decrepit/cast/cast.c - boringssl - Git at Google

 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
  * This package is an SSL implementation written
  * by Eric Young (eay@cryptsoft.com).
  * The implementation was written so as to conform with Netscapes SSL.
  *
  * This library is free for commercial and non-commercial use as long as
  * the following conditions are aheared to.  The following conditions
  * apply to all code found in this distribution, be it the RC4, RSA,
  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  * included with this distribution is covered by the same copyright terms
  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  *
  * Copyright remains Eric Young's, and as such any Copyright notices in
  * the code are not to be removed.
  * If this package is used in a product, Eric Young should be given attribution
  * as the author of the parts of the library used.
  * This can be in the form of a textual message at program startup or
  * in documentation (online or textual) provided with the package.
  *
  * 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 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. All advertising materials mentioning features or use of this software
  *    must display the following acknowledgement:
  *    "This product includes cryptographic software written by
  *     Eric Young (eay@cryptsoft.com)"
  *    The word 'cryptographic' can be left out if the rouines from the library
  *    being used are not cryptographic related :-).
  * 4. If you include any Windows specific code (or a derivative thereof) from
  *    the apps directory (application code) you must include an acknowledgement:
  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  *
  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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.
  *
  * The licence and distribution terms for any publically available version or
  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  * copied and put under another distribution licence
  * [including the GNU Public Licence.]. */

 #include <openssl/cast.h>

 #if defined(OPENSSL_WINDOWS)
 #pragma warning(push, 3)
 #include <intrin.h>
 #pragma warning(pop)
 #endif

 #include "internal.h"
 #include "../macros.h"


 void CAST_ecb_encrypt(const uint8_t *in, uint8_t *out, const CAST_KEY *ks,
                       int enc) {
   uint32_t d[2];

   n2l(in, d[0]);
   n2l(in, d[1]);
   if (enc) {
     CAST_encrypt(d, ks);
   } else {
     CAST_decrypt(d, ks);
   }
   l2n(d[0], out);
   l2n(d[1], out);
 }

 #if defined(OPENSSL_WINDOWS) && defined(_MSC_VER)
 #define ROTL(a, n) (_lrotl(a, n))
 #else
 #define ROTL(a, n) ((((a) << (n)) | ((a) >> ((-(n))&31))) & 0xffffffffL)
 #endif

 #define E_CAST(n, key, L, R, OP1, OP2, OP3)                                   \
   {                                                                           \
     uint32_t a, b, c, d;                                                      \
     t = (key[n * 2] OP1 R) & 0xffffffff;                                      \
     t = ROTL(t, (key[n * 2 + 1]));                                            \
     a = CAST_S_table0[(t >> 8) & 0xff];                                       \
     b = CAST_S_table1[(t)&0xff];                                              \
     c = CAST_S_table2[(t >> 24) & 0xff];                                      \
     d = CAST_S_table3[(t >> 16) & 0xff];                                      \
     L ^= (((((a OP2 b)&0xffffffffL)OP3 c) & 0xffffffffL)OP1 d) & 0xffffffffL; \
   }

 void CAST_encrypt(uint32_t *data, const CAST_KEY *key) {
   uint32_t l, r, t;
   const uint32_t *k;

   k = &key->data[0];
   l = data[0];
   r = data[1];

   E_CAST(0, k, l, r, +, ^, -);
   E_CAST(1, k, r, l, ^, -, +);
   E_CAST(2, k, l, r, -, +, ^);
   E_CAST(3, k, r, l, +, ^, -);
   E_CAST(4, k, l, r, ^, -, +);
   E_CAST(5, k, r, l, -, +, ^);
   E_CAST(6, k, l, r, +, ^, -);
   E_CAST(7, k, r, l, ^, -, +);
   E_CAST(8, k, l, r, -, +, ^);
   E_CAST(9, k, r, l, +, ^, -);
   E_CAST(10, k, l, r, ^, -, +);
   E_CAST(11, k, r, l, -, +, ^);

   if (!key->short_key) {
     E_CAST(12, k, l, r, +, ^, -);
     E_CAST(13, k, r, l, ^, -, +);
     E_CAST(14, k, l, r, -, +, ^);
     E_CAST(15, k, r, l, +, ^, -);
   }

   data[1] = l & 0xffffffffL;
   data[0] = r & 0xffffffffL;
 }

 void CAST_decrypt(uint32_t *data, const CAST_KEY *key) {
   uint32_t l, r, t;
   const uint32_t *k;

   k = &key->data[0];
   l = data[0];
   r = data[1];

   if (!key->short_key) {
     E_CAST(15, k, l, r, +, ^, -);
     E_CAST(14, k, r, l, -, +, ^);
     E_CAST(13, k, l, r, ^, -, +);
     E_CAST(12, k, r, l, +, ^, -);
   }

