committed: send switch request */
 253   KXS_SWITCH                            /* Switched: send confirmation */
 254 };
 255
 256 /* --- Tunnel structure --- *
 257  *
 258  * Used to maintain system-specific information about the tunnel interface.
 259  */
 260
 261 #if TUN_TYPE == TUN_LINUX
 262 #  include <linux/if.h>
 263 #  include <linux/if_tun.h>
 264 #endif
 265
 266 typedef struct tunnel {
 267 #if TUN_TYPE == TUN_UNET
 268   sel_file f;                           /* Selector for Usernet device */
 269   struct peer *p;                       /* Pointer to my peer */
 270 #elif TUN_TYPE == TUN_LINUX
 271   sel_file f;                           /* Selector for TUN/TAP device */
 272   struct peer *p;                       /* Pointer to my peer */
 273   char ifn[IFNAMSIZ];                   /* Interface name buffer */
 274 #elif TUN_TYPE == TUN_BSD
 275   sel_file f;                           /* Selector for tunnel device */
 276   struct peer *p;                       /* Pointer to my peer */
 277   unsigned n;                           /* Number of my tunnel device */
 278 #else
 279 #  error "No support for this tunnel type"
 280 #endif
 281 } tunnel;
 282
 283 /* --- Peer statistics --- *
 284  *
 285  * Contains various interesting and not-so-interesting statistics about a
 286  * peer.  This is updated by various parts of the code.  The format of the
 287  * structure isn't considered private, and @p_stats@ returns a pointer to the
 288  * statistics block for a given peer.
 289  */
 290
 291 typedef struct stats {
 292   unsigned long sz_in, sz_out;          /* Size of all data in and out */
 293   unsigned long sz_kxin, sz_kxout;      /* Size of key exchange messages */
 294   unsigned long sz_ipin, sz_ipout;      /* Size of encapsulated IP packets */
 295   time_t t_start, t_last;               /* Time peer created, last recv */
 296   unsigned long n_reject;               /* Number of rejected packets */
 297   unsigned long n_in, n_out;            /* Number of packets in and out */
 298   unsigned long n_kxin, n_kxout;        /* Number of key exchange packets */
 299   unsigned long n_ipin, n_ipout;        /* Number of encrypted packets */
 300 } stats;
 301
 302 /* --- Peer structure --- *
 303  *
 304  * The main structure which glues everything else together.
 305  */
 306
 307 typedef struct peer {
 308   struct peer *next, *prev;             /* Links to next and previous */
 309   char *name;                           /* Name of this peer */
 310   tunnel t;                             /* Tunnel for local packets */
 311   keyset *ks;                           /* List head for keysets */
 312   buf b;                                /* Buffer for sending packets */
 313   addr peer;                            /* Peer socket address */
 314   size_t sasz;                          /* Socket address size */
 315   stats st;                             /* Statistics */
 316   keyexch kx;                           /* Key exchange protocol block */
 317 } peer;
 318
 319 /* --- Admin structure --- */
 320
 321 #define OBUFSZ 16384u
 322
 323 typedef struct obuf {
 324   struct obuf *next;                    /* Next buffer in list */
 325   char *p_in, *p_out;                   /* Pointers into the buffer */
 326   char buf[OBUFSZ];                     /* The actual buffer */
 327 } obuf;
 328
 329 typedef struct admin {
 330   struct admin *next, *prev;            /* Links to next and previous */
 331   unsigned f;                           /* Various useful flags */
 332 #ifndef NTRACE
 333   unsigned seq;                         /* Sequence number for tracing */
 334 #endif
 335   char *pname;                          /* Peer name to create */
 336   char *paddr;                          /* Address string to resolve */
 337   obuf *o_head, *o_tail;                /* Output buffer list */
 338   selbuf b;                             /* Line buffer for commands */
 339   sel_file w;                           /* Selector for write buffering */
 340   bres_client r;                        /* Background resolver task */
 341   sel_timer t;                          /* Timer for resolver */
 342   addr peer;                            /* Address to set */
 343   size_t sasz;                          /* Size of the address */
 344 } admin;
 345
 346 #define AF_DEAD 1u                      /* Destroy this admin block */
 347 #define AF_LOCK 2u                      /* Don't destroy it yet */
 348
 349 /*----- Global variables --------------------------------------------------*/
 350
 351 extern sel_state sel;                   /* Global I/O event state */
 352 extern group *gg;                       /* The group we work in */
 353 extern mp *kpriv;                       /* Our private key */
 354 extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ];
 355
 356 #ifndef NTRACE
 357 extern const trace_opt tr_opts[];       /* Trace options array */
 358 extern unsigned tr_flags;               /* Trace options flags */
 359 #endif
 360
 361 /*----- Other macros ------------------------------------------------------*/
 362
 363 #define TIMER noise_timer(RAND_GLOBAL)
 364
 365 /*----- Key management ----------------------------------------------------*/
 366
 367 /* --- @km_interval@ --- *
 368  *
 369  * Arguments:   ---
 370  *
 371  * Returns:     Zero if OK, nonzero to force reloading of keys.
