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
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * TrIPE is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with TrIPE; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
34 /*----- Header files ------------------------------------------------------*/
50 #include <sys/types.h>
57 #include <sys/socket.h>
59 #include <netinet/in.h>
60 #include <arpa/inet.h>
66 #include <mLib/alloc.h>
67 #include <mLib/arena.h>
68 #include <mLib/base64.h>
69 #include <mLib/bres.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/gcipher.h>
95 #include <catacomb/gmac.h>
96 #include <catacomb/grand.h>
97 #include <catacomb/key.h>
98 #include <catacomb/paranoia.h>
100 #include <catacomb/noise.h>
101 #include <catacomb/rand.h>
103 #include <catacomb/mp.h>
104 #include <catacomb/mprand.h>
105 #include <catacomb/dh.h>
106 #include <catacomb/ec.h>
107 #include <catacomb/ec-keys.h>
108 #include <catacomb/group.h>
111 #include "protocol.h"
117 /*----- Magic numbers -----------------------------------------------------*/
119 /* --- Trace flags --- */
127 #define T_KEYEXCH 64u
128 #define T_KEYMGMT 128u
130 /* T_PRIVSEP in priv.h */
136 #define SEC(n) (n##u)
137 #define MIN(n) (n##u * 60u)
138 #define F_2P32 (65536.0*65536.0)
139 #define MEG(n) (n##ul * 1024ul * 1024ul)
141 /* --- Timing parameters --- */
143 #define T_EXP MIN(60) /* Expiry time for a key */
144 #define T_REGEN MIN(40) /* Regeneration time for a key */
146 #define T_VALID SEC(20) /* Challenge validity period */
147 #define T_RETRYMIN SEC(2) /* Minimum retry interval */
148 #define T_RETRYMAX MIN(5) /* Maximum retry interval */
149 #define T_RETRYGROW (5.0/4.0) /* Retry interval growth factor */
151 #define T_WOBBLE (1.0/3.0) /* Relative timer randomness */
153 /* --- Other things --- */
155 #define PKBUFSZ 65536
157 /*----- Cipher selections -------------------------------------------------*/
159 typedef struct keyset keyset
;
160 typedef struct algswitch algswitch
;
162 typedef struct bulkcrypto
{
165 int (*check
)(const algswitch */
*a*/
, dstr */
*e*/
);
166 size_t (*overhead
)(const algswitch */
*a*/
);
167 int (*encrypt
)(keyset */
*ks*/
, unsigned /*ty*/, buf */
*b*/
, buf */
*bb*/
);
168 int (*decrypt
)(keyset */
*ks*/
, unsigned /*ty*/,
169 buf */
*b*/
, buf */
*bb*/
, uint32 */
*seq*/
);
177 const gchash
*h
; /* Hash function */
178 const gccipher
*mgf
; /* Mask-generation function */
179 const struct bulkcrypto
*bulk
; /* Bulk crypto transformation */
180 const gccipher
*c
; /* Symmetric encryption scheme */
181 const gcmac
*m
; /* Message authentication code */
182 const gccipher
*b
; /* Block cipher */
183 size_t hashsz
; /* Hash output size */
184 size_t tagsz
; /* Length to truncate MAC tags */
185 size_t expsz
; /* Size of data to process */
186 size_t cksz
, mksz
, bksz
; /* Key lengths for things */
189 typedef struct kdata
{
190 unsigned ref
; /* Reference counter */
191 struct knode
*kn
; /* Pointer to cache entry */
192 char *tag
; /* Full tag name of the key */
193 group
*g
; /* The group we work in */
194 size_t indexsz
; /* Size of exponent for the group */
195 mp
*kpriv
; /* The private key (or null) */
196 ge
*kpub
; /* The public key */
197 time_t t_exp
; /* Expiry time of the key */
198 algswitch algs
; /* Collection of algorithms */
201 typedef struct knode
{
202 sym_base _b
; /* Symbol table intrusion */
203 unsigned f
; /* Various flags */
204 #define KNF_BROKEN 1u /* Don't use this key any more */
205 struct keyhalf
*kh
; /* Pointer to the home keyhalf */
206 kdata
*kd
; /* Pointer to the key data */
209 #define MAXHASHSZ 64 /* Largest possible hash size */
211 #define HASH_STRING(h, s) GH_HASH((h), (s), sizeof(s))
213 extern const struct bulkcrypto bulktab
[];
215 /*----- Data structures ---------------------------------------------------*/
217 /* --- Socket addresses --- *
219 * A magic union of supported socket addresses.