   E_CAST(11, k, l, r, -, +, ^);
   E_CAST(10, k, r, l, ^, -, +);
   E_CAST(9, k, l, r, +, ^, -);
   E_CAST(8, k, r, l, -, +, ^);
   E_CAST(7, k, l, r, ^, -, +);
   E_CAST(6, k, r, l, +, ^, -);
   E_CAST(5, k, l, r, -, +, ^);
   E_CAST(4, k, r, l, ^, -, +);
   E_CAST(3, k, l, r, +, ^, -);
   E_CAST(2, k, r, l, -, +, ^);
   E_CAST(1, k, l, r, ^, -, +);
   E_CAST(0, k, r, l, +, ^, -);

   data[1] = l & 0xffffffffL;
   data[0] = r & 0xffffffffL;
 }

 void CAST_cbc_encrypt(const uint8_t *in, uint8_t *out, long length,
                       const CAST_KEY *ks, uint8_t *iv, int enc) {
   uint32_t tin0, tin1;
   uint32_t tout0, tout1, xor0, xor1;
   long l = length;
   uint32_t tin[2];

   if (enc) {
     n2l(iv, tout0);
     n2l(iv, tout1);
     iv -= 8;
     for (l -= 8; l >= 0; l -= 8) {
       n2l(in, tin0);
       n2l(in, tin1);
       tin0 ^= tout0;
       tin1 ^= tout1;
       tin[0] = tin0;
       tin[1] = tin1;
       CAST_encrypt(tin, ks);
       tout0 = tin[0];
       tout1 = tin[1];
       l2n(tout0, out);
       l2n(tout1, out);
     }
     if (l != -8) {
       n2ln(in, tin0, tin1, l + 8);
       tin0 ^= tout0;
       tin1 ^= tout1;
       tin[0] = tin0;
       tin[1] = tin1;
       CAST_encrypt(tin, ks);
       tout0 = tin[0];
       tout1 = tin[1];
       l2n(tout0, out);
       l2n(tout1, out);
     }
     l2n(tout0, iv);
     l2n(tout1, iv);
   } else {
     n2l(iv, xor0);
     n2l(iv, xor1);
     iv -= 8;
     for (l -= 8; l >= 0; l -= 8) {
       n2l(in, tin0);
       n2l(in, tin1);
       tin[0] = tin0;
       tin[1] = tin1;
       CAST_decrypt(tin, ks);
       tout0 = tin[0] ^ xor0;
       tout1 = tin[1] ^ xor1;
       l2n(tout0, out);
       l2n(tout1, out);
       xor0 = tin0;
       xor1 = tin1;
     }
     if (l != -8) {
       n2l(in, tin0);
       n2l(in, tin1);
       tin[0] = tin0;
       tin[1] = tin1;
       CAST_decrypt(tin, ks);
       tout0 = tin[0] ^ xor0;
       tout1 = tin[1] ^ xor1;
       l2nn(tout0, tout1, out, l + 8);
       xor0 = tin0;
       xor1 = tin1;
     }
     l2n(xor0, iv);
     l2n(xor1, iv);
   }
   tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;
   tin[0] = tin[1] = 0;
 }

 #define CAST_exp(l, A, a, n)   \
   A[n / 4] = l;                \
   a[n + 3] = (l)&0xff;         \
   a[n + 2] = (l >> 8) & 0xff;  \
   a[n + 1] = (l >> 16) & 0xff; \
   a[n + 0] = (l >> 24) & 0xff;
 #define S4 CAST_S_table4
 #define S5 CAST_S_table5
 #define S6 CAST_S_table6
 #define S7 CAST_S_table7

 void CAST_set_key(CAST_KEY *key, size_t len, const uint8_t *data) {
   uint32_t x[16];
   uint32_t z[16];
   uint32_t k[32];
   uint32_t X[4], Z[4];
   uint32_t l, *K;
   size_t i;

   for (i = 0; i < 16; i++) {
     x[i] = 0;
   }

   if (len > 16) {
     len = 16;
   }

   for (i = 0; i < len; i++) {
     x[i] = data[i];
   }

   if (len <= 10) {
     key->short_key = 1;
   } else {
     key->short_key = 0;
   }