 372  *
 373  * Use:         Called on the interval timer to perform various useful jobs.
 374  */
 375
 376 extern int km_interval(void);
 377
 378 /* --- @km_init@ --- *
 379  *
 380  * Arguments:   @const char *kr_priv@ = private keyring file
 381  *              @const char *kr_pub@ = public keyring file
 382  *              @const char *tag@ = tag to load
 383  *
 384  * Returns:     ---
 385  *
 386  * Use:         Initializes, and loads the private key.
 387  */
 388
 389 extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/,
 390                     const char */*tag*/);
 391
 392 /* --- @km_getpubkey@ --- *
 393  *
 394  * Arguments:   @const char *tag@ = public key tag to load
 395  *              @ge *kpub@ = where to put the public key
 396  *              @time_t *t_exp@ = where to put the expiry time
 397  *
 398  * Returns:     Zero if OK, nonzero if it failed.
 399  *
 400  * Use:         Fetches a public key from the keyring.
 401  */
 402
 403 extern int km_getpubkey(const char */*tag*/, ge */*kpub*/,
 404                         time_t */*t_exp*/);
 405
 406 /*----- Key exchange ------------------------------------------------------*/
 407
 408 /* --- @kx_start@ --- *
 409  *
 410  * Arguments:   @keyexch *kx@ = pointer to key exchange context
 411  *
 412  * Returns:     ---
 413  *
 414  * Use:         Stimulates a key exchange.  If a key exchage is in progress,
 415  *              a new challenge is sent (unless the quiet timer forbids
 416  *              this); if no exchange is in progress, one is commenced.
 417  */
 418
 419 extern void kx_start(keyexch */*kx*/);
 420
 421 /* --- @kx_message@ --- *
 422  *
 423  * Arguments:   @keyexch *kx@ = pointer to key exchange context
 424  *              @unsigned msg@ = the message code
 425  *              @buf *b@ = pointer to buffer containing the packet
 426  *
 427  * Returns:     ---
 428  *
 429  * Use:         Reads a packet containing key exchange messages and handles
 430  *              it.
 431  */
 432
 433 extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
 434
 435 /* --- @kx_free@ --- *
 436  *
 437  * Arguments:   @keyexch *kx@ = pointer to key exchange context
 438  *
 439  * Returns:     ---
 440  *
 441  * Use:         Frees everything in a key exchange context.
 442  */
 443
 444 extern void kx_free(keyexch */*kx*/);
 445
 446 /* --- @kx_newkeys@ --- *
 447  *
 448  * Arguments:   @keyexch *kx@ = pointer to key exchange context
 449  *
 450  * Returns:     ---
 451  *
 452  * Use:         Informs the key exchange module that its keys may have
 453  *              changed.  If fetching the new keys fails, the peer will be
 454  *              destroyed, we log messages and struggle along with the old
 455  *              keys.
 456  */
 457
 458 extern void kx_newkeys(keyexch */*kx*/);
 459
 460 /* --- @kx_init@ --- *
 461  *
 462  * Arguments:   @keyexch *kx@ = pointer to key exchange context
 463  *              @peer *p@ = pointer to peer context
 464  *              @keyset **ks@ = pointer to keyset list
 465  *
 466  * Returns:     Zero if OK, nonzero if it failed.