224 struct sockaddr_in sin
;
227 /* --- Mapping keyed on addresses --- */
229 typedef struct addrmap
{
234 typedef struct addrmap_base
{
239 /* --- Sequence number checking --- */
241 typedef struct seqwin
{
242 uint32 seq
; /* First acceptable input sequence */
243 uint32 win
; /* Window of acceptable numbers */
246 #define SEQ_WINSZ 32 /* Bits in sequence number window */
248 /* --- A symmetric keyset --- *
250 * A keyset contains a set of symmetric keys for encrypting and decrypting
251 * packets. Keysets are stored in a list, sorted in reverse order of
252 * creation, so that the most recent keyset (the one most likely to be used)
255 * Each keyset has a time limit and a data limit. The keyset is destroyed
256 * when either it has existed for too long, or it has been used to encrypt
257 * too much data. New key exchanges are triggered when keys are close to
262 struct keyset
*next
; /* Next active keyset in the list */
263 unsigned ref
; /* Reference count for keyset */
264 struct peer
*p
; /* Pointer to peer structure */
265 time_t t_exp
; /* Expiry time for this keyset */
266 unsigned long sz_exp
, sz_regen
; /* Data limits for the keyset */
267 T( unsigned seq
; ) /* Sequence number for tracing */
268 unsigned f
; /* Various useful flags */
269 const bulkcrypto
*bulk
; /* Bulk crypto transform */
270 size_t tagsz
; /* Length to truncate MAC tags */
272 gcipher
*c
; /* Keyset cipher for encryption */
273 gmac
*m
; /* Keyset MAC for integrity */
274 gcipher
*b
; /* Block cipher, just in case */
276 uint32 oseq
; /* Outbound sequence number */
277 seqwin iseq
; /* Inbound sequence number */
280 #define KSF_LISTEN 1u /* Don't encrypt packets yet */
281 #define KSF_LINK 2u /* Key is in a linked list */
283 #define KSERR_REGEN -1 /* Regenerate keys */
284 #define KSERR_NOKEYS -2 /* No keys left */
285 #define KSERR_DECRYPT -3 /* Unable to decrypt message */
286 #define KSERR_SEQ -4 /* Incorrect sequence number */
287 #define KSERR_MALFORMED -5 /* Input ciphertext is broken */
289 /* --- Key exchange --- *
291 * TrIPE uses the Wrestlers Protocol for its key exchange. The Wrestlers
292 * Protocol has a number of desirable features (e.g., perfect forward
293 * secrecy, and zero-knowledge authentication) which make it attractive for
294 * use in TrIPE. The Wrestlers Protocol was designed by Mark Wooding and
298 typedef struct retry
{
299 double t
; /* Current retry time */
304 typedef struct kxchal
{
305 struct keyexch
*kx
; /* Pointer back to key exchange */
306 ge
*c
; /* Responder's challenge */
307 ge
*r
; /* My reply to the challenge */
308 keyset
*ks
; /* Pointer to temporary keyset */
309 unsigned f
; /* Various useful flags */
310 sel_timer t
; /* Response timer for challenge */
311 retry rs
; /* Retry state */
312 octet hc
[MAXHASHSZ
]; /* Hash of his challenge */
313 octet ck
[MAXHASHSZ
]; /* His magical check value */
314 octet hswrq_in
[MAXHASHSZ
]; /* Inbound switch request message */
315 octet hswok_in
[MAXHASHSZ
]; /* Inbound switch confirmation */
316 octet hswrq_out
[MAXHASHSZ
]; /* Outbound switch request message */
317 octet hswok_out
[MAXHASHSZ
]; /* Outbound switch confirmation */
320 typedef struct keyexch
{
321 struct peer
*p
; /* Pointer back to the peer */
322 kdata
*kpriv
; /* Private key and related info */
323 kdata
*kpub
; /* Peer's public key */
324 keyset
**ks
; /* Peer's list of keysets */
325 unsigned f
; /* Various useful flags */
326 unsigned s
; /* Current state in exchange */
327 sel_timer t
; /* Timer for next exchange */
328 retry rs
; /* Retry state */
329 mp
*alpha
; /* My temporary secret */
330 ge
*c
; /* My challenge */
331 ge
*rx
; /* The expected response */
332 unsigned nr
; /* Number of extant responses */
333 time_t t_valid
; /* When this exchange goes bad */
334 octet hc
[MAXHASHSZ
]; /* Hash of my challenge */
335 kxchal
*r
[KX_NCHAL
]; /* Array of challenges */
338 #define KXF_TIMER 1u /* Waiting for a timer to go off */
339 #define KXF_DEAD 2u /* The key-exchanger isn't up */
340 #define KXF_PUBKEY 4u /* Key exchanger has a public key */
341 #define KXF_CORK 8u /* Don't send anything yet */
344 KXS_DEAD
, /* Uninitialized state (magical) */
345 KXS_CHAL
, /* Main answer-challenges state */
346 KXS_COMMIT
, /* Committed: send switch request */
347 KXS_SWITCH
/* Switched: send confirmation */
350 /* --- Tunnel structure --- *
352 * Used to maintain system-specific information about the tunnel interface.
355 typedef struct tunnel tunnel
;
358 typedef struct tunnel_ops
{
359 const char *name
; /* Name of this tunnel driver */
360 unsigned flags
; /* Various interesting flags */
361 #define TUNF_PRIVOPEN 1u /* Need helper to open file */
362 void (*init
)(void); /* Initializes the system */
363 tunnel
*(*create
)(struct peer */
*p*/
, int /*fd*/, char **/
*ifn*/
);
364 /* Initializes a new tunnel */
365 void (*setifname
)(tunnel */
*t*/
, const char */
*ifn*/
);
366 /* Notifies ifname change */
367 void (*inject
)(tunnel */
*t*/
, buf */
*b*/
); /* Sends packet through if */
368 void (*destroy
)(tunnel */
*t*/
); /* Destroys a tunnel */
371 #ifndef TUN_INTERNALS
372 struct tunnel
{ const tunnel_ops
*ops
; };
375 /* --- Peer statistics --- *
377 * Contains various interesting and not-so-interesting statistics about a
378 * peer. This is updated by various parts of the code. The format of the
379 * structure isn't considered private, and @p_stats@ returns a pointer to the
380 * statistics block for a given peer.
