X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/52307feec17cefc54d626f7737f650675eefab96..7ed14135434df136e971a43b1774b827714ef7f9:/tripe.h diff --git a/tripe.h b/tripe.h index f3816b40..8d70c1f6 100644 --- a/tripe.h +++ b/tripe.h @@ -1,6 +1,6 @@ /* -*-c-*- * - * $Id: tripe.h,v 1.7 2001/03/03 12:07:08 mdw Exp $ + * $Id: tripe.h,v 1.16 2003/07/13 11:19:49 mdw Exp $ * * Main header file for TrIPE * @@ -29,6 +29,36 @@ /*----- 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. * @@ -121,6 +151,7 @@ #include #include +#include "buf.h" #include "util.h" #undef sun @@ -132,6 +163,7 @@ #define TUN_NOTDEF 0 #define TUN_UNET 1 #define TUN_BSD 2 +#define TUN_LINUX 3 /* --- Trace flags --- */ @@ -197,16 +229,17 @@ /* --- Symmetric encryption and keysets --- * * - * Packets consist of a 64-bit MAC, a 32-bit sequence number, and the + * Packets consist of an 80-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. + * 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 * @@ -234,6 +267,7 @@ #include #include +#include #include #include @@ -247,20 +281,15 @@ #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 --- * * @@ -288,6 +317,7 @@ 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 */ @@ -323,7 +353,7 @@ typedef struct kxchal { 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 */ @@ -337,6 +367,7 @@ typedef struct keyexch { 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 */ @@ -347,6 +378,8 @@ typedef struct keyexch { } 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) */ @@ -360,10 +393,19 @@ 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 */ @@ -486,13 +528,15 @@ extern void km_init(const char */*kr_priv*/, const char */*kr_pub*/, * * 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 ------------------------------------------------------*/ @@ -581,6 +625,7 @@ 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. * @@ -600,7 +645,8 @@ 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@ --- * * @@ -626,6 +672,7 @@ 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 * @@ -639,11 +686,13 @@ 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 * @@ -654,7 +703,8 @@ 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@ --- * * @@ -695,6 +745,7 @@ 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 * @@ -703,11 +754,13 @@ 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 * @@ -716,7 +769,8 @@ 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 ------------------------------------------*/ @@ -854,14 +908,15 @@ 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@ --- * * @@ -988,191 +1043,6 @@ 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_getu16@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * @uint16 *w@ = where to put the word - * - * Returns: Zero if OK, or nonzero if there wasn't a word there. - * - * Use: Gets a 16-bit word from a buffer. - */ - -extern int buf_getu16(buf */*b*/, uint16 */*w*/); - -/* --- @buf_putu16@ --- * - * - * Arguments: @buf *b@ = pointer to a buffer block - * @uint16 w@ = word to write - * - * Returns: Zero if OK, nonzero if there wasn't enough space. - * - * Use: Puts a 16-but word in a buffer. - */ - -extern int buf_putu16(buf */*b*/, uint16 /*w*/); - -/* --- @buf_getu32@ --- * - * - * 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_getu32(buf */*b*/, uint32 */*w*/); - -/* --- @buf_putu32@ --- * - * - * 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_putu32(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@ --- *