--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rogue4/xcrypt.c	Sat Oct 24 16:52:52 2009 +0000
@@ -0,0 +1,684 @@
+/*
+ * FreeSec: libcrypt
+ *
+ * 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.
+ * 3. Neither the name(s) of the author(s) 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(S) 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(S) 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.
+ *
+ *
+ * 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.
+ *
+ * NOTE:
+ * This file has a static version of des_setkey() so that crypt.o exports
+ * only the crypt() interface. This is required to make binaries linked
+ * against crypt.o exportable or re-exportable from the USA.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+extern unsigned long int md_ntohl(unsigned long int x);
+extern unsigned long int md_htonl(unsigned long int x);
+
+#define _PASSWORD_EFMT1 '_'
+
+static unsigned 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 unsigned char	inv_key_perm[64];
+static unsigned 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 unsigned char	key_shifts[16] = {
+	1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
+};
+
+static unsigned char	inv_comp_perm[56];
+static unsigned 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 unsigned char	u_sbox[8][64];
+static unsigned 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 unsigned char	un_pbox[32];
+static unsigned 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 unsigned int 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 unsigned char	bits8[8] = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 };
+
+static unsigned int saltbits;
+static int	old_salt;
+static unsigned int *bits28, *bits24;
+static unsigned char	init_perm[64], final_perm[64];
+static unsigned int en_keysl[16], en_keysr[16];
+static unsigned int de_keysl[16], de_keysr[16];
+static int	des_initialised = 0;
+static unsigned char	m_sbox[4][4096];
+static unsigned int psbox[4][256];
+static unsigned int ip_maskl[8][256], ip_maskr[8][256];
+static unsigned int fp_maskl[8][256], fp_maskr[8][256];
+static unsigned int key_perm_maskl[8][128], key_perm_maskr[8][128];
+static unsigned int comp_maskl[8][128], comp_maskr[8][128];
+static unsigned int old_rawkey0, old_rawkey1;
+
+static unsigned 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;
+	unsigned int	*p, *il, *ir, *fl, *fr;
+
+	old_rawkey0 = old_rawkey1 = 0;
+	saltbits = 0;
+	old_salt = 0;
+	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++) {
+		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]) = 0;
+			*(ir = &ip_maskr[k][i]) = 0;
+			*(fl = &fp_maskl[k][i]) = 0;
+			*(fr = &fp_maskr[k][i]) = 0;
+			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]) = 0;
+			*(ir = &key_perm_maskr[k][i]) = 0;
+			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]) = 0;
+			*(ir = &comp_maskr[k][i]) = 0;
+			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]) = 0;
+			for (j = 0; j < 8; j++) {
+				if (i & bits8[j])
+					*p |= bits32[un_pbox[8 * b + j]];
+			}
+		}
+
+	des_initialised = 1;
+}
+
+static void
+setup_salt(int salt)
+{
+	unsigned int	obit, saltbit;
+	int	i;
+
+	if (salt == old_salt)
+		return;
+	old_salt = salt;
+
+	saltbits = 0;
+	saltbit = 1;
+	obit = 0x800000;
+	for (i = 0; i < 24; i++) {
+		if (salt & saltbit)
+			saltbits |= obit;
+		saltbit <<= 1;
+		obit >>= 1;
+	}
+}
+
+static int
+des_setkey(const unsigned char *key)
+{
+	unsigned int k0, k1, rawkey0, rawkey1;
+	int	shifts, round;
+
+	if (!des_initialised)
+		des_init();
+
+	rawkey0 = md_ntohl(*(unsigned int *) key);
+	rawkey1 = md_ntohl(*(unsigned int *) (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++) {
+		unsigned int	t0, t1;
+
+		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(unsigned int l_in, unsigned int r_in, unsigned int *l_out, 
+       unsigned int *r_out, int count)
+{
+	/*
+	 *	l_in, r_in, l_out, and r_out are in pseudo-"big-endian" format.
+	 */
+	unsigned int	l, r, *kl, *kr, *kl1, *kr1;
+	unsigned int	f = 0, r48l, r48r;
+	int		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);
+}
+
+static int
+des_cipher(const unsigned char *in, unsigned char *out, int salt, int count)
+{
+	unsigned int l_out, r_out, rawl, rawr;
+	unsigned int x[2];
+	int	retval;
+
+	if (!des_initialised)
+		des_init();
+
+	setup_salt(salt);
+
+	memcpy(x, in, sizeof x);
+	rawl = md_ntohl(x[0]);
+	rawr = md_ntohl(x[1]);
+	retval = do_des(rawl, rawr, &l_out, &r_out, count);
+
+	x[0] = md_htonl(l_out);
+	x[1] = md_htonl(r_out);
+	memcpy(out, x, sizeof x);
+	return(retval);
+}
+
+char *
+xcrypt(const char *key, const char *setting)
+{
+	int		i;
+	unsigned int	count, salt, l, r0, r1, keybuf[2];
+	unsigned char		*p, *q;
+	static unsigned char	output[21];
+
+	if (!des_initialised)
+		des_init();
+
+	/*
+	 * Copy the key, shifting each character up by one bit
+	 * and padding with zeros.
+	 */
+	q = (unsigned char *) keybuf;
+	while ((q - (unsigned char *) keybuf) < sizeof(keybuf)) {
+		if ((*q++ = *key << 1))
+			key++;
+	}
+	if (des_setkey((unsigned char *) keybuf))
+		return(NULL);
+
+	if (*setting == _PASSWORD_EFMT1) {
+		/*
+		 * "new"-style:
+		 *	setting - underscore, 4 bytes of count, 4 bytes of salt
+		 *	key - unlimited characters
+		 */
+		for (i = 1, count = 0; i < 5; i++)
+			count |= ascii_to_bin(setting[i]) << (i - 1) * 6;
+
+		for (i = 5, salt = 0; i < 9; i++)
+			salt |= ascii_to_bin(setting[i]) << (i - 5) * 6;
+
+		while (*key) {
+			/*
+			 * Encrypt the key with itself.
+			 */
+			if (des_cipher((unsigned char*)keybuf, (unsigned char*)keybuf, 0, 1))
+				return(NULL);
+			/*
+			 * And XOR with the next 8 characters of the key.
+			 */
+			q = (unsigned char *) keybuf;
+			while (((q - (unsigned char *) keybuf) < sizeof(keybuf)) &&
+					*key)
+				*q++ ^= *key++ << 1;
+
+			if (des_setkey((unsigned char *) keybuf))
+				return(NULL);
+		}
+		strncpy((char *)output, setting, 9);
+
+		/*
+		 * Double check that we weren't given a short setting.
+		 * If we were, the above code will probably have created
+		 * wierd values for count and salt, but we don't really care.
+		 * Just make sure the output string doesn't have an extra
+		 * NUL in it.
+		 */
+		output[9] = '\0';
+		p = output + strlen((const char *)output);
+	} else {
+		/*
+		 * "old"-style:
+		 *	setting - 2 bytes of salt
+		 *	key - up to 8 characters
+		 */
+		count = 25;
+
+		salt = (ascii_to_bin(setting[1]) << 6)
+		     |  ascii_to_bin(setting[0]);
+
+		output[0] = setting[0];
+		/*
+		 * If the encrypted password that the salt was extracted from