383 typedef struct stats
{
384 unsigned long sz_in
, sz_out
; /* Size of all data in and out */
385 unsigned long sz_kxin
, sz_kxout
; /* Size of key exchange messages */
386 unsigned long sz_ipin
, sz_ipout
; /* Size of encapsulated IP packets */
387 time_t t_start
, t_last
, t_kx
; /* Time peer created, last pk, kx */
388 unsigned long n_reject
; /* Number of rejected packets */
389 unsigned long n_in
, n_out
; /* Number of packets in and out */
390 unsigned long n_kxin
, n_kxout
; /* Number of key exchange packets */
391 unsigned long n_ipin
, n_ipout
; /* Number of encrypted packets */
394 /* --- Peer structure --- *
396 * The main structure which glues everything else together.
399 typedef struct peerspec
{
400 char *name
; /* Peer's name */
401 char *privtag
; /* Private key tag */
402 char *tag
; /* Public key tag */
403 const tunnel_ops
*tops
; /* Tunnel operations */
404 unsigned long t_ka
; /* Keep alive interval */
405 addr sa
; /* Socket address to speak to */
406 size_t sasz
; /* Socket address size */
407 unsigned f
; /* Flags for the peer */
408 #define PSF_KXMASK 255u /* Key-exchange flags to set */
409 #define PSF_MOBILE 256u /* Address may change rapidly */
412 typedef struct peer_byname
{
417 typedef struct peer_byaddr
{
422 typedef struct peer
{
423 peer_byname
*byname
; /* Lookup-by-name block */
424 peer_byaddr
*byaddr
; /* Lookup-by-address block */
425 struct ping
*pings
; /* Pings we're waiting for */
426 peerspec spec
; /* Specifications for this peer */
427 tunnel
*t
; /* Tunnel for local packets */
428 char *ifname
; /* Interface name for tunnel */
429 keyset
*ks
; /* List head for keysets */
430 buf b
; /* Buffer for sending packets */
431 stats st
; /* Statistics */
432 keyexch kx
; /* Key exchange protocol block */
433 sel_timer tka
; /* Timer for keepalives */
436 typedef struct peer_iter
{ sym_iter i
; } peer_iter
;
438 typedef struct ping
{
439 struct ping
*next
, *prev
; /* Links to next and previous */
440 peer
*p
; /* Peer so we can free it */
441 unsigned msg
; /* Kind of response expected */
442 uint32 id
; /* Id so we can recognize response */
443 octet magic
[32]; /* Some random data */
444 sel_timer t
; /* Timeout for ping */
445 void (*func
)(int /*rc*/, void */
*arg*/
); /* Function to call when done */
446 void *arg
; /* Argument for callback */
457 /* --- Admin structure --- */
459 #define OBUFSZ 16384u
461 typedef struct obuf
{
462 struct obuf
*next
; /* Next buffer in list */
463 char *p_in
, *p_out
; /* Pointers into the buffer */
464 char buf
[OBUFSZ
]; /* The actual buffer */
467 typedef struct oqueue
{
468 obuf
*hd
, *tl
; /* Head and tail pointers */
473 typedef struct admin_bgop
{
474 struct admin_bgop
*next
, *prev
; /* Links to next and previous */
475 struct admin
*a
; /* Owner job */
476 char *tag
; /* Tag string for messages */
477 void (*cancel
)(struct admin_bgop
*); /* Destructor function */
480 typedef struct admin_resop
{
481 admin_bgop bg
; /* Background operation header */
482 char *addr
; /* Hostname to be resolved */
483 bres_client r
; /* Background resolver task */
484 sel_timer t
; /* Timer for resolver */
485 addr sa
; /* Socket address */
486 size_t sasz
; /* Socket address size */
487 void (*func
)(struct admin_resop
*, int); /* Handler */
490 enum { ARES_OK
, ARES_FAIL
};
492 typedef struct admin_addop
{
493 admin_resop r
; /* Name resolution header */
494 peerspec peer
; /* Peer pending creation */
497 typedef struct admin_pingop
{
498 admin_bgop bg
; /* Background operation header */
499 ping ping
; /* Ping pending response */
500 struct timeval pingtime
; /* Time last ping was sent */
503 typedef struct admin_service
{
504 sym_base _b
; /* Hash table base structure */
505 char *version
; /* The provided version */
506 struct admin
*prov
; /* Which client provides me */
507 struct admin_service
*next
, *prev
; /* Client's list of services */
510 typedef struct admin_svcop
{
511 admin_bgop bg
; /* Background operation header */
512 struct admin
*prov
; /* Client servicing this job */
513 unsigned index
; /* This job's index */
514 struct admin_svcop
*next
, *prev
; /* Links for provider's jobs */
517 typedef struct admin_jobentry
{
518 unsigned short seq
; /* Zero if unused */
520 admin_svcop
*op
; /* Operation, if slot in use, ... */
521 uint32 next
; /* ... or index of next free slot */
525 typedef struct admin_jobtable
{
526 uint32 n
, sz
; /* Used slots and table size */
527 admin_svcop
*active
; /* List of active jobs */
528 uint32 free
; /* Index of first free slot */
529 admin_jobentry
*v
; /* And the big array of entries */
532 typedef struct admin
{
533 struct admin
*next
, *prev
; /* Links to next and previous */
534 unsigned f
; /* Various useful flags */
535 unsigned ref
; /* Reference counter */
537 unsigned seq
; /* Sequence number for tracing */
539 oqueue out
; /* Output buffer list */
540 oqueue delay
; /* Delayed output buffer list */
541 admin_bgop
*bg
