/* -*-c-*-
*
- * $Id: tripe.h,v 1.7 2001/03/03 12:07:08 mdw Exp $
+ * $Id: tripe.h,v 1.8 2001/06/19 22:10:57 mdw Exp $
*
* Main header file for TrIPE
*
/*----- Revision history --------------------------------------------------*
*
* $Log: tripe.h,v $
+ * 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.
*
#include <catacomb/mprand.h>
#include <catacomb/dh.h>
+#include "buf.h"
#include "util.h"
#undef sun
/* --- 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
*
#define HASH_DONE rmd160_done
#define HASHSZ RMD160_HASHSZ
-/*----- Data structures ---------------------------------------------------*/
+#define SEQSZ 4
+#define IVSZ BLOWFISH_BLKSZ
+#define MACSZ 10
-/* --- Buffers --- *
- *
- * Buffers provide a simple stream-like interface for building and parsing
- * packets.
- */
-
-typedef struct buf {
- octet *base, *p, *limit; /* Pointers to the buffer */
- unsigned f; /* Various flags */
-} buf;
-
-#define BF_BROKEN 1u /* Buffer is broken */
+/*----- Data structures ---------------------------------------------------*/
/* --- Socket addresses --- *
*
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@ --- *
~mdw / tripe / blobdiff