diff src/misc/mpi/rand_prime.c @ 191:1c15b283127b libtomcrypt-orig

Import of libtomcrypt 1.02 with manual path rename rearrangement etc
author Matt Johnston <matt@ucc.asn.au>
date Fri, 06 May 2005 13:23:02 +0000
parents
children 39d5d58461d6
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/misc/mpi/rand_prime.c	Fri May 06 13:23:02 2005 +0000
@@ -0,0 +1,66 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, [email protected], http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/**
+  @file rand_prime.c
+  Generate a random prime, Tom St Denis
+*/  
+#ifdef MPI
+
+struct rng_data {
+   prng_state *prng;
+   int         wprng;
+};
+
+static int rand_prime_helper(unsigned char *dst, int len, void *dat)
+{
+   return (int)prng_descriptor[((struct rng_data *)dat)->wprng].read(dst, len, ((struct rng_data *)dat)->prng);
+}
+
+int rand_prime(mp_int *N, long len, prng_state *prng, int wprng)
+{
+   struct rng_data rng;
+   int             type, err;
+
+   LTC_ARGCHK(N != NULL);
+
+   /* allow sizes between 2 and 256 bytes for a prime size */
+   if (len < 16 || len > 4096) { 
+      return CRYPT_INVALID_PRIME_SIZE;
+   }
+   
+   /* valid PRNG? Better be! */
+   if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
+      return err; 
+   }
+
+   /* setup our callback data, then world domination! */
+   rng.prng  = prng;
+   rng.wprng = wprng;
+
+   /* get type */
+   if (len < 0) {
+      type = LTM_PRIME_BBS;
+      len = -len;
+   } else {
+      type = 0;
+   }
+  type |= LTM_PRIME_2MSB_ON;
+
+   /* New prime generation makes the code even more cryptoish-insane.  Do you know what this means!!!
+      -- Gir:  Yeah, oh wait, er, no.
+    */
+   return mpi_to_ltc_error(mp_prime_random_ex(N, mp_prime_rabin_miller_trials(len), len, type, rand_prime_helper, &rng));
+}
+      
+#endif
+