X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/7ed14135434df136e971a43b1774b827714ef7f9..de014da64011b21929158b746803d69cbfb05ee6:/tripe.h diff --git a/tripe.h b/tripe.h index 8d70c1f6..a358fb91 100644 --- a/tripe.h +++ b/tripe.h @@ -1,6 +1,6 @@ /* -*-c-*- * - * $Id: tripe.h,v 1.16 2003/07/13 11:19:49 mdw Exp $ + * $Id$ * * Main header file for TrIPE * @@ -26,63 +26,6 @@ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ -/*----- Revision history --------------------------------------------------* - * - * $Log: tripe.h,v $ - * Revision 1.16 2003/07/13 11:19:49 mdw - * Incopatible protocol fix! Include message type code under MAC tag to prevent - * cut-and-paste from key-exchange messages to general packet transport. - * - * Revision 1.15 2003/05/16 12:09:03 mdw - * Allow binding to a chosen address. - * - * Revision 1.14 2003/04/06 10:36:33 mdw - * Rearrange so as not to include Linux headers unless we need to. - * - * Revision 1.13 2003/04/06 10:26:35 mdw - * Report peer name on decrypt errors. - * - * Revision 1.12 2003/04/06 10:25:17 mdw - * Support Linux TUN/TAP device. Fix some bugs. - * - * Revision 1.11 2002/01/13 14:57:42 mdw - * Fix crap typo. - * - * Revision 1.10 2002/01/13 14:54:58 mdw - * Provide MGF macros. - * - * Revision 1.9 2001/06/22 19:40:36 mdw - * Support expiry of other peers' public keys. - * - * Revision 1.8 2001/06/19 22:10:57 mdw - * Some more constants for the algorithms. Document the packet format - * change for non-malleability. Moved @buf@ definitions to separate header - * file. - * - * Revision 1.7 2001/03/03 12:07:08 mdw - * Rename word get and put functions now that there's 16-bit support. - * - * Revision 1.6 2001/02/19 19:11:09 mdw - * Output buffering on admin connections. - * - * Revision 1.5 2001/02/16 21:41:43 mdw - * Major changes. See source files for details. - * - * Revision 1.4 2001/02/05 19:56:37 mdw - * Sequence number protection, and BSD tunnels. - * - * Revision 1.3 2001/02/04 01:17:55 mdw - * Create a configuration header file to tidy up command lines. - * - * Revision 1.2 2001/02/03 22:40:29 mdw - * Put timer information into the entropy pool when packets are received - * and on similar events. Reseed the generator on the interval timer. - * - * Revision 1.1 2001/02/03 20:26:37 mdw - * Initial checkin. - * - */ - #ifndef TRIPE_H #define TRIPE_H @@ -97,6 +40,7 @@ #include #include #include +#include #include #include #include @@ -136,6 +80,9 @@ #include #include #include +#include + +#include #include #include @@ -147,24 +94,19 @@ #include #include -#include #include #include +#include +#include +#include -#include "buf.h" +#include "tripe-protocol.h" #include "util.h" #undef sun /*----- Magic numbers -----------------------------------------------------*/ -/* --- Tunnel types --- */ - -#define TUN_NOTDEF 0 -#define TUN_UNET 1 -#define TUN_BSD 2 -#define TUN_LINUX 3 - /* --- Trace flags --- */ #define T_TUNNEL 1u @@ -188,106 +130,23 @@ #define PKBUFSZ 65536 -/*----- TrIPE protocol ----------------------------------------------------*/ - -/* --- TrIPE message format --- * - * - * A packet begins with a single-byte message type. The top four bits are a - * category code used to send the message to the right general place in the - * code; the bottom bits identify the actual message type. - */ - -#define MSG_CATMASK 0xf0 -#define MSG_TYPEMASK 0x0f - -/* --- Encrypted message packets --- * - * - * Messages of category @MSG_PACKET@ contain encrypted network packets. The - * message content is a symmetric-encrypted block (see below). Reception of - * a packet encrypted under a new key implicitly permits that key to be used - * to send further packets. - * - * The only packet