X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/832a2ab6980070401d02e0143a2bd3ece7a3e9db..3cdc3f3a27e8c4f4fe692009d868c773d298a68c:/tripe.h diff --git a/tripe.h b/tripe.h index 9f7fd5d7..320a2ca5 100644 --- a/tripe.h +++ b/tripe.h @@ -1,6 +1,6 @@ /* -*-c-*- * - * $Id: tripe.h,v 1.5 2001/02/16 21:41:43 mdw Exp $ + * $Id$ * * Main header file for TrIPE * @@ -26,27 +26,6 @@ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ -/*----- Revision history --------------------------------------------------* - * - * $Log: tripe.h,v $ - * 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 @@ -101,6 +80,8 @@ #include #include +#include + #include #include #include @@ -111,10 +92,13 @@ #include #include -#include #include #include +#include +#include +#include +#include "tripe-protocol.h" #include "util.h" #undef sun @@ -126,6 +110,7 @@ #define TUN_NOTDEF 0 #define TUN_UNET 1 #define TUN_BSD 2 +#define TUN_LINUX 3 /* --- Trace flags --- */ @@ -150,111 +135,25 @@ #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 a 64-bit MAC, a 32-bit sequence number, and the - * encrypted payload. - * - * The MAC is computed using the HMAC construction with RIPEMD160 over the - * sequence number and the original packet plaintext; the first 64 bits of - * the output are used. - * - * The plaintext is encrypted using Blowfish in CBC mode with ciphertext - * stealing (as described in [Schneier]. The initialization vector is - * precisely the 64-bit MAC computed previously. - * - * 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 - -#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; -/*----- Data structures ---------------------------------------------------*/ - -/* --- Buffers --- * - * - * Buffers provide a simple stream-like interface for building and parsing - * packets. - */ +#define MAXHASHSZ 64 /* Largest possible hash size */ -typedef struct buf { - octet *base, *p, *limit; /* Pointers to the buffer */ - unsigned f; /* Various flags */ -} buf; +#define HASH_STRING(h, s) GH_HASH((h), (s), sizeof(s)) -#define BF_BROKEN 1u /* Buffer is broken */ +/*----- Data structures ---------------------------------------------------*/ /* --- Socket addresses --- * * @@ -282,11 +181,13 @@ typedef union addr { typedef struct keyset { struct keyset *next; /* Next active keyset in the list */ unsigned ref; /* Reference count for keyset */ + struct peer *p; /* Pointer to peer structure */ time_t t_exp; /* Expiry time for this keyset */ unsigned long sz_exp; /* Data limit for the 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 */ @@ -311,17 +212,17 @@ 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 hrx[HASHSZ]; /* My expected reply hash */ - 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 hc[MAXHASHSZ]; /* Hash of his challenge */ + mp *ck; /* The check value */ + 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 { @@ -330,17 +231,20 @@ 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; #define KXF_TIMER 1u /* Waiting for a timer to go off */ +#define KXF_DEAD 2u /* The key-exchanger isn't up */ +#define KXF_PUBKEY 4u /* Key exchanger has a public key */ enum { KXS_DEAD, /* Uninitialized state (magical) */ @@ -354,10 +258,19 @@ enum { * Used to maintain system-specific information about the tunnel interface. */ +#if TUN_TYPE == TUN_LINUX +# include +# include +#endif + typedef struct tunnel { -#if TUN_TYPE == TUN_UNET +#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 */ @@ -379,7 +292,7 @@ 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 */ @@ -405,26 +318,50 @@ typedef struct peer { /* --- Admin structure --- */ +#define OBUFSZ 16384u + +typedef struct obuf { + struct obuf *next; /* Next buffer in list */ + char *p_in, *p_out; /* Pointers into the buffer */ + char buf[OBUFSZ]; /* The actual buffer */ +} obuf; + typedef struct admin { struct admin *next, *prev; /* Links to next and previous */ - selbuf b; /* Line buffer for commands */ - int fd; /* File descriptor for output */ + 