spritz/spritz%2B%2B.h

/* spritz++, C++ header-only implementation
 *
 * Copyright (c) 2015 Marc Alexander Lehmann <libev@schmorp.de>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modifica-
 * tion, 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
 * CIAL, 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 OTH-
 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License ("GPL") version 2 or any later version,
 * in which case the provisions of the GPL are applicable instead of
 * the above. If you wish to allow the use of your version of this file
 * only under the terms of the GPL and not to allow others to use your
 * version of this file under the BSD license, indicate your decision
 * by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL. If you do not delete the
 * provisions above, a recipient may use your version of this file under
 * either the BSD or the GPL.
 */

#include <assert.h>
#include <stdint.h>
#include <sys/types.h>

struct spritz
{
  enum { N = 256 };

  uint8_t a, i, j, k, z, w;
  uint8_t S[N];

  spritz ()
  {
    a =
    i =
    j =
    k =
    z = 0;
    w = 1;

    uint_fast8_t v = N - 1;
    do
      S[v] = v;
    while (v--);
  }

  void update ()
  {
    i += w;
    j = k + S[j + S[i]];
    k = k + i + S[j];
    swap (S[i], S[j]);
  }

  void whip (uint_fast16_t r)
  {
    while (r--)
      update ();

    w += 2;
  }

  static void swap (uint8_t &a, uint8_t &b)
  {
    uint8_t c = a;
            a = b;
            b = c;
  }

  void crush ()
  {
    for (uint_fast16_t v = 0; v < (N >> 1); ++v)
      if (S[v] > S[N - 1 - v])
        swap (S[v], S[N - 1 - v]);
  }

  void shuffle ()
  {
    whip (2 * N); crush ();
    whip (2 * N); crush ();
    whip (2 * N);

    a = 0;
  }

  void shuffle_absorb ()
  {
    if (a == (N >> 1))
      shuffle ();
  }

  void absorb_nibble (uint8_t x)
  {
    shuffle_absorb ();

    swap (S[a], S[(N >> 1) + x]);
    ++a;
  }

  void absorb_byte (uint8_t b)
  {
    absorb_nibble (b & 15);
    absorb_nibble (b >> 4);
  }
  
  void absorb (const void *I, size_t I_len)
  {
    uint8_t *i = (uint8_t *)I;

    while (I_len--)
      absorb_byte (*i++);
  }

  void absorb_stop ()
  {
    shuffle_absorb ();

    ++a;
  }

  // commonly used helper function
  void absorb_stop (const void *I, size_t I_len)
  {
    absorb (I, I_len);
    absorb_stop ();
  }

  void shuffle_squeeze ()
  {
    if (a)
      shuffle ();
  }

  uint8_t output ()
  {
    return S[j + S[i + S[z + k]]];
  }

  // slightly faster internal helper, drip without squeeze preparation
  uint8_t drip_nosqueeze ()
  {
    update ();
    return output ();
  }

  void squeeze (void *P, size_t P_len)
  {
    shuffle_squeeze ();

    uint8_t *p = (uint8_t *)P;

    while (P_len--)
      *p++ = drip_nosqueeze ();
  }

  uint8_t drip ()
  {
    shuffle_squeeze ();

    return drip_nosqueeze ();
  }
};

// what follows is wrappers that make using spritz easier and less error-prone

// spritz-xor variant of cipher
struct spritz_xor : protected spritz
{
  // key K required, IV optional
  spritz_xor (const void *K, size_t K_len, const void *IV = 0, size_t IV_len = 0)
  {
    absorb (K, K_len);

    if (IV)
      {
        absorb_stop ();
        absorb (IV, IV_len);
      }

    shuffle_squeeze ();
  }

  // can be called multiple times/incrementally
  // can work inplace
  // works for both encryption and decryption
  void crypt (const void *I, void *O, size_t len)
  {
    const uint8_t *i = (const uint8_t *)I;
          uint8_t *o = (      uint8_t *)O;

    while (len--)
      *o++ = *i++ ^ drip_nosqueeze ();
  }
};

struct spritz_hash : protected spritz
{
  spritz_hash ()
  {
  }

  // can be called multiple times/incrementally
  void add (const void *M, size_t M_len)
  {
    absorb (M, M_len);
  }

  // must be called at most once at the end
  void hash (void *H, size_t H_len)
  {
    absorb_stop ();
    assert (H_len <= 0xff);
    absorb_byte (H_len);

    squeeze (H, H_len);
  }
};

struct spritz_mac : protected spritz_hash
{
  spritz_mac (const void *K, size_t K_len)
  {
    absorb_stop (K, K_len);
  }

  // use add to incrementally add data
  using spritz_hash::add;

