3 * Main header file for TrIPE
5 * (c) 2001 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Trivial IP Encryption (TrIPE).
12 * TrIPE is free software: you can redistribute it and/or modify it under
13 * the terms of the GNU General Public License as published by the Free
14 * Software Foundation; either version 3 of the License, or (at your
15 * option) any later version.
17 * TrIPE is distributed in the hope that it will be useful, but WITHOUT
18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22 * You should have received a copy of the GNU General Public License
23 * along with TrIPE. If not, see <https://www.gnu.org/licenses/>.
33 /*----- Header files ------------------------------------------------------*/
49 #include <sys/types.h>
56 #include <sys/socket.h>
58 #include <netinet/in.h>
59 #include <arpa/inet.h>
65 #include <mLib/alloc.h>
66 #include <mLib/arena.h>
67 #include <mLib/base64.h>
68 #include <mLib/bres.h>
69 #include <mLib/codec.h>
70 #include <mLib/daemonize.h>
71 #include <mLib/dstr.h>
73 #include <mLib/fdflags.h>
74 #include <mLib/fdpass.h>
75 #include <mLib/fwatch.h>
76 #include <mLib/hash.h>
77 #include <mLib/macros.h>
78 #include <mLib/mdup.h>
79 #include <mLib/mdwopt.h>
80 #include <mLib/quis.h>
81 #include <mLib/report.h>
83 #include <mLib/selbuf.h>
87 #include <mLib/trace.h>
89 #include <mLib/versioncmp.h>
91 #include <catacomb/buf.h>
92 #include <catacomb/ct.h>
94 #include <catacomb/chacha.h>
95 #include <catacomb/gcipher.h>
96 #include <catacomb/gmac.h>
97 #include <catacomb/grand.h>
98 #include <catacomb/key.h>
99 #include <catacomb/paranoia.h>
100 #include <catacomb/poly1305.h>
101 #include <catacomb/salsa20.h>
103 #include <catacomb/noise.h>
104 #include <catacomb/rand.h>
106 #include <catacomb/mp.h>
107 #include <catacomb/mpmont.h>
108 #include <catacomb/mprand.h>
109 #include <catacomb/dh.h>
110 #include <catacomb/ec.h>
111 #include <catacomb/ec-raw.h>
112 #include <catacomb/ec-keys.h>
113 #include <catacomb/x25519.h>
114 #include <catacomb/x448.h>
117 #include "protocol.h"
123 /*----- Magic numbers -----------------------------------------------------*/
125 /* --- Trace flags --- */
133 #define T_KEYEXCH 64u
134 #define T_KEYMGMT 128u
136 /* T_PRIVSEP in priv.h */
142 #define SEC(n) (n##u)
143 #define MIN(n) (n##u * 60u)
144 #define F_2P32 (65536.0*65536.0)
145 #define MEG(n) (n##ul * 1024ul * 1024ul)
147 /* --- Timing parameters --- */
149 #define T_EXP MIN(60) /* Expiry time for a key */
150 #define T_REGEN MIN(40) /* Regeneration time for a key */
152 #define T_VALID SEC(20) /* Challenge validity period */
153 #define T_RETRYMIN SEC(2) /* Minimum retry interval */
154 #define T_RETRYMAX MIN(5) /* Maximum retry interval */
155 #define T_RETRYGROW (5.0/4.0) /* Retry interval growth factor */
157 #define T_WOBBLE (1.0/3.0) /* Relative timer randomness */
159 /* --- Other things --- */
161 #define PKBUFSZ 65536
163 /*----- Cipher selections -------------------------------------------------*/
165 typedef struct keyset keyset;
166 typedef struct algswitch algswitch;
167 typedef struct kdata kdata;
168 typedef struct admin admin;
170 typedef struct dhgrp {
171 const struct dhops *ops;
175 typedef struct dhsc dhsc;
176 typedef struct dhge dhge;
179 DHFMT_STD, /* Fixed-width format, suitable for encryption */
180 DHFMT_HASH, /* Deterministic format, suitable for hashing */
181 DHFMT_VAR /* Variable-width-format, mostly a bad idea */
184 typedef struct deriveargs {
185 const char *what; /* Operation name (hashed) */
186 unsigned f; /* Flags */
187 #define DF_IN 1u /* Make incoming key */
188 #define DF_OUT 2u /* Make outgoing key */
189 const gchash *hc; /* Hash class */
190 const octet *k; /* Pointer to contributions */
191 size_t x, y, z; /* Markers in contributions */
194 typedef struct bulkalgs {
195 const struct bulkops *ops;
198 typedef struct bulkctx {
199 const struct bulkops *ops;
202 typedef struct bulkchal {
203 const struct bulkops *ops;
207 typedef struct dhops {
210 int (*ldpriv)(key_file */*kf*/, key */*k*/, key_data */*d*/,
211 kdata */*kd*/, dstr */*t*/, dstr */*e*/);
212 /* Load a private key from @d@, storing the data in @kd@. The key's
213 * file and key object are in @kf@ and @k@, mostly in case its
214 * attributes are interesting; the key tag is in @t@; errors are
215 * reported by writing tokens to @e@ and returning nonzero.
218 int (*ldpub)(key_file */*kf*/, key */*k*/, key_data */*d*/,
219 kdata */*kd*/, dstr */*t*/, dstr */*e*/);
220 /* Load a public key from @d@, storing the data in @kd@. The key's
221 * file and key object are in @kf@ and @k@, mostly in case its
222 * attributes are interesting; the key tag is in @t@; errors are
223 * reported by writing tokens to @e@ and returning nonzero.
226 const char *(*checkgrp)(const dhgrp */*g*/);
227 /* Check that the group is valid; return null on success, or an error
231 void (*grpinfo)(const dhgrp */*g*/, admin */*a*/);
232 /* Report on the group to an admin client. */
234 T( void (*tracegrp)(const dhgrp */*g*/); )
235 /* Trace a description of the group. */
237 int (*samegrpp)(const dhgrp */*g*/, const dhgrp */*gg*/);
238 /* Return nonzero if the two group objects represent the same
242 void (*freegrp)(dhgrp */*g*/);
243 /* Free a group and the resources it holds. */
245 dhsc *(*ldsc)(const dhgrp */*g*/, const void */*p*/, size_t /*sz*/);
246 /* Load a scalar from @p@, @sz@ and return it. Return null on
250 int (*stsc)(const dhgrp */*g*/,
251 void */*p*/, size_t /*sz*/, const dhsc */*x*/);
252 /* Store a scalar at @p@, @sz@. Return nonzero on error. */
254 dhsc *(*randsc)(const dhgrp */*g*/);
255 /* Return a random scalar. */
257 T( const char *(*scstr)(const dhgrp */*g*/, const dhsc */*x*/); )
258 /* Return a human-readable representation of @x@; @buf_t@ may be used
262 void (*freesc)(const dhgrp */*g*/, dhsc */*x*/);
263 /* Free a scalar and the resources it holds. */
265 dhge *(*ldge)(const dhgrp */*g*/, buf */*b*/, int /*fmt*/);
266 /* Load a group element from @b@, encoded using format @fmt@. Return
270 int (*stge)(const dhgrp */*g*/, buf */*b*/,
271 const dhge */*Y*/, int /*fmt*/);
272 /* Store a group element in @b@, encoded using format @fmt@. Return
276 int (*checkge)(const dhgrp */*h*/, const dhge */*Y*/);
277 /* Check a group element for validity. Return zero if everything
278 * checks out; nonzero on failure.