   K = &k[0];
   X[0] = ((x[0] << 24) | (x[1] << 16) | (x[2] << 8) | x[3]) & 0xffffffffL;
   X[1] = ((x[4] << 24) | (x[5] << 16) | (x[6] << 8) | x[7]) & 0xffffffffL;
   X[2] = ((x[8] << 24) | (x[9] << 16) | (x[10] << 8) | x[11]) & 0xffffffffL;
   X[3] = ((x[12] << 24) | (x[13] << 16) | (x[14] << 8) | x[15]) & 0xffffffffL;

   for (;;) {
     l = X[0] ^ S4[x[13]] ^ S5[x[15]] ^ S6[x[12]] ^ S7[x[14]] ^ S6[x[8]];
     CAST_exp(l, Z, z, 0);
     l = X[2] ^ S4[z[0]] ^ S5[z[2]] ^ S6[z[1]] ^ S7[z[3]] ^ S7[x[10]];
     CAST_exp(l, Z, z, 4);
     l = X[3] ^ S4[z[7]] ^ S5[z[6]] ^ S6[z[5]] ^ S7[z[4]] ^ S4[x[9]];
     CAST_exp(l, Z, z, 8);
     l = X[1] ^ S4[z[10]] ^ S5[z[9]] ^ S6[z[11]] ^ S7[z[8]] ^ S5[x[11]];
     CAST_exp(l, Z, z, 12);

     K[0] = S4[z[8]] ^ S5[z[9]] ^ S6[z[7]] ^ S7[z[6]] ^ S4[z[2]];
     K[1] = S4[z[10]] ^ S5[z[11]] ^ S6[z[5]] ^ S7[z[4]] ^ S5[z[6]];
     K[2] = S4[z[12]] ^ S5[z[13]] ^ S6[z[3]] ^ S7[z[2]] ^ S6[z[9]];
     K[3] = S4[z[14]] ^ S5[z[15]] ^ S6[z[1]] ^ S7[z[0]] ^ S7[z[12]];

     l = Z[2] ^ S4[z[5]] ^ S5[z[7]] ^ S6[z[4]] ^ S7[z[6]] ^ S6[z[0]];
     CAST_exp(l, X, x, 0);
     l = Z[0] ^ S4[x[0]] ^ S5[x[2]] ^ S6[x[1]] ^ S7[x[3]] ^ S7[z[2]];
     CAST_exp(l, X, x, 4);
     l = Z[1] ^ S4[x[7]] ^ S5[x[6]] ^ S6[x[5]] ^ S7[x[4]] ^ S4[z[1]];
     CAST_exp(l, X, x, 8);
     l = Z[3] ^ S4[x[10]] ^ S5[x[9]] ^ S6[x[11]] ^ S7[x[8]] ^ S5[z[3]];
     CAST_exp(l, X, x, 12);

     K[4] = S4[x[3]] ^ S5[x[2]] ^ S6[x[12]] ^ S7[x[13]] ^ S4[x[8]];
     K[5] = S4[x[1]] ^ S5[x[0]] ^ S6[x[14]] ^ S7[x[15]] ^ S5[x[13]];
     K[6] = S4[x[7]] ^ S5[x[6]] ^ S6[x[8]] ^ S7[x[9]] ^ S6[x[3]];
     K[7] = S4[x[5]] ^ S5[x[4]] ^ S6[x[10]] ^ S7[x[11]] ^ S7[x[7]];

     l = X[0] ^ S4[x[13]] ^ S5[x[15]] ^ S6[x[12]] ^ S7[x[14]] ^ S6[x[8]];
     CAST_exp(l, Z, z, 0);
     l = X[2] ^ S4[z[0]] ^ S5[z[2]] ^ S6[z[1]] ^ S7[z[3]] ^ S7[x[10]];
     CAST_exp(l, Z, z, 4);
     l = X[3] ^ S4[z[7]] ^ S5[z[6]] ^ S6[z[5]] ^ S7[z[4]] ^ S4[x[9]];
     CAST_exp(l, Z, z, 8);
     l = X[1] ^ S4[z[10]] ^ S5[z[9]] ^ S6[z[11]] ^ S7[z[8]] ^ S5[x[11]];
     CAST_exp(l, Z, z, 12);

