crypt.c

vxworks的tcpip协议栈源码

	register char *encp;
	register int i;
	register int t;
	int salt;
	int num_iter, salt_size;
	C_block keyblock, rsltblock;

	for (i = 0; i < 8; i++) {
		if ((t = 2*(unsigned char)(*key)) != 0)
			key++;
		keyblock.b[i] = t;
	}
	if (des_setkey((char *)keyblock.b))	/* also initializes "a64toi" */
		return (NULL);

	encp = &cryptresult[0];
	switch (*setting) {
	default:
		num_iter = 25;
		salt_size = 2;
	}

	salt = 0;
	for (i = salt_size; --i >= 0; ) {
		if ((t = (unsigned char)setting[i]) == '\0')
			t = '.';
		encp[i] = t;
		salt = (salt<<6) | a64toi[t];
	}
	encp += salt_size;
	if (des_cipher((char *)&constdatablock, (char *)&rsltblock,
	    salt, num_iter))
		return (NULL);

	/*
	 * Encode the 64 cipher bits as 11 ascii characters.
	 */
	i = ((int)((rsltblock.b[0]<<8) | rsltblock.b[1])<<8) |
	    rsltblock.b[2];
	encp[3] = itoa64[i&0x3f];	i >>= 6;
	encp[2] = itoa64[i&0x3f];	i >>= 6;
	encp[1] = itoa64[i&0x3f];	i >>= 6;
	encp[0] = itoa64[i];		encp += 4;
	i = ((int)((rsltblock.b[3]<<8) | rsltblock.b[4])<<8) |
	    rsltblock.b[5];
	encp[3] = itoa64[i&0x3f];	i >>= 6;
	encp[2] = itoa64[i&0x3f];	i >>= 6;
	encp[1] = itoa64[i&0x3f];	i >>= 6;
	encp[0] = itoa64[i];		encp += 4;
	i = ((int)((rsltblock.b[6])<<8) | rsltblock.b[7])<<2;
	encp[2] = itoa64[i&0x3f];	i >>= 6;
	encp[1] = itoa64[i&0x3f];	i >>= 6;
	encp[0] = itoa64[i];

	encp[3] = 0;

	return (cryptresult);
}


/*
 * The Key Schedule, filled in by des_setkey() or setkey().
 */
#define	KS_SIZE	16
static C_block	KS[KS_SIZE];

/*
 * Set up the key schedule from the key.
 */
STATIC int des_setkey(key)
	register const char *key;
{
	register DCL_BLOCK(K, K0, K1);
	register C_block *ptabp;
	register int i;
	static int des_ready = 0;

	if (!des_ready) {
		init_des();
		des_ready = 1;
	}

	PERM6464(K,K0,K1,(unsigned char *)key,(C_block *)PC1ROT);
	key = (char *)&KS[0];
	STORE(K&~0x03030303L, K0&~0x03030303L, K1, *(C_block *)key);
	for (i = 1; i < 16; i++) {
		key += sizeof(C_block);
		STORE(K,K0,K1,*(C_block *)key);
		ptabp = (C_block *)PC2ROT[Rotates[i]-1];
		PERM6464(K,K0,K1,(unsigned char *)key,ptabp);
		STORE(K&~0x03030303L, K0&~0x03030303L, K1, *(C_block *)key);
	}
	return (0);
}

/*
 * Encrypt (or decrypt if num_iter < 0) the 8 chars at "in" with abs(num_iter)
 * iterations of DES, using the the given 24-bit salt and the pre-computed key
 * schedule, and store the resulting 8 chars at "out" (in == out is permitted).
 *
 * NOTE: the performance of this routine is critically dependent on your
 * compiler and machine architecture.
 */
STATIC int des_cipher(in, out, salt, num_iter)
	const char *in;
	char *out;
	long salt;
	int num_iter;
{
	/* variables that we want in registers, most important first */
#if defined(pdp11)
	register int j;
#endif
	register int L0, L1, R0, R1, k;
	register C_block *kp;
	register int ks_inc, loop_count;
	C_block B;