281 int (*eq)(const dhgrp */*g*/, const dhge */*Y*/, const dhge */*Z*/);
282 /* Return nonzero if @Y@ and @Z@ are equal. */
284 dhge *(*mul)(const dhgrp */*g*/, const dhsc */*x*/, const dhge */*Y*/);
285 /* Multiply a group element by a scalar, resulting in a shared-secret
286 * group element. If @y@ is null, then multiply the well-known
290 T( const char *(*gestr)(const dhgrp */*g*/, const dhge */*Y*/); )
291 /* Return a human-readable representation of @Y@; @buf_t@ may be used
295 void (*freege)(const dhgrp */*g*/, dhge */*Y*/);
296 /* Free a group element and the resources it holds. */
300 typedef struct bulkops {
303 bulkalgs *(*getalgs)(const algswitch */*asw*/, dstr */*e*/,
304 key_file */*kf*/, key */*k*/);
305 /* Determine algorithms to use and return a @bulkalgs@ object
306 * representing the decision. On error, write tokens to @e@ and
310 T( void (*tracealgs)(const bulkalgs */*a*/); )
311 /* Write trace information about the algorithm selection. */
313 int (*checkalgs)(bulkalgs */*a*/, const algswitch */*asw*/, dstr */*e*/);
314 /* Check that the algorithms in @a@ and @asw@ are acceptable. On
315 * error, write tokens to @e@ and return @-1@; otherwise return zero.
318 int (*samealgsp)(const bulkalgs */*a*/, const bulkalgs */*aa*/);
319 /* If @a@ and @aa@ represent the same algorithm selection, return
320 * nonzero; if not, return zero.
323 void (*alginfo)(const bulkalgs */*a*/, admin */*adm*/);
324 /* Report on the algorithm selection to an admin client: call
325 * @a_info@ with appropriate key-value pairs.
328 size_t (*overhead)(const bulkalgs */*a*/);
329 /* Return the per-packet overhead of the bulk transform, in bytes. */
331 size_t (*expsz)(const bulkalgs */*a*/);
332 /* Return the total size limit for the bulk transform, in bytes,
333 * after which the keys must no longer be used.
336 bulkctx *(*genkeys)(const bulkalgs */*a*/, const deriveargs */*a*/);
337 /* Generate session keys and construct and return an appropriate
338 * context for using them. The offsets @a->x@, @a->y@ and @a->z@
339 * separate the key material into three parts. Between @a->k@ and
340 * @a->k + a->x@ is `my' contribution to the key material; between
341 * @a->k + a->x@ and @a->k + a->y@ is `your' contribution; and
342 * between @a->k + a->y@ and @a->k + a->z@ is a shared value we made
343 * together. These are used to construct (up to) two collections of
344 * symmetric keys: one for outgoing messages, the other for incoming
345 * messages. If @a->x == 0@ (or @a->y == a->x@) then my (or your)
346 * contribution is omitted.
349 bulkchal *(*genchal)(const bulkalgs */*a*/);
350 /* Construct and return a challenge issuing and verification
351 * context with a fresh random key.
354 void (*freealgs)(bulkalgs */*a*/);
355 /* Release an algorithm selection object. (Associated bulk
356 * encryption contexts and challenge contexts may still exist and
357 * must remain valid.)
360 int (*encrypt)(bulkctx */*bc*/, unsigned /*ty*/,
361 buf */*b*/, buf */*bb*/, uint32 /*seq*/);
362 /* Encrypt the packet in @b@, with type @ty@ (which doesn't need
363 * encoding separately) and sequence number @seq@ (which must be
364 * recoverable by @decrypt@), and write the result to @bb@. On
365 * error, return a @KSERR_...@ code and/or break the output buffer.
368 int (*decrypt)(bulkctx */*bc*/, unsigned /*ty*/,
369 buf */*b*/, buf */*bb*/, uint32 */*seq*/);
370 /* Decrypt the packet in @b@, with type @ty@, writing the result to
371 * @bb@ and storing the incoming (claimed) sequence number in @seq@.
372 * On error, return a @KSERR_...@ code.
375 void (*freectx)(bulkctx */*a*/);
376 /* Release a bulk encryption context and the resources it holds. */
378 int (*chaltag)(bulkchal */*bc*/, const void */*m*/, size_t /*msz*/,
379 uint32 /*seq*/, void */*t*/);
380 /* Calculate a tag for the challenge in @m@, @msz@, with the sequence
381 * number @seq@, and write it to @t@. Return @-1@ on error, zero on
385 int (*chalvrf)(bulkchal */*bc*/, const void */*m*/, size_t /*msz*/,
386 uint32 /*seq*/, const void */*t*/);
387 /* Check the tag @t@ on @m@, @msz@ and @seq@: return zero if the tag
388 * is OK, nonzero if it's bad.
391 void (*freechal)(bulkchal */*bc*/);
392 /* Release a challenge context and the resources it holds. */
397 const gchash *h; size_t hashsz; /* Hash function */
398 const gccipher *mgf; /* Mask-generation function */
399 bulkalgs *bulk; /* Bulk crypto algorithms */
403 unsigned ref; /* Reference counter */
404 struct knode *kn; /* Pointer to cache entry */
405 uint32 id; /* The underlying key's id */
406 char *tag; /* Full tag name of the key */
407 dhgrp *grp; /* The group we work in */
408 dhsc *k; /* The private key (or null) */
409 dhge *K; /* The public key */
410 time_t t_exp; /* Expiry time of the key */
411 algswitch algs; /* Collection of algorithms */
414 typedef struct knode {
415 sym_base _b; /* Symbol table intrusion */
416 unsigned f; /* Various flags */
417 #define KNF_BROKEN 1u /* Don't use this key any more */
418 struct keyhalf *kh; /* Pointer to the home keyhalf */
419 kdata *kd; /* Pointer to the key data */
422 #define MAXHASHSZ 64 /* Largest possible hash size */
424 #define HASH_STRING(h, s) GH_HASH((h), (s), sizeof(s))
426 extern const dhops dhtab[];
427 extern const bulkops bulktab[];
429 /*----- Data structures ---------------------------------------------------*/
431 /* --- Socket addresses --- *
433 * A magic union of supported socket addresses.
