/*
* FreeSec: libcrypt for NetBSD
*
* Copyright (c) 1994 David Burren
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the author nor the names of other contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*
* This is an original implementation of the DES and the crypt(3) interfaces
* by David Burren <davidb@werj.com.au>.
*
* An excellent reference on the underlying algorithm (and related
* algorithms) is:
*
* B. Schneier, Applied Cryptography: protocols, algorithms,
* and source code in C, John Wiley & Sons, 1994.
*
* Note that in that book's description of DES the lookups for the initial,
* pbox, and final permutations are inverted (this has been brought to the
* attention of the author). A list of errata for this book has been
* posted to the sci.crypt newsgroup by the author and is available for FTP.
*
* ARCHITECTURE ASSUMPTIONS:
* This code assumes that u_longs are 32 bits. It will probably not
* operate on 64-bit machines without modifications.
* It is assumed that the 8-byte arrays passed by reference can be
* addressed as arrays of u_longs (ie. the CPU is not picky about
* alignment).
*/
#include <sys/types.h>
#include <sys/param.h>
#include <arpa/inet.h>
#include <pwd.h>
#ifdef DEBUG
# include <stdio.h>
#endif
static u_char IP[64] = {
58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8,
57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7
};
static u_char inv_key_perm[64];
static u_char u_key_perm[56];
static u_char key_perm[56] = {
57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18,
10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36,
63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22,
14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4
};
static u_char key_shifts[16] = {
1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
};
static u_char inv_comp_perm[56];
static u_char comp_perm[48] = {
14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10,
23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2,
41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48,
44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32
};
/*
* No E box is used, as it's replaced by some ANDs, shifts, and ORs.
*/
static u_char u_sbox[8][64];
static u_char sbox[8][64] = {
{
14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13
},
{
15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9
},
{
10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12
},
{
7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14
},
{
2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3
},
{
12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13
},
{
4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12
},
{
13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11
}
};
static u_char un_pbox[32];
static u_char pbox[32] = {
16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10,
2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25
};
static u_long bits32[32] =
{
0x80000000, 0x40000000, 0x20000000, 0x10000000,
0x08000000, 0x04000000, 0x02000000, 0x01000000,
0x00800000, 0x00400000, 0x00200000, 0x00100000,
0x00080000, 0x00040000, 0x00020000, 0x00010000,
0x00008000, 0x00004000, 0x00002000, 0x00001000,
0x00000800, 0x00000400, 0x00000200, 0x00000100,
0x00000080, 0x00000040, 0x00000020, 0x00000010,
0x00000008, 0x00000004, 0x00000002, 0x00000001
};
static u_char bits8[8] = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 };
static u_long saltbits;
static long old_salt;
static u_long *bits28, *bits24;
static u_char init_perm[64], final_perm[64];
static u_long en_keysl[16], en_keysr[16];
static u_long de_keysl[16], de_keysr[16];
static int des_initialised = 0;
static u_char m_sbox[4][4096];
static u_long psbox[4][256];
static u_long ip_maskl[8][256], ip_maskr[8][256];
static u_long fp_maskl[8][256], fp_maskr[8][256];
static u_long key_perm_maskl[8][128], key_perm_maskr[8][128];
static u_long comp_maskl[8][128], comp_maskr[8][128];
static u_long old_rawkey0, old_rawkey1;
static u_char ascii64[] =
"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
/* 0000000000111111111122222222223333333333444444444455555555556666 */
/* 0123456789012345678901234567890123456789012345678901234567890123 */
static inline int
ascii_to_bin(char ch)
{
if (ch > 'z')
return(0);
if (ch >= 'a')
return(ch - 'a' + 38);
if (ch > 'Z')
return(0);
if (ch >= 'A')
return(ch - 'A' + 12);
if (ch > '9')
return(0);
if (ch >= '.')
return(ch - '.');
return(0);
}
static void
des_init()
{
int i, j, b, k, inbit, obit;
u_long *p, *il, *ir, *fl, *fr;
old_rawkey0 = old_rawkey1 = 0L;
saltbits = 0L;
old_salt = 0L;
bits24 = (bits28 = bits32 + 4) + 4;
/*
* Invert the S-boxes, reordering the input bits.
