text: /*
   * FreeSec: libcrypt for NetBSD
   *
   * Copyright (c) 1994 David Burren
   * All rights reserved.
   *
   * Adapted for FreeBSD-2.0 by Geoffrey M. Rehmet
   *	this file should now *only* export crypt(), in order to make
   *	binaries of libcrypt exportable from the USA
   *
   * Adapted for FreeBSD-4.0 by Mark R V Murray
   *	this file should now *only* export crypt_des(), in order to make
   *	a module that can be optionally included in libcrypt.
   *
   * 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 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.
   *
   * 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:
   *	It is assumed that the 8-byte arrays passed by reference can be
   *	addressed as arrays of uint32_t's (ie. the CPU is not picky about
   *	alignment).
   */
  
  
  /* Parts busybox doesn't need or had optimized */
  #define USE_PRECOMPUTED_u_sbox 1
  #define USE_REPETITIVE_SPEEDUP 0
  #define USE_ip_mask 0
  #define USE_de_keys 0
  
  
  /* A pile of data */
  static const uint8_t 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 const uint8_t 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 const uint8_t key_shifts[16] = {
  	1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
  };
  
  static const uint8_t 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.
   */
  #if !USE_PRECOMPUTED_u_sbox
  static const uint8_t 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
  	}
  };
  #else /* precomputed, with half-bytes packed into one byte */
  static const uint8_t u_sbox[8][32] = {
  	{	0x0e, 0xf4, 0x7d, 0x41, 0xe2, 0x2f, 0xdb, 0x18,
  		0xa3, 0x6a, 0xc6, 0xbc, 0x95, 0x59, 0x30, 0x87,
  		0xf4, 0xc1, 0x8e, 0x28, 0x4d, 0x96, 0x12, 0x7b,
  		0x5f, 0xbc, 0x39, 0xe7, 0xa3, 0x0a, 0x65, 0xd0,
  	},
  	{	0x3f, 0xd1, 0x48, 0x7e, 0xf6, 0x2b, 0x83, 0xe4,
  		0xc9, 0x07, 0x12, 0xad, 0x6c, 0x90, 0xb5, 0x5a,
  		0xd0, 0x8e, 0xa7, 0x1b, 0x3a, 0xf4, 0x4d, 0x21,
  		0xb5, 0x68, 0x7c, 0xc6, 0x09, 0x53, 0xe2, 0x9f,
  	},
  	{	0xda, 0x70, 0x09, 0x9e, 0x36, 0x43, 0x6f, 0xa5,
  		0x21, 0x8d, 0x5c, 0xe7, 0xcb, 0xb4, 0xf2, 0x18,
  		0x1d, 0xa6, 0xd4, 0x09, 0x68, 0x9f, 0x83, 0x70,
  		0x4b, 0xf1, 0xe2, 0x3c, 0xb5, 0x5a, 0x2e, 0xc7,
  	},
  	{	0xd7, 0x8d, 0xbe, 0x53, 0x60, 0xf6, 0x09, 0x3a,
  		0x41, 0x72, 0x28, 0xc5, 0x1b, 0xac, 0xe4, 0x9f,
  		0x3a, 0xf6, 0x09, 0x60, 0xac, 0x1b, 0xd7, 0x8d,
  		0x9f, 0x41, 0x53, 0xbe, 0xc5, 0x72, 0x28, 0xe4,
  	},
  	{	0xe2, 0xbc, 0x24, 0xc1, 0x47, 0x7a, 0xdb, 0x16,
  		0x58, 0x05, 0xf3, 0xaf, 0x3d, 0x90, 0x8e, 0x69,
  		0xb4, 0x82, 0xc1, 0x7b, 0x1a, 0xed, 0x27, 0xd8,
  		0x6f, 0xf9, 0x0c, 0x95, 0xa6, 0x43, 0x50, 0x3e,
  	},
  	{	0xac, 0xf1, 0x4a, 0x2f, 0x79, 0xc2, 0x96, 0x58,
  		0x60, 0x1d, 0xd3, 0xe4, 0x0e, 0xb7, 0x35, 0x8b,
  		0x49, 0x3e, 0x2f, 0xc5, 0x92, 0x58, 0xfc, 0xa3,
  		0xb7, 0xe0, 0x14, 0x7a, 0x61, 0x0d, 0x8b, 0xd6,
  	},
  	{	0xd4, 0x0b, 0xb2, 0x7e, 0x4f, 0x90, 0x18, 0xad,
  		0xe3, 0x3c, 0x59, 0xc7, 0x25, 0xfa, 0x86, 0x61,
  		0x61, 0xb4, 0xdb, 0x8d, 0x1c, 0x43, 0xa7, 0x7e,
  		0x9a, 0x5f, 0x06, 0xf8, 0xe0, 0x25, 0x39, 0xc2,
  	},
  	{	0x1d, 0xf2, 0xd8, 0x84, 0xa6, 0x3f, 0x7b, 0x41,
  		0xca, 0x59, 0x63, 0xbe, 0x05, 0xe0, 0x9c, 0x27,
  		0x27, 0x1b, 0xe4, 0x71, 0x49, 0xac, 0x8e, 0xd2,
  		0xf0, 0xc6, 0x9a, 0x0d, 0x3f, 0x53, 0x65, 0xb8,
  	},
  };
  #endif
  