     K[8] = S4[z[3]] ^ S5[z[2]] ^ S6[z[12]] ^ S7[z[13]] ^ S4[z[9]];
     K[9] = S4[z[1]] ^ S5[z[0]] ^ S6[z[14]] ^ S7[z[15]] ^ S5[z[12]];
     K[10] = S4[z[7]] ^ S5[z[6]] ^ S6[z[8]] ^ S7[z[9]] ^ S6[z[2]];
     K[11] = S4[z[5]] ^ S5[z[4]] ^ S6[z[10]] ^ S7[z[11]] ^ S7[z[6]];

     l = Z[2] ^ S4[z[5]] ^ S5[z[7]] ^ S6[z[4]] ^ S7[z[6]] ^ S6[z[0]];
     CAST_exp(l, X, x, 0);
     l = Z[0] ^ S4[x[0]] ^ S5[x[2]] ^ S6[x[1]] ^ S7[x[3]] ^ S7[z[2]];
     CAST_exp(l, X, x, 4);
     l = Z[1] ^ S4[x[7]] ^ S5[x[6]] ^ S6[x[5]] ^ S7[x[4]] ^ S4[z[1]];
     CAST_exp(l, X, x, 8);
     l = Z[3] ^ S4[x[10]] ^ S5[x[9]] ^ S6[x[11]] ^ S7[x[8]] ^ S5[z[3]];
     CAST_exp(l, X, x, 12);

     K[12] = S4[x[8]] ^ S5[x[9]] ^ S6[x[7]] ^ S7[x[6]] ^ S4[x[3]];
     K[13] = S4[x[10]] ^ S5[x[11]] ^ S6[x[5]] ^ S7[x[4]] ^ S5[x[7]];
     K[14] = S4[x[12]] ^ S5[x[13]] ^ S6[x[3]] ^ S7[x[2]] ^ S6[x[8]];
     K[15] = S4[x[14]] ^ S5[x[15]] ^ S6[x[1]] ^ S7[x[0]] ^ S7[x[13]];
     if (K != k) {
       break;
     }
     K += 16;
   }

   for (i = 0; i < 16; i++) {
     key->data[i * 2] = k[i];
     key->data[i * 2 + 1] = ((k[i + 16]) + 16) & 0x1f;
   }
 }

 /* The input and output encrypted as though 64bit cfb mode is being used. The
  * extra state information to record how much of the 64bit block we have used
  * is contained in *num. */
 void CAST_cfb64_encrypt(const uint8_t *in, uint8_t *out, long length,
                         const CAST_KEY *schedule, uint8_t *ivec, int *num,
                         int enc) {
   uint32_t v0, v1, t;
   int n = *num;
   long l = length;
   uint32_t ti[2];
   uint8_t *iv, c, cc;