	L0 = salt;
	TO_SIX_BIT(salt, L0);	/* convert to 4*(6+2) format */

#if defined(vax) || defined(pdp11)
	salt = ~salt;	/* "x &~ y" is faster than "x & y". */
#define	SALT (~salt)
#else
#define	SALT salt
#endif

#if defined(MUST_ALIGN)
	B.b[0] = in[0]; B.b[1] = in[1]; B.b[2] = in[2]; B.b[3] = in[3];
	B.b[4] = in[4]; B.b[5] = in[5]; B.b[6] = in[6]; B.b[7] = in[7];
	LOAD(L,L0,L1,B);
#else
	LOAD(L,L0,L1,*(C_block *)in);
#endif
	LOADREG(R,R0,R1,L,L0,L1);
	L0 &= 0x55555555L;
	L1 &= 0x55555555L;
	L0 = (L0 << 1) | L1;	/* L0 is the even-numbered input bits */
	R0 &= 0xaaaaaaaaL;
	R1 = (R1 >> 1) & 0x55555555L;
	L1 = R0 | R1;		/* L1 is the odd-numbered input bits */
	STORE(L,L0,L1,B);
	PERM3264(L,L0,L1,B.b,  (C_block *)IE3264);	/* even bits */
	PERM3264(R,R0,R1,B.b+4,(C_block *)IE3264);	/* odd bits */

	if (num_iter >= 0)
	{		/* encryption */
		kp = &KS[0];
		ks_inc  = sizeof(*kp);
	}
	else
	{		/* decryption */
		num_iter = -num_iter;
		kp = &KS[KS_SIZE-1];
		ks_inc  = -(long)sizeof(*kp);
	}

	while (--num_iter >= 0) {
		loop_count = 8;
		do {

#define	SPTAB(t, i) \
	    (*(int*)((unsigned char *)t + i*(sizeof(int)/4)))
#if defined(gould)
			/* use this if B.b[i] is evaluated just once ... */
#define	DOXOR(x,y,i)	x^=SPTAB(SPE[0][i],B.b[i]); y^=SPTAB(SPE[1][i],B.b[i]);
#else
#if defined(pdp11)
			/* use this if your "long" int indexing is slow */
#define	DOXOR(x,y,i)	j=B.b[i]; x^=SPTAB(SPE[0][i],j); y^=SPTAB(SPE[1][i],j);
#else
			/* use this if "k" is allocated to a register ... */
#define	DOXOR(x,y,i)	k=B.b[i]; x^=SPTAB(SPE[0][i],k); y^=SPTAB(SPE[1][i],k);
#endif
#endif

#define	CRUNCH(p0, p1, q0, q1)	\
			k = (q0 ^ q1) & SALT;	\
			B.b32.i0 = k ^ q0 ^ kp->b32.i0;		\
			B.b32.i1 = k ^ q1 ^ kp->b32.i1;		\
			kp = (C_block *)((char *)kp+ks_inc);	\
							\
			DOXOR(p0, p1, 0);		\
			DOXOR(p0, p1, 1);		\
			DOXOR(p0, p1, 2);		\
			DOXOR(p0, p1, 3);		\
			DOXOR(p0, p1, 4);		\
			DOXOR(p0, p1, 5);		\
			DOXOR(p0, p1, 6);		\
			DOXOR(p0, p1, 7);

			CRUNCH(L0, L1, R0, R1);
			CRUNCH(R0, R1, L0, L1);
		} while (--loop_count != 0);
		kp = (C_block *)((char *)kp-(ks_inc*KS_SIZE));


		/* swap L and R */
		L0 ^= R0;  L1 ^= R1;
		R0 ^= L0;  R1 ^= L1;
		L0 ^= R0;  L1 ^= R1;
	}