 467  *
 468  * Use:         Initializes a key exchange module.  The module currently
 469  *              contains no keys, and will attempt to initiate a key
 470  *              exchange.
 471  */
 472
 473 extern int kx_init(keyexch */*kx*/, peer */*p*/, keyset **/*ks*/);
 474
 475 /*----- Keysets and symmetric cryptography --------------------------------*/
 476
 477 /* --- @ks_drop@ --- *
 478  *
 479  * Arguments:   @keyset *ks@ = pointer to a keyset
 480  *
 481  * Returns:     ---
 482  *
 483  * Use:         Decrements a keyset's reference counter.  If the counter hits
 484  *              zero, the keyset is freed.
 485  */
 486
 487 extern void ks_drop(keyset */*ks*/);
 488
 489 /* --- @ks_gen@ --- *
 490  *
 491  * Arguments:   @const void *k@ = pointer to key material
 492  *              @size_t x, y, z@ = offsets into key material (see below)
 493  *              @peer *p@ = pointer to peer information
 494  *
 495  * Returns:     A pointer to the new keyset.
 496  *
 497  * Use:         Derives a new keyset from the given key material.  The
 498  *              offsets @x@, @y@ and @z@ separate the key material into three
 499  *              parts.  Between the @k@ and @k + x@ is `my' contribution to
 500  *              the key material; between @k + x@ and @k + y@ is `your'
 501  *              contribution; and between @k + y@ and @k + z@ is a shared
 502  *              value we made together.  These are used to construct two
 503  *              pairs of symmetric keys.  Each pair consists of an encryption
 504  *              key and a message authentication key.  One pair is used for
 505  *              outgoing messages, the other for incoming messages.
 506  *
 507  *              The new key is marked so that it won't be selected for output
 508  *              by @ksl_encrypt@.  You can still encrypt data with it by
 509  *              calling @ks_encrypt@ directly.
 510  */
 511
 512 extern keyset *ks_gen(const void */*k*/,
 513                       size_t /*x*/, size_t /*y*/, size_t /*z*/,
 514                       peer */*p*/);
 515
 516 /* --- @ks_tregen@ --- *
 517  *
 518  * Arguments:   @keyset *ks@ = pointer to a keyset
 519  *
 520  * Returns:     The time at which moves ought to be made to replace this key.
 521  */
 522
 523 extern time_t ks_tregen(keyset */*ks*/);
 524
 525 /* --- @ks_activate@ --- *
 526  *
 527  * Arguments:   @keyset *ks@ = pointer to a keyset
 528  *
 529  * Returns:     ---
 530  *
 531  * Use:         Activates a keyset, so that it can be used for encrypting
 532  *              outgoing messages.
 533  */
 534
 535 extern void ks_activate(keyset */*ks*/);
 536
 537 /* --- @ks_encrypt@ --- *
 538  *
 539  * Arguments:   @keyset *ks@ = pointer to a keyset
 540  *              @unsigned ty@ = message type
 541  *              @buf *b@ = pointer to input buffer
 542  *              @buf *bb@ = pointer to output buffer
 543  *
 544  * Returns:     Zero if OK, nonzero if the key needs replacing.  If the
 545  *              encryption failed, the output buffer is broken and zero is
 546  *              returned.
 547  *
 548  * Use:         Encrypts a block of data using the key.  Note that the `key
 549  *              ought to be replaced' notification is only ever given once
 550  *              for each key.  Also note that this call forces a keyset to be
 551  *              used even if it's marked as not for data output.
 552  */
 553
 554 extern int ks_encrypt(keyset */*ks*/, unsigned /*ty*/,
 555                       buf */*b*/, buf */*bb*/);
 556
 557 /* --- @ks_decrypt@ --- *
 558  *
 559  * Arguments:   @keyset *ks@ = pointer to a keyset
 560  *              @unsigned ty@ = expected type code
 561  *              @buf *b@ = pointer to an input buffer
 562  *              @buf *bb@ = pointer to an output buffer
 563  *
 564  * Returns:     Zero on success, or nonzero if there was some problem.