   iv = ivec;
   if (enc) {
     while (l--) {
       if (n == 0) {
         n2l(iv, v0);
         ti[0] = v0;
         n2l(iv, v1);
         ti[1] = v1;
         CAST_encrypt((uint32_t *)ti, schedule);
         iv = ivec;
         t = ti[0];
         l2n(t, iv);
         t = ti[1];
         l2n(t, iv);
         iv = ivec;
       }
       c = *(in++) ^ iv[n];
       *(out++) = c;
       iv[n] = c;
       n = (n + 1) & 0x07;
     }
   } else {
     while (l--) {
       if (n == 0) {
         n2l(iv, v0);
         ti[0] = v0;
         n2l(iv, v1);
         ti[1] = v1;
         CAST_encrypt((uint32_t *)ti, schedule);
         iv = ivec;
         t = ti[0];
         l2n(t, iv);
         t = ti[1];
         l2n(t, iv);
         iv = ivec;
       }
       cc = *(in++);
       c = iv[n];
       iv[n] = cc;
       *(out++) = c ^ cc;
       n = (n + 1) & 0x07;
     }
   }
   v0 = v1 = ti[0] = ti[1] = t = c = cc = 0;
   *num = n;
 }
	/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
	* All rights reserved.
	*
	* This package is an SSL implementation written
	* by Eric Young (eay@cryptsoft.com).
	* The implementation was written so as to conform with Netscapes SSL.
	*
	* This library is free for commercial and non-commercial use as long as
	* the following conditions are aheared to. The following conditions
	* apply to all code found in this distribution, be it the RC4, RSA,
	* lhash, DES, etc., code; not just the SSL code. The SSL documentation
	* included with this distribution is covered by the same copyright terms
	* except that the holder is Tim Hudson (tjh@cryptsoft.com).
	*
	* Copyright remains Eric Young's, and as such any Copyright notices in
	* the code are not to be removed.
	* If this package is used in a product, Eric Young should be given attribution
	* as the author of the parts of the library used.
	* This can be in the form of a textual message at program startup or
	* in documentation (online or textual) provided with the package.
	*
	* 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 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. All advertising materials mentioning features or use of this software
	* must display the following acknowledgement:
	* "This product includes cryptographic software written by
	* Eric Young (eay@cryptsoft.com)"
	* The word 'cryptographic' can be left out if the rouines from the library
	* being used are not cryptographic related :-).
	* 4. If you include any Windows specific code (or a derivative thereof) from
	* the apps directory (application code) you must include an acknowledgement:
	* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
	*
	* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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.
	*
	* The licence and distribution terms for any publically available version or
	* derivative of this code cannot be changed. i.e. this code cannot simply be
	* copied and put under another distribution licence
	* [including the GNU Public Licence.]. */

	#include <openssl/cast.h>

	#if defined(OPENSSL_WINDOWS)
	#pragma warning(push, 3)
	#include <intrin.h>
	#pragma warning(pop)
	#endif

	#include "internal.h"
	#include "../macros.h"


	void CAST_ecb_encrypt(const uint8_t in, uint8_t out, const CAST_KEY *ks,
	int enc) {
	uint32_t d[2];

	n2l(in, d[0]);
	n2l(in, d[1]);
	if (enc) {
	CAST_encrypt(d, ks);
	} else {
	CAST_decrypt(d, ks);
	}
	l2n(d[0], out);
	l2n(d[1], out);
	}

	#if defined(OPENSSL_WINDOWS) && defined(_MSC_VER)
	#define ROTL(a, n) (_lrotl(a, n))
	#else
	#define ROTL(a, n) ((((a) << (n)) \| ((a) >> ((-(n))&31))) & 0xffffffffL)
	#endif

	#define E_CAST(n, key, L, R, OP1, OP2, OP3) \
	{ \
	uint32_t a, b, c, d; \
	t = (key[n * 2] OP1 R) & 0xffffffff; \
	t = ROTL(t, (key[n * 2 + 1])); \
	a = CAST_S_table0[(t >> 8) & 0xff]; \
	b = CAST_S_table1[(t)&0xff]; \
	c = CAST_S_table2[(t >> 24) & 0xff]; \
	d = CAST_S_table3[(t >> 16) & 0xff]; \
	L ^= (((((a OP2 b)&0xffffffffL)OP3 c) & 0xffffffffL)OP1 d) & 0xffffffffL; \
	}

	void CAST_encrypt(uint32_t data, const CAST_KEY key) {
	uint32_t l, r, t;
	const uint32_t *k;

	k = &key->data[0];
	l = data[0];
	r = data[1];

	E_CAST(0, k, l, r, +, ^, -);
	E_CAST(1, k, r, l, ^, -, +);
	E_CAST(2, k, l, r, -, +, ^);
	E_CAST(3, k, r, l, +, ^, -);
	E_CAST(4, k, l, r, ^, -, +);
	E_CAST(5, k, r, l, -, +, ^);
	E_CAST(6, k, l, r, +, ^, -);
	E_CAST(7, k, r, l, ^, -, +);
	E_CAST(8, k, l, r, -, +, ^);
	E_CAST(9, k, r, l, +, ^, -);
	E_CAST(10, k, l, r, ^, -, +);
	E_CAST(11, k, r, l, -, +, ^);

	if (!key->short_key) {
	E_CAST(12, k, l, r, +, ^, -);
	E_CAST(13, k, r, l, ^, -, +);
	E_CAST(14, k, l, r, -, +, ^);
	E_CAST(15, k, r, l, +, ^, -);
	}

	data[1] = l & 0xffffffffL;
	data[0] = r & 0xffffffffL;
	}

	void CAST_decrypt(uint32_t data, const CAST_KEY key) {
	uint32_t l, r, t;
	const uint32_t *k;

	k = &key->data[0];
	l = data[0];
	r = data[1];

	if (!key->short_key) {
	E_CAST(15, k, l, r, +, ^, -);
	E_CAST(14, k, r, l, -, +, ^);
	E_CAST(13, k, l, r, ^, -, +);
	E_CAST(12, k, r, l, +, ^, -);
	}