438 struct sockaddr_in sin;
441 /* --- Mapping keyed on addresses --- */
443 typedef struct addrmap {
448 typedef struct addrmap_base {
453 /* --- Sequence number checking --- */
455 typedef struct seqwin {
456 uint32 seq; /* First acceptable input sequence */
457 uint32 win; /* Window of acceptable numbers */
460 #define SEQ_WINSZ 32 /* Bits in sequence number window */
462 /* --- A symmetric keyset --- *
464 * A keyset contains a set of symmetric keys for encrypting and decrypting
465 * packets. Keysets are stored in a list, sorted in reverse order of
466 * creation, so that the most recent keyset (the one most likely to be used)
469 * Each keyset has a time limit and a data limit. The keyset is destroyed
470 * when either it has existed for too long, or it has been used to encrypt
471 * too much data. New key exchanges are triggered when keys are close to
475 enum { DIR_IN, DIR_OUT, NDIR };
478 struct keyset *next; /* Next active keyset in the list */
479 unsigned ref; /* Reference count for keyset */
480 struct peer *p; /* Pointer to peer structure */
481 time_t t_exp; /* Expiry time for this keyset */
482 unsigned long sz_exp, sz_regen; /* Data limits for the keyset */
483 T( unsigned seq; ) /* Sequence number for tracing */
484 unsigned f; /* Various useful flags */
485 bulkctx *bulk; /* Bulk crypto transform */
486 uint32 oseq; /* Outbound sequence number */
487 seqwin iseq; /* Inbound sequence number */
490 #define KSF_LISTEN 1u /* Don't encrypt packets yet */
491 #define KSF_LINK 2u /* Key is in a linked list */
493 #define KSERR_REGEN -1 /* Regenerate keys */
494 #define KSERR_NOKEYS -2 /* No keys left */
495 #define KSERR_DECRYPT -3 /* Unable to decrypt message */
496 #define KSERR_SEQ -4 /* Incorrect sequence number */
497 #define KSERR_MALFORMED -5 /* Input ciphertext is broken */
499 /* --- Key exchange --- *
501 * TrIPE uses the Wrestlers Protocol for its key exchange. The Wrestlers
502 * Protocol has a number of desirable features (e.g., perfect forward
503 * secrecy, and zero-knowledge authentication) which make it attractive for
504 * use in TrIPE. The Wrestlers Protocol was designed by Mark Wooding and
508 typedef struct retry {
509 double t; /* Current retry time */
514 typedef struct kxchal {
515 struct keyexch *kx; /* Pointer back to key exchange */
516 dhge *C; /* Responder's challenge */
517 dhge *R; /* My reply to the challenge */
518 keyset *ks; /* Pointer to temporary keyset */
519 unsigned f; /* Various useful flags */
520 sel_timer t; /* Response timer for challenge */
521 retry rs; /* Retry state */
522 octet hc[MAXHASHSZ]; /* Hash of his challenge */
523 octet ck[MAXHASHSZ]; /* His magical check value */
524 octet hswrq_in[MAXHASHSZ]; /* Inbound switch request message */
525 octet hswok_in[MAXHASHSZ]; /* Inbound switch confirmation */
526 octet hswrq_out[MAXHASHSZ]; /* Outbound switch request message */
527 octet hswok_out[MAXHASHSZ]; /* Outbound switch confirmation */
530 typedef struct keyexch {
531 struct peer *p; /* Pointer back to the peer */
532 kdata *kpriv; /* Private key and related info */
533 kdata *kpub; /* Peer's public key */
534 keyset **ks; /* Peer's list of keysets */
535 unsigned f; /* Various useful flags */
536 unsigned s; /* Current state in exchange */
537 sel_timer t; /* Timer for next exchange */
538 retry rs; /* Retry state */
539 dhsc *a; /* My temporary secret */
540 dhge *C; /* My challenge */
541 dhge *RX; /* The expected response */
542 unsigned nr; /* Number of extant responses */
543 time_t t_valid; /* When this exchange goes bad */
544 octet hc[MAXHASHSZ]; /* Hash of my challenge */
545 kxchal *r[KX_NCHAL]; /* Array of challenges */
548 #define KXF_TIMER 1u /* Waiting for a timer to go off */
549 #define KXF_DEAD 2u /* The key-exchanger isn't up */
550 #define KXF_PUBKEY 4u /* Key exchanger has a public key */
551 #define KXF_CORK 8u /* Don't send anything yet */
554 KXS_DEAD, /* Uninitialized state (magical) */
555 KXS_CHAL, /* Main answer-challenges state */
556 KXS_COMMIT, /* Committed: send switch request */
557 KXS_SWITCH /* Switched: send confirmation */
560 /* --- Tunnel structure --- *
562 * Used to maintain system-specific information about the tunnel interface.
565 typedef struct tunnel tunnel;
568 typedef struct tunnel_ops {
569 const char *name; /* Name of this tunnel driver */
570 unsigned flags; /* Various interesting flags */
571 #define TUNF_PRIVOPEN 1u /* Need helper to open file */
572 void (*init)(void); /* Initializes the system */
573 tunnel *(*create)(struct peer */*p*/, int /*fd*/, char **/*ifn*/);
574 /* Initializes a new tunnel */
575 void (*setifname)(tunnel */*t*/, const char */*ifn*/);
576 /* Notifies ifname change */
577 void (*inject)(tunnel */*t*/, buf */*b*/); /* Sends packet through if */
578 void (*destroy)(tunnel */*t*/); /* Destroys a tunnel */
581 #ifndef TUN_INTERNALS
582 struct tunnel { const tunnel_ops *ops; };
585 /* --- Peer statistics --- *
587 * Contains various interesting and not-so-interesting statistics about a
588 * peer. This is updated by various parts of the code. The format of the
589 * structure isn't considered private, and @p_stats@ returns a pointer to the
590 * statistics block for a given peer.
593 typedef struct stats {
594 unsigned long sz_in, sz_out; /* Size of all data in and out */
595 unsigned long sz_kxin, sz_kxout; /* Size of key exchange messages */
596 unsigned long sz_ipin, sz_ipout; /* Size of encapsulated IP packets */
597 time_t t_start, t_last, t_kx; /* Time peer created, last pk, kx */
598 unsigned long n_reject; /* Number of rejected packets */
599 unsigned long n_in, n_out; /* Number of packets in and out */
600 unsigned long n_kxin, n_kxout; /* Number of key exchange packets */
601 unsigned long n_ipin, n_ipout; /* Number of encrypted packets */
604 /* --- Peer structure --- *
606 * The main structure which glues everything else together.