; /* Backgrounded operations */
542 admin_service
*svcs
; /* Which services I provide */
543 admin_jobtable j
; /* Table of outstanding jobs */
544 selbuf b
; /* Line buffer for commands */
545 sel_file w
; /* Selector for write buffering */
548 #define AF_DEAD 1u /* Destroy this admin block */
549 #define AF_CLOSE 2u /* Client closed connection */
550 #define AF_NOTE 4u /* Catch notifications */
551 #define AF_WARN 8u /* Catch warning messages */
553 #define AF_TRACE 16u /* Catch tracing */
555 #define AF_FOREGROUND 32u /* Quit server when client closes */
558 # define AF_ALLMSGS (AF_NOTE | AF_TRACE | AF_WARN)
560 # define AF_ALLMSGS (AF_NOTE | AF_WARN)
563 /*----- Global variables --------------------------------------------------*/
565 extern sel_state sel
; /* Global I/O event state */
566 extern octet buf_i
[PKBUFSZ
], buf_o
[PKBUFSZ
], buf_t
[PKBUFSZ
], buf_u
[PKBUFSZ
];
567 extern const tunnel_ops
*tunnels
[]; /* Table of tunnels (0-term) */
568 extern const tunnel_ops
*tun_default
; /* Default tunnel to use */
569 extern kdata
*master
; /* Default private key */
570 extern const char *tag_priv
; /* Default private key tag */
573 extern const trace_opt tr_opts
[]; /* Trace options array */
574 extern unsigned tr_flags
; /* Trace options flags */
577 /*----- Other macros ------------------------------------------------------*/
579 #define TIMER noise_timer(RAND_GLOBAL)
581 /*----- Key management ----------------------------------------------------*/
583 /* --- @km_init@ --- *
585 * Arguments: @const char *privkr@ = private keyring file
586 * @const char *pubkr@ = public keyring file
587 * @const char *ptag@ = default private-key tag
591 * Use: Initializes the key-management machinery, loading the
592 * keyrings and so on.
595 extern void km_init(const char */
*privkr*/
, const char */
*pubkr*/
,
596 const char */
*ptag*/
);
598 /* --- @km_reload@ --- *
602 * Returns: Zero if OK, nonzero to force reloading of keys.
604 * Use: Checks the keyrings to see if they need reloading.
607 extern int km_reload(void);
609 /* --- @km_findpub@, @km_findpriv@ --- *
611 * Arguments: @const char *tag@ = key tag to load
613 * Returns: Pointer to the kdata object if successful, or null on error.
615 * Use: Fetches a public or private key from the keyring.
618 extern kdata
*km_findpub(const char */
*tag*/
);
619 extern kdata
*km_findpriv(const char */
*tag*/
);
621 /* --- @km_samealgsp@ --- *
623 * Arguments: @const kdata *kdx, *kdy@ = two key data objects
625 * Returns: Nonzero if their two algorithm selections are the same.
627 * Use: Checks sameness of algorithm selections: used to ensure that
628 * peers are using sensible algorithms.
631 extern int km_samealgsp(const kdata */
*kdx*/
, const kdata */
*kdy*/
);
633 /* --- @km_ref@ --- *
635 * Arguments: @kdata *kd@ = pointer to the kdata object
639 * Use: Claim a new reference to a kdata object.
642 extern void km_ref(kdata */
*kd*/
);
644 /* --- @km_unref@ --- *
646 * Arguments: @kdata *kd@ = pointer to the kdata object
650 * Use: Releases a reference to a kdata object.
653 extern void km_unref(kdata */
*kd*/
);
655 /* --- @km_tag@ --- *
657 * Arguments: @kdata *kd@ - pointer to the kdata object
659 * Returns: A pointer to the short tag by which the kdata was loaded.
662 extern const char *km_tag(kdata */
*kd*/
);
664 /*----- Key exchange ------------------------------------------------------*/
666 /* --- @kx_start@ --- *
668 * Arguments: @keyexch *kx@ = pointer to key exchange context
669 * @int forcep@ = nonzero to ignore the quiet timer
673 * Use: Stimulates a key exchange. If a key exchage is in progress,
674 * a new challenge is sent (unless the quiet timer forbids
675 * this); if no exchange is in progress, one is commenced.
678 extern void kx_start(keyexch */
*kx*/
, int /*forcep*/);
680 /* --- @kx_message@ --- *
682 * Arguments: @keyexch *kx@ = pointer to key exchange context
683 * @unsigned msg@ = the message code
684 * @buf *b@ = pointer to buffer containing the packet
688 * Use: Reads a packet containing key exchange messages and handles
692 extern void kx_message(keyexch */
*kx*/
, unsigned /*msg*/, buf */
*b*/
);
694 /* --- @kx_free@ --- *
696 * Arguments: @keyexch *kx@ = pointer to key exchange context
700 * Use: Frees everything in a key exchange context.
703 extern void kx_free(keyexch */
*kx*/
);
705 /* --- @kx_newkeys@ --- *
707 * Arguments: @keyexch *kx@ = pointer to key exchange context
711 * Use: Informs the key exchange module that its keys may have
712 * changed. If fetching the new keys fails, the peer will be
713 * destroyed, we log messages and struggle along with the old
717 extern void kx_newkeys(keyexch */
*kx*/
);
719 /* --- @kx_init@ --- *
721 * Arguments: @keyexch *kx@ = pointer to key exchange context
722 * @peer *p@ = pointer to peer context
723 * @keyset **ks@ = pointer to keyset list
724 * @unsigned f@ = various useful flags
726 * Returns: Zero if OK, nonzero if it failed.
