📄 crypt.c
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/*
* Involve the rest of the password 8 characters at a time.
*/
while (*key) {
if (des_cipher((char *)&keyblock,
(char *)&keyblock, 0L, 1))
return (NULL);
for (i = 0; i < 8; i++) {
if ((t = 2*(unsigned char)(*key)) != 0)
key++;
keyblock.b[i] ^= t;
}
if (des_setkey((char *)keyblock.b))
return (NULL);
}
*encp++ = *setting++;
/* get iteration count */
num_iter = 0;
for (i = 4; --i >= 0; ) {
if ((t = (unsigned char)setting[i]) == '\0')
t = '.';
encp[i] = t;
num_iter = (num_iter<<6) | a64toi[t];
}
setting += 4;
encp += 4;
salt_size = 4;
break;
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 = ((long)((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 = ((long)((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 = ((long)((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.
*/
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.
*/
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 long 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 = -(int)sizeof(*kp);
}
while (--num_iter >= 0) {
loop_count = 8;
do {
#define SPTAB(t, i) (*(long *)((unsigned char *)t + i*(sizeof(long)/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
init_des()
{
register int i, j;
register long 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] = (unsigned char)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] = (unsigned char)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);
}
}
return(0);
}
/*
* 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
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);
}
}
return(0);
}
/*
* "setkey" routine (for backwards compatibility)
*/
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)
*/
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
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
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