*/
for (i = 0; i < 8; i++)
for (j = 0; j < 64; j++) {
b = (j & 0x20) | ((j & 1) << 4) | ((j >> 1) & 0xf);
u_sbox[i][j] = sbox[i][b];
}
/*
* Convert the inverted S-boxes into 4 arrays of 8 bits.
* Each will handle 12 bits of the S-box input.
*/
for (b = 0; b < 4; b++)
for (i = 0; i < 64; i++)
for (j = 0; j < 64; j++)
m_sbox[b][(i << 6) | j] =
(u_sbox[(b << 1)][i] << 4) |
u_sbox[(b << 1) + 1][j];
/*
* Set up the initial & final permutations into a useful form, and
* initialise the inverted key permutation.
*/
for (i = 0; i < 64; i++) {
init_perm[final_perm[i] = IP[i] - 1] = i;
inv_key_perm[i] = 255;
}
/*
* Invert the key permutation and initialise the inverted key
* compression permutation.
*/
for (i = 0; i < 56; i++) {
u_key_perm[i] = key_perm[i] - 1;
inv_key_perm[key_perm[i] - 1] = i;
inv_comp_perm[i] = 255;
}
/*
* Invert the key compression permutation.
*/
for (i = 0; i < 48; i++) {
inv_comp_perm[comp_perm[i] - 1] = i;
}
/*
* Set up the OR-mask arrays for the initial and final permutations,
* and for the key initial and compression permutations.
*/
for (k = 0; k < 8; k++) {
for (i = 0; i < 256; i++) {
*(il = &ip_maskl[k][i]) = 0L;
*(ir = &ip_maskr[k][i]) = 0L;
*(fl = &fp_maskl[k][i]) = 0L;
*(fr = &fp_maskr[k][i]) = 0L;
for (j = 0; j < 8; j++) {
inbit = 8 * k + j;
if (i & bits8[j]) {
if ((obit = init_perm[inbit]) < 32)
*il |= bits32[obit];
else
*ir |= bits32[obit-32];
if ((obit = final_perm[inbit]) < 32)
*fl |= bits32[obit];
else
*fr |= bits32[obit - 32];
}
}
}
for (i = 0; i < 128; i++) {
*(il = &key_perm_maskl[k][i]) = 0L;
*(ir = &key_perm_maskr[k][i]) = 0L;
for (j = 0; j < 7; j++) {
inbit = 8 * k + j;
if (i & bits8[j + 1]) {
if ((obit = inv_key_perm[inbit]) == 255)
continue;
if (obit < 28)
*il |= bits28[obit];
else
*ir |= bits28[obit - 28];
}
}
*(il = &comp_maskl[k][i]) = 0L;
*(ir = &comp_maskr[k][i]) = 0L;
for (j = 0; j < 7; j++) {
inbit = 7 * k + j;
if (i & bits8[j + 1]) {
if ((obit=inv_comp_perm[inbit]) == 255)
continue;
if (obit < 24)
*il |= bits24[obit];
else
*ir |= bits24[obit - 24];
}
}
}
}
/*
* Invert the P-box permutation, and convert into OR-masks for
* handling the output of the S-box arrays setup above.
*/
for (i = 0; i < 32; i++)
un_pbox[pbox[i] - 1] = i;
for (b = 0; b < 4; b++)
for (i = 0; i < 256; i++) {
*(p = &psbox[b][i]) = 0L;
for (j = 0; j < 8; j++) {
if (i & bits8[j])
*p |= bits32[un_pbox[8 * b + j]];
}
}
des_initialised = 1;
}
static void
setup_salt(long salt)
{
u_long obit, saltbit;
int i;
if (salt == old_salt)
return;
old_salt = salt;
saltbits = 0L;
saltbit = 1;
obit = 0x800000;
for (i = 0; i < 24; i++) {
if (salt & saltbit)
saltbits |= obit;
saltbit <<= 1;
obit >>= 1;
}
}
int
des_setkey(const char *key)
{
u_long k0, k1, rawkey0, rawkey1;
int shifts, i, b, round;
if (!des_initialised)
des_init();
rawkey0 = ntohl(*(u_long *) key);
rawkey1 = ntohl(*(u_long *) (key + 4));
if ((rawkey0 | rawkey1)
&& rawkey0 == old_rawkey0
&& rawkey1 == old_rawkey1) {
/*
* Already setup for this key.
