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-rw-r--r--src/lib/isaac.c133
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diff --git a/src/lib/isaac.c b/src/lib/isaac.c
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+/*
+------------------------------------------------------------------------------
+http://burtleburtle.net/bob/rand/isaac.html
+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: make a portable version
+ 010626: Note this is public domain
+------------------------------------------------------------------------------
+*/
+
+RCSID("$Id$")
+
+#include <freeradius-devel/libradius.h>
+
+#define RANDSIZL (8) /* I recommend 8 for crypto, 4 for simulations */
+#define RANDSIZ (1<<RANDSIZL)
+
+#define ind(mm,x) ((mm)[(x>>2)&(RANDSIZ-1)])
+#define rngstep(mix,a,b,mm,m,m2,r,x) \
+{ \
+ x = *m; \
+ a = ((a^(mix)) + *(m2++)) & 0xffffffff; \
+ *(m++) = y = (ind(mm,x) + a + b) & 0xffffffff; \
+ *(r++) = b = (ind(mm,y>>RANDSIZL) + x) & 0xffffffff; \
+}
+
+void fr_isaac(fr_randctx *ctx)
+{
+ register uint32_t a,b,x,y,*m,*mm,*m2,*r,*mend;
+ mm=ctx->randmem; r=ctx->randrsl;
+ a = ctx->randa; b = (ctx->randb + (++ctx->randc)) & 0xffffffff;
+ 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==1), then use the contents of randrsl[] to initialize mm[]. */
+void fr_randinit(fr_randctx *ctx, int flag)
+{
+ int i;
+ uint32_t a,b,c,d,e,f,g,h;
+ uint32_t *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 {
+ for (i=0; i<RANDSIZ; i+=8) {
+ /* fill in mm[] with messy stuff */
+ 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;
+ }
+ }
+
+ fr_isaac(ctx); /* fill in the first set of results */
+ ctx->randcnt=RANDSIZ; /* prepare to use the first set of results */
+}
+
+
+#ifdef TEST
+/*
+ * For testing. Output should be the same as
+ *
+ * http://burtleburtle.net/bob/rand/randvect.txt
+ */
+int main()
+{
+ uint32_t i,j;
+ fr_randctx ctx;
+
+ ctx.randa = ctx.randb = ctx.randc = (uint32_t)0;
+
+ for (i=0; i<256; ++i) ctx.randrsl[i]=(uint32_t)0;
+ fr_randinit(&ctx, 1);
+ for (i=0; i<2; ++i) {
+ fr_isaac(&ctx);
+ for (j=0; j<256; ++j) {
+ printf("%.8lx",ctx.randrsl[j]);
+ if ((j&7)==7) printf("\n");
+ }
+ }
+}
+#endif