728 * Use: Initializes a key exchange module. The module currently
729 * contains no keys, and will attempt to initiate a key
733 extern int kx_init(keyexch */
*kx*/
, peer */
*p*/
,
734 keyset
**/
*ks*/
, unsigned /*f*/);
736 /*----- Keysets and symmetric cryptography --------------------------------*/
738 /* --- @ks_drop@ --- *
740 * Arguments: @keyset *ks@ = pointer to a keyset
744 * Use: Decrements a keyset's reference counter. If the counter hits
745 * zero, the keyset is freed.
748 extern void ks_drop(keyset */
*ks*/
);
750 /* --- @ks_gen@ --- *
752 * Arguments: @const void *k@ = pointer to key material
753 * @size_t x, y, z@ = offsets into key material (see below)
754 * @peer *p@ = pointer to peer information
756 * Returns: A pointer to the new keyset.
758 * Use: Derives a new keyset from the given key material. The
759 * offsets @x@, @y@ and @z@ separate the key material into three
760 * parts. Between the @k@ and @k + x@ is `my' contribution to
761 * the key material; between @k + x@ and @k + y@ is `your'
762 * contribution; and between @k + y@ and @k + z@ is a shared
763 * value we made together. These are used to construct two
764 * pairs of symmetric keys. Each pair consists of an encryption
765 * key and a message authentication key. One pair is used for
766 * outgoing messages, the other for incoming messages.
768 * The new key is marked so that it won't be selected for output
769 * by @ksl_encrypt@. You can still encrypt data with it by
770 * calling @ks_encrypt@ directly.
773 extern keyset
*ks_gen(const void */
*k*/
,
774 size_t /*x*/, size_t /*y*/, size_t /*z*/,
777 /* --- @ks_activate@ --- *
779 * Arguments: @keyset *ks@ = pointer to a keyset
783 * Use: Activates a keyset, so that it can be used for encrypting
787 extern void ks_activate(keyset */
*ks*/
);
789 /* --- @ks_encrypt@ --- *
791 * Arguments: @keyset *ks@ = pointer to a keyset
792 * @unsigned ty@ = message type
793 * @buf *b@ = pointer to input buffer
794 * @buf *bb@ = pointer to output buffer
796 * Returns: Zero if successful; @KSERR_REGEN@ if we should negotiate a
797 * new key; @KSERR_NOKEYS@ if the key is not usable. Also
798 * returns zero if there was insufficient buffer (but the output
799 * buffer is broken in this case).
801 * Use: Encrypts a block of data using the key. Note that the `key
802 * ought to be replaced' notification is only ever given once
803 * for each key. Also note that this call forces a keyset to be
804 * used even if it's marked as not for data output.
806 * The encryption transform is permitted to corrupt @buf_u@ for
807 * its own purposes. Neither the source nor destination should
808 * be within @buf_u@; and callers mustn't expect anything stored
809 * in @buf_u@ to still
812 extern int ks_encrypt(keyset */
*ks*/
, unsigned /*ty*/,
813 buf */
*b*/
, buf */
*bb*/
);
815 /* --- @ks_decrypt@ --- *
817 * Arguments: @keyset *ks@ = pointer to a keyset
818 * @unsigned ty@ = expected type code
819 * @buf *b@ = pointer to an input buffer
820 * @buf *bb@ = pointer to an output buffer
822 * Returns: Zero on success; @KSERR_DECRYPT@ on failure. Also returns
823 * zero if there was insufficient buffer (but the output buffer
824 * is broken in this case).
826 * Use: Attempts to decrypt a message using a given key. Note that
827 * requesting decryption with a key directly won't clear a
828 * marking that it's not for encryption.
830 * The decryption transform is permitted to corrupt @buf_u@ for
831 * its own purposes. Neither the source nor destination should
832 * be within @buf_u@; and callers mustn't expect anything stored
833 * in @buf_u@ to still
836 extern int ks_decrypt(keyset */
*ks*/
, unsigned /*ty*/,
837 buf */
*b*/
, buf */
*bb*/
);
839 /* --- @ksl_free@ --- *
841 * Arguments: @keyset **ksroot@ = pointer to keyset list head
845 * Use: Frees (releases references to) all of the keys in a keyset.
848 extern void ksl_free(keyset
**/
*ksroot*/
);
850 /* --- @ksl_link@ --- *
852 * Arguments: @keyset **ksroot@ = pointer to keyset list head
853 * @keyset *ks@ = pointer to a keyset
857 * Use: Links a keyset into a list. A keyset can only be on one list
858 * at a time. Bad things happen otherwise.
861 extern void ksl_link(keyset
**/
*ksroot*/
, keyset */
*ks*/
);
863 /* --- @ksl_prune@ --- *
865 * Arguments: @keyset **ksroot@ = pointer to keyset list head
869 * Use: Prunes the keyset list by removing keys which mustn't be used
873 extern void ksl_prune(keyset
**/
*ksroot*/
);
875 /* --- @ksl_encrypt@ --- *
877 * Arguments: @keyset **ksroot@ = pointer to keyset list head
878 * @unsigned ty@ = message type
879 * @buf *b@ = pointer to input buffer
880 * @buf *bb@ = pointer to output buffer
882 * Returns: Zero if successful; @KSERR_REGEN@ if it's time to negotiate a
883 * new key; @KSERR_NOKEYS@ if there are no suitable keys
884 * available. Also returns zero if there was insufficient
885 * buffer space (but the output buffer is broken in this case).
887 * Use: Encrypts a packet.
