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#include "os.h"
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#include <mp.h>
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#include <libsec.h>
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typedef struct State{
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	QLock		lock;
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	int		seeded;
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	uvlong		seed;
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	DES3state	des3;
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} State;
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static State x917state;
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static void
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X917(uchar *rand, int nrand)
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{
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	int i, m, n8;
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	uvlong I, x;
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	/* 1. Compute intermediate value I = Ek(time). */
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	I = nsec();
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	triple_block_cipher(x917state.des3.expanded, (uchar*)&I, 0); /* two-key EDE */
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	/* 2. x[i] = Ek(I^seed);  seed = Ek(x[i]^I); */
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	m = (nrand+7)/8;
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	for(i=0; i<m; i++){
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		x = I ^ x917state.seed;
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		triple_block_cipher(x917state.des3.expanded, (uchar*)&x, 0);
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		n8 = (nrand>8) ? 8 : nrand;
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		memcpy(rand, (uchar*)&x, n8);
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		rand += 8;
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		nrand -= 8;
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		x ^= I;
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		triple_block_cipher(x917state.des3.expanded, (uchar*)&x, 0);
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		x917state.seed = x;
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	}
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}
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static void
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X917init(void)
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{
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	int n;
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	uchar mix[128];
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	uchar key3[3][8];
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	ulong *ulp;
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	ulp = (ulong*)key3;
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	for(n = 0; n < sizeof(key3)/sizeof(ulong); n++)
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		ulp[n] = truerand();
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	setupDES3state(&x917state.des3, key3, nil);
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	X917(mix, sizeof mix);
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	x917state.seeded = 1;
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}
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void
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genrandom(uchar *p, int n)
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{
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	qlock(&x917state.lock);
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	if(x917state.seeded == 0)
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		X917init();
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	X917(p, n);
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	qunlock(&x917state.lock);
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}