609 typedef struct peerspec {
610 char *name; /* Peer's name */
611 char *privtag; /* Private key tag */
612 char *tag; /* Public key tag */
613 const tunnel_ops *tops; /* Tunnel operations */
614 unsigned long t_ka; /* Keep alive interval */
615 addr sa; /* Socket address to speak to */
616 unsigned f; /* Flags for the peer */
617 #define PSF_KXMASK 255u /* Key-exchange flags to set */
618 #define PSF_MOBILE 256u /* Address may change rapidly */
621 typedef struct peer_byname {
626 typedef struct peer_byaddr {
631 typedef struct peer {
632 peer_byname *byname; /* Lookup-by-name block */
633 peer_byaddr *byaddr; /* Lookup-by-address block */
634 struct ping *pings; /* Pings we're waiting for */
635 peerspec spec; /* Specifications for this peer */
636 tunnel *t; /* Tunnel for local packets */
637 char *ifname; /* Interface name for tunnel */
638 keyset *ks; /* List head for keysets */
639 buf b; /* Buffer for sending packets */
640 stats st; /* Statistics */
641 keyexch kx; /* Key exchange protocol block */
642 sel_timer tka; /* Timer for keepalives */
645 typedef struct peer_iter { sym_iter i; } peer_iter;
647 typedef struct ping {
648 struct ping *next, *prev; /* Links to next and previous */
649 peer *p; /* Peer so we can free it */
650 unsigned msg; /* Kind of response expected */
651 uint32 id; /* Id so we can recognize response */
652 octet magic[32]; /* Some random data */
653 sel_timer t; /* Timeout for ping */
654 void (*func)(int /*rc*/, void */*arg*/); /* Function to call when done */
655 void *arg; /* Argument for callback */
666 /* --- Admin structure --- */
668 #define OBUFSZ 16384u
670 typedef struct obuf {
671 struct obuf *next; /* Next buffer in list */
672 char *p_in, *p_out; /* Pointers into the buffer */
673 char buf[OBUFSZ]; /* The actual buffer */
676 typedef struct oqueue {
677 obuf *hd, *tl; /* Head and tail pointers */
682 typedef struct admin_bgop {
683 struct admin_bgop *next, *prev; /* Links to next and previous */
684 struct admin *a; /* Owner job */
685 char *tag; /* Tag string for messages */
686 void (*cancel)(struct admin_bgop *); /* Destructor function */
689 typedef struct admin_resop {
690 admin_bgop bg; /* Background operation header */
691 char *addr; /* Hostname to be resolved */
692 bres_client r; /* Background resolver task */
693 sel_timer t; /* Timer for resolver */
694 addr sa; /* Socket address */
695 size_t sasz; /* Socket address size */
696 void (*func)(struct admin_resop *, int); /* Handler */
699 enum { ARES_OK, ARES_FAIL };
701 typedef struct admin_addop {
702 admin_resop r; /* Name resolution header */
703 peerspec peer; /* Peer pending creation */
706 typedef struct admin_pingop {
707 admin_bgop bg; /* Background operation header */
708 ping ping; /* Ping pending response */
709 struct timeval pingtime; /* Time last ping was sent */
712 typedef struct admin_service {
713 sym_base _b; /* Hash table base structure */
714 char *version; /* The provided version */
715 struct admin *prov; /* Which client provides me */
716 struct admin_service *next, *prev; /* Client's list of services */
719 typedef struct admin_svcop {
720 admin_bgop bg; /* Background operation header */
721 struct admin *prov; /* Client servicing this job */
722 unsigned index; /* This job's index */
723 struct admin_svcop *next, *prev; /* Links for provider's jobs */
726 typedef struct admin_jobentry {
727 unsigned short seq; /* Zero if unused */
729 admin_svcop *op; /* Operation, if slot in use, ... */
730 uint32 next; /* ... or index of next free slot */
734 typedef struct admin_jobtable {
735 uint32 n, sz; /* Used slots and table size */
736 admin_svcop *active; /* List of active jobs */
737 uint32 free; /* Index of first free slot */
738 admin_jobentry *v; /* And the big array of entries */
742 struct admin *next, *prev; /* Links to next and previous */
743 unsigned f; /* Various useful flags */
744 unsigned ref; /* Reference counter */
746 unsigned seq; /* Sequence number for tracing */
748 oqueue out; /* Output buffer list */
749 oqueue delay; /* Delayed output buffer list */
750 admin_bgop *bg; /* Backgrounded operations */
751 admin_service *svcs; /* Which services I provide */
752 admin_jobtable j; /* Table of outstanding jobs */
753 selbuf b; /* Line buffer for commands */
754 sel_file w; /* Selector for write buffering */
757 #define AF_DEAD 1u /* Destroy this admin block */
758 #define AF_CLOSE 2u /* Client closed connection */
759 #define AF_NOTE 4u /* Catch notifications */
760 #define AF_WARN 8u /* Catch warning messages */
762 # define AF_TRACE 16u /* Catch tracing */
764 #define AF_FOREGROUND 32u /* Quit server when client closes */
767 # define AF_ALLMSGS (AF_NOTE | AF_TRACE | AF_WARN)
769 # define AF_ALLMSGS (AF_NOTE | AF_WARN)
772 /*----- Global variables --------------------------------------------------*/
774 extern sel_state sel; /* Global I/O event state */
775 extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ], buf_u[PKBUFSZ];
776 extern const tunnel_ops *tunnels[]; /* Table of tunnels (0-term) */
777 extern const tunnel_ops *tun_default; /* Default tunnel to use */
778 extern kdata *master; /* Default private key */
779 extern const char *tag_priv; /* Default private key tag */
782 extern const trace_opt tr_opts[]; /* Trace options array */
783 extern unsigned tr_flags; /* Trace options flags */
786 /*----- Other macros ------------------------------------------------------*/
789 do { rand_quick(RAND_GLOBAL); noise_timer(RAND_GLOBAL); } while (0)
791 /*----- Key management ----------------------------------------------------*/
793 /* --- @km_init@ --- *
795 * Arguments: @const char *privkr@ = private keyring file
796 * @const char *pubkr@ = public keyring file
797 * @const char *ptag@ = default private-key tag
801 * Use: Initializes the key-management machinery, loading the
802 * keyrings and so on.
805 extern void km_init(const char */*privkr*/, const char */*pubkr*/,
806 const char */*ptag*/);
808 /* --- @km_reload@ --- *
812 * Returns: Zero if OK, nonzero to force reloading of keys.
814 * Use: Checks the keyrings to see if they need reloading.
817 extern int km_reload(void);
819 /* --- @km_findpub@, @km_findpriv@ --- *
821 * Arguments: @const char *tag@ = key tag to load
823 * Returns: Pointer to the kdata object if successful, or null on error.
825 * Use: Fetches a public or private key from the keyring.
828 extern kdata *km_findpub(const char */*tag*/);
829 extern kdata *km_findpriv(const char */*tag*/);
831 /* --- @km_findpubbyid@, @km_findprivbyid@ --- *
833 * Arguments: @uint32 id@ = key id to load
835 * Returns: Pointer to the kdata object if successful, or null on error.