 565  *
 566  * Use:         Attempts to decrypt a message using a given key.  Note that
 567  *              requesting decryption with a key directly won't clear a
 568  *              marking that it's not for encryption.
 569  */
 570
 571 extern int ks_decrypt(keyset */*ks*/, unsigned /*ty*/,
 572                       buf */*b*/, buf */*bb*/);
 573
 574 /* --- @ksl_free@ --- *
 575  *
 576  * Arguments:   @keyset **ksroot@ = pointer to keyset list head
 577  *
 578  * Returns:     ---
 579  *
 580  * Use:         Frees (releases references to) all of the keys in a keyset.
 581  */
 582
 583 extern void ksl_free(keyset **/*ksroot*/);
 584
 585 /* --- @ksl_link@ --- *
 586  *
 587  * Arguments:   @keyset **ksroot@ = pointer to keyset list head
 588  *              @keyset *ks@ = pointer to a keyset
 589  *
 590  * Returns:     ---
 591  *
 592  * Use:         Links a keyset into a list.  A keyset can only be on one list
 593  *              at a time.  Bad things happen otherwise.
 594  */
 595
 596 extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
 597
 598 /* --- @ksl_prune@ --- *
 599  *
 600  * Arguments:   @keyset **ksroot@ = pointer to keyset list head
 601  *
 602  * Returns:     ---
 603  *
 604  * Use:         Prunes the keyset list by removing keys which mustn't be used
 605  *              any more.
 606  */
 607
 608 extern void ksl_prune(keyset **/*ksroot*/);
 609
 610 /* --- @ksl_encrypt@ --- *
 611  *
 612  * Arguments:   @keyset **ksroot@ = pointer to keyset list head
 613  *              @unsigned ty@ = message type
 614  *              @buf *b@ = pointer to input buffer
 615  *              @buf *bb@ = pointer to output buffer
 616  *
 617  * Returns:     Nonzero if a new key is needed.
 618  *
 619  * Use:         Encrypts a packet.
 620  */
 621
 622 extern int ksl_encrypt(keyset **/*ksroot*/, unsigned /*ty*/,
 623                        buf */*b*/, buf */*bb*/);
 624
 625 /* --- @ksl_decrypt@ --- *
 626  *
 627  * Arguments:   @keyset **ksroot@ = pointer to keyset list head
 628  *              @unsigned ty@ = expected type code
 629  *              @buf *b@ = pointer to input buffer
 630  *              @buf *bb@ = pointer to output buffer
 631  *
 632  * Returns:     Nonzero if the packet couldn't be decrypted.
 633  *
 634  * Use:         Decrypts a packet.
 635  */
 636
 637 extern int ksl_decrypt(keyset **/*ksroot*/, unsigned /*ty*/,
 638                        buf */*b*/, buf */*bb*/);
 639
 640 /*----- Administration interface ------------------------------------------*/
 641
 642 /* --- @a_warn@ --- *
 643  *
 644  * Arguments:   @const char *fmt@ = pointer to format string
 645  *              @...@ = other arguments
 646  *
 647  * Returns:     ---
 648  *
 649  * Use:         Informs all admin connections of a warning.
 650  */
 651
 652 extern void a_warn(const char */*fmt*/, ...);
 653
 654 /* --- @a_create@ --- *
 655  *
 656  * Arguments:   @int fd_in, fd_out@ = file descriptors to use
 657  *
 658  * Returns:     ---
 659  *
 660  * Use:         Creates a new admin connection.
 661  */
 662
 663 extern void a_create(int /*fd_in*/, int /*fd_out*/);
 664
 665 /* --- @a_quit@ --- *
 666  *
 667  * Arguments:   ---
 668  *
 669  * Returns:     ---
 670  *
 671  * Use:         Shuts things down nicely.
 672  */
 673
 674 extern void a_quit(void);
 675
 676 /* --- @a_daemon@ --- *
 677  *
 678  * Arguments:   ---
 679  *
 680  * Returns:     ---
 681  *
 682  * Use:         Informs the admin module that it's a daemon.
 683  */
 684
 685 extern void a_daemon(void);
 686
 687 /* --- @a_init@ --- *
 688  *
 689  * Arguments:   @const char *sock@ = socket name to create
 690  *
 691  * Returns:     ---
 692  *
 693  * Use:         Creates the admin listening socket.
