/* -*-c-*-
*
- * $Id: tripe.h,v 1.6 2001/02/19 19:11:09 mdw Exp $
+ * $Id: tripe.h,v 1.17 2003/10/15 09:30:18 mdw Exp $
*
* Main header file for TrIPE
*
/*----- Revision history --------------------------------------------------*
*
* $Log: tripe.h,v $
+ * Revision 1.17 2003/10/15 09:30:18 mdw
+ * Add support for Ethereal protocol analysis.
+ *
+ * Revision 1.16 2003/07/13 11:19:49 mdw
+ * Incompatible 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.
*
#include <mLib/sub.h>
#include <mLib/trace.h>
+#include <catacomb/buf.h>
+
#include <catacomb/gcipher.h>
#include <catacomb/gmac.h>
#include <catacomb/grand.h>
#include <catacomb/mprand.h>
#include <catacomb/dh.h>
+#include "tripe-protocol.h"
#include "util.h"
#undef sun
#define TUN_NOTDEF 0
#define TUN_UNET 1
#define TUN_BSD 2
+#define TUN_LINUX 3
/* --- Trace flags --- */
#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 <catacomb/blowfish.h>
#include <catacomb/blowfish-cbc.h>
+#include <catacomb/blowfish-counter.h>
#include <catacomb/rmd160.h>
#include <catacomb/rmd160-hmac.h>
#define HASH_DONE rmd160_done
#define HASHSZ RMD160_HASHSZ
-/*----- Data structures ---------------------------------------------------*/
-
-/* --- Buffers --- *
- *
- * Buffers provide a simple stream-like interface for building and parsing
- * packets.
- */
+#define MGF_CTX blowfish_counterctx
+#define MGF_INIT blowfish_counterinit
+#define MGF_CRYPT blowfish_counterencrypt
-typedef struct buf {
- octet *base, *p, *limit; /* Pointers to the buffer */
- unsigned f; /* Various flags */
-} buf;
+#define SEQSZ 4
+#define IVSZ BLOWFISH_BLKSZ
+#define MACSZ 10
-#define BF_BROKEN 1u /* Buffer is broken */
+/*----- Data structures ---------------------------------------------------*/
/* --- Socket addresses --- *
*
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 */
sel_timer t; /* Response timer for challenge */
octet hc[HASHSZ]; /* Hash of his challenge */
- octet hrx[HASHSZ]; /* My expected reply hash */
+ 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 */
unsigned s; /* Current state in exchange */
sel_timer t; /* Timer for next exchange */
dh_pub 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 */
} 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) */
* Used to maintain system-specific information about the tunnel interface.
*/
+#if TUN_TYPE == TUN_LINUX
+# include <linux/if.h>
+# include <linux/if_tun.h>
+#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 */
*
* Arguments: @const char *tag@ = public key tag to load
* @dh_pub *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*/, dh_pub */*kpub*/,
+ time_t */*t_exp*/);
/*----- Key exchange ------------------------------------------------------*/
*
* 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.
*
*/
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@ --- *
*
/* --- @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
*
* 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
*
* 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@ --- *
*
/* --- @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
*
* 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
*
* 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 ------------------------------------------*/
/* --- @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@ --- *
*
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@ --- *
~mdw / tripe / blobdiff