type accepted is zero. - * - * Packets may be encrypted under any live keyset, but should use the most - * recent one. - */ - -#define MSG_PACKET 0x00 - -/* --- Key exchange packets --- */ - -#define MSG_KEYEXCH 0x10 - -#define KX_PRECHAL 0u -#define KX_COOKIE 1u -#define KX_CHAL 2u -#define KX_REPLY 3u -#define KX_SWITCH 4u -#define KX_SWITCHOK 5u -#define KX_NMSG 6u - -/* --- Symmetric encryption and keysets --- * - * - * Packets consist of an 80-bit MAC, a 32-bit sequence number, and the - * encrypted payload. - * - * The plaintext is encrypted using Blowfish in CBC mode with ciphertext - * stealing (as described in [Schneier]. The initialization vector is - * selected randomly, and prepended to the actual ciphertext. - * - * The MAC is computed using the HMAC construction with RIPEMD160 over the - * sequence number and the ciphertext (with IV); the first 80 bits of the - * output are used. (This is the minimum allowed by the draft FIPS for HMAC, - * and the recommended truncation.) - * - * A keyset consists of - * - * * an integrity (MAC) key; - * * a confidentiality (encryption) key; and - * * a sequence numbering space - * - * in each direction. The packets sent by a host encrypted under a - * particular keyset are assigned consecutive sequence numbers starting from - * zero. The receiving host must ensure that it only accepts each packet at - * most once. It should maintain a window of sequence numbers: packets with - * numbers beyond the end of the window are accepted and cause the window to - * be advanced; packets with numbers before the start of the window are - * rejected; packets with numbers which appear within the window are accepted - * only if the number has not been seen before. - * - * When a host sends a @KX_SWITCH@ or @KX_SWITCHOK@ message, it installs the - * newly-negotiated keyset in a `listen-only' state: it may not send a packet - * encrypted under the keyset until either it has received a @KX_SWITCH@ or - * @KX_SWITCHOK@ message, or a @MSG_PACKET@ encrypted under the keyset, from - * its peer. - */ - /*----- Cipher selections -------------------------------------------------*/ -#include -#include -#include -#include -#include - -#define CIPHER (&blowfish_cbc) -#define MAC (&rmd160_hmac) +typedef struct algswitch { + const gccipher *c; /* Symmetric encryption scheme */ + const gccipher *mgf; /* Mask-generation function */ + const gchash *h; /* Hash function */ + const gcmac *m; /* Message authentication code */ + size_t hashsz; /* Hash output size */ + size_t tagsz; /* Length to truncate MAC tags */ + size_t cksz, mksz; /* Key lengths for @c@ and @m@ */ +} algswitch; -#define HASH_CTX rmd160_ctx -#define HASH_INIT rmd160_init -#define HASH rmd160_hash -#define HASH_STRING(c, s) HASH((c), s, sizeof(s)) -#define HASH_DONE rmd160_done -#define HASHSZ RMD160_HASHSZ +extern algswitch algs; -#define MGF_CTX blowfish_counterctx -#define MGF_INIT blowfish_counterinit -#define MGF_CRYPT blowfish_counterencrypt +#define MAXHASHSZ 64 /* Largest possible hash size */ -#define SEQSZ 4 -#define IVSZ BLOWFISH_BLKSZ -#define MACSZ 10 +#define HASH_STRING(h, s) GH_HASH((h), (s), sizeof(s)) /*----- Data structures ---------------------------------------------------*/ @@ -323,6 +182,7 @@ typedef struct keyset { T( unsigned seq; ) /* Sequence number for tracing */ unsigned f; /* Various useful flags */ gcipher *cin, *cout; /* Keyset ciphers for encryption */ + size_t tagsz; /* Length to truncate MAC tags */ gmac *min, *mout; /* Keyset MACs for integrity */ uint32 oseq; /* Outbound sequence number */ uint32 iseq, iwin; /* Inbound sequence number */ @@ -347,17 +207,17 @@ typedef struct keyset { typedef struct kxchal { struct