890 extern int ksl_encrypt(keyset
**/
*ksroot*/
, unsigned /*ty*/,
891 buf */
*b*/
, buf */
*bb*/
);
893 /* --- @ksl_decrypt@ --- *
895 * Arguments: @keyset **ksroot@ = pointer to keyset list head
896 * @unsigned ty@ = expected type code
897 * @buf *b@ = pointer to input buffer
898 * @buf *bb@ = pointer to output buffer
900 * Returns: Zero on success; @KSERR_DECRYPT@ on failure. Also returns
901 * zero if there was insufficient buffer (but the output buffer
902 * is broken in this case).
904 * Use: Decrypts a packet.
907 extern int ksl_decrypt(keyset
**/
*ksroot*/
, unsigned /*ty*/,
908 buf */
*b*/
, buf */
*bb*/
);
910 /*----- Challenges --------------------------------------------------------*/
914 * Arguments: @buf *b@ = where to put the challenge
916 * Returns: Zero if OK, nonzero on error.
918 * Use: Issues a new challenge.
921 extern int c_new(buf */
*b*/
);
923 /* --- @c_check@ --- *
925 * Arguments: @buf *b@ = where to find the challenge
927 * Returns: Zero if OK, nonzero if it didn't work.
929 * Use: Checks a challenge. On failure, the buffer is broken.
932 extern int c_check(buf */
*b*/
);
934 /*----- Administration interface ------------------------------------------*/
936 #define A_END ((char *)0)
938 /* --- @a_vformat@ --- *
940 * Arguments: @dstr *d@ = where to leave the formatted message
941 * @const char *fmt@ = pointer to format string
942 * @va_list ap@ = arguments in list
946 * Use: Main message token formatting driver. The arguments are
947 * interleaved formatting tokens and their parameters, finally
948 * terminated by an entry @A_END@.
952 * * "*..." ... -- pretokenized @dstr_putf@-like string
954 * * "?ADDR" SOCKADDR -- a socket address, to be converted
956 * * "?B64" BUFFER SIZE -- binary data to be base64-encoded
958 * * "?TOKENS" VECTOR -- null-terminated vector of tokens
960 * * "?PEER" PEER -- peer's name
962 * * "?ERRNO" ERRNO -- system error code
964 * * "[!]..." ... -- @dstr_putf@-like string as single token
967 extern void a_vformat(dstr */
*d*/
, const char */
*fmt*/
, va_list /*ap*/);
969 /* --- @a_format@ --- *
971 * Arguments: @dstr *d@ = where to leave the formatted message
972 * @const char *fmt@ = pointer to format string
976 * Use: Writes a tokenized message into a string, for later
980 extern void EXECL_LIKE(0) a_format(dstr */
*d*/
, const char */
*fmt*/
, ...);
982 /* --- @a_warn@ --- *
984 * Arguments: @const char *fmt@ = pointer to format string
985 * @...@ = other arguments
989 * Use: Informs all admin connections of a warning.
992 extern void EXECL_LIKE(0) a_warn(const char */
*fmt*/
, ...);
994 /* --- @a_notify@ --- *
996 * Arguments: @const char *fmt@ = pointer to format string
997 * @...@ = other arguments
1001 * Use: Sends a notification to interested admin connections.
1004 extern void EXECL_LIKE(0) a_notify(const char */
*fmt*/
, ...);
1006 /* --- @a_create@ --- *
1008 * Arguments: @int fd_in, fd_out@ = file descriptors to use
1009 * @unsigned f@ = initial flags to set
1013 * Use: Creates a new admin connection.
1016 extern void a_create(int /*fd_in*/, int /*fd_out*/, unsigned /*f*/);
1018 /* --- @a_quit@ --- *
1024 * Use: Shuts things down nicely.
1027 extern void a_quit(void);
1029 /* --- @a_preselect@ --- *
1035 * Use: Informs the admin module that we're about to select again,
1036 * and that it should do cleanup things it has delayed until a
1040 extern void a_preselect(void);
1042 /* --- @a_daemon@ --- *
1048 * Use: Informs the admin module that it's a daemon.
1051 extern void a_daemon(void);
1053 /* --- @a_init@ --- *
1055 * Arguments: @const char *sock@ = socket name to create
1056 * @uid_t u@ = user to own the socket
1057 * @gid_t g@ = group to own the socket
1058 * @mode_t m@ = permissions to set on the socket
1062 * Use: Creates the admin listening socket.
1065 extern void a_init(const char */
*sock*/
,
1066 uid_t
/*u*/, gid_t
/*g*/, mode_t
/*m*/);
1068 /*----- Mapping with addresses as keys ------------------------------------*/
1070 /* --- @am_create@ --- *
1072 * Arguments: @addrmap *m@ = pointer to map
1076 * Use: Create an address map, properly set up.
1079 extern void am_create(addrmap */
*m*/
);
1081 /* --- @am_destroy@ --- *
1083 * Arguments: @addrmap *m@ = pointer to map
1087 * Use: Destroy an address map, throwing away all the entries.
1090 extern void am_destroy(addrmap */
*m*/
);
1092 /* --- @am_find@ --- *
1094 * Arguments: @addrmap *m@ = pointer to map
1095 * @const addr *a@ = address to look up
1096 * @size_t sz@ = size of block to allocate
1097 * @unsigned *f@ = where to store flags
1099 * Returns: Pointer to found item, or null.
1101 * Use: Finds a record with the given IP address, set @*f@ nonzero
1102 * and returns it. If @sz@ is zero, and no match was found,
1103 * return null; otherwise allocate a new block of @sz@ bytes,
1104 * clear @*f@ to zero and return the block pointer.