  // must be called at most once at the end
  void mac (void *H, size_t H_len)
  {
    hash (H, H_len);
  }
};

struct spritz_aead : protected spritz_mac
{
  spritz_aead (const void *K, size_t K_len)
  : spritz_mac (K, K_len)
  {
  }

  // must be called after construction, before data
  void nonce (const void *N, size_t N_len)
  {
    absorb_stop (N, N_len);
  }

  // must be called after nonce, before crypt
  void associated_data (const void *D, size_t D_len)
  {
    absorb_stop (D, D_len);
  }

  // must be called after data, only once, before mac
  // works for both encryption and decryption
  void crypt (const void *I, void *O, size_t len)
  {
    const uint8_t *i = (const uint8_t *)I;
          uint8_t *o = (      uint8_t *)O;

    uint8_t x[N >> 2];

    while (len)
      {
        uint8_t l = len > sizeof (x) ? sizeof (x) : len;
        len -= l;

        squeeze (x, l);

        for (uint_fast8_t j = 0; j < l; ++j)
          absorb_byte (*o++ = *i++ ^ x[j]);
      }
  }

  // call mac() at most once at the end
  using spritz_mac::mac;
};

struct spritz_drbg : protected spritz
{
  // seed optional, can be done via put
  spritz_drbg (const void *S = 0, size_t S_len = 0)
  {
    absorb (S, S_len);
  }

  // add additional entropy
  void put (const void *S, size_t S_len)
  {
    absorb (S, S_len);
  }

  // get random bytes
  void get (void *R, size_t R_len)
  {
    squeeze (R, R_len);
  }
};