keyexch *kx; /* Pointer back to key exchange */ - mp *c; /* Responder's challenge */ - mp *r; /* My reply to the challenge */ + ge *c; /* Responder's challenge */ + ge *r; /* My reply to the challenge */ keyset *ks; /* Pointer to temporary keyset */ unsigned f; /* Various useful flags */ sel_timer t; /* Response timer for challenge */ - octet hc[HASHSZ]; /* Hash of his challenge */ + octet hc[MAXHASHSZ]; /* Hash of his challenge */ mp *ck; /* The check value */ - octet hswrq_in[HASHSZ]; /* Inbound switch request message */ - octet hswok_in[HASHSZ]; /* Inbound switch confirmation */ - octet hswrq_out[HASHSZ]; /* Outbound switch request message */ - octet hswok_out[HASHSZ]; /* Outbound switch confirmation */ + octet hswrq_in[MAXHASHSZ]; /* Inbound switch request message */ + octet hswok_in[MAXHASHSZ]; /* Inbound switch confirmation */ + octet hswrq_out[MAXHASHSZ]; /* Outbound switch request message */ + octet hswok_out[MAXHASHSZ]; /* Outbound switch confirmation */ } kxchal; typedef struct keyexch { @@ -366,14 +226,14 @@ typedef struct keyexch { unsigned f; /* Various useful flags */ unsigned s; /* Current state in exchange */ sel_timer t; /* Timer for next exchange */ - dh_pub kpub; /* Peer's public key */ + ge *kpub; /* Peer's public key */ time_t texp_kpub; /* Expiry time for public key */ mp *alpha; /* My temporary secret */ - mp *c; /* My challenge */ - mp *rx; /* The expected response */ + ge *c; /* My challenge */ + ge *rx; /* The expected response */ unsigned nr; /* Number of extant responses */ time_t t_valid; /* When this exchange goes bad */ - octet hc[HASHSZ]; /* Hash of my challenge */ + octet hc[MAXHASHSZ]; /* Hash of my challenge */ kxchal *r[KX_NCHAL]; /* Array of challenges */ } keyexch; @@ -393,27 +253,21 @@ enum { * Used to maintain system-specific information about the tunnel interface. */ -#if TUN_TYPE == TUN_LINUX -# include -# include -#endif +typedef struct tunnel tunnel; +struct peer; -typedef struct tunnel { -#if TUN_TYPE == TUN_UNET - sel_file f; /* Selector for Usernet device */ - struct peer *p; /* Pointer to my peer */ -#elif TUN_TYPE == TUN_LINUX - sel_file f; /* Selector for TUN/TAP device */ - struct peer *p; /* Pointer to my peer */ - char ifn[IFNAMSIZ]; /* Interface name buffer */ -#elif TUN_TYPE == TUN_BSD - sel_file f; /* Selector for tunnel device */ - struct peer *p; /* Pointer to my peer */ - unsigned n; /* Number of my tunnel device */ -#else -# error "No support for this tunnel type" +typedef struct tunnel_ops { + const char *name; /* Name of this tunnel driver */ + void (*init)(void); /* Initializes the system */ + tunnel *(*create)(struct peer */*p*/); /* Initializes a new tunnel */ + const char *(*ifname)(tunnel */*t*/); /* Returns tunnel's interface name */ + void (*inject)(tunnel */*t*/, buf */*b*/); /* Sends packet through if */ + void (*destroy)(tunnel */*t*/); /* Destroys a tunnel */ +} tunnel_ops; + +#ifndef TUN_INTERNALS +struct tunnel { const tunnel_ops *ops; }; #endif -} tunnel; /* --- Peer statistics --- * * @@ -427,7 +281,7 @@ typedef struct stats { unsigned long sz_in, sz_out; /* Size of all data in and out */ unsigned long sz_kxin, sz_kxout; /* Size of key exchange messages */ unsigned long sz_ipin, sz_ipout; /* Size of encapsulated IP packets */ - time_t t_start, t_last; /* Time peer created, last recv */ + time_t t_start, t_last, t_kx; /* Time peer created, last pk, kx */ unsigned long n_reject; /* Number of rejected packets */ unsigned long n_in, n_out; /* Number of packets in and out */ unsigned long n_kxin, n_kxout; /* Number of key exchange packets */ @@ -439,18 +293,45 @@ typedef struct stats { * The main structure which glues everything else together. */ +typedef struct