1107 extern void *am_find(addrmap */
*m*/
, const addr */
*a*/
,
1108 size_t /*sz*/, unsigned */
*f*/
);
1110 /* --- @am_remove@ --- *
1112 * Arguments: @addrmap *m@ = pointer to map
1113 * @void *i@ = pointer to the item
1117 * Use: Removes an item from the map.
1120 extern void am_remove(addrmap */
*m*/
, void */
*i*/
);
1122 /*----- Privilege separation ----------------------------------------------*/
1124 /* --- @ps_trace@ --- *
1126 * Arguments: @unsigned mask@ = trace mask to check
1127 * @const char *fmt@ = message format
1128 * @...@ = values for placeholders
1132 * Use: Writes a trace message.
1135 T( extern void PRINTF_LIKE(2, 3)
1136 ps_trace(unsigned /*mask*/, const char */
*fmt*/
, ...); )
1138 /* --- @ps_warn@ --- *
1140 * Arguments: @const char *fmt@ = message format
1141 * @...@ = values for placeholders
1145 * Use: Writes a warning message.
1148 extern void PRINTF_LIKE(1, 2) ps_warn(const char */
*fmt*/
, ...);
1150 /* --- @ps_tunfd@ --- *
1152 * Arguments: @const tunnel_ops *tops@ = pointer to tunnel operations
1153 * @char **ifn@ = where to put the interface name
1155 * Returns: The file descriptor, or @-1@ on error.
1157 * Use: Fetches a file descriptor for a tunnel driver.
1160 extern int ps_tunfd(const tunnel_ops */
*tops*/
, char **/
*ifn*/
);
1162 /* --- @ps_split@ --- *
1164 * Arguments: @int detachp@ = whether to detach the child from its terminal
1168 * Use: Separates off the privileged tunnel-opening service from the
1169 * rest of the server.
1172 extern void ps_split(int /*detachp*/);
1174 /* --- @ps_quit@ --- *
1180 * Use: Detaches from the helper process.
1183 extern void ps_quit(void);
1185 /*----- Peer management ---------------------------------------------------*/
1187 /* --- @p_txstart@ --- *
1189 * Arguments: @peer *p@ = pointer to peer block
1190 * @unsigned msg@ = message type code
1192 * Returns: A pointer to a buffer to write to.
1194 * Use: Starts sending to a peer. Only one send can happen at a
1198 extern buf
*p_txstart(peer */
*p*/
, unsigned /*msg*/);
1200 /* --- @p_txend@ --- *
1202 * Arguments: @peer *p@ = pointer to peer block
1206 * Use: Sends a packet to the peer.
1209 extern void p_txend(peer */
*p*/
);
1211 /* --- @p_pingsend@ --- *
1213 * Arguments: @peer *p@ = destination peer
1214 * @ping *pg@ = structure to fill in
1215 * @unsigned type@ = message type
1216 * @unsigned long timeout@ = how long to wait before giving up
1217 * @void (*func)(int, void *)@ = callback function
1218 * @void *arg@ = argument for callback
1220 * Returns: Zero if successful, nonzero if it failed.
1222 * Use: Sends a ping to a peer. Call @func@ with a nonzero argument
1223 * if we get an answer within the timeout, or zero if no answer.
1226 extern int p_pingsend(peer */
*p*/
, ping */
*pg*/
, unsigned /*type*/,
1227 unsigned long /*timeout*/,
1228 void (*/
*func*/
)(int, void *), void */
*arg*/
);
1230 /* --- @p_pingdone@ --- *
1232 * Arguments: @ping *p@ = ping structure
1233 * @int rc@ = return code to pass on
1237 * Use: Disposes of a ping structure, maybe sending a notification.
1240 extern void p_pingdone(ping */
*p*/
, int /*rc*/);
1242 /* --- @p_greet@ --- *
1244 * Arguments: @peer *p@ = peer to send to
1245 * @const void *c@ = pointer to challenge
1246 * @size_t sz@ = size of challenge
1250 * Use: Sends a greeting packet.
1253 extern void p_greet(peer */
*p*/
, const void */
*c*/
, size_t /*sz*/);
1255 /* --- @p_tun@ --- *
1257 * Arguments: @peer *p@ = pointer to peer block
1258 * @buf *b@ = buffer containing incoming packet
1262 * Use: Handles a packet which needs to be sent to a peer.
1265 extern void p_tun(peer */
*p*/
, buf */
*b*/
);
1267 /* --- @p_keyreload@ --- *
1273 * Use: Forces a check of the daemon's keyring files.
1276 extern void p_keyreload(void);
1278 /* --- @p_interval@ --- *
1284 * Use: Called periodically to do tidying.
1287 extern void p_interval(void);
1289 /* --- @p_stats@ --- *
1291 * Arguments: @peer *p@ = pointer to a peer block
1293 * Returns: A pointer to the peer's statistics.
1296 extern stats
*p_stats(peer */
*p*/
);
1298 /* --- @p_ifname@ --- *
1300 * Arguments: @peer *p@ = pointer to a peer block
1302 * Returns: A pointer to the peer's interface name.
1305 extern const char *p_ifname(peer */
*p*/
);
1307 /* --- @p_setifname@ --- *
1309 * Arguments: @peer *p@ = pointer to a peer block
1310 * @const char *name@ = pointer to the new name
1314 * Use: Changes the name held for a peer's interface.
1317 extern void p_setifname(peer */
*p*/
, const char */
*name*/
);
1319 /* --- @p_addr@ --- *
1321 * Arguments: @peer *p@ = pointer to a peer block
1323 * Returns: A pointer to the peer's address.