837 * Use: Fetches a public or private key from the keyring given its
841 extern kdata *km_findpubbyid(uint32 /*id*/);
842 extern kdata *km_findprivbyid(uint32 /*id*/);
844 /* --- @km_samealgsp@ --- *
846 * Arguments: @const kdata *kdx, *kdy@ = two key data objects
848 * Returns: Nonzero if their two algorithm selections are the same.
850 * Use: Checks sameness of algorithm selections: used to ensure that
851 * peers are using sensible algorithms.
854 extern int km_samealgsp(const kdata */*kdx*/, const kdata */*kdy*/);
856 /* --- @km_ref@ --- *
858 * Arguments: @kdata *kd@ = pointer to the kdata object
862 * Use: Claim a new reference to a kdata object.
865 extern void km_ref(kdata */*kd*/);
867 /* --- @km_unref@ --- *
869 * Arguments: @kdata *kd@ = pointer to the kdata object
873 * Use: Releases a reference to a kdata object.
876 extern void km_unref(kdata */*kd*/);
878 /* --- @km_tag@ --- *
880 * Arguments: @kdata *kd@ - pointer to the kdata object
882 * Returns: A pointer to the short tag by which the kdata was loaded.
885 extern const char *km_tag(kdata */*kd*/);
887 /*----- Key exchange ------------------------------------------------------*/
889 /* --- @kx_start@ --- *
891 * Arguments: @keyexch *kx@ = pointer to key exchange context
892 * @int forcep@ = nonzero to ignore the quiet timer
896 * Use: Stimulates a key exchange. If a key exchage is in progress,
897 * a new challenge is sent (unless the quiet timer forbids
898 * this); if no exchange is in progress, one is commenced.
901 extern void kx_start(keyexch */*kx*/, int /*forcep*/);
903 /* --- @kx_message@ --- *
905 * Arguments: @keyexch *kx@ = pointer to key exchange context
906 * @unsigned msg@ = the message code
907 * @buf *b@ = pointer to buffer containing the packet
911 * Use: Reads a packet containing key exchange messages and handles
915 extern void kx_message(keyexch */*kx*/, unsigned /*msg*/, buf */*b*/);
917 /* --- @kx_free@ --- *
919 * Arguments: @keyexch *kx@ = pointer to key exchange context
923 * Use: Frees everything in a key exchange context.
926 extern void kx_free(keyexch */*kx*/);
928 /* --- @kx_newkeys@ --- *
930 * Arguments: @keyexch *kx@ = pointer to key exchange context
934 * Use: Informs the key exchange module that its keys may have
935 * changed. If fetching the new keys fails, the peer will be
936 * destroyed, we log messages and struggle along with the old
940 extern void kx_newkeys(keyexch */*kx*/);
942 /* --- @kx_setup@ --- *
944 * Arguments: @keyexch *kx@ = pointer to key exchange context
945 * @peer *p@ = pointer to peer context
946 * @keyset **ks@ = pointer to keyset list
947 * @unsigned f@ = various useful flags
949 * Returns: Zero if OK, nonzero if it failed.
951 * Use: Initializes a key exchange module. The module currently
952 * contains no keys, and will attempt to initiate a key
956 extern int kx_setup(keyexch */*kx*/, peer */*p*/,
957 keyset **/*ks*/, unsigned /*f*/);
959 /*----- Keysets and symmetric cryptography --------------------------------*/
961 /* --- @ks_drop@ --- *
963 * Arguments: @keyset *ks@ = pointer to a keyset
967 * Use: Decrements a keyset's reference counter. If the counter hits
968 * zero, the keyset is freed.
971 extern void ks_drop(keyset */*ks*/);
973 /* --- @ks_gen@ --- *
975 * Arguments: @deriveargs *a@ = key derivation parameters (modified)
976 * @peer *p@ = pointer to peer information
978 * Returns: A pointer to the new keyset.
980 * Use: Derives a new keyset from the given key material. This will
981 * set the @what@, @f@, and @hc@ members in @*a@; other members
982 * must be filled in by the caller.
984 * The new key is marked so that it won't be selected for output
985 * by @ksl_encrypt@. You can still encrypt data with it by
986 * calling @ks_encrypt@ directly.
989 extern keyset *ks_gen(deriveargs */*a*/, peer */*p*/);
991 /* --- @ks_activate@ --- *
993 * Arguments: @keyset *ks@ = pointer to a keyset
997 * Use: Activates a keyset, so that it can be used for encrypting
1001 extern void ks_activate(keyset */*ks*/);
1003 /* --- @ks_encrypt@ --- *
1005 * Arguments: @keyset *ks@ = pointer to a keyset
1006 * @unsigned ty@ = message type
1007 * @buf *b@ = pointer to input buffer
1008 * @buf *bb@ = pointer to output buffer
1010 * Returns: Zero if successful; @KSERR_REGEN@ if we should negotiate a
1011 * new key; @KSERR_NOKEYS@ if the key is not usable. Also
1012 * returns zero if there was insufficient buffer (but the output
1013 * buffer is broken in this case).
1015 * Use: Encrypts a block of data using the key. Note that the `key
1016 * ought to be replaced' notification is only ever given once
1017 * for each key. Also note that this call forces a keyset to be
1018 * used even if it's marked as not for data output.
1020 * The encryption transform is permitted to corrupt @buf_u@ for
1021 * its own purposes. Neither the source nor destination should
1022 * be within @buf_u@; and callers mustn't expect anything stored
1023 * in @buf_u@ to still
1026 extern int ks_encrypt(keyset */*ks*/, unsigned /*ty*/,
1027 buf */*b*/, buf */*bb*/);
1029 /* --- @ks_decrypt@ --- *
1031 * Arguments: @keyset *ks@ = pointer to a keyset
1032 * @unsigned ty@ = expected type code
1033 * @buf *b@ = pointer to an input buffer
1034 * @buf *bb@ = pointer to an output buffer
1036 * Returns: Zero on success; @KSERR_DECRYPT@ on failure. Also returns
1037 * zero if there was insufficient buffer (but the output buffer
1038 * is broken in this case).
1040 * Use: Attempts to decrypt a message using a given key. Note that
1041 * requesting decryption with a key directly won't clear a
1042 * marking that it's not for encryption.
1044 * The decryption transform is permitted to corrupt @buf_u@ for
1045 * its own purposes. Neither the source nor destination should
1046 * be within @buf_u@; and callers mustn't expect anything stored
1047 * in @buf_u@ to still
1050 extern int ks_decrypt(keyset */*ks*/, unsigned /*ty*/,
1051 buf */*b*/, buf */*bb*/);
1053 /* --- @ksl_free@ --- *
1055 * Arguments: @keyset **ksroot@ = pointer to keyset list head
1059 * Use: Frees (releases references to) all of the keys in a keyset.
1062 extern void ksl_free(keyset **/*ksroot*/);
1064 /* --- @ksl_link@ --- *
1066 * Arguments: @keyset **ksroot@ = pointer to keyset list head
1067 * @keyset *ks@ = pointer to a keyset
1071 * Use: Links a keyset into a list. A keyset can only be on one list
1072 * at a time. Bad things happen otherwise.