peerspec { + char *name; /* Peer's name */ + const tunnel_ops *tops; /* Tunnel operations */ + unsigned long t_ka; /* Keep alive interval */ + addr sa; /* Socket address to speak to */ + size_t sasz; /* Socket address size */ +} peerspec; + typedef struct peer { struct peer *next, *prev; /* Links to next and previous */ - char *name; /* Name of this peer */ - tunnel t; /* Tunnel for local packets */ + struct ping *pings; /* Pings we're waiting for */ + peerspec spec; /* Specifications for this peer */ + tunnel *t; /* Tunnel for local packets */ keyset *ks; /* List head for keysets */ buf b; /* Buffer for sending packets */ - addr peer; /* Peer socket address */ - size_t sasz; /* Socket address size */ stats st; /* Statistics */ keyexch kx; /* Key exchange protocol block */ + sel_timer tka; /* Timer for keepalives */ } peer; +typedef struct ping { + struct ping *next, *prev; /* Links to next and previous */ + peer *p; /* Peer so we can free it */ + unsigned msg; /* Kind of response expected */ + uint32 id; /* Id so we can recognize response */ + octet magic[32]; /* Some random data */ + sel_timer t; /* Timeout for ping */ + void (*func)(int /*rc*/, void */*arg*/); /* Function to call when done */ + void *arg; /* Argument for callback */ +} ping; + +enum { + PING_NONOTIFY = -1, + PING_OK = 0, + PING_TIMEOUT, + PING_PEERDIED, + PING_MAX +}; + /* --- Admin structure --- */ #define OBUFSZ 16384u @@ -461,32 +342,69 @@ typedef struct obuf { char buf[OBUFSZ]; /* The actual buffer */ } obuf; +typedef struct oqueue { + obuf *hd, *tl; /* Head and tail pointers */ +} oqueue; + +struct admin; + +typedef struct admin_bgop { + struct admin_bgop *next, *prev; /* Links to next and previous */ + struct admin *a; /* Owner job */ + char *tag; /* Tag string for messages */ + void (*cancel)(struct admin_bgop *); /* Destructor function */ +} admin_bgop; + +typedef struct admin_addop { + admin_bgop bg; /* Background operation header */ + peerspec peer; /* Peer pending creation */ + char *paddr; /* Hostname to be resolved */ + bres_client r; /* Background resolver task */ + sel_timer t; /* Timer for resolver */ +} admin_addop; + +typedef struct admin_pingop { + admin_bgop bg; /* Background operation header */ + ping ping; /* Ping pending response */ + struct timeval pingtime; /* Time last ping was sent */ +} admin_pingop; + typedef struct admin { struct admin *next, *prev; /* Links to next and previous */ unsigned f; /* Various useful flags */ #ifndef NTRACE unsigned seq; /* Sequence number for tracing */ #endif - char *pname; /* Peer name to create */ - char *paddr; /* Address string to resolve */ - obuf *o_head, *o_tail; /* Output buffer list */ + oqueue out; /* Output buffer list */ + oqueue delay; /* Delayed output buffer list */ + admin_bgop *bg; /* Backgrounded operations */ selbuf b; /* Line buffer for commands */ sel_file w; /* Selector for write buffering */ - bres_client r; /* Background resolver task */ - sel_timer t; /* Timer for resolver */ - addr peer; /* Address to set */ - size_t sasz; /* Size of the address */ } admin; #define AF_DEAD 1u /* Destroy this admin block */ #define AF_LOCK 2u /* Don't destroy it yet */ +#define AF_NOTE 4u /* Catch notifications */ +#define AF_WARN 8u /* Catch warning messages */ +#ifndef NTRACE + #define AF_TRACE 16u /* Catch tracing */ +#endif +#define AF_CLOSE 32u /* Client closed connection */ + +#ifndef NTRACE +# define AF_ALLMSGS (AF_NOTE | AF_TRACE | AF_WARN) +#else +# define AF_ALLMSGS (AF_NOTE | AF_WARN) +#endif /*----- Global variables --------------------------------------------------*/ extern sel_state sel; /* Global I/O event state */ -extern dh_priv kpriv; /* Our private key */ -extern mpmont