1326 extern const addr
*p_addr(peer */
*p*/
);
1328 /* --- @p_init@ --- *
1330 * Arguments: @struct in_addr addr@ = address to bind to
1331 * @unsigned port@ = port number to listen to
1335 * Use: Initializes the peer system; creates the socket.
1338 extern void p_init(struct in_addr
/*addr*/, unsigned /*port*/);
1340 /* --- @p_port@ --- *
1344 * Returns: Port number used for socket.
1347 unsigned p_port(void);
1349 /* --- @p_create@ --- *
1351 * Arguments: @peerspec *spec@ = information about this peer
1353 * Returns: Pointer to the peer block, or null if it failed.
1355 * Use: Creates a new named peer block. No peer is actually attached
1359 extern peer
*p_create(peerspec */
*spec*/
);
1361 /* --- @p_name@ --- *
1363 * Arguments: @peer *p@ = pointer to a peer block
1365 * Returns: A pointer to the peer's name.
1367 * Use: Equivalent to @p_spec(p)->name@.
1370 extern const char *p_name(peer */
*p*/
);
1372 /* --- @p_tag@ --- *
1374 * Arguments: @peer *p@ = pointer to a peer block
1376 * Returns: A pointer to the peer's public key tag.
1379 extern const char *p_tag(peer */
*p*/
);
1381 /* --- @p_privtag@ --- *
1383 * Arguments: @peer *p@ = pointer to a peer block
1385 * Returns: A pointer to the peer's private key tag.
1388 extern const char *p_privtag(peer */
*p*/
);
1390 /* --- @p_spec@ --- *
1392 * Arguments: @peer *p@ = pointer to a peer block
1394 * Returns: Pointer to the peer's specification
1397 extern const peerspec
*p_spec(peer */
*p*/
);
1399 /* --- @p_findbyaddr@ --- *
1401 * Arguments: @const addr *a@ = address to look up
1403 * Returns: Pointer to the peer block, or null if not found.
1405 * Use: Finds a peer by address.
1408 extern peer
*p_findbyaddr(const addr */
*a*/
);
1410 /* --- @p_find@ --- *
1412 * Arguments: @const char *name@ = name to look up
1414 * Returns: Pointer to the peer block, or null if not found.
1416 * Use: Finds a peer by name.
1419 extern peer
*p_find(const char */
*name*/
);
1421 /* --- @p_destroy@ --- *
1423 * Arguments: @peer *p@ = pointer to a peer
1427 * Use: Destroys a peer.
1430 extern void p_destroy(peer */
*p*/
);
1432 /* --- @FOREACH_PEER@ --- *
1434 * Arguments: @p@ = name to bind to each peer
1435 * @stuff@ = thing to do for each item
1437 * Use: Does something for each current peer.
1440 #define FOREACH_PEER(p, stuff) do { \
1443 for (p_mkiter(&i_); (p = p_next(&i_)) != 0; ) stuff \
1446 /* --- @p_mkiter@ --- *
1448 * Arguments: @peer_iter *i@ = pointer to an iterator
1452 * Use: Initializes the iterator.
1455 extern void p_mkiter(peer_iter */
*i*/
);
1457 /* --- @p_next@ --- *
1459 * Arguments: @peer_iter *i@ = pointer to an iterator
1461 * Returns: Next peer, or null if at the end.
1463 * Use: Returns the next peer.
1466 extern peer
*p_next(peer_iter */
*i*/
);
1468 /*----- Tunnel drivers ----------------------------------------------------*/
1471 extern const tunnel_ops tun_linux
;
1475 extern const tunnel_ops tun_unet
;
1479 extern const tunnel_ops tun_bsd
;
1482 extern const tunnel_ops tun_slip
;
1484 /*----- Other handy utilities ---------------------------------------------*/
1486 /* --- @mpstr@ --- *
1488 * Arguments: @mp *m@ = a multiprecision integer
1490 * Returns: A pointer to the integer's textual representation.
1492 * Use: Converts a multiprecision integer to a string. Corrupts
1496 extern const char *mpstr(mp */
*m*/
);
1498 /* --- @gestr@ --- *
1500 * Arguments: @group *g@ = a group
1501 * @ge *x@ = a group element
1503 * Returns: A pointer to the element's textual representation.
1505 * Use: Converts a group element to a string. Corrupts
1509 extern const char *gestr(group */
*g*/
, ge */
*x*/
);
1511 /* --- @timestr@ --- *
1513 * Arguments: @time_t t@ = a time to convert
1515 * Returns: A pointer to a textual representation of the time.
1517 * Use: Converts a time to a textual representation. Corrupts
1521 extern const char *timestr(time_t /*t*/);
1523 /* --- @mystrieq@ --- *
1525 * Arguments: @const char *x, *y@ = two strings
1527 * Returns: True if @x@ and @y are equal, up to case.
1530 extern int mystrieq(const char */
*x*/
, const char */
*y*/
);
1532 /* --- @seq_reset@ --- *
1534 * Arguments: @seqwin *s@ = sequence-checking window
1538 * Use: Resets a sequence number window.
1541 extern void seq_reset(seqwin */
*s*/
);
1543 /* --- @seq_check@ --- *
1545 * Arguments: @seqwin *s@ = sequence-checking window
1546 * @uint32 q@ = sequence number to check
1547 * @const char *service@ = service to report message from
1549 * Returns: A @SEQ_@ code.
1551 * Use: Checks a sequence number against the window, updating things
1555 extern int seq_check(seqwin */
*s*/
, uint32
/*q*/, const char */
*service*/
);
1557 /*----- That's all, folks -------------------------------------------------*/