Revision:	1.3
Committed:	Fri Jan 9 23:21:41 2015 UTC (9 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.2:	+37 -2 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.3	/* spritz++, C++ header-only implementation
2			*
3			* Copyright (c) 2015 Marc Alexander Lehmann <libev@schmorp.de>
4			* All rights reserved.
5			*
6			* Redistribution and use in source and binary forms, with or without modifica-
7			* tion, are permitted provided that the following conditions are met:
8			*
9			* 1. Redistributions of source code must retain the above copyright notice,
10			* this list of conditions and the following disclaimer.
11			*
12			* 2. Redistributions in binary form must reproduce the above copyright
13			* notice, this list of conditions and the following disclaimer in the
14			* documentation and/or other materials provided with the distribution.
15			*
16			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
18			* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19			* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
20			* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21			* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22			* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23			* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
24			* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
25			* OF THE POSSIBILITY OF SUCH DAMAGE.
26			*
27			* Alternatively, the contents of this file may be used under the terms of
28			* the GNU General Public License ("GPL") version 2 or any later version,
29			* in which case the provisions of the GPL are applicable instead of
30			* the above. If you wish to allow the use of your version of this file
31			* only under the terms of the GPL and not to allow others to use your
32			* version of this file under the BSD license, indicate your decision
33			* by deleting the provisions above and replace them with the notice
34			* and other provisions required by the GPL. If you do not delete the
35			* provisions above, a recipient may use your version of this file under
36			* either the BSD or the GPL.
37			*/
38	root	1.2
39	root	1.1	#include <assert.h>
40			#include <stdint.h>
41			#include <sys/types.h>
42
43			struct spritz
44			{
45			enum { N = 256 };
46
47			uint8_t a, i, j, k, z, w;
48			uint8_t S[N];
49
50			spritz ()
51			{
52			a =
53			i =
54			j =
55			k =
56			z = 0;
57			w = 1;
58
59			uint_fast8_t v = N - 1;
60			do
61			S[v] = v;
62			while (v--);
63			}
64
65			void update ()
66			{
67			i += w;
68			j = k + S[j + S[i]];
69			k = k + i + S[j];
70			swap (S[i], S[j]);
71			}
72
73			void whip (uint_fast16_t r)
74			{
75			while (r--)
76			update ();
77
78			w += 2;
79			}
80
81			static void swap (uint8_t &a, uint8_t &b)
82			{
83			uint8_t c = a;
84			a = b;
85			b = c;
86			}
87
88			void crush ()
89			{
90			for (uint_fast16_t v = 0; v < (N >> 1); ++v)
91			if (S[v] > S[N - 1 - v])
92			swap (S[v], S[N - 1 - v]);
93			}
94
95			void shuffle ()
96			{
97			whip (2 * N); crush ();
98			whip (2 * N); crush ();
99			whip (2 * N);
100
101			a = 0;
102			}
103
104			void shuffle_absorb ()
105			{
106			if (a == (N >> 1))
107			shuffle ();
108			}
109
110			void absorb_nibble (uint8_t x)
111			{
112			shuffle_absorb ();
113
114			swap (S[a], S[(N >> 1) + x]);
115			++a;
116			}
117
118			void absorb_byte (uint8_t b)
119			{
120			absorb_nibble (b & 15);
121			absorb_nibble (b >> 4);
122			}
123
124			void absorb (const void *I, size_t I_len)
125			{
126			uint8_t i = (uint8_t )I;
127
128			while (I_len--)
129			absorb_byte (*i++);
130			}
131
132			void absorb_stop ()
133			{
134			shuffle_absorb ();
135
136			++a;
137			}
138
139			// commonly used helper function
140			void absorb_stop (const void *I, size_t I_len)
141			{
142			absorb (I, I_len);
143			absorb_stop ();
144			}
145
146			void shuffle_squeeze ()
147			{
148			if (a)
149			shuffle ();
150			}
151
152			uint8_t output ()
153			{
154			return S[j + S[i + S[z + k]]];
155			}
156
157			// slightly faster internal helper, drip without squeeze preparation
158			uint8_t drip_nosqueeze ()
159			{
160			update ();
161			return output ();
162			}
163
164			void squeeze (void *P, size_t P_len)
165			{
166			shuffle_squeeze ();
167
168			uint8_t p = (uint8_t )P;
169
170			while (P_len--)
171			*p++ = drip_nosqueeze ();
172			}
173
174			uint8_t drip ()
175			{
176			shuffle_squeeze ();
177
178			return drip_nosqueeze ();
179			}
180			};
181
182			// what follows is wrappers that make using spritz easier and less error-prone
183
184			// spritz-xor variant of cipher
185			struct spritz_xor : protected spritz
186			{
187			// key K required, IV optional
188			spritz_xor (const void K, size_t K_len, const void IV = 0, size_t IV_len = 0)
189			{
190			absorb (K, K_len);
191
192			if (IV)
193			{
194			absorb_stop ();
195			absorb (IV, IV_len);
196			}
197
198			shuffle_squeeze ();
199			}
200
201			// can be called multiple times/incrementally
202			// can work inplace
203			// works for both encryption and decryption
204			void crypt (const void I, void O, size_t len)
205			{
206			const uint8_t i = (const uint8_t )I;
207			uint8_t o = ( uint8_t )O;
208
209			while (len--)
210			o++ = i++ ^ drip_nosqueeze ();
211			}
212			};
213
214			struct spritz_hash : protected spritz
215			{
216			spritz_hash ()
217			{
218			}
219
220			// can be called multiple times/incrementally
221			void add (const void *M, size_t M_len)
222			{
223			absorb (M, M_len);
224			}
225
226			// must be called at most once at the end
227			void hash (void *H, size_t H_len)
228			{
229			absorb_stop ();
230			assert (H_len <= 0xff);
231			absorb_byte (H_len);
232
233			squeeze (H, H_len);
234			}
235			};
236
237			struct spritz_mac : protected spritz_hash
238			{
239			spritz_mac (const void *K, size_t K_len)
240			{
241			absorb_stop (K, K_len);
242			}
243
244			// use add to incrementally add data
245			using spritz_hash::add;
246
247			// must be called at most once at the end
248			void mac (void *H, size_t H_len)
249			{
250			hash (H, H_len);
251			}
252			};
253
254			struct spritz_aead : protected spritz_mac
255			{
256			spritz_aead (const void *K, size_t K_len)
257			: spritz_mac (K, K_len)
258			{
259			}
260
261			// must be called after construction, before data
262			void nonce (const void *N, size_t N_len)
263			{
264			absorb_stop (N, N_len);
265			}
266
267			// must be called after nonce, before crypt
268			void associated_data (const void *D, size_t D_len)
269			{
270			absorb_stop (D, D_len);
271			}
272
273			// must be called after data, only once, before mac
274			// works for both encryption and decryption
275			void crypt (const void I, void O, size_t len)
276			{
277			const uint8_t i = (const uint8_t )I;
278			uint8_t o = ( uint8_t )O;
279
280			uint8_t x[N >> 2];
281
282			while (len)
283			{
284			uint8_t l = len > sizeof (x) ? sizeof (x) : len;
285			len -= l;
286
287			squeeze (x, l);
288
289			for (uint_fast8_t j = 0; j < l; ++j)
290			absorb_byte (o++ = i++ ^ x[j]);
291			}
292			}
293
294			// call mac() at most once at the end
295			using spritz_mac::mac;
296			};
297
298			struct spritz_drbg : protected spritz
299			{
300			// seed optional, can be done via put
301			spritz_drbg (const void *S = 0, size_t S_len = 0)
302			{
303			absorb (S, S_len);
304			}
305
306			// add additional entropy
307			void put (const void *S, size_t S_len)
308			{
309			absorb (S, S_len);
310			}
311
312			// get random bytes
313			void get (void *R, size_t R_len)
314			{
315			squeeze (R, R_len);
316			}
317			};
318