	E_CAST(11, k, l, r, -, +, ^);
	E_CAST(10, k, r, l, ^, -, +);
	E_CAST(9, k, l, r, +, ^, -);
	E_CAST(8, k, r, l, -, +, ^);
	E_CAST(7, k, l, r, ^, -, +);
	E_CAST(6, k, r, l, +, ^, -);
	E_CAST(5, k, l, r, -, +, ^);
	E_CAST(4, k, r, l, ^, -, +);
	E_CAST(3, k, l, r, +, ^, -);
	E_CAST(2, k, r, l, -, +, ^);
	E_CAST(1, k, l, r, ^, -, +);
	E_CAST(0, k, r, l, +, ^, -);

	data[1] = l & 0xffffffffL;
	data[0] = r & 0xffffffffL;
	}

	void CAST_cbc_encrypt(const uint8_t in, uint8_t out, long length,
	const CAST_KEY ks, uint8_t iv, int enc) {
	uint32_t tin0, tin1;
	uint32_t tout0, tout1, xor0, xor1;
	long l = length;
	uint32_t tin[2];

	if (enc) {
	n2l(iv, tout0);
	n2l(iv, tout1);
	iv -= 8;
	for (l -= 8; l >= 0; l -= 8) {
	n2l(in, tin0);
	n2l(in, tin1);
	tin0 ^= tout0;
	tin1 ^= tout1;
	tin[0] = tin0;
	tin[1] = tin1;
	CAST_encrypt(tin, ks);
	tout0 = tin[0];
	tout1 = tin[1];
	l2n(tout0, out);
	l2n(tout1, out);
	}
	if (l != -8) {
	n2ln(in, tin0, tin1, l + 8);
	tin0 ^= tout0;
	tin1 ^= tout1;
	tin[0] = tin0;
	tin[1] = tin1;
	CAST_encrypt(tin, ks);
	tout0 = tin[0];
	tout1 = tin[1];
	l2n(tout0, out);
	l2n(tout1, out);
	}
	l2n(tout0, iv);
	l2n(tout1, iv);
	} else {
	n2l(iv, xor0);
	n2l(iv, xor1);
	iv -= 8;
	for (l -= 8; l >= 0; l -= 8) {
	n2l(in, tin0);
	n2l(in, tin1);
	tin[0] = tin0;
	tin[1] = tin1;
	CAST_decrypt(tin, ks);
	tout0 = tin[0] ^ xor0;
	tout1 = tin[1] ^ xor1;
	l2n(tout0, out);
	l2n(tout1, out);
	xor0 = tin0;
	xor1 = tin1;
	}
	if (l != -8) {
	n2l(in, tin0);
	n2l(in, tin1);
	tin[0] = tin0;
	tin[1] = tin1;
	CAST_decrypt(tin, ks);
	tout0 = tin[0] ^ xor0;
	tout1 = tin[1] ^ xor1;
	l2nn(tout0, tout1, out, l + 8);
	xor0 = tin0;
	xor1 = tin1;
	}
	l2n(xor0, iv);
	l2n(xor1, iv);
	}
	tin0 = tin1 = tout0 = tout1 = xor0 = xor1 = 0;
	tin[0] = tin[1] = 0;
	}

