X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fprngs%2Frng_make_prng.c;fp=libtomcrypt%2Fsrc%2Fprngs%2Frng_make_prng.c;h=b01c325c60bc0bb4ae69a236dcd5586df18c54ec;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage

diff --git a/libtomcrypt/src/prngs/rng_make_prng.c b/libtomcrypt/src/prngs/rng_make_prng.c
new file mode 100644
index 0000000..b01c325
--- /dev/null
+++ b/libtomcrypt/src/prngs/rng_make_prng.c
@@ -0,0 +1,69 @@
+/* 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.
+ */
+#include "tomcrypt.h"
+
+#ifdef LTC_RNG_MAKE_PRNG
+/**
+  @file rng_make_prng.c
+  portable way to get secure random bits to feed a PRNG  (Tom St Denis)
+*/
+
+/**
+  Create a PRNG from a RNG
+  @param bits     Number of bits of entropy desired (64 ... 1024)
+  @param wprng    Index of which PRNG to setup
+  @param prng     [out] PRNG state to initialize
+  @param callback A pointer to a void function for when the RNG is slow, this can be NULL
+  @return CRYPT_OK if successful
+*/
+int rng_make_prng(int bits, int wprng, prng_state *prng,
+                  void (*callback)(void))
+{
+   unsigned char buf[256];
+   int err;
+
+   LTC_ARGCHK(prng != NULL);
+
+   /* check parameter */
+   if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
+      return err;
+   }
+
+   if (bits < 64 || bits > 1024) {
+      return CRYPT_INVALID_PRNGSIZE;
+   }
+
+   if ((err = prng_descriptor[wprng].start(prng)) != CRYPT_OK) {
+      return err;
+   }
+
+   bits = ((bits/8)+((bits&7)!=0?1:0)) * 2;
+   if (rng_get_bytes(buf, (unsigned long)bits, callback) != (unsigned long)bits) {
+      return CRYPT_ERROR_READPRNG;
+   }
+
+   if ((err = prng_descriptor[wprng].add_entropy(buf, (unsigned long)bits, prng)) != CRYPT_OK) {
+      return err;
+   }
+
+   if ((err = prng_descriptor[wprng].ready(prng)) != CRYPT_OK) {
+      return err;
+   }
+
+   #ifdef LTC_CLEAN_STACK
+      zeromem(buf, sizeof(buf));
+   #endif
+   return CRYPT_OK;
+}
+#endif /* #ifdef LTC_RNG_MAKE_PRNG */
+
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */