/* -*-c-*-
*
- * $Id: bbs.h,v 1.4 2000/06/17 10:45:48 mdw Exp $
+ * $Id$
*
* The Blum-Blum-Shub random bit generator
*
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: bbs.h,v $
- * Revision 1.4 2000/06/17 10:45:48 mdw
- * Minor changes for key fetching. Typesetting fixes.
- *
- * Revision 1.3 2000/02/12 18:21:02 mdw
- * Overhaul of key management (again).
- *
- * Revision 1.2 1999/12/22 15:52:08 mdw
- * Rename `bbs_params' to `bbs_param' for consistency.
- *
- * Revision 1.1 1999/12/10 23:14:59 mdw
- * Blum-Blum-Shub generator, and Blum-Goldwasser encryption.
- *
- */
-
/*----- Notes on the BBS generator ----------------------------------------*
*
* The Blum-Blum-Shub generator takes the least significant bits from the
mp *n;
} bbs_pub;
-typedef struct bbs_param {
+typedef struct bbs_priv {
mp *p, *q; /* Prime factors (3 mod 4) */
mp *n; /* Product @pq@ -- a Blum integer */
-} bbs_param, bbs_priv;
+} bbs_priv;
/*----- Key fetching ------------------------------------------------------*/
extern const key_fetchdef bbs_privfetch[];
#define BBS_PRIVFETCHSZ 7
+/* --- @bbs_pubfree@, @bbs_privfree@ --- *
+ *
+ * Arguments: @bbs_pub *bp@, @bbs_priv *bp@ = pointer to key block
+ *
+ * Returns: ---
+ *
+ * Use: Frees a BBS key block.
+ */
+
+extern void bbs_pubfree(bbs_pub */*bp*/);
+extern void bbs_privfree(bbs_priv */*bp*/);
+
/*----- The basic generator -----------------------------------------------*/
/* --- @bbs_create@ --- *
/*----- Large forwards and backwards jumps --------------------------------*/
-/* --- @bbs_ff@ --- *
- *
- * Arguments: @bbs *b@ = pointer to a BBS generator state
- * @bbs_param *bp@ = pointer to BBS modulus factors
- * @unsigned long n@ = number of steps to make
- *
- * Returns: ---
- *
- * Use: `Fast-forwards' a Blum-Blum-Shub generator by @n@ steps.
- * Requires the factorization of the Blum modulus to do this
- * efficiently.
- */
-
-extern void bbs_ff(bbs */*b*/, bbs_param */*bp*/, unsigned long /*n*/);
-
-/* --- @bbs_rew@ --- *
+/* --- @bbs_{ff,rew}{,n}@ --- *
*
* Arguments: @bbs *b@ = pointer to a BBS generator state
- * @bbs_param *bp@ = pointer to BBS modulus factors
- * @unsigned long n@ = number of steps to make
+ * @const bbs_priv *bp@ = pointer to BBS modulus factors
+ * @mp *n@, @unsigned long n@ = number of steps to make
*
* Returns: ---
*
- * Use: `Rewinds' a Blum-Blum-Shub generator by @n@ steps.
- * Requires the factorization of the Blum modulus to do this
- * at all.
+ * Use: `Fast-forwards' or rewinds a Blum-Blum-Shub generator by @n@
+ * steps. The @...n@ versions take an @unsigned long@ argument;
+ * the non-@...n@ versions a multiprecision integer. If @n@ is
+ * negative then the generator is stepped in the reverse
+ * direction.
*/
-extern void bbs_rew(bbs */*b*/, bbs_param */*bp*/, unsigned long /*n*/);
+extern void bbs_ff(bbs */*b*/, const bbs_priv */*bp*/, mp */*n*/);
+extern void bbs_ffn(bbs */*b*/, const bbs_priv */*bp*/, unsigned long /*n*/);
+extern void bbs_rew(bbs */*b*/, const bbs_priv */*bp*/, mp */*n*/);
+extern void bbs_rewn(bbs */*b*/, const bbs_priv */*bp*/, unsigned long /*n*/);
/*----- Parameter generation ----------------------------------------------*/
/* --- @bbs_gen@ --- *
*
- * Arguments: @bbs_param *bp@ = pointer to parameter block
+ * Arguments: @bbs_priv *bp@ = pointer to parameter block
* @unsigned nbits@ = number of bits in the modulus
* @grand *r@ = pointer to random number source
* @unsigned n@ = number of attempts to make
* Shub pseudorandom bit generator.
*/
-extern int bbs_gen(bbs_param */*bp*/, unsigned /*nbits*/, grand */*r*/,
+extern int bbs_gen(bbs_priv */*bp*/, unsigned /*nbits*/, grand */*r*/,
unsigned /*n*/, pgen_proc */*event*/, void */*ectx*/);
/*----- Generic random number generator interface -------------------------*/
/* --- Blum-Blum-Shub-specific misc op codes --- */
enum {
- BBS_SET = GRAND_SPECIFIC /* @mp *x@ */
+ BBS_SET = GRAND_SPECIFIC('B'), /* @mp *x@ */
+ BBS_STEP, /* @void@ */
+ BBS_STEPSZ, /* @void@ */
+ BBS_BITS, /* @unsigned bits, uint32 *w@ */
+ BBS_WRAP, /* @void@ */
+ BBS_FF, /* @bbs_priv *p, mp *n@ */
+ BBS_FFN, /* @bbs_priv *p, unsigned long n@ */
+ BBS_REW, /* @bbs_priv *p, mp *n@ */
+ BBS_REWN, /* @bbs_priv *p, unsigned long n@ */
+ BBS_MOD, /* @mp **n@ */
+ BBS_STATE /* @mp **x@ */
};
/*----- That's all, folks -------------------------------------------------*/