 694  */
 695
 696 extern void a_init(const char */*sock*/);
 697
 698 /*----- Peer management ---------------------------------------------------*/
 699
 700 /* --- @p_txstart@ --- *
 701  *
 702  * Arguments:   @peer *p@ = pointer to peer block
 703  *              @unsigned msg@ = message type code
 704  *
 705  * Returns:     A pointer to a buffer to write to.
 706  *
 707  * Use:         Starts sending to a peer.  Only one send can happen at a
 708  *              time.
 709  */
 710
 711 extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
 712
 713 /* --- @p_txend@ --- *
 714  *
 715  * Arguments:   @peer *p@ = pointer to peer block
 716  *
 717  * Returns:     ---
 718  *
 719  * Use:         Sends a packet to the peer.
 720  */
 721
 722 extern void p_txend(peer */*p*/);
 723
 724 /* --- @p_tun@ --- *
 725  *
 726  * Arguments:   @peer *p@ = pointer to peer block
 727  *              @buf *b@ = buffer containing incoming packet
 728  *
 729  * Returns:     ---
 730  *
 731  * Use:         Handles a packet which needs to be sent to a peer.
 732  */
 733
 734 extern void p_tun(peer */*p*/, buf */*b*/);
 735
 736 /* --- @p_interval@ --- *
 737  *
 738  * Arguments:   ---
 739  *
 740  * Returns:     ---
 741  *
 742  * Use:         Called periodically to do tidying.
 743  */
 744
 745 extern void p_interval(void);
 746
 747 /* --- @p_stats@ --- *
 748  *
 749  * Arguments:   @peer *p@ = pointer to a peer block
 750  *
 751  * Returns:     A pointer to the peer's statistics.
 752  */
 753
 754 extern stats *p_stats(peer */*p*/);
 755
 756 /* --- @p_ifname@ --- *
 757  *
 758  * Arguments:   @peer *p@ = pointer to a peer block
 759  *
 760  * Returns:     A pointer to the peer's interface name.
 761  */
 762
 763 extern const char *p_ifname(peer */*p*/);
 764
 765 /* --- @p_addr@ --- *
 766  *
 767  * Arguments:   @peer *p@ = pointer to a peer block
 768  *
 769  * Returns:     A pointer to the peer's address.
 770  */
 771
 772 extern const addr *p_addr(peer */*p*/);
 773
 774 /* --- @p_init@ --- *
 775  *
 776  * Arguments:   @struct in_addr addr@ = address to bind to
 777  *              @unsigned port@ = port number to listen to
 778  *
 779  * Returns:     ---
 780  *
 781  * Use:         Initializes the peer system; creates the socket.
 782  */
 783
 784 extern void p_init(struct in_addr /*addr*/, unsigned /*port*/);
 785
 786 /* --- @p_port@ --- *
 787  *
 788  * Arguments:   ---
 789  *
 790  * Returns:     Port number used for socket.
 791  */
 792
 793 unsigned p_port(void);
 794
 795 /* --- @p_create@ --- *
 796  *
 797  * Arguments:   @const char *name@ = name for this peer
 798  *              @struct sockaddr *sa@ = socket address of peer
 799  *              @size_t sz@ = size of socket address
 800  *
 801  * Returns:     Pointer to the peer block, or null if it failed.
 802  *
 803  * Use:         Creates a new named peer block.  No peer is actually attached
 804  *              by this point.
 805  */
 806
 807 extern peer *p_create(const char */*name*/,
 808                       struct sockaddr */*sa*/, size_t /*sz*/);
 809
 810 /* --- @p_name@ --- *
 811  *
 812  * Arguments:   @peer *p@ = pointer to a peer block
 813  *
 814  * Returns:     A pointer to the peer's name.
 815  */
 816
 817 extern const char *p_name(peer */*p*/);
 818
 819 /* --- @p_find@ --- *
 820  *
 821  * Arguments:   @const char *name@ = name to look up
 822  *
 823  * Returns:     Pointer to the peer block, or null if not found.
 824  *
 825  * Use:         Finds a peer by name.