	#define CAST_exp(l, A, a, n) \
	A[n / 4] = l; \
	a[n + 3] = (l)&0xff; \
	a[n + 2] = (l >> 8) & 0xff; \
	a[n + 1] = (l >> 16) & 0xff; \
	a[n + 0] = (l >> 24) & 0xff;
	#define S4 CAST_S_table4
	#define S5 CAST_S_table5
	#define S6 CAST_S_table6
	#define S7 CAST_S_table7

	void CAST_set_key(CAST_KEY key, size_t len, const uint8_t data) {
	uint32_t x[16];
	uint32_t z[16];
	uint32_t k[32];
	uint32_t X[4], Z[4];
	uint32_t l, *K;
	size_t i;

	for (i = 0; i < 16; i++) {
	x[i] = 0;
	}

	if (len > 16) {
	len = 16;
	}

	for (i = 0; i < len; i++) {
	x[i] = data[i];
	}

	if (len <= 10) {
	key->short_key = 1;
	} else {
	key->short_key = 0;
	}

	K = &k[0];
	X[0] = ((x[0] << 24) \| (x[1] << 16) \| (x[2] << 8) \| x[3]) & 0xffffffffL;
	X[1] = ((x[4] << 24) \| (x[5] << 16) \| (x[6] << 8) \| x[7]) & 0xffffffffL;
	X[2] = ((x[8] << 24) \| (x[9] << 16) \| (x[10] << 8) \| x[11]) & 0xffffffffL;
	X[3] = ((x[12] << 24) \| (x[13] << 16) \| (x[14] << 8) \| x[15]) & 0xffffffffL;

	for (;;) {
	l = X[0] ^ S4[x[13]] ^ S5[x[15]] ^ S6[x[12]] ^ S7[x[14]] ^ S6[x[8]];
	CAST_exp(l, Z, z, 0);
	l = X[2] ^ S4[z[0]] ^ S5[z[2]] ^ S6[z[1]] ^ S7[z[3]] ^ S7[x[10]];
	CAST_exp(l, Z, z, 4);
	l = X[3] ^ S4[z[7]] ^ S5[z[6]] ^ S6[z[5]] ^ S7[z[4]] ^ S4[x[9]];
	CAST_exp(l, Z, z, 8);
	l = X[1] ^ S4[z[10]] ^ S5[z[9]] ^ S6[z[11]] ^ S7[z[8]] ^ S5[x[11]];
	CAST_exp(l, Z, z, 12);

	K[0] = S4[z[8]] ^ S5[z[9]] ^ S6[z[7]] ^ S7[z[6]] ^ S4[z[2]];
	K[1] = S4[z[10]] ^ S5[z[11]] ^ S6[z[5]] ^ S7[z[4]] ^ S5[z[6]];
	K[2] = S4[z[12]] ^ S5[z[13]] ^ S6[z[3]] ^ S7[z[2]] ^ S6[z[9]];
	K[3] = S4[z[14]] ^ S5[z[15]] ^ S6[z[1]] ^ S7[z[0]] ^ S7[z[12]];

	l = Z[2] ^ S4[z[5]] ^ S5[z[7]] ^ S6[z[4]] ^ S7[z[6]] ^ S6[z[0]];
	CAST_exp(l, X, x, 0);
	l = Z[0] ^ S4[x[0]] ^ S5[x[2]] ^ S6[x[1]] ^ S7[x[3]] ^ S7[z[2]];
	CAST_exp(l, X, x, 4);
	l = Z[1] ^ S4[x[7]] ^ S5[x[6]] ^ S6[x[5]] ^ S7[x[4]] ^ S4[z[1]];
	CAST_exp(l, X, x, 8);
	l = Z[3] ^ S4[x[10]] ^ S5[x[9]] ^ S6[x[11]] ^ S7[x[8]] ^ S5[z[3]];
	CAST_exp(l, X, x, 12);

	K[4] = S4[x[3]] ^ S5[x[2]] ^ S6[x[12]] ^ S7[x[13]] ^ S4[x[8]];
	K[5] = S4[x[1]] ^ S5[x[0]] ^ S6[x[14]] ^ S7[x[15]] ^ S5[x[13]];
	K[6] = S4[x[7]] ^ S5[x[6]] ^ S6[x[8]] ^ S7[x[9]] ^ S6[x[3]];
	K[7] = S4[x[5]] ^ S5[x[4]] ^ S6[x[10]] ^ S7[x[11]] ^ S7[x[7]];

	l = X[0] ^ S4[x[13]] ^ S5[x[15]] ^ S6[x[12]] ^ S7[x[14]] ^ S6[x[8]];
	CAST_exp(l, Z, z, 0);
	l = X[2] ^ S4[z[0]] ^ S5[z[2]] ^ S6[z[1]] ^ S7[z[3]] ^ S7[x[10]];
	CAST_exp(l, Z, z, 4);
	l = X[3] ^ S4[z[7]] ^ S5[z[6]] ^ S6[z[5]] ^ S7[z[4]] ^ S4[x[9]];
	CAST_exp(l, Z, z, 8);
	l = X[1] ^ S4[z[10]] ^ S5[z[9]] ^ S6[z[11]] ^ S7[z[8]] ^ S5[x[11]];
	CAST_exp(l, Z, z, 12);

