As the size of random value delivered by twister_genrand_int32 is not derived from the size of the 
unsigned long on given platform, but it is always only 0x00000000 - 0xFFFFFFFF we need as special 
function to print it to a byte stream buffer byte by byte.
Issue reported upstream in : https://github.com/martijnvanbrummelen/nwipe/issues/7

diff -ru nwipe-8a9a71822148cb9c82d971030dafd8d374fd1f48/src/prng.c nwipe-8a9a71822148cb9c82d971030dafd8d374fd1f48.new/src/prng.c
--- nwipe-8a9a71822148cb9c82d971030dafd8d374fd1f48/src/prng.c	2014-10-19 21:49:22.000000000 +0200
+++ nwipe-8a9a71822148cb9c82d971030dafd8d374fd1f48.new/src/prng.c	2015-06-22 23:54:38.111837575 +0200
@@ -25,6 +25,7 @@
 #include "mt19937ar-cok.h"
 #include "isaac_rand.h"
 
+
 nwipe_prng_t nwipe_twister =
 {
 	"Mersenne Twister (mt19937ar-cok)",
@@ -40,6 +41,25 @@
 };
 
 
+/* Print given number of bytes from unsigned integer number to a byte stream buffer starting with low-endian*/
+int nwipe_u32tobuffer(u8 *buffer, u32 rand, int len)
+{
+	int i;
+	u8 c;	//single char
+	if (len > sizeof(u32))
+	{
+		nwipe_log( NWIPE_LOG_FATAL, "Tried to print longer number than the value passed." );
+		len = sizeof(u32);
+	}
+
+	for (i=0 ; i < len; i++)
+	{
+		c=rand & 0xFFUL;
+		rand = rand >> 8;
+		buffer[i]=c;
+	}
+	return 0;
+}
 
 int nwipe_twister_init( NWIPE_PRNG_INIT_SIGNATURE )
 {
@@ -54,23 +74,23 @@
 
 int nwipe_twister_read( NWIPE_PRNG_READ_SIGNATURE )
 {
+	u32 i=0;
 	u32 ii;
-	u32 words = count / sizeof( u32 );
-	u32 remain = count % sizeof( u32 );
+	u32 words = count / SIZE_OF_TWISTER ;  // the values of twister_genrand_int32 is strictly 4 bytes
+	u32 remain = count % SIZE_OF_TWISTER ; // the values of twister_genrand_int32 is strictly 4 bytes
 
-	/* Twister returns 4-bytes per call, so cast the buffer into words. */
+	/* Twister returns 4-bytes per call, so progress by 4 bytes. */
 	for( ii = 0; ii < words; ++ii )
 	{
-		((u32*)buffer)[ii] = twister_genrand_int32( (twister_state_t*)*state );
+		nwipe_u32tobuffer((u8*)(buffer+i), twister_genrand_int32( (twister_state_t*)*state ), SIZE_OF_TWISTER) ;
+		i = i + SIZE_OF_TWISTER;
 	}
 
-	/* Fill the buffer tail if the count is not evenly divided by the size of u32. */
-	for( ii = 1; ii <= remain; ++ii )
+	/* If there is some remainder copy only relevant number of bytes to not overflow the buffer. */
+	if ( remain > 0 )
 	{
-		/* Notice how three bytes are discarded by doing this. */
-		((u8*)buffer)[count-ii] = twister_genrand_int32( (twister_state_t*)*state );
+		nwipe_u32tobuffer((u8*)(buffer+i), twister_genrand_int32( (twister_state_t*)*state ), remain) ;
 	}
-	 
 	return 0;
 }
 
diff -ru nwipe-8a9a71822148cb9c82d971030dafd8d374fd1f48/src/prng.h nwipe-8a9a71822148cb9c82d971030dafd8d374fd1f48.new/src/prng.h
--- nwipe-8a9a71822148cb9c82d971030dafd8d374fd1f48/src/prng.h	2014-10-19 21:49:22.000000000 +0200
+++ nwipe-8a9a71822148cb9c82d971030dafd8d374fd1f48.new/src/prng.h	2015-06-22 23:43:46.578397378 +0200
@@ -51,6 +51,10 @@
 int nwipe_isaac_init( NWIPE_PRNG_INIT_SIGNATURE );
 int nwipe_isaac_read( NWIPE_PRNG_READ_SIGNATURE );
 
+/* Size of the twister is not derived from the architecture, but it is strictly 4 bytes */
+#define SIZE_OF_TWISTER 4
+
+
 #endif /* PRNG_H_ */
 
 /* eof */