2 ------------------------------------------------------------------------------
3 http://burtleburtle.net/bob/rand/isaac.html
4 rand.c: By Bob Jenkins. My random number generator, ISAAC. Public Domain
6 960327: Creation (addition of randinit, really)
7 970719: use context, not global variables, for internal state
8 980324: make a portable version
9 010626: Note this is public domain
10 ------------------------------------------------------------------------------
13 #include <freeradius-devel/ident.h>
16 #include <freeradius-devel/autoconf.h>
17 #include <freeradius-devel/missing.h>
18 #include <freeradius-devel/libradius.h>
20 #define RANDSIZL (8) /* I recommend 8 for crypto, 4 for simulations */
21 #define RANDSIZ (1<<RANDSIZL)
23 #define ind(mm,x) ((mm)[(x>>2)&(RANDSIZ-1)])
24 #define rngstep(mix,a,b,mm,m,m2,r,x) \
27 a = ((a^(mix)) + *(m2++)) & 0xffffffff; \
28 *(m++) = y = (ind(mm,x) + a + b) & 0xffffffff; \
29 *(r++) = b = (ind(mm,y>>RANDSIZL) + x) & 0xffffffff; \
32 void lrad_isaac(lrad_randctx *ctx)
34 register uint32_t a,b,x,y,*m,*mm,*m2,*r,*mend;
35 mm=ctx->randmem; r=ctx->randrsl;
36 a = ctx->randa; b = (ctx->randb + (++ctx->randc)) & 0xffffffff;
37 for (m = mm, mend = m2 = m+(RANDSIZ/2); m<mend; )
39 rngstep( a<<13, a, b, mm, m, m2, r, x);
40 rngstep( a>>6 , a, b, mm, m, m2, r, x);
41 rngstep( a<<2 , a, b, mm, m, m2, r, x);
42 rngstep( a>>16, a, b, mm, m, m2, r, x);
44 for (m2 = mm; m2<mend; )
46 rngstep( a<<13, a, b, mm, m, m2, r, x);
47 rngstep( a>>6 , a, b, mm, m, m2, r, x);
48 rngstep( a<<2 , a, b, mm, m, m2, r, x);
49 rngstep( a>>16, a, b, mm, m, m2, r, x);
51 ctx->randb = b; ctx->randa = a;
55 #define mix(a,b,c,d,e,f,g,h) \
57 a^=b<<11; d+=a; b+=c; \
58 b^=c>>2; e+=b; c+=d; \
59 c^=d<<8; f+=c; d+=e; \
60 d^=e>>16; g+=d; e+=f; \
61 e^=f<<10; h+=e; f+=g; \
62 f^=g>>4; a+=f; g+=h; \
63 g^=h<<8; b+=g; h+=a; \
64 h^=a>>9; c+=h; a+=b; \
67 /* if (flag==1), then use the contents of randrsl[] to initialize mm[]. */
68 void lrad_randinit(lrad_randctx *ctx, int flag)
71 uint32_t a,b,c,d,e,f,g,h;
73 ctx->randa = ctx->randb = ctx->randc = 0;
76 a=b=c=d=e=f=g=h=0x9e3779b9; /* the golden ratio */
78 for (i=0; i<4; ++i) { /* scramble it */
83 /* initialize using the contents of r[] as the seed */
84 for (i=0; i<RANDSIZ; i+=8) {
85 a+=r[i ]; b+=r[i+1]; c+=r[i+2]; d+=r[i+3];
86 e+=r[i+4]; f+=r[i+5]; g+=r[i+6]; h+=r[i+7];
88 m[i ]=a; m[i+1]=b; m[i+2]=c; m[i+3]=d;
89 m[i+4]=e; m[i+5]=f; m[i+6]=g; m[i+7]=h;
91 /* do a second pass to make all of the seed affect all of m */
92 for (i=0; i<RANDSIZ; i+=8) {
93 a+=m[i ]; b+=m[i+1]; c+=m[i+2]; d+=m[i+3];
94 e+=m[i+4]; f+=m[i+5]; g+=m[i+6]; h+=m[i+7];
96 m[i ]=a; m[i+1]=b; m[i+2]=c; m[i+3]=d;
97 m[i+4]=e; m[i+5]=f; m[i+6]=g; m[i+7]=h;
100 for (i=0; i<RANDSIZ; i+=8) {
101 /* fill in mm[] with messy stuff */
102 mix(a,b,c,d,e,f,g,h);
103 m[i ]=a; m[i+1]=b; m[i+2]=c; m[i+3]=d;
104 m[i+4]=e; m[i+5]=f; m[i+6]=g; m[i+7]=h;
108 lrad_isaac(ctx); /* fill in the first set of results */
109 ctx->randcnt=RANDSIZ; /* prepare to use the first set of results */
115 * For testing. Output should be the same as
117 * http://burtleburtle.net/bob/rand/randvect.txt
124 ctx.randa = ctx.randb = ctx.randc = (uint32_t)0;
126 for (i=0; i<256; ++i) ctx.randrsl[i]=(uint32_t)0;
127 lrad_randinit(&ctx, 1);
128 for (i=0; i<2; ++i) {
130 for (j=0; j<256; ++j) {
131 printf("%.8lx",ctx.randrsl[j]);
132 if ((j&7)==7) printf("\n");