mg; /* Montgomery context for DH group */ +extern group *gg; /* The group we work in */ +extern mp *kpriv; /* Our private key */ extern octet buf_i[PKBUFSZ], buf_o[PKBUFSZ], buf_t[PKBUFSZ]; +extern const tunnel_ops *tunnels[]; /* Table of tunnels (0-term) */ +extern const tunnel_ops *tun_default; /* Default tunnel to use */ #ifndef NTRACE extern const trace_opt tr_opts[]; /* Trace options array */ @@ -499,16 +417,16 @@ extern unsigned tr_flags; /* Trace options flags */ /*----- Key management ----------------------------------------------------*/ -/* --- @km_interval@ --- * +/* --- @km_reload@ --- * * * Arguments: --- * * Returns: Zero if OK, nonzero to force reloading of keys. * - * Use: Called on the interval timer to perform various useful jobs. + * Use: Checks the keyrings to see if they need reloading. */ -extern int km_interval(void); +extern int km_reload(void); /* --- @km_init@ --- * * @@ -527,7 +445,7 @@ extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/, /* --- @km_getpubkey@ --- * * * Arguments: @const char *tag@ = public key tag to load - * @dh_pub *kpub@ = where to put the public key + * @ge *kpub@ = where to put the public key * @time_t *t_exp@ = where to put the expiry time * * Returns: Zero if OK, nonzero if it failed. @@ -535,7 +453,7 @@ extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/, * Use: Fetches a public key from the keyring. */ -extern int km_getpubkey(const char */*tag*/, dh_pub */*kpub*/, +extern int km_getpubkey(const char */*tag*/, ge */*kpub*/, time_t */*t_exp*/); /*----- Key exchange ------------------------------------------------------*/ @@ -543,6 +461,7 @@ extern int km_getpubkey(const char */*tag*/, dh_pub */*kpub*/, /* --- @kx_start@ --- * * * Arguments: @keyexch *kx@ = pointer to key exchange context + * @int forcep@ = nonzero to ignore the quiet timer * * Returns: --- * @@ -551,7 +470,7 @@ extern int km_getpubkey(const char */*tag*/, dh_pub */*kpub*/, * this); if no exchange is in progress, one is commenced. */ -extern void kx_start(keyexch */*kx*/); +extern void kx_start(keyexch */*kx*/, int /*forcep*/); /* --- @kx_message@ --- * * @@ -786,16 +705,29 @@ extern int ksl_decrypt(keyset **/*ksroot*/, unsigned /*ty*/, extern void a_warn(const char */*fmt*/, ...); +/* --- @a_notify@ --- * + * + * Arguments: @const char *fmt@ = pointer to format string + * @...@ = other arguments + * + * Returns: --- + * + * Use: Sends a notification to interested admin connections. + */ + +extern void a_notify(const char */*fmt*/, ...); + /* --- @a_create@ --- * * * Arguments: @int fd_in, fd_out@ = file descriptors to use + * @unsigned f@ = initial flags to set * * Returns: --- * * Use: Creates a new admin connection. */ -extern void a_create(int /*fd_in*/, int /*fd_out*/); +extern void a_create(int /*fd_in*/, int /*fd_out*/, unsigned /*f*/); /* --- @a_quit@ --- * * @@ -856,6 +788,37 @@ extern buf *p_txstart(peer */*p*/, unsigned /*msg*/); extern void p_txend(peer */*p*/); +/* --- @p_pingsend@ --- * + * + * Arguments: @peer *p@ = destination peer + * @ping *pg@ = structure to fill in + * @unsigned type@ = message type + * @unsigned long timeout@ = how long to wait before giving up + * @void (*func)(int, void *)@ = callback function + * @void *arg@ = argument for callback + * + * Returns: Zero if successful, nonzero if it failed. + * + * Use: Sends a ping to a peer. Call @func@ with a nonzero argument + * if we get an answer within the timeout, or zero if no answer. + */ + +extern int p_pingsend(peer */*p*/, ping */*pg*/, unsigned /*type*/, + unsigned long /*timeout*/, + void (*/*func*/)(int, void *), void */*arg*/); + +/* --- @p_pingdone@ --- * + * + * Arguments: @ping *p@ = ping structure + * @int rc@ = return code to pass on + * + * Returns: --- + * + * Use: Disposes of a ping structure, maybe sending a notification. + */ + +extern void p_pingdone(ping */*p*/, int /*rc*/); + /* --- @p_tun@ --- * * * Arguments: @peer *p@ = pointer to peer block @@ -868,6 +831,17 @@ extern void p_txend(peer */*p*/); extern void p_tun(peer */*p*/, buf */*b*/); +/* --- @p_keyreload@ --- * + * + * Arguments: --- + * + * Returns: --- + * + * Use: Forces a check of the daemon's keyring files. + */ + +extern void p_keyreload(void); + /* --- @p_interval@ --- * * * Arguments: --- @@ -929,9 +903,7 @@ unsigned p_port(void); /* --- @p_create@ --- * * - * Arguments: @const char *name@ = name for this peer - * @struct sockaddr *sa@ = socket address of peer - * @size_t sz@ = size of socket address + * Arguments: @peerspec *spec@ = information about this peer * * Returns: Pointer to the peer block, or null if it failed. * @@ -939,8 +911,7 @@ unsigned p_port(void); * by this point. */ -extern peer *p_create(const char */*name*/, - struct sockaddr */*sa*/, size_t /*sz*/); +extern peer *p_create(peerspec */*spec*/); /* --- @p_name@ --- * * @@ -985,63 +956,21 @@ extern void p_destroy(peer */*p*/); extern peer *p_first(void); extern peer *p_next(peer */*p*/); -/*----- Tunnel interface --------------------------------------------------*/ - -/* --- @tun_init@ --- * - * - * Arguments: --- - * - * Returns: --- - * - * Use: Initializes the tunneling system. Maybe this will require - * opening file descriptors or something. - */ - -extern void tun_init(void); +/*----- Tunnel drivers ----------------------------------------------------*/ -/* --- @tun_create@ --- * - * - * Arguments: @tunnel *t@ = pointer to tunnel block - * @peer *p@ = pointer to peer block - * - * Returns: Zero if it worked, nonzero on failure. - * - * Use: Initializes a new tunnel. - */ - -extern int tun_create(tunnel */*t*/, peer */*p*/); - -/* --- @tun_ifname@ --- * - * - * Arguments: @tunnel *t@ = pointer to tunnel block - * - * Returns: A pointer to the tunnel's interface name. - */ - -extern const char *tun_ifname(tunnel */*t*/); - -/* --- @tun_inject@ --- * - * - * Arguments: @tunnel *t@ = pointer to tunnel block - * @buf *b@ = buffer to send - * - * Returns: --- - * - * Use: Injects a packet into the local network stack. - */ +#ifdef TUN_LINUX + extern const tunnel_ops tun_linux; +#endif -extern void tun_inject(tunnel */*t*/, buf */*b*/); +#ifdef TUN_UNET + extern const tunnel_ops tun_unet; +#endif -/* --- @tun_destroy@ --- * - * - * Arguments: @tunnel *t@ = pointer to tunnel block - * - * Returns: --- - * - * Use: Destroys a tunnel. - */ +#ifdef TUN_BSD + extern const tunnel_ops tun_bsd; +#endif -extern void tun_destroy(tunnel */*t*/); +extern const tunnel_ops tun_slip; /*----- Other handy utilities ---------------------------------------------*/ @@ -1057,6 +986,19 @@ extern void tun_destroy(tunnel */*t*/); extern const char *mpstr(mp */*m*/); +/* --- @gestr@ --- * + * + * Arguments: @group *g@ = a group + * @ge *x@ = a group element + * + * Returns: A pointer to the element's textual representation. + * + * Use: Converts a group element to a string. Corrupts + * @buf_t@. + */ + +extern const char *gestr(group */*g*/, ge */*x*/); + /* --- @timestr@ --- * * * Arguments: @time_t t@ = a time to convert @@ -1069,6 +1011,15 @@ extern const char *mpstr(mp */*m*/); extern const char *timestr(time_t /*t*/); +/* --- @mystrieq@ --- * + * + * Arguments: @const char *x, *y@ = two strings + * + * Returns: True if @x@ and @y are equal, up to case. + */ + +extern int mystrieq(const char */*x*/, const char */*y*/); + /*----- That's all, folks -------------------------------------------------*/ #ifdef __cplusplus