  static const uint8_t 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 const uint32_t 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 const uint8_t bits8[8] = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 };
  
  
  static 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 stuff that stays resident and doesn't change after
   * being initialized, and therefore doesn't need to be made
   * reentrant. */
  struct const_des_ctx {
  #if USE_ip_mask
  	uint8_t	init_perm[64]; /* referenced 2 times */
  #endif
  	uint8_t	final_perm[64]; /* 2 times */
  	uint8_t	m_sbox[4][4096]; /* 5 times */
  };
  #define C (*cctx)
  #define init_perm  (C.init_perm )
  #define final_perm (C.final_perm)
  #define m_sbox     (C.m_sbox    )
  
  static struct const_des_ctx*
  const_des_init(void)
  {
  	unsigned i, j, b;
  	struct const_des_ctx *cctx;
  
  #if !USE_PRECOMPUTED_u_sbox
  	uint8_t	u_sbox[8][64];
  
  	cctx = xmalloc(sizeof(*cctx));
  
  	/* 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];
  		}
  	}
  	for (i = 0; i < 8; i++) {
  		fprintf(stderr, "\t{\t");
  		for (j = 0; j < 64; j+=2)
  			fprintf(stderr, " 0x%02x,", u_sbox[i][j] + u_sbox[i][j+1]*16);
  		fprintf(stderr, "\n\t},\n");
  	}
  	/*
  	 * 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] =
  					(uint8_t)((u_sbox[(b << 1)][i] << 4) |
  						u_sbox[(b << 1) + 1][j]);
  #else
  	cctx = xmalloc(sizeof(*cctx));
  
  	/*
  	 * 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++) {
  		uint8_t lo, hi;
  		hi = u_sbox[(b << 1)][i / 2];
  		if (!(i & 1))
  			hi <<= 4;
  		lo = u_sbox[(b << 1) + 1][j / 2];
  		if (j & 1)
  			lo >>= 4;
  		m_sbox[b][(i << 6) | j] = (hi & 0xf0) | (lo & 0x0f);
  	}
  #endif
  
  	/*
  	 * Set up the initial & final permutations into a useful form.
  	 */
  	for (i = 0; i < 64; i++) {
  		final_perm[i] = IP[i] - 1;
  #if USE_ip_mask
  		init_perm[final_perm[i]] = (uint8_t)i;
  #endif
  	}
  
