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authorDees_Troy <dees_troy@teamw.in>2013-05-04 14:39:56 +0200
committerDees_Troy <dees_troy@yahoo.com>2013-06-22 23:16:55 +0200
commit83bd483f3db1df4b69c1612030e1a1be05b303ad (patch)
treed5c7b468b831244bfcd90aadda98b9d359d0d280 /openaes/src/isaac/rand.c
parentFix building of updater binary (diff)
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Diffstat (limited to 'openaes/src/isaac/rand.c')
-rw-r--r--openaes/src/isaac/rand.c137
1 files changed, 137 insertions, 0 deletions
diff --git a/openaes/src/isaac/rand.c b/openaes/src/isaac/rand.c
new file mode 100644
index 000000000..63babc721
--- /dev/null
+++ b/openaes/src/isaac/rand.c
@@ -0,0 +1,137 @@
+/*
+------------------------------------------------------------------------------
+rand.c: By Bob Jenkins. My random number generator, ISAAC. Public Domain.
+MODIFIED:
+ 960327: Creation (addition of randinit, really)
+ 970719: use context, not global variables, for internal state
+ 980324: added main (ifdef'ed out), also rearranged randinit()
+ 010626: Note that this is public domain
+------------------------------------------------------------------------------
+*/
+#ifndef STANDARD
+#include "standard.h"
+#endif
+#ifndef RAND
+#include "rand.h"
+#endif
+
+
+#define ind(mm,x) (*(ub4 *)((ub1 *)(mm) + ((x) & ((RANDSIZ-1)<<2))))
+#define rngstep(mix,a,b,mm,m,m2,r,x) \
+{ \
+ x = *m; \
+ a = (a^(mix)) + *(m2++); \
+ *(m++) = y = ind(mm,x) + a + b; \
+ *(r++) = b = ind(mm,y>>RANDSIZL) + x; \
+}
+
+void isaac(ctx)
+randctx *ctx;
+{
+ register ub4 a,b,x,y,*m,*mm,*m2,*r,*mend;
+ mm=ctx->randmem; r=ctx->randrsl;
+ a = ctx->randa; b = ctx->randb + (++ctx->randc);
+ for (m = mm, mend = m2 = m+(RANDSIZ/2); m<mend; )
+ {
+ rngstep( a<<13, a, b, mm, m, m2, r, x);
+ rngstep( a>>6 , a, b, mm, m, m2, r, x);
+ rngstep( a<<2 , a, b, mm, m, m2, r, x);
+ rngstep( a>>16, a, b, mm, m, m2, r, x);
+ }
+ for (m2 = mm; m2<mend; )
+ {
+ rngstep( a<<13, a, b, mm, m, m2, r, x);
+ rngstep( a>>6 , a, b, mm, m, m2, r, x);
+ rngstep( a<<2 , a, b, mm, m, m2, r, x);
+ rngstep( a>>16, a, b, mm, m, m2, r, x);
+ }
+ ctx->randb = b; ctx->randa = a;
+}
+
+
+#define mix(a,b,c,d,e,f,g,h) \
+{ \
+ a^=b<<11; d+=a; b+=c; \
+ b^=c>>2; e+=b; c+=d; \
+ c^=d<<8; f+=c; d+=e; \
+ d^=e>>16; g+=d; e+=f; \
+ e^=f<<10; h+=e; f+=g; \
+ f^=g>>4; a+=f; g+=h; \
+ g^=h<<8; b+=g; h+=a; \
+ h^=a>>9; c+=h; a+=b; \
+}
+
+/* if (flag==TRUE), then use the contents of randrsl[] to initialize mm[]. */
+void randinit(ctx, flag)
+randctx *ctx;
+word flag;
+{
+ word i;
+ ub4 a,b,c,d,e,f,g,h;
+ ub4 *m,*r;
+ ctx->randa = ctx->randb = ctx->randc = 0;
+ m=ctx->randmem;
+ r=ctx->randrsl;
+ a=b=c=d=e=f=g=h=0x9e3779b9; /* the golden ratio */
+
+ for (i=0; i<4; ++i) /* scramble it */
+ {
+ mix(a,b,c,d,e,f,g,h);
+ }
+
+ if (flag)
+ {
+ /* initialize using the contents of r[] as the seed */
+ for (i=0; i<RANDSIZ; i+=8)
+ {
+ a+=r[i ]; b+=r[i+1]; c+=r[i+2]; d+=r[i+3];
+ e+=r[i+4]; f+=r[i+5]; g+=r[i+6]; h+=r[i+7];
+ mix(a,b,c,d,e,f,g,h);
+ m[i ]=a; m[i+1]=b; m[i+2]=c; m[i+3]=d;
+ m[i+4]=e; m[i+5]=f; m[i+6]=g; m[i+7]=h;
+ }
+ /* do a second pass to make all of the seed affect all of m */
+ for (i=0; i<RANDSIZ; i+=8)
+ {
+ a+=m[i ]; b+=m[i+1]; c+=m[i+2]; d+=m[i+3];
+ e+=m[i+4]; f+=m[i+5]; g+=m[i+6]; h+=m[i+7];
+ mix(a,b,c,d,e,f,g,h);
+ m[i ]=a; m[i+1]=b; m[i+2]=c; m[i+3]=d;
+ m[i+4]=e; m[i+5]=f; m[i+6]=g; m[i+7]=h;
+ }
+ }
+ else
+ {
+ /* fill in m[] with messy stuff */
+ for (i=0; i<RANDSIZ; i+=8)
+ {
+ mix(a,b,c,d,e,f,g,h);
+ m[i ]=a; m[i+1]=b; m[i+2]=c; m[i+3]=d;
+ m[i+4]=e; m[i+5]=f; m[i+6]=g; m[i+7]=h;
+ }
+ }
+
+ isaac(ctx); /* fill in the first set of results */
+ ctx->randcnt=RANDSIZ; /* prepare to use the first set of results */
+}
+
+
+#ifdef NEVER
+int main()
+{
+ ub4 i,j;
+ randctx ctx;
+ ctx.randa=ctx.randb=ctx.randc=(ub4)0;
+ for (i=0; i<256; ++i) ctx.randrsl[i]=(ub4)0;
+ randinit(&ctx, TRUE);
+ for (i=0; i<2; ++i)
+ {
+ isaac(&ctx);
+ for (j=0; j<256; ++j)
+ {
+ printf("%.8lx",ctx.randrsl[j]);
+ if ((j&7)==7) printf("\n");
+ }
+ }
+}
+#endif