* This optimisation fails on a zero key (which is weak and
* has bad parity anyway) in order to simplify the starting
* conditions.
*/
return(0);
}
old_rawkey0 = rawkey0;
old_rawkey1 = rawkey1;
/*
* Do key permutation and split into two 28-bit subkeys.
*/
k0 = key_perm_maskl[0][rawkey0 >> 25]
| key_perm_maskl[1][(rawkey0 >> 17) & 0x7f]
| key_perm_maskl[2][(rawkey0 >> 9) & 0x7f]
| key_perm_maskl[3][(rawkey0 >> 1) & 0x7f]
| key_perm_maskl[4][rawkey1 >> 25]
| key_perm_maskl[5][(rawkey1 >> 17) & 0x7f]
| key_perm_maskl[6][(rawkey1 >> 9) & 0x7f]
| key_perm_maskl[7][(rawkey1 >> 1) & 0x7f];
k1 = key_perm_maskr[0][rawkey0 >> 25]
| key_perm_maskr[1][(rawkey0 >> 17) & 0x7f]
| key_perm_maskr[2][(rawkey0 >> 9) & 0x7f]
| key_perm_maskr[3][(rawkey0 >> 1) & 0x7f]
| key_perm_maskr[4][rawkey1 >> 25]
| key_perm_maskr[5][(rawkey1 >> 17) & 0x7f]
| key_perm_maskr[6][(rawkey1 >> 9) & 0x7f]
| key_perm_maskr[7][(rawkey1 >> 1) & 0x7f];
/*
* Rotate subkeys and do compression permutation.
*/
shifts = 0;
for (round = 0; round < 16; round++) {
u_long t0, t1;
int bit;
shifts += key_shifts[round];
t0 = (k0 << shifts) | (k0 >> (28 - shifts));
t1 = (k1 << shifts) | (k1 >> (28 - shifts));
de_keysl[15 - round] =
en_keysl[round] = comp_maskl[0][(t0 >> 21) & 0x7f]
| comp_maskl[1][(t0 >> 14) & 0x7f]
| comp_maskl[2][(t0 >> 7) & 0x7f]
| comp_maskl[3][t0 & 0x7f]
| comp_maskl[4][(t1 >> 21) & 0x7f]
| comp_maskl[5][(t1 >> 14) & 0x7f]
| comp_maskl[6][(t1 >> 7) & 0x7f]
| comp_maskl[7][t1 & 0x7f];
de_keysr[15 - round] =
en_keysr[round] = comp_maskr[0][(t0 >> 21) & 0x7f]
| comp_maskr[1][(t0 >> 14) & 0x7f]
| comp_maskr[2][(t0 >> 7) & 0x7f]
| comp_maskr[3][t0 & 0x7f]
| comp_maskr[4][(t1 >> 21) & 0x7f]
| comp_maskr[5][(t1 >> 14) & 0x7f]
| comp_maskr[6][(t1 >> 7) & 0x7f]
| comp_maskr[7][t1 & 0x7f];
}
return(0);
}
static int
do_des( u_long l_in, u_long r_in, u_long *l_out, u_long *r_out, int count)
{
/*
* l_in, r_in, l_out, and r_out are in pseudo-"big-endian" format.
*/
u_long mask, rawl, rawr, l, r, *kl, *kr, *kl1, *kr1;
u_long f, r48l, r48r;
int i, j, b, round;
if (count == 0) {
return(1);
} else if (count > 0) {
/*
* Encrypting
*/
kl1 = en_keysl;
kr1 = en_keysr;
} else {
/*
* Decrypting
*/
count = -count;
kl1 = de_keysl;
kr1 = de_keysr;
}
/*
* Do initial permutation (IP).