  	return cctx;
  }
  
  
  struct des_ctx {
  	const struct const_des_ctx *const_ctx;
  	uint32_t saltbits; /* referenced 5 times */
  #if USE_REPETITIVE_SPEEDUP
  	uint32_t old_salt; /* 3 times */
  	uint32_t old_rawkey0, old_rawkey1; /* 3 times each */
  #endif
  	uint8_t	un_pbox[32]; /* 2 times */
  	uint8_t	inv_comp_perm[56]; /* 3 times */
  	uint8_t	inv_key_perm[64]; /* 3 times */
  	uint32_t en_keysl[16], en_keysr[16]; /* 2 times each */
  #if USE_de_keys
  	uint32_t de_keysl[16], de_keysr[16]; /* 2 times each */
  #endif
  #if USE_ip_mask
  	uint32_t ip_maskl[8][256], ip_maskr[8][256]; /* 9 times each */
  #endif
  	uint32_t fp_maskl[8][256], fp_maskr[8][256]; /* 9 times each */
  	uint32_t key_perm_maskl[8][128], key_perm_maskr[8][128]; /* 9 times */
  	uint32_t comp_maskl[8][128], comp_maskr[8][128]; /* 9 times each */
  	uint32_t psbox[4][256]; /* 5 times */
  };
  #define D (*ctx)
  #define const_ctx       (D.const_ctx      )
  #define saltbits        (D.saltbits       )
  #define old_salt        (D.old_salt       )
  #define old_rawkey0     (D.old_rawkey0    )
  #define old_rawkey1     (D.old_rawkey1    )
  #define un_pbox         (D.un_pbox        )
  #define inv_comp_perm   (D.inv_comp_perm  )
  #define inv_key_perm    (D.inv_key_perm   )
  #define en_keysl        (D.en_keysl       )
  #define en_keysr        (D.en_keysr       )
  #define de_keysl        (D.de_keysl       )
  #define de_keysr        (D.de_keysr       )
  #define ip_maskl        (D.ip_maskl       )
  #define ip_maskr        (D.ip_maskr       )
  #define fp_maskl        (D.fp_maskl       )
  #define fp_maskr        (D.fp_maskr       )
  #define key_perm_maskl  (D.key_perm_maskl )
  #define key_perm_maskr  (D.key_perm_maskr )
  #define comp_maskl      (D.comp_maskl     )
  #define comp_maskr      (D.comp_maskr     )
  #define psbox           (D.psbox          )
  
  static struct des_ctx*
  des_init(struct des_ctx *ctx, const struct const_des_ctx *cctx)
  {
  	int i, j, b, k, inbit, obit;
  	uint32_t p;
  	const uint32_t *bits28, *bits24;
  
  	if (!ctx)
  		ctx = xmalloc(sizeof(*ctx));
  	const_ctx = cctx;
  
  #if USE_REPETITIVE_SPEEDUP
  	old_rawkey0 = old_rawkey1 = 0;
  	old_salt = 0;
  #endif
  	saltbits = 0;
  	bits28 = bits32 + 4;
  	bits24 = bits28 + 4;
  
  	/* Initialise the inverted key permutation. */
  	for (i = 0; i < 64; 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] = (uint8_t)i;
  		inv_comp_perm[i] = 255;
  	}
  
  	/* Invert the key compression permutation. */
  	for (i = 0; i < 48; i++) {
  		inv_comp_perm[comp_perm[i] - 1] = (uint8_t)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++) {
  		uint32_t il, ir;
  		uint32_t fl, fr;
  		for (i = 0; i < 256; i++) {
  #if USE_ip_mask
  			il = 0;
  			ir = 0;
  #endif
  			fl = 0;
  			fr = 0;
  			for (j = 0; j < 8; j++) {
  				inbit = 8 * k + j;
  				if (i & bits8[j]) {
  #if USE_ip_mask
  					obit = init_perm[inbit];
  					if (obit < 32)
  						il |= bits32[obit];
  					else
  						ir |= bits32[obit - 32];
  #endif
  					obit = final_perm[inbit];
  					if (obit < 32)
  						fl |= bits32[obit];
  					else
  						fr |= bits32[obit - 32];
  				}
  			}
  #if USE_ip_mask
  			ip_maskl[k][i] = il;
  			ip_maskr[k][i] = ir;
  #endif
  			fp_maskl[k][i] = fl;
  			fp_maskr[k][i] = fr;
  		}
  		for (i = 0; i < 128; i++) {
  			il = 0;
  			ir = 0;
  			for (j = 0; j < 7; j++) {
  				inbit = 8 * k + j;
  				if (i & bits8[j + 1]) {
  					obit = inv_key_perm[inbit];
  					if (obit == 255)
  						continue;
  					if (obit < 28)
  						il |= bits28[obit];
  					else
  						ir |= bits28[obit - 28];
  				}
  			}
  			key_perm_maskl[k][i] = il;
  			key_perm_maskr[k][i] = ir;
  			il = 0;
  			ir = 0;
  			for (j = 0; j < 7; j++) {
  				inbit = 7 * k + j;
  				if (i & bits8[j + 1]) {
  					obit = inv_comp_perm[inbit];
  					if (obit == 255)
  						continue;
  					if (obit < 24)
  						il |= bits24[obit];
  					else
  						ir |= bits24[obit - 24];
  				}
  			}
  			comp_maskl[k][i] = il;
  			comp_maskr[k][i] = ir;
  		}
  	}
  
  	/*
  	 * 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] = (uint8_t)i;
  
  	for (b = 0; b < 4; b++) {
  		for (i = 0; i < 256; i++) {
  			p = 0;
  			for (j = 0; j < 8; j++) {
  				if (i & bits8[j])
  					p |= bits32[un_pbox[8 * b + j]];
  			}
  			psbox[b][i] = p;
  		}
  	}
  
  	return ctx;
  }
  
  
  static void
  setup_salt(struct des_ctx *ctx, uint32_t salt)
  {
  	uint32_t obit, saltbit;
  	int i;
  
  #if USE_REPETITIVE_SPEEDUP
  	if (salt == old_salt)
  		return;
  	old_salt = salt;
  #endif
  
  	saltbits = 0;
  	saltbit = 1;
  	obit = 0x800000;
  	for (i = 0; i < 24; i++) {
  		if (salt & saltbit)
  			saltbits |= obit;
  		saltbit <<= 1;
  		obit >>= 1;
  	}
  }
  
  static void
  des_setkey(struct des_ctx *ctx, const char *key)
  {
  	uint32_t k0, k1, rawkey0, rawkey1;
  	int shifts, round;
  
  	rawkey0 = ntohl(*(const uint32_t *) key);
  	rawkey1 = ntohl(*(const uint32_t *) (key + 4));
  
  #if USE_REPETITIVE_SPEEDUP
  	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;
  	}
  	old_rawkey0 = rawkey0;
  	old_rawkey1 = rawkey1;
  #endif
  
  	/*
  	 * 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++) {
  		uint32_t t0, t1;
  
  		shifts += key_shifts[round];
  
  		t0 = (k0 << shifts) | (k0 >> (28 - shifts));
  		t1 = (k1 << shifts) | (k1 >> (28 - shifts));
  
  #if USE_de_keys
  		de_keysl[15 - round] =
  #endif
  		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];
  
  #if USE_de_keys
  		de_keysr[15 - round] =
  #endif
  		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];
  	}
  }
  
  
  static void
  do_des(struct des_ctx *ctx, /*uint32_t l_in, uint32_t r_in,*/ uint32_t *l_out, uint32_t *r_out, int count)
  {
  	const struct const_des_ctx *cctx = const_ctx;
  	/*
  	 * l_in, r_in, l_out, and r_out are in pseudo-"big-endian" format.
  	 */
  	uint32_t l, r, *kl, *kr;
  	static uint32_t f; /* silence gcc */
  	uint32_t r48l, r48r;
  	int round;
  
  	/* Do initial permutation (IP). */
  #if USE_ip_mask
  	uint32_t l_in = 0;
  	uint32_t r_in = 0;
  	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];
  #elif 0 /* -65 bytes (using the fact that l_in == r_in == 0) */
  	l = r = 0;
  	for (round = 0; round < 8; round++) {
  		l |= ip_maskl[round][0];
  		r |= ip_maskr[round][0];
  	}
  	bb_error_msg("l:%x r:%x", l, r); /* reports 0, 0 always! */
  #else /* using the fact that ip_maskX[] is constant (written to by des_init) */
  	l = r = 0;
  #endif
  
  	do {
  		/* Do each round. */
  		kl = en_keysl;
  		kr = en_keysr;
  		round = 16;
  		do {
  			/* 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;
  		} while (--round);
  		r = l;
  		l = f;
  	} while (--count);
  
  	/* 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];
  }
  
  #define DES_OUT_BUFSIZE 21
  
  static void
  to64_msb_first(char *s, unsigned v)
  {
  #if 0
  	*s++ = ascii64[(v >> 18) & 0x3f]; /* bits 23..18 */
  	*s++ = ascii64[(v >> 12) & 0x3f]; /* bits 17..12 */
  	*s++ = ascii64[(v >> 6) & 0x3f]; /* bits 11..6 */
  	*s   = ascii64[v & 0x3f]; /* bits 5..0 */
  #endif
  	*s++ = i64c(v >> 18); /* bits 23..18 */
  	*s++ = i64c(v >> 12); /* bits 17..12 */
  	*s++ = i64c(v >> 6); /* bits 11..6 */
  	*s   = i64c(v); /* bits 5..0 */
  }
  
  static char *
  NOINLINE
  des_crypt(struct des_ctx *ctx, char output[DES_OUT_BUFSIZE],
  		const unsigned char *key, const unsigned char *setting)
  {
  	uint32_t salt, r0, r1, keybuf[2];
  	uint8_t *q;
  
