/* -*-c-*-
*
- * $Id: dh.h,v 1.1 1999/11/20 22:24:44 mdw Exp $
+ * $Id: dh.h,v 1.7 2001/02/03 16:08:24 mdw Exp $
+ *
+ * Diffie-Hellman and related public-key systems
*
- * [Diffie-Hellman key negotiation *
* (c) 1999 Straylight/Edgeware
*/
/*----- Revision history --------------------------------------------------*
*
* $Log: dh.h,v $
- * Revision 1.1 1999/11/20 22:24:44 mdw
- * Add Diffie-Hellman support.
+ * Revision 1.7 2001/02/03 16:08:24 mdw
+ * Add consistency checking for public keys.
+ *
+ * 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).
*
*/
-#ifndef DH_H
-#define DH_H
+#ifndef CATACOMB_DH_H
+#define CATACOMB_DH_H
#ifdef __cplusplus
extern "C" {
/*----- Header files ------------------------------------------------------*/
-#ifndef MP_H
-# include "mp.h"
+#ifndef CATACOMB_GRAND_H
+# include "grand.h"
#endif
-/*----- Event codes -------------------------------------------------------*/
+#ifndef CATACOMB_KEY_H
+# include "key.h"
+#endif
+
+#ifndef CATACOMB_KEYCHECK_H
+# include "keycheck.h"
+#endif
+
+#ifndef CATACOMB_PGEN_H
+# include "pgen.h"
+#endif
-enum {
- DHEV_OK,
+/*----- Data structures ---------------------------------------------------*/
- DHEV_FAIL,
- DHEV_PASS
-};
+typedef struct dh_param {
+ mp *p, *q; /* Prime numbers %$p$% and %$q$% */
+ mp *g; /* Generates order-%$q$% subgroup */
+} dh_param;
+
+typedef struct dh_pub {
+ dh_param dp; /* Shared parameters */
+ mp *y; /* Public key */
+} dh_pub;
+
+typedef struct dh_priv {
+ dh_param dp; /* Shared parameters */
+ mp *x; /* Private key */
+ mp *y; /* %$y \equiv g^x \pmod{p}$% */
+} 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_prime@ --- *
+/* --- @dh_gen@ --- *
+ *
+ * Arguments: @dh_param *dp@ = pointer to output parameter block
+ * @unsigned ql@ = length of %$q$% in bits, or zero
+ * @unsigned pl@ = length of %$p$% in bits
+ * @unsigned steps@ = number of steps to go
+ * @grand *r@ = random number source
+ * @pgen_proc *event@ = event handler function
+ * @void *ectx@ = argument for the event handler
+ *
+ * Returns: @PGEN_DONE@ if it worked, @PGEN_ABORT@ if it didn't.
+ *
+ * Use: Generates Diffie-Hellman parameters.
+ *
+ * The parameters are a prime %$q$%, relatively small, and a
+ * large prime %$p = kq + 1$% for some %$k$%, together with a
+ * generator %$g$% of the cyclic subgroup of order %$q$%. These
+ * are actually the same as the DSA parameter set, but the
+ * generation algorithm is different. Also, if @ql@ is zero,
+ * this algorithm forces %$k = 2$%, and chooses %$g = 4$%. Make
+ * sure you have something interesting to do if you choose this
+ * option.
+ */
+
+extern int dh_gen(dh_param */*dp*/, unsigned /*ql*/, unsigned /*pl*/,
+ 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.
*
- * Arguments: @mp *s@ = start point for search (must be odd)
- * @size_t n@ = number of concerted attempts to make, or zero
- * @void (*proc)(int ev, void *p)@ = event handler
- * @void *p@ = argument for event handler
+ * 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*/);
+
+/* --- @dh_checkparam@ --- *
*
- * Returns: A prime number %$p$% where %$p = 2q + 1$% for prime %$q$%.
+ * Arguments: @keycheck *kc@ = keycheck state
+ * @const dh_param *dp@ = pointer to the parameter set
+ * @mp **v@ = optional vector of factors
+ * @size_t n@ = size of vector
*
- * Use: Finds a safe prime by sequential search from a given starting
- * point. If it fails, a null pointer is returned.
+ * Returns: Zero if all OK, or return status from function.
*
- * The event handler is informed of the progress of the search.
- * It may abort the search at any time by returning a nonzero
- * value.
+ * Use: Checks a set of Diffie-Hellman parameters for consistency and
+ * security.
*/
-extern mp *dh_prime(mp */*s*/, size_t /*n*/,
- int (*proc)(int /*ev*/, void */*p*/), void */*p*/);
+extern int dh_checkparam(keycheck */*kc*/, const dh_param */*dp*/,
+ mp **/*v*/, size_t /*n*/);
/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff