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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 16:00:33 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 16:00:33 +0000
commit96fcf3ea3a51071dfeca141b7c9b0e5e3e5365a8 (patch)
tree51d766882e3eacda67f6a3b0df8ae3df7d157e20 /src/isaac_rand/isaac_rand.c
parentInitial commit. (diff)
downloadnwipe-upstream.tar.xz
nwipe-upstream.zip
Adding upstream version 0.34.upstream/0.34upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/isaac_rand/isaac_rand.c')
-rw-r--r--src/isaac_rand/isaac_rand.c169
1 files changed, 169 insertions, 0 deletions
diff --git a/src/isaac_rand/isaac_rand.c b/src/isaac_rand/isaac_rand.c
new file mode 100644
index 0000000..c9220e0
--- /dev/null
+++ b/src/isaac_rand/isaac_rand.c
@@ -0,0 +1,169 @@
+/*
+------------------------------------------------------------------------------
+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 "isaac_standard.h"
+#endif
+#ifndef RAND
+#include "isaac_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