  	/*
  	 * Copy the key, shifting each character up by one bit
  	 * and padding with zeros.
  	 */
  	q = (uint8_t *)keybuf;
  	while (q - (uint8_t *)keybuf != 8) {
  		*q = *key << 1;
  		if (*q)
  			key++;
  		q++;
  	}
  	des_setkey(ctx, (char *)keybuf);
  
  	/*
  	 * setting - 2 bytes of salt
  	 * key - up to 8 characters
  	 */
  	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
  	 * is only 1 character long, the salt will be corrupted.  We
  	 * need to ensure that the output string doesn't have an extra
  	 * NUL in it!
  	 */
  	output[1] = setting[1] ? setting[1] : output[0];
  
  	setup_salt(ctx, salt);
  	/* Do it. */
  	do_des(ctx, /*0, 0,*/ &r0, &r1, 25 /* count */);
  
  	/* Now encode the result. */
  #if 0
  {
  	uint32_t l = (r0 >> 8);
  	q = (uint8_t *)output + 2;
  	*q++ = ascii64[(l >> 18) & 0x3f]; /* bits 31..26 of r0 */
  	*q++ = ascii64[(l >> 12) & 0x3f]; /* bits 25..20 of r0 */
  	*q++ = ascii64[(l >> 6) & 0x3f]; /* bits 19..14 of r0 */
  	*q++ = ascii64[l & 0x3f]; /* bits 13..8 of r0 */
  	l = ((r0 << 16) | (r1 >> 16));
  	*q++ = ascii64[(l >> 18) & 0x3f]; /* bits 7..2 of r0 */
  	*q++ = ascii64[(l >> 12) & 0x3f]; /* bits 1..2 of r0 and 31..28 of r1 */
  	*q++ = ascii64[(l >> 6) & 0x3f]; /* bits 27..22 of r1 */
  	*q++ = ascii64[l & 0x3f]; /* bits 21..16 of r1 */
  	l = r1 << 2;
  	*q++ = ascii64[(l >> 12) & 0x3f]; /* bits 15..10 of r1 */
  	*q++ = ascii64[(l >> 6) & 0x3f]; /* bits 9..4 of r1 */
  	*q++ = ascii64[l & 0x3f]; /* bits 3..0 of r1 + 00 */
  	*q = 0;
  }
  #else
  	/* Each call takes low-order 24 bits and stores 4 chars */
  	/* bits 31..8 of r0 */
  	to64_msb_first(output + 2, (r0 >> 8));
  	/* bits 7..0 of r0 and 31..16 of r1 */
  	to64_msb_first(output + 6, (r0 << 16) | (r1 >> 16));
  	/* bits 15..0 of r1 and two zero bits (plus extra zero byte) */
  	to64_msb_first(output + 10, (r1 << 8));
  	/* extra zero byte is encoded as '.', fixing it */
  	output[13] = '\0';
  #endif
  
  	return output;
  }
  
  #undef USE_PRECOMPUTED_u_sbox
  #undef USE_REPETITIVE_SPEEDUP
  #undef USE_ip_mask
  #undef USE_de_keys
  
  #undef C
  #undef init_perm
  #undef final_perm
  #undef m_sbox
  #undef D
  #undef const_ctx
  #undef saltbits
  #undef old_salt
  #undef old_rawkey0
  #undef old_rawkey1
  #undef un_pbox
  #undef inv_comp_perm
  #undef inv_key_perm
  #undef en_keysl
  #undef en_keysr
  #undef de_keysl
  #undef de_keysr
  #undef ip_maskl
  #undef ip_maskr
  #undef fp_maskl
  #undef fp_maskr
  #undef key_perm_maskl
  #undef key_perm_maskr
  #undef comp_maskl
  #undef comp_maskr
  #undef psbox
  