	K[8] = S4[z[3]] ^ S5[z[2]] ^ S6[z[12]] ^ S7[z[13]] ^ S4[z[9]];
	K[9] = S4[z[1]] ^ S5[z[0]] ^ S6[z[14]] ^ S7[z[15]] ^ S5[z[12]];
	K[10] = S4[z[7]] ^ S5[z[6]] ^ S6[z[8]] ^ S7[z[9]] ^ S6[z[2]];
	K[11] = S4[z[5]] ^ S5[z[4]] ^ S6[z[10]] ^ S7[z[11]] ^ S7[z[6]];

	l = Z[2] ^ S4[z[5]] ^ S5[z[7]] ^ S6[z[4]] ^ S7[z[6]] ^ S6[z[0]];
	CAST_exp(l, X, x, 0);
	l = Z[0] ^ S4[x[0]] ^ S5[x[2]] ^ S6[x[1]] ^ S7[x[3]] ^ S7[z[2]];
	CAST_exp(l, X, x, 4);
	l = Z[1] ^ S4[x[7]] ^ S5[x[6]] ^ S6[x[5]] ^ S7[x[4]] ^ S4[z[1]];
	CAST_exp(l, X, x, 8);
	l = Z[3] ^ S4[x[10]] ^ S5[x[9]] ^ S6[x[11]] ^ S7[x[8]] ^ S5[z[3]];
	CAST_exp(l, X, x, 12);

	K[12] = S4[x[8]] ^ S5[x[9]] ^ S6[x[7]] ^ S7[x[6]] ^ S4[x[3]];
	K[13] = S4[x[10]] ^ S5[x[11]] ^ S6[x[5]] ^ S7[x[4]] ^ S5[x[7]];
	K[14] = S4[x[12]] ^ S5[x[13]] ^ S6[x[3]] ^ S7[x[2]] ^ S6[x[8]];
	K[15] = S4[x[14]] ^ S5[x[15]] ^ S6[x[1]] ^ S7[x[0]] ^ S7[x[13]];
	if (K != k) {
	break;
	}
	K += 16;
	}

	for (i = 0; i < 16; i++) {
	key->data[i * 2] = k[i];
	key->data[i * 2 + 1] = ((k[i + 16]) + 16) & 0x1f;
	}
	}

	/* The input and output encrypted as though 64bit cfb mode is being used. The
	* extra state information to record how much of the 64bit block we have used
	* is contained in num. /
	void CAST_cfb64_encrypt(const uint8_t in, uint8_t out, long length,
	const CAST_KEY schedule, uint8_t ivec, int *num,
	int enc) {
	uint32_t v0, v1, t;
	int n = *num;
	long l = length;
	uint32_t ti[2];
	uint8_t *iv, c, cc;

	iv = ivec;
	if (enc) {
	while (l--) {
	if (n == 0) {
	n2l(iv, v0);
	ti[0] = v0;
	n2l(iv, v1);
	ti[1] = v1;
	CAST_encrypt((uint32_t *)ti, schedule);
	iv = ivec;
	t = ti[0];
	l2n(t, iv);
	t = ti[1];
	l2n(t, iv);
	iv = ivec;
	}
	c = *(in++) ^ iv[n];
	*(out++) = c;
	iv[n] = c;
	n = (n + 1) & 0x07;
	}
	} else {
	while (l--) {
	if (n == 0) {
	n2l(iv, v0);
	ti[0] = v0;
	n2l(iv, v1);
	ti[1] = v1;
	CAST_encrypt((uint32_t *)ti, schedule);
	iv = ivec;
	t = ti[0];
	l2n(t, iv);
	t = ti[1];
	l2n(t, iv);
	iv = ivec;
	}
	cc = *(in++);
	c = iv[n];
	iv[n] = cc;
	*(out++) = c ^ cc;
	n = (n + 1) & 0x07;
	}
	}
	v0 = v1 = ti[0] = ti[1] = t = c = cc = 0;
	*num = n;
	}