 826  */
 827
 828 extern peer *p_find(const char */*name*/);
 829
 830 /* --- @p_destroy@ --- *
 831  *
 832  * Arguments:   @peer *p@ = pointer to a peer
 833  *
 834  * Returns:     ---
 835  *
 836  * Use:         Destroys a peer.
 837  */
 838
 839 extern void p_destroy(peer */*p*/);
 840
 841 /* --- @p_first@, @p_next@ --- *
 842  *
 843  * Arguments:   @peer *p@ = a peer block
 844  *
 845  * Returns:     @peer_first@ returns the first peer in some ordering;
 846  *              @peer_next@ returns the peer following a given one in the
 847  *              same ordering.  Null is returned for the end of the list.
 848  */
 849
 850 extern peer *p_first(void);
 851 extern peer *p_next(peer */*p*/);
 852
 853 /*----- Tunnel interface --------------------------------------------------*/
 854
 855 /* --- @tun_init@ --- *
 856  *
 857  * Arguments:   ---
 858  *
 859  * Returns:     ---
 860  *
 861  * Use:         Initializes the tunneling system.  Maybe this will require
 862  *              opening file descriptors or something.
 863  */
 864
 865 extern void tun_init(void);
 866
 867 /* --- @tun_create@ --- *
 868  *
 869  * Arguments:   @tunnel *t@ = pointer to tunnel block
 870  *              @peer *p@ = pointer to peer block
 871  *
 872  * Returns:     Zero if it worked, nonzero on failure.
 873  *
 874  * Use:         Initializes a new tunnel.
 875  */
 876
 877 extern int tun_create(tunnel */*t*/, peer */*p*/);
 878
 879 /* --- @tun_ifname@ --- *
 880  *
 881  * Arguments:   @tunnel *t@ = pointer to tunnel block
 882  *
 883  * Returns:     A pointer to the tunnel's interface name.
 884  */
 885
 886 extern const char *tun_ifname(tunnel */*t*/);
 887
 888 /* --- @tun_inject@ --- *
 889  *
 890  * Arguments:   @tunnel *t@ = pointer to tunnel block
 891  *              @buf *b@ = buffer to send
 892  *
 893  * Returns:     ---
 894  *
 895  * Use:         Injects a packet into the local network stack.
 896  */
 897
 898 extern void tun_inject(tunnel */*t*/, buf */*b*/);
 899
 900 /* --- @tun_destroy@ --- *
 901  *
 902  * Arguments:   @tunnel *t@ = pointer to tunnel block
 903  *
 904  * Returns:     ---
 905  *
 906  * Use:         Destroys a tunnel.
 907  */
 908
 909 extern void tun_destroy(tunnel */*t*/);
 910
 911 /*----- Other handy utilities ---------------------------------------------*/
 912
 913 /* --- @mpstr@ --- *
 914  *
 915  * Arguments:   @mp *m@ = a multiprecision integer
 916  *
 917  * Returns:     A pointer to the integer's textual representation.
 918  *
 919  * Use:         Converts a multiprecision integer to a string.  Corrupts
 920  *              @buf_t@.
 921  */
 922
 923 extern const char *mpstr(mp */*m*/);
 924
 925 /* --- @gestr@ --- *
 926  *
 927  * Arguments:   @group *g@ = a group
 928  *              @ge *x@ = a group element
 929  *
 930  * Returns:     A pointer to the element's textual representation.
 931  *
 932  * Use:         Converts a group element to a string.  Corrupts
 933  *              @buf_t@.
 934  */
 935
 936 extern const char *gestr(group */*g*/, ge */*x*/);
 937
 938 /* --- @timestr@ --- *
 939  *
 940  * Arguments:   @time_t t@ = a time to convert
 941  *
 942  * Returns:     A pointer to a textual representation of the time.
 943  *
 944  * Use:         Converts a time to a textual representation.  Corrupts
 945  *              @buf_t@.
 946  */
 947
 948 extern const char *timestr(time_t /*t*/);
 949
 950 /*----- That's all, folks -------------------------------------------------*/
 951
 952 #ifdef __cplusplus
 953   }
 954 #endif
 955
 956 #endif