1075 extern void ksl_link(keyset **/*ksroot*/, keyset */*ks*/);
1077 /* --- @ksl_prune@ --- *
1079 * Arguments: @keyset **ksroot@ = pointer to keyset list head
1083 * Use: Prunes the keyset list by removing keys which mustn't be used
1087 extern void ksl_prune(keyset **/*ksroot*/);
1089 /* --- @ksl_encrypt@ --- *
1091 * Arguments: @keyset **ksroot@ = pointer to keyset list head
1092 * @unsigned ty@ = message type
1093 * @buf *b@ = pointer to input buffer
1094 * @buf *bb@ = pointer to output buffer
1096 * Returns: Zero if successful; @KSERR_REGEN@ if it's time to negotiate a
1097 * new key; @KSERR_NOKEYS@ if there are no suitable keys
1098 * available. Also returns zero if there was insufficient
1099 * buffer space (but the output buffer is broken in this case).
1101 * Use: Encrypts a packet.
1104 extern int ksl_encrypt(keyset **/*ksroot*/, unsigned /*ty*/,
1105 buf */*b*/, buf */*bb*/);
1107 /* --- @ksl_decrypt@ --- *
1109 * Arguments: @keyset **ksroot@ = pointer to keyset list head
1110 * @unsigned ty@ = expected type code
1111 * @buf *b@ = pointer to input buffer
1112 * @buf *bb@ = pointer to output buffer
1114 * Returns: Zero on success; @KSERR_DECRYPT@ on failure. Also returns
1115 * zero if there was insufficient buffer (but the output buffer
1116 * is broken in this case).
1118 * Use: Decrypts a packet.
1121 extern int ksl_decrypt(keyset **/*ksroot*/, unsigned /*ty*/,
1122 buf */*b*/, buf */*bb*/);
1124 /*----- Challenges --------------------------------------------------------*/
1126 /* --- @c_new@ --- *
1128 * Arguments: @const void *m@ = pointer to associated message, or null
1129 * @size_t msz@ = length of associated message
1130 * @buf *b@ = where to put the challenge
1132 * Returns: Zero if OK, nonzero on error.
1134 * Use: Issues a new challenge.
1137 extern int c_new(const void */*m*/, size_t /*msz*/, buf */*b*/);
1139 /* --- @c_check@ --- *
1141 * Arguments: @const void *m@ = pointer to associated message, or null
1142 * @size_t msz@ = length of associated message
1143 * @buf *b@ = where to find the challenge
1145 * Returns: Zero if OK, nonzero if it didn't work.
1147 * Use: Checks a challenge. On failure, the buffer is broken.
1150 extern int c_check(const void */*m*/, size_t /*msz*/, buf */*b*/);
1152 /*----- Administration interface ------------------------------------------*/
1154 #define A_END ((char *)0)
1156 /* --- @a_vformat@ --- *
1158 * Arguments: @dstr *d@ = where to leave the formatted message
1159 * @const char *fmt@ = pointer to format string
1160 * @va_list *ap@ = arguments in list
1164 * Use: Main message token formatting driver. The arguments are
1165 * interleaved formatting tokens and their parameters, finally
1166 * terminated by an entry @A_END@.
1168 * Tokens recognized:
1170 * * "*..." ... -- pretokenized @dstr_putf@-like string
1172 * * "?ADDR" SOCKADDR -- a socket address, to be converted
1174 * * "?B64" BUFFER SIZE -- binary data to be base64-encoded
1176 * * "?TOKENS" VECTOR -- null-terminated vector of tokens
1178 * * "?PEER" PEER -- peer's name
1180 * * "?ERRNO" ERRNO -- system error code
1182 * * "[!]..." ... -- @dstr_putf@-like string as single token
1185 extern void a_vformat(dstr */*d*/, const char */*fmt*/, va_list */*ap*/);
1187 /* --- @a_format@ --- *
1189 * Arguments: @dstr *d@ = where to leave the formatted message
1190 * @const char *fmt@ = pointer to format string
1194 * Use: Writes a tokenized message into a string, for later
1198 extern void EXECL_LIKE(0) a_format(dstr */*d*/, const char */*fmt*/, ...);
1200 /* --- @a_info@ --- *
1202 * Arguments: @admin *a@ = connection
1203 * @const char *fmt@ = format string
1204 * @...@ = other arguments
1208 * Use: Report information to an admin client.
1211 extern void EXECL_LIKE(0) a_info(admin */*a*/, const char */*fmt*/, ...);
1213 /* --- @a_warn@ --- *
1215 * Arguments: @const char *fmt@ = pointer to format string
1216 * @...@ = other arguments
1220 * Use: Informs all admin connections of a warning.
1223 extern void EXECL_LIKE(0) a_warn(const char */*fmt*/, ...);
1225 /* --- @a_notify@ --- *
1227 * Arguments: @const char *fmt@ = pointer to format string
1228 * @...@ = other arguments
1232 * Use: Sends a notification to interested admin connections.
1235 extern void EXECL_LIKE(0) a_notify(const char */*fmt*/, ...);
1237 /* --- @a_create@ --- *
1239 * Arguments: @int fd_in, fd_out@ = file descriptors to use
1240 * @unsigned f@ = initial flags to set
1244 * Use: Creates a new admin connection.
1247 extern void a_create(int /*fd_in*/, int /*fd_out*/, unsigned /*f*/);
1249 /* --- @a_quit@ --- *
1255 * Use: Shuts things down nicely.
1258 extern void a_quit(void);
1260 /* --- @a_preselect@ --- *
1266 * Use: Informs the admin module that we're about to select again,
1267 * and that it should do cleanup things it has delayed until a
1271 extern void a_preselect(void);
1273 /* --- @a_daemon@ --- *
1279 * Use: Informs the admin module that it's a daemon.
1282 extern void a_daemon(void);
1284 /* --- @a_init@ --- *
1286 * Arguments: @const char *sock@ = socket name to create
1287 * @uid_t u@ = user to own the socket
1288 * @gid_t g@ = group to own the socket
1289 * @mode_t m@ = permissions to set on the socket
1293 * Use: Creates the admin listening socket.
1296 extern void a_init(const char */*sock*/,
1297 uid_t /*u*/, gid_t /*g*/, mode_t /*m*/);
1299 /*----- Mapping with addresses as keys ------------------------------------*/
1301 /* --- @am_create@ --- *
1303 * Arguments: @addrmap *m@ = pointer to map
1307 * Use: Create an address map, properly set up.
1310 extern void am_create(addrmap */*m*/);
1312 /* --- @am_destroy@ --- *
1314 * Arguments: @addrmap *m@ = pointer to map
1318 * Use: Destroy an address map, throwing away all the entries.
