/* -*-c-*-
*
- * $Id: dh.h,v 1.3 2000/02/12 18:21:02 mdw Exp $
+ * $Id: dh.h,v 1.6 2000/07/29 10:01:16 mdw Exp $
*
* Diffie-Hellman and related public-key systems
*
/*----- Revision history --------------------------------------------------*
*
* $Log: dh.h,v $
+ * Revision 1.6 2000/07/29 10:01:16 mdw
+ * Supply commentry for the Diffie-Hellman parameters. Add Lim-Lee
+ * parameter generation.
+ *
+ * Revision 1.5 2000/07/01 11:20:51 mdw
+ * New functions for freeing public and private keys.
+ *
+ * Revision 1.4 2000/06/17 10:52:47 mdw
+ * Minor changes for key fetching.
+ *
* Revision 1.3 2000/02/12 18:21:02 mdw
* Overhaul of key management (again).
*
# include "grand.h"
#endif
+#ifndef CATACOMB_KEY_H
+# include "key.h"
+#endif
+
#ifndef CATACOMB_PGEN_H
# include "pgen.h"
#endif
/*----- Data structures ---------------------------------------------------*/
-typedef struct dh_param {
- mp *p, *q;
+typedef struct dh_param { /* Prime numbers %$p$% and %$q$% */
+ mp *p, *q; /* Generates order-%$q$% subgroup */
mp *g;
} dh_param;
+typedef struct dh_pub { /* Shared parameters */
+ dh_param dp; /* Public key */
+ mp *y;
+} dh_pub;
+
+typedef struct dh_priv { /* Shared parameters */
+ dh_param dp; /* Private key */
+ mp *x; /* %$y \equiv g^x \pmod{p}$% */
+ mp *y;
+} dh_priv;
+
+/*----- Key fetching ------------------------------------------------------*/
+
+extern const key_fetchdef dh_paramfetch[];
+#define DH_PARAMFETCHSZ 5
+
+extern const key_fetchdef dh_pubfetch[];
+#define DH_PUBFETCHSZ 6
+
+extern const key_fetchdef dh_privfetch[];
+#define DH_PRIVFETCHSZ 9
+
+/* --- @dh_paramfree@, @dh_pubfree@, @dh_privfree@ --- *
+ *
+ * Arguments: @dh_param *dp@, @dh_pub *dp@, @dh_priv *dp@ = pointer to
+ * key block to free
+ *
+ * Returns: ---
+ *
+ * Use: Frees a Diffie-Hellman key block.
+ */
+
+extern void dh_paramfree(dh_param */*dp*/);
+extern void dh_pubfree(dh_pub */*dp*/);
+extern void dh_privfree(dh_priv */*dp*/);
+
/*----- Functions provided ------------------------------------------------*/
/* --- @dh_gen@ --- *
unsigned /*steps*/, grand */*r*/, pgen_proc */*event*/,
void */*ectx*/);
+/* --- @dh_limlee@ --- *
+ *
+ * Arguments: @dh_param *dp@ = pointer to output parameter block
+ * @unsigned ql@ = length of smallest factor of %$(p - 1)/2$%
+ * @unsigned pl@ = length of %$p$% in bits
+ * @unsigned flags@ = other generation flags
+ * @unsigned steps@ = number of steps to go
+ * @grand *r@ = random number source
+ * @pgen_proc *oev@ = outer event handler function
+ * @void *oec@ = argument for the outer event handler
+ * @pgen_proc *iev@ = inner event handler function
+ * @void *iec@ = argument for the inner event handler
+ * @size_t *nf@, @mp ***f@ = output array for factors
+ *
+ * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it didn't.
+ *
+ * Use: Generates Diffie-Hellman parameters based on a Lim-Lee prime.
+ *
+ * The modulus is a large prime %$p = 2 \prod q_i + 1$%, @pl@
+ * bits long, where the %$q_i$% are smaller primes each at least
+ * @ql@ bits long. It is safe to set @nf@ and @f@ to zero if
+ * you're not interested in the factor values.
+ *
+ * The returned %$g$% generates a subgroup of order %$q_0$% (the
+ * first factor, returned as @f[0]@), if the flag @DH_SUBGROUP@
+ * is set on entry; otherwise %$g$% will have order
+ * %$(p - 1)/2$%.
+ */
+
+#define DH_SUBGROUP 1u
+
+extern int dh_limlee(dh_param */*dp*/, unsigned /*ql*/, unsigned /*pl*/,
+ unsigned /*flags*/, unsigned /*steps*/, grand */*r*/,
+ pgen_proc */*oev*/, void */*oec*/, pgen_proc */*iev*/,
+ void */*iec*/, size_t */*nf*/, mp ***/*f*/);
+
/*----- That's all, folks -------------------------------------------------*/
#ifdef __cplusplus