*/
l = ip_maskl[0][l_in >> 24]
| ip_maskl[1][(l_in >> 16) & 0xff]
| ip_maskl[2][(l_in >> 8) & 0xff]
| ip_maskl[3][l_in & 0xff]
| ip_maskl[4][r_in >> 24]
| ip_maskl[5][(r_in >> 16) & 0xff]
| ip_maskl[6][(r_in >> 8) & 0xff]
| ip_maskl[7][r_in & 0xff];
r = ip_maskr[0][l_in >> 24]
| ip_maskr[1][(l_in >> 16) & 0xff]
| ip_maskr[2][(l_in >> 8) & 0xff]
| ip_maskr[3][l_in & 0xff]
| ip_maskr[4][r_in >> 24]
| ip_maskr[5][(r_in >> 16) & 0xff]
| ip_maskr[6][(r_in >> 8) & 0xff]
| ip_maskr[7][r_in & 0xff];
while (count--) {
/*
* Do each round.
*/
kl = kl1;
kr = kr1;
round = 16;
while (round--) {
/*
* Expand R to 48 bits (simulate the E-box).
*/
r48l = ((r & 0x00000001) << 23)
| ((r & 0xf8000000) >> 9)
| ((r & 0x1f800000) >> 11)
| ((r & 0x01f80000) >> 13)
| ((r & 0x001f8000) >> 15);
r48r = ((r & 0x0001f800) << 7)
| ((r & 0x00001f80) << 5)
| ((r & 0x000001f8) << 3)
| ((r & 0x0000001f) << 1)
| ((r & 0x80000000) >> 31);
/*
* Do salting for crypt() and friends, and
* XOR with the permuted key.
*/
f = (r48l ^ r48r) & saltbits;
r48l ^= f ^ *kl++;
r48r ^= f ^ *kr++;
/*
* Do sbox lookups (which shrink it back to 32 bits)
* and do the pbox permutation at the same time.
*/
f = psbox[0][m_sbox[0][r48l >> 12]]
| psbox[1][m_sbox[1][r48l & 0xfff]]
| psbox[2][m_sbox[2][r48r >> 12]]
| psbox[3][m_sbox[3][r48r & 0xfff]];
/*
* Now that we've permuted things, complete f().
*/
f ^= l;
l = r;
r = f;
}
r = l;
l = f;
}
/*
* Do final permutation (inverse of IP).
*/
*l_out = fp_maskl[0][l >> 24]
| fp_maskl[1][(l >> 16) & 0xff]
| fp_maskl[2][(l >> 8) & 0xff]
| fp_maskl[3][l & 0xff]
| fp_maskl[4][r >> 24]
| fp_maskl[5][(r >> 16) & 0xff]
| fp_maskl[6][(r >> 8) & 0xff]
| fp_maskl[7][r & 0xff];
*r_out = fp_maskr[0][l >> 24]
| fp_maskr[1][(l >> 16) & 0xff]
| fp_maskr[2][(l >> 8) & 0xff]
| fp_maskr[3][l & 0xff]
| fp_maskr[4][r >> 24]
| fp_maskr[5][(r >> 16) & 0xff]
| fp_maskr[6][(r >> 8) & 0xff]
| fp_maskr[7][r & 0xff];
return(0);
}
int
des_cipher(const char *in, char *out, long salt, int count)
{
u_long l_out, r_out, rawl, rawr;
int retval;
if (!des_initialised)
des_init();
setup_salt(salt);
rawl = ntohl(*((u_long *) in)++);
rawr = ntohl(*((u_long *) in));
retval = do_des(rawl, rawr, &l_out, &r_out, count);
*((u_long *) out)++ = htonl(l_out);
*((u_long *) out) = htonl(r_out);
return(retval);
}
int
setkey(char *key)
{
int i, j;
u_long packed_keys[2];
u_char *p;
p = (u_char *) packed_keys;
for (i = 0; i < 8; i++) {
p[i] = 0;
for (j = 0; j < 8; j++)
if (*key++ & 1)
p[i] |= bits8[j];
}
return(des_setkey(p));
}
int
encrypt(char *block, int flag)
{
u_long io[2];
u_char *p;
int i, j, retval;
if (!des_initialised)
des_init();
setup_salt(0L);
p = block;
for (i = 0; i < 2; i++) {
io[i] = 0L;
for (j = 0; j < 32; j++)
if (*p++ & 1)
io[i] |= bits32[j];
}
retval = do_des(io[0], io[1], io, io + 1, flag ? -1 : 1);
for (i = 0; i < 2; i++)
for (j = 0; j < 32; j++)
block[(i << 5) | j] = (io[i] & bits32[j]) ? 1 : 0;
return(retval);
}