1321 extern void am_destroy(addrmap */*m*/);
1323 /* --- @am_find@ --- *
1325 * Arguments: @addrmap *m@ = pointer to map
1326 * @const addr *a@ = address to look up
1327 * @size_t sz@ = size of block to allocate
1328 * @unsigned *f@ = where to store flags
1330 * Returns: Pointer to found item, or null.
1332 * Use: Finds a record with the given IP address, set @*f@ nonzero
1333 * and returns it. If @sz@ is zero, and no match was found,
1334 * return null; otherwise allocate a new block of @sz@ bytes,
1335 * clear @*f@ to zero and return the block pointer.
1338 extern void *am_find(addrmap */*m*/, const addr */*a*/,
1339 size_t /*sz*/, unsigned */*f*/);
1341 /* --- @am_remove@ --- *
1343 * Arguments: @addrmap *m@ = pointer to map
1344 * @void *i@ = pointer to the item
1348 * Use: Removes an item from the map.
1351 extern void am_remove(addrmap */*m*/, void */*i*/);
1353 /*----- Privilege separation ----------------------------------------------*/
1355 /* --- @ps_trace@ --- *
1357 * Arguments: @unsigned mask@ = trace mask to check
1358 * @const char *fmt@ = message format
1359 * @...@ = values for placeholders
1363 * Use: Writes a trace message.
1366 T( extern void PRINTF_LIKE(2, 3)
1367 ps_trace(unsigned /*mask*/, const char */*fmt*/, ...); )
1369 /* --- @ps_warn@ --- *
1371 * Arguments: @const char *fmt@ = message format
1372 * @...@ = values for placeholders
1376 * Use: Writes a warning message.
1379 extern void PRINTF_LIKE(1, 2) ps_warn(const char */*fmt*/, ...);
1381 /* --- @ps_tunfd@ --- *
1383 * Arguments: @const tunnel_ops *tops@ = pointer to tunnel operations
1384 * @char **ifn@ = where to put the interface name
1386 * Returns: The file descriptor, or @-1@ on error.
1388 * Use: Fetches a file descriptor for a tunnel driver.
1391 extern int ps_tunfd(const tunnel_ops */*tops*/, char **/*ifn*/);
1393 /* --- @ps_split@ --- *
1395 * Arguments: @int detachp@ = whether to detach the child from its terminal
1399 * Use: Separates off the privileged tunnel-opening service from the
1400 * rest of the server.
1403 extern void ps_split(int /*detachp*/);
1405 /* --- @ps_quit@ --- *
1411 * Use: Detaches from the helper process.
1414 extern void ps_quit(void);
1416 /*----- Peer management ---------------------------------------------------*/
1418 /* --- @p_updateaddr@ --- *
1420 * Arguments: @peer *p@ = pointer to peer block
1421 * @const addr *a@ = address to associate with this peer
1423 * Returns: Zero if the address was changed; @+1@ if it was already
1426 * Use: Updates our idea of @p@'s address.
1429 extern int p_updateaddr(peer */*p*/, const addr */*a*/);
1431 /* --- @p_txstart@ --- *
1433 * Arguments: @peer *p@ = pointer to peer block
1434 * @unsigned msg@ = message type code
1436 * Returns: A pointer to a buffer to write to.
1438 * Use: Starts sending to a peer. Only one send can happen at a
1442 extern buf *p_txstart(peer */*p*/, unsigned /*msg*/);
1444 /* --- @p_txend@ --- *
1446 * Arguments: @peer *p@ = pointer to peer block
1450 * Use: Sends a packet to the peer.
1453 extern void p_txend(peer */*p*/);
1455 /* --- @p_pingsend@ --- *
1457 * Arguments: @peer *p@ = destination peer
1458 * @ping *pg@ = structure to fill in
1459 * @unsigned type@ = message type
1460 * @unsigned long timeout@ = how long to wait before giving up
1461 * @void (*func)(int, void *)@ = callback function
1462 * @void *arg@ = argument for callback
1464 * Returns: Zero if successful, nonzero if it failed.
1466 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
1467 * if we get an answer within the timeout, or zero if no answer.
1470 extern int p_pingsend(peer */*p*/, ping */*pg*/, unsigned /*type*/,
1471 unsigned long /*timeout*/,
1472 void (*/*func*/)(int, void *), void */*arg*/);
1474 /* --- @p_pingdone@ --- *
1476 * Arguments: @ping *p@ = ping structure
1477 * @int rc@ = return code to pass on
1481 * Use: Disposes of a ping structure, maybe sending a notification.
1484 extern void p_pingdone(ping */*p*/, int /*rc*/);
1486 /* --- @p_greet@ --- *
1488 * Arguments: @peer *p@ = peer to send to
1489 * @const void *c@ = pointer to challenge
1490 * @size_t sz@ = size of challenge
1494 * Use: Sends a greeting packet.
1497 extern void p_greet(peer */*p*/, const void */*c*/, size_t /*sz*/);
1499 /* --- @p_tun@ --- *
1501 * Arguments: @peer *p@ = pointer to peer block
1502 * @buf *b@ = buffer containing incoming packet
1506 * Use: Handles a packet which needs to be sent to a peer.
1509 extern void p_tun(peer */*p*/, buf */*b*/);
1511 /* --- @p_keyreload@ --- *
1517 * Use: Forces a check of the daemon's keyring files.
1520 extern void p_keyreload(void);
1522 /* --- @p_interval@ --- *
1528 * Use: Called periodically to do tidying.
1531 extern void p_interval(void);
1533 /* --- @p_stats@ --- *
1535 * Arguments: @peer *p@ = pointer to a peer block
1537 * Returns: A pointer to the peer's statistics.
1540 extern stats *p_stats(peer */*p*/);
1542 /* --- @p_ifname@ --- *
1544 * Arguments: @peer *p@ = pointer to a peer block
1546 * Returns: A pointer to the peer's interface name.
1549 extern const char *p_ifname(peer */*p*/);
1551 /* --- @p_setifname@ --- *
1553 * Arguments: @peer *p@ = pointer to a peer block
1554 * @const char *name@ = pointer to the new name
1558 * Use: Changes the name held for a peer's interface.
1561 extern void p_setifname(peer */*p*/, const char */*name*/);
1563 /* --- @p_addr@ --- *
1565 * Arguments: @peer *p@ = pointer to a peer block
1567 * Returns: A pointer to the peer's address.
1570 extern const addr *p_addr(peer */*p*/);
1572 /* --- @p_init@ --- *
1574 * Arguments: @struct in_addr addr@ = address to bind to
1575 * @unsigned port@ = port number to listen to
1579 * Use: Initializes the peer system; creates the socket.
1582 extern void p_init(struct in_addr /*addr*/, unsigned /*port*/);
1584 /* --- @p_port@ --- *
1588 * Returns: Port number used for socket.
1591 unsigned p_port(void);
1593 /* --- @p_create@ --- *
1595 * Arguments: @peerspec *spec@ = information about this peer
1597 * Returns: Pointer to the peer block, or null if it failed.