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 */ + 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 */ +#ifndef NTRACE + #define AF_TRACE 8u /* Catch tracing */ +#endif +#define AF_WARN 16u /* Catch warning messages */ + +#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]; #ifndef NTRACE @@ -466,14 +403,16 @@ 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. * * 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 ------------------------------------------------------*/ @@ -562,6 +501,7 @@ extern void ks_drop(keyset */*ks*/); * * Arguments: @const void *k@ = pointer to key material * @size_t x, y, z@ = offsets into key material (see below) + * @peer *p@ = pointer to peer information * * Returns: A pointer to the new keyset. * @@ -581,7 +521,8 @@ extern void ks_drop(keyset */*ks*/); */ extern keyset *ks_gen(const void */*k*/, - size_t /*x*/, size_t /*y*/, size_t /*z*/); + size_t /*x*/, size_t /*y*/, size_t /*z*/, + peer */*p*/); /* --- @ks_tregen@ --- * * @@ -607,6 +548,7 @@ extern void ks_activate(keyset */*ks*/); /* --- @ks_encrypt@ --- * * * Arguments: @keyset *ks@ = pointer to a keyset + * @unsigned ty@ = message type * @buf *b@ = pointer to input buffer * @buf *bb@ = pointer to output buffer * @@ -620,11 +562,13 @@ extern void ks_activate(keyset */*ks*/); * used even if it's marked as not for data output. */ -extern int ks_encrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/); +extern int ks_encrypt(keyset */*ks*/, unsigned /*ty*/, + buf */*b*/, buf */*bb*/); /* --- @ks_decrypt@ --- * * * Arguments: @keyset *ks@ = pointer to a keyset + * @unsigned ty@ = expected type code * @buf *b@ = pointer to an input buffer * @buf *bb@ = pointer to an output buffer * @@ -635,7 +579,8 @@ extern int ks_encrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/); * marking that it's not for encryption. */ -extern int ks_decrypt(keyset */*ks*/, buf */*b*/, buf */*bb*/); +extern int ks_decrypt(keyset */*ks*/, unsigned /*ty*/, + buf */*b*/, buf */*bb*/); /* --- @ksl_free@ --- * * @@ -676,6 +621,7 @@ extern void ksl_prune(keyset **/*ksroot*/); /* --- @ksl_encrypt@ --- * * * Arguments: @keyset **ksroot@ = pointer to keyset list head + * @unsigned ty@ = message type * @buf *b@ = pointer to input buffer * @buf *bb@ = pointer to output buffer * @@ -684,11 +630,13 @@ extern void ksl_prune(keyset **/*ksroot*/); * Use: Encrypts a packet. */ -extern int ksl_encrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/); +extern int ksl_encrypt(keyset **/*ksroot*/, unsigned /*ty*/, + buf */*b*/, buf */*bb*/); /* --- @ksl_decrypt@ --- * * * Arguments: @keyset **ksroot@ = pointer to keyset list head + * @unsigned ty@ = expected type code * @buf *b@ = pointer to input buffer * @buf *bb@ = pointer to output buffer * @@ -697,7 +645,8 @@ extern int ksl_encrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/); * Use: Decrypts a packet. */ -extern int ksl_decrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/); +extern int ksl_decrypt(keyset **/*ksroot*/, unsigned /*ty*/, + buf */*b*/, buf */*bb*/); /*----- Administration interface ------------------------------------------*/ @@ -713,16 +662,29 @@ extern int ksl_decrypt(keyset **/*ksroot*/, buf */*b*/, buf */*bb*/); 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@ --- * * @@ -835,14 +797,15 @@ extern const addr *p_addr(peer */*p*/); /* --- @p_init@ --- * * - * Arguments: @unsigned port@ = port number to listen to + * Arguments: @struct in_addr addr@ = address to bind to + * @unsigned port@ = port number to listen to * * Returns: --- * * Use: Initializes the peer system; creates the socket. */ -extern void p_init(unsigned /*port*/); +extern void p_init(struct in_addr /*addr*/, unsigned /*port*/); /* --- @p_port@ --- * * @@ -969,167 +932,6 @@ extern void tun_inject(tunnel */*t*/, buf */*b*/); extern void tun_destroy(tunnel */*t*/); -/*----- Buffer handling ---------------------------------------------------*/ - -/* --- Useful macros --- */ - -#define BBASE(b) ((b)->base) -#define BLIM(b) ((b)->limit) -#define BCUR(b) ((b)->p) -#define BSZ(b) ((b)->limit - (b)->base) -#define BLEN(b) ((b)->p - (b)->base) -#define BLEFT(b) ((b)->limit - (b)->p) -#define BSTEP(b, sz) ((b)->p += (sz)) -#define BBAD(b) ((b)->f & BF_BROKEN) -#define BOK(b) (!BBAD(b)) - -#define BENSURE(b, sz) \ - (BBAD(b) ? -1 : (sz) > BLEFT(b) ? (b)->f |= BF_BROKEN, -1 : 0) - -/* --- @buf_init@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * @void *p@ = pointer to a buffer - * @size_t sz@ = size of the buffer - * - * Returns: --- - * - * Use: Initializes the buffer block appropriately. - */ - -extern void buf_init(buf */*b*/, void */*p*/, size_t /*sz*/); - -/* --- @buf_break@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * - * Returns: Some negative value. - * - * Use: Marks a buffer as broken. - */ - -extern int buf_break(buf */*b*/); - -/* --- @buf_flip@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * - * Returns: --- - * - * Use: Flips a buffer so that if you've just been writing to it, - * you can now read from the bit you've written. - */ - -extern void buf_flip(buf */*b*/); - -/* --- @buf_ensure@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * @size_t sz@ = size of data wanted - * - * Returns: Zero if it worked, nonzero if there wasn't enough space. - * - * Use: Ensures that there are @sz@ bytes still in the buffer. - */ - -extern int buf_ensure(buf */*b*/, size_t /*sz*/); - -/* --- @buf_get@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * @size_t sz@ = size of the buffer - * - * Returns: Pointer to the place in the buffer. - * - * Use: Reserves a space in the buffer of the requested size, and - * returns its start address. - */ - -extern void *buf_get(buf */*b*/, size_t /*sz*/); - -/* --- @buf_put@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * @const void *p@ = pointer to a buffer - * @size_t sz@ = size of the buffer - * - * Returns: Zero if it worked, nonzero if there wasn't enough space. - * - * Use: Fetches data from some place and puts it in the buffer - */ - -extern int buf_put(buf */*b*/, const void */*p*/, size_t /*sz*/); - -/* --- @buf_getbyte@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * - * Returns: A byte, or less than zero if there wasn't a byte there. - * - * Use: Gets a single byte from a buffer. - */ - -extern int buf_getbyte(buf */*b*/); - -/* --- @buf_putbyte@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * @int ch@ = byte to write - * - * Returns: Zero if OK, nonzero if there wasn't enough space. - * - * Use: Puts a single byte in a buffer. - */ - -extern int buf_putbyte(buf */*b*/, int /*ch*/); - -/* --- @buf_getword@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * @uint32 *w@ = where to put the word - * - * Returns: Zero if OK, or nonzero if there wasn't a word there. - * - * Use: Gets a 32-bit word from a buffer. - */ - -extern int buf_getword(buf */*b*/, uint32 */*w*/); - -/* --- @buf_putword@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * @uint32 w@ = word to write - * - * Returns: Zero if OK, nonzero if there wasn't enough space. - * - * Use: Puts a 32-but word in a buffer. - */ - -extern int buf_putword(buf */*b*/, uint32 /*w*/); - -/* --- @buf_getmp@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * - * Returns: A multiprecision integer, or null if there wasn't one there. - * - * Use: Gets a multiprecision integer from a buffer. - */ - -extern mp *buf_getmp(buf */*b*/); - -/* --- @buf_putmp@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * @mp *m@ = a multiprecision integer - * - * Returns: Zero if it worked, nonzero if there wasn't enough space. - * - * Use: Puts a multiprecision integer to a buffer. - */ - -extern int buf_putmp(buf */*b*/, mp */*m*/); - /*----- Other handy utilities ---------------------------------------------*/ /* --- @mpstr@ --- * @@ -1144,6 +946,19 @@ extern int buf_putmp(buf */*b*/, mp */*m*/); 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