	/* store the encrypted (or decrypted) result */
	L0 = ((L0 >> 3) & 0x0f0f0f0fL) | ((L1 << 1) & 0xf0f0f0f0L);
	L1 = ((R0 >> 3) & 0x0f0f0f0fL) | ((R1 << 1) & 0xf0f0f0f0L);
	STORE(L,L0,L1,B);
	PERM6464(L,L0,L1,B.b, (C_block *)CF6464);
#if defined(MUST_ALIGN)
	STORE(L,L0,L1,B);
	out[0] = B.b[0]; out[1] = B.b[1]; out[2] = B.b[2]; out[3] = B.b[3];
	out[4] = B.b[4]; out[5] = B.b[5]; out[6] = B.b[6]; out[7] = B.b[7];
#else
	STORE(L,L0,L1,*(C_block *)out);
#endif
	return (0);
}


/*
 * Initialize various tables.  This need only be done once.  It could even be
 * done at compile time, if the compiler were capable of that sort of thing.
 */
STATIC
void
init_des()
{
	register int i, j;
	register int k;
	register int tableno;
	static unsigned char perm[64], tmp32[32];	/* "static" for speed */

	/*
	 * table that converts chars "./0-9A-Za-z"to integers 0-63.
	 */
	for (i = 0; i < 64; i++)
		a64toi[itoa64[i]] = i;

	/*
	 * PC1ROT - bit reverse, then PC1, then Rotate, then PC2.
	 */
	for (i = 0; i < 64; i++)
		perm[i] = 0;
	for (i = 0; i < 64; i++) {
		if ((k = PC2[i]) == 0)
			continue;
		k += Rotates[0]-1;
		if ((k%28) < Rotates[0]) k -= 28;
		k = PC1[k];
		if (k > 0) {
			k--;
			k = (k|07) - (k&07);
			k++;
		}
		perm[i] = k;
	}
#ifdef DEBUG
	prtab("pc1tab", perm, 8);
#endif
	init_perm(PC1ROT, perm, 8, 8);

	/*
	 * PC2ROT - PC2 inverse, then Rotate (once or twice), then PC2.
	 */
	for (j = 0; j < 2; j++) {
		unsigned char pc2inv[64];
		for (i = 0; i < 64; i++)
			perm[i] = pc2inv[i] = 0;
		for (i = 0; i < 64; i++) {
			if ((k = PC2[i]) == 0)
				continue;
			pc2inv[k-1] = i+1;
		}
		for (i = 0; i < 64; i++) {
			if ((k = PC2[i]) == 0)
				continue;
			k += j;
			if ((k%28) <= j) k -= 28;
			perm[i] = pc2inv[k];
		}
#ifdef DEBUG
		prtab("pc2tab", perm, 8);
#endif
		init_perm(PC2ROT[j], perm, 8, 8);
	}

	/*
	 * Bit reverse, then initial permutation, then expansion.
	 */
	for (i = 0; i < 8; i++) {
		for (j = 0; j < 8; j++) {
			k = (j < 2)? 0: IP[ExpandTr[i*6+j-2]-1];
			if (k > 32)
				k -= 32;
			else if (k > 0)
				k--;
			if (k > 0) {
				k--;
				k = (k|07) - (k&07);
				k++;
			}
			perm[i*8+j] = k;
		}
	}
#ifdef DEBUG
	prtab("ietab", perm, 8);
#endif
	init_perm(IE3264, perm, 4, 8);

	/*
	 * Compression, then final permutation, then bit reverse.
	 */
	for (i = 0; i < 64; i++) {
		k = IP[CIFP[i]-1];
		if (k > 0) {
			k--;
			k = (k|07) - (k&07);
			k++;
		}
		perm[k-1] = i+1;
	}
#ifdef DEBUG
	prtab("cftab", perm, 8);
#endif
	init_perm(CF6464, perm, 8, 8);