1599 * Use: Creates a new named peer block. No peer is actually attached
1603 extern peer *p_create(peerspec */*spec*/);
1605 /* --- @p_name@ --- *
1607 * Arguments: @peer *p@ = pointer to a peer block
1609 * Returns: A pointer to the peer's name.
1611 * Use: Equivalent to @p_spec(p)->name@.
1614 extern const char *p_name(peer */*p*/);
1616 /* --- @p_tag@ --- *
1618 * Arguments: @peer *p@ = pointer to a peer block
1620 * Returns: A pointer to the peer's public key tag.
1623 extern const char *p_tag(peer */*p*/);
1625 /* --- @p_privtag@ --- *
1627 * Arguments: @peer *p@ = pointer to a peer block
1629 * Returns: A pointer to the peer's private key tag.
1632 extern const char *p_privtag(peer */*p*/);
1634 /* --- @p_spec@ --- *
1636 * Arguments: @peer *p@ = pointer to a peer block
1638 * Returns: Pointer to the peer's specification
1641 extern const peerspec *p_spec(peer */*p*/);
1643 /* --- @p_findbyaddr@ --- *
1645 * Arguments: @const addr *a@ = address to look up
1647 * Returns: Pointer to the peer block, or null if not found.
1649 * Use: Finds a peer by address.
1652 extern peer *p_findbyaddr(const addr */*a*/);
1654 /* --- @p_find@ --- *
1656 * Arguments: @const char *name@ = name to look up
1658 * Returns: Pointer to the peer block, or null if not found.
1660 * Use: Finds a peer by name.
1663 extern peer *p_find(const char */*name*/);
1665 /* --- @p_destroy@ --- *
1667 * Arguments: @peer *p@ = pointer to a peer
1671 * Use: Destroys a peer.
1674 extern void p_destroy(peer */*p*/);
1676 /* --- @FOREACH_PEER@ --- *
1678 * Arguments: @p@ = name to bind to each peer
1679 * @stuff@ = thing to do for each item
1681 * Use: Does something for each current peer.
1684 #define FOREACH_PEER(p, stuff) do { \
1687 for (p_mkiter(&i_); (p = p_next(&i_)) != 0; ) stuff \
1690 /* --- @p_mkiter@ --- *
1692 * Arguments: @peer_iter *i@ = pointer to an iterator
1696 * Use: Initializes the iterator.
1699 extern void p_mkiter(peer_iter */*i*/);
1701 /* --- @p_next@ --- *
1703 * Arguments: @peer_iter *i@ = pointer to an iterator
1705 * Returns: Next peer, or null if at the end.
1707 * Use: Returns the next peer.
1710 extern peer *p_next(peer_iter */*i*/);
1712 /*----- Tunnel drivers ----------------------------------------------------*/
1715 extern const tunnel_ops tun_linux;
1719 extern const tunnel_ops tun_unet;
1723 extern const tunnel_ops tun_bsd;
1726 extern const tunnel_ops tun_slip;
1728 /*----- Other handy utilities ---------------------------------------------*/
1730 /* --- @timestr@ --- *
1732 * Arguments: @time_t t@ = a time to convert
1734 * Returns: A pointer to a textual representation of the time.
1736 * Use: Converts a time to a textual representation. Corrupts
1740 extern const char *timestr(time_t /*t*/);
1742 /* --- @mystrieq@ --- *
1744 * Arguments: @const char *x, *y@ = two strings
1746 * Returns: True if @x@ and @y are equal, up to case.
1749 extern int mystrieq(const char */*x*/, const char */*y*/);
1751 /* --- @addrsz@ --- *
1753 * Arguments: @const addr *a@ = a network address
1755 * Returns: The size of the address, for passing into the sockets API.
1758 extern socklen_t addrsz(const addr */*a*/);
1760 /* --- @seq_reset@ --- *
1762 * Arguments: @seqwin *s@ = sequence-checking window
1766 * Use: Resets a sequence number window.
1769 extern void seq_reset(seqwin */*s*/);
1771 /* --- @seq_check@ --- *
1773 * Arguments: @seqwin *s@ = sequence-checking window
1774 * @uint32 q@ = sequence number to check
1775 * @const char *service@ = service to report message from
1777 * Returns: A @SEQ_@ code.
1779 * Use: Checks a sequence number against the window, updating things
1783 extern int seq_check(seqwin */*s*/, uint32 /*q*/, const char */*service*/);
1785 typedef struct ratelim {
1786 unsigned n, max, persec;
1787 struct timeval when;
1790 /* --- @ratelim_init@ --- *
1792 * Arguments: @ratelim *r@ = rate-limiting state to fill in
1793 * @unsigned persec@ = credit to accumulate per second
1794 * @unsigned max@ = maximum credit to retain
1798 * Use: Initialize a rate-limiting state.
1801 extern void ratelim_init(ratelim */*r*/,
1802 unsigned /*persec*/, unsigned /*max*/);
1804 /* --- @ratelim_withdraw@ --- *
1806 * Arguments: @ratelim *r@ = rate-limiting state
1807 * @unsigned n@ = credit to withdraw
1809 * Returns: Zero if successful; @-1@ if there is unsufficient credit
1811 * Use: Updates the state with any accumulated credit. Then, if
1812 * there there are more than @n@ credits available, withdraw @n@
1813 * and return successfully; otherwise, report failure.
1816 extern int ratelim_withdraw(ratelim */*r*/, unsigned /*n*/);
1818 /* --- @ies_encrypt@ --- *
1820 * Arguments: @kdata *kpub@ = recipient's public key
1821 * @unsigned ty@ = message type octet
1822 * @buf *b@ = input message buffer
1823 * @buf *bb@ = output buffer for the ciphertext
1825 * Returns: On error, returns a @KSERR_...@ code or breaks the buffer;
1826 * on success, returns zero and the buffer is good.
1828 * Use: Encrypts a message for a recipient, given their public key.
1829 * This does not (by itself) provide forward secrecy or sender
1830 * authenticity. The ciphertext is self-delimiting (unlike
1834 extern int ies_encrypt(kdata */*kpub*/, unsigned /*ty*/,
1835 buf */*b*/, buf */*bb*/);
1837 /* --- @ies_decrypt@ --- *
1839 * Arguments: @kdata *kpub@ = private key key
1840 * @unsigned ty@ = message type octet
1841 * @buf *b@ = input ciphertext buffer
1842 * @buf *bb@ = output buffer for the message
1844 * Returns: On error, returns a @KSERR_...@ code; on success, returns
1845 * zero and the buffer is good.
1847 * Use: Decrypts a message encrypted using @ies_encrypt@, given our
1851 extern int ies_decrypt(kdata */*kpriv*/, unsigned /*ty*/,
1852 buf */*b*/, buf */*bb*/);
1854 /*----- That's all, folks -------------------------------------------------*/