	/*
	 * SPE table
	 */
	for (i = 0; i < 48; i++)
		perm[i] = P32Tr[ExpandTr[i]-1];
	for (tableno = 0; tableno < 8; tableno++) {
		for (j = 0; j < 64; j++)  {
			k = (((j >> 0) &01) << 5)|
			    (((j >> 1) &01) << 3)|
			    (((j >> 2) &01) << 2)|
			    (((j >> 3) &01) << 1)|
			    (((j >> 4) &01) << 0)|
			    (((j >> 5) &01) << 4);
			k = S[tableno][k];
			k = (((k >> 3)&01) << 0)|
			    (((k >> 2)&01) << 1)|
			    (((k >> 1)&01) << 2)|
			    (((k >> 0)&01) << 3);
			for (i = 0; i < 32; i++)
				tmp32[i] = 0;
			for (i = 0; i < 4; i++)
				tmp32[4 * tableno + i] = (k >> i) & 01;
			k = 0;
			for (i = 24; --i >= 0; )
				k = (k<<1) | tmp32[perm[i]-1];
			TO_SIX_BIT(SPE[0][tableno][j], k);
			k = 0;
			for (i = 24; --i >= 0; )
				k = (k<<1) | tmp32[perm[i+24]-1];
			TO_SIX_BIT(SPE[1][tableno][j], k);
		}
	}
}

/*
 * Initialize "perm" to represent transformation "p", which rearranges
 * (perhaps with expansion and/or contraction) one packed array of bits
 * (of size "chars_in" characters) into another array (of size "chars_out"
 * characters).
 *
 * "perm" must be all-zeroes on entry to this routine.
 */
STATIC
void
init_perm(perm, p, chars_in, chars_out)
	C_block perm[64/CHUNKBITS][1<<CHUNKBITS];
	unsigned char p[64];
	int chars_in, chars_out;
{
	register int i, j, k, l;

	for (k = 0; k < chars_out*8; k++) {	/* each output bit position */
		l = p[k] - 1;		/* where this bit comes from */
		if (l < 0)
			continue;	/* output bit is always 0 */
		i = l>>LGCHUNKBITS;	/* which chunk this bit comes from */
		l = 1<<(l&(CHUNKBITS-1));	/* mask for this bit */
		for (j = 0; j < (1<<CHUNKBITS); j++) {	/* each chunk value */
			if ((j & l) != 0)
				perm[i][j].b[k>>3] |= 1<<(k&07);
		}
	}
}

/*
 * "setkey" routine (for backwards compatibility)
 */
int setkey(key)
	register const char *key;
{
	register int i, j, k;
	C_block keyblock;

	for (i = 0; i < 8; i++) {
		k = 0;
		for (j = 0; j < 8; j++) {
			k <<= 1;
			k |= (unsigned char)*key++;
		}
		keyblock.b[i] = k;
	}
	return (des_setkey((char *)keyblock.b));
}

/*
 * "encrypt" routine (for backwards compatibility)
 */
int encrypt(block, flag)
	register char *block;
	int flag;
{
	register int i, j, k;
	C_block cblock;

	for (i = 0; i < 8; i++) {
		k = 0;
		for (j = 0; j < 8; j++) {
			k <<= 1;
			k |= (unsigned char)*block++;
		}
		cblock.b[i] = k;
	}
	if (des_cipher((char *)&cblock, (char *)&cblock, 0L, (flag ? -1: 1)))
		return (1);
	for (i = 7; i >= 0; i--) {
		k = cblock.b[i];
		for (j = 7; j >= 0; j--) {
			*--block = k&01;
			k >>= 1;
		}
	}
	return (0);
}

#ifdef DEBUG
STATIC
void
prtab(s, t, num_rows)
	char *s;
	unsigned char *t;
	int num_rows;
{
	register int i, j;

	(void)printf("%s:\n", s);
	for (i = 0; i < num_rows; i++) {
		for (j = 0; j < 8; j++) {
			 (void)printf("%3d", t[i*8+j]);
		}
		(void)printf("\n");
	}
	(void)printf("\n");
}
#endif

/*******************************************************************************
*
* cryptRtnInit - install cryptographic authentication routine into hook
*
* RETURNS: N/A
*
* NOMANUAL
*/

void cryptRtnInit
    (
    FUNCPTR *cryptRtnHook
    )
    {
    *cryptRtnHook = (FUNCPTR) crypt;
    }