3 * $Id: seal.c,v 1.1 2000/06/17 12:08:34 mdw Exp $
5 * The SEAL pseudo-random function family
7 * (c) 2000 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Catacomb.
14 * Catacomb is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (at your option) any later version.
19 * Catacomb is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU Library General Public License for more details.
24 * You should have received a copy of the GNU Library General Public
25 * License along with Catacomb; if not, write to the Free
26 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
30 /*----- Revision history --------------------------------------------------*
33 * Revision 1.1 2000/06/17 12:08:34 mdw
38 /*----- Header files ------------------------------------------------------*/
44 #include <mLib/bits.h>
53 /*----- Global variables --------------------------------------------------*/
55 const octet seal_keysz
[] = { KSZ_ANY
, SHA_HASHSZ
};
57 /*----- Main code ---------------------------------------------------------*/
61 * Arguments: @uint32 *p@ = output table
62 * @size_t sz@ = size of the output table
63 * @const void *k@ = pointer to key material
64 * @unsigned i@ = integer offset
68 * Use: Initializes a SEAL key table.
71 static void gamma(uint32
*p
, size_t sz
, const void *k
, unsigned i
)
73 uint32 buf
[80] = { 0 };
75 uint32 aa
= LOAD32(kk
);
76 uint32 bb
= LOAD32(kk
+ 4);
77 uint32 cc
= LOAD32(kk
+ 8);
78 uint32 dd
= LOAD32(kk
+ 12);
79 uint32 ee
= LOAD32(kk
+ 16);
81 unsigned skip
= i
% 5;
84 /* --- While there's hashing to do, do hashing --- */
87 uint32 a
= aa
, b
= bb
, c
= cc
, d
= dd
, e
= ee
;
90 /* --- Initialize and expand the buffer --- */
94 for (j
= 16; j
< 80; j
++) {
95 uint32 x
= buf
[j
- 3] ^ buf
[j
- 8] ^ buf
[j
- 14] ^ buf
[j
- 16];
99 /* --- Definitions for round functions --- */
101 #define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
102 #define G(x, y, z) ((x) ^ (y) ^ (z))
103 #define H(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
105 #define T(v, w, x, y, z, i, f, k) do { \
107 z = ROL32(v, 5) + f(w, x, y) + z + buf[i] + k; \
109 _x = v; v = z; z = y; y = x; x = w; w = _x; \
112 #define FF(v, w, x, y, z, i) T(v, w, x, y, z, i, F, 0x5a827999)
113 #define GG(v, w, x, y, z, i) T(v, w, x, y, z, i, G, 0x6ed9eba1)
114 #define HH(v, w, x, y, z, i) T(v, w, x, y, z, i, H, 0x8f1bbcdc)
115 #define II(v, w, x, y, z, i) T(v, w, x, y, z, i, G, 0xca62c1d6)
117 /* --- The main compression function --- *
119 * Since this isn't doing bulk hashing, do it the easy way.
122 for (j
= 0; j
< 20; j
++)
123 FF(a
, b
, c
, d
, e
, j
);
124 for (j
= 20; j
< 40; j
++)
125 GG(a
, b
, c
, d
, e
, j
);
126 for (j
= 40; j
< 60; j
++)
127 HH(a
, b
, c
, d
, e
, j
);
128 for (j
= 60; j
< 80; j
++)
129 II(a
, b
, c
, d
, e
, j
);
131 /* --- Do the chaining at the end --- */
133 a
+= aa
; b
+= bb
; c
+= cc
; d
+= dd
; e
+= ee
;
135 /* --- Write to the output buffer --- */
139 if (sz
) { *p
++ = a
; sz
--; }
141 if (sz
) { *p
++ = b
; sz
--; }
143 if (sz
) { *p
++ = c
; sz
--; }
145 if (sz
) { *p
++ = d
; sz
--; }
147 if (sz
) { *p
++ = e
; sz
--; }
153 /* --- @seal_initkey@ --- *
155 * Arguments: @seal_key *k@ = pointer to key block
156 * @const void *buf@ = pointer to key material
157 * @size_t sz@ = size of the key material
161 * Use: Initializes a SEAL key block. The key material may be any
162 * size, but if it's not 20 bytes long it's passed to SHA for
166 void seal_initkey(seal_key
*k
, const void *buf
, size_t sz
)
168 /* --- Hash the key if it's the wrong size --- */
170 if (sz
== SHA_HASHSZ
)
171 memcpy(k
->k
, buf
, sizeof(k
->k
));
175 sha_hash(&c
, buf
, sz
);
179 /* --- Expand the key to fit the various tables --- */
181 gamma(k
->t
, 512, k
->k
, 0);
182 gamma(k
->s
, 256, k
->k
, 0x1000);
183 gamma(k
->r
, SEAL_R
, k
->k
, 0x2000);
186 /* --- @seal_reset@ --- *
188 * Arguments: @seal_ctx *c@ = pointer to a SEAL context
192 * Use: Resets the context so that more data can be extracted from
196 static void seal_reset(seal_ctx
*c
)
203 /* --- Initialize the new chaining variables --- */
205 if (c
->l
>= SEAL_R
) {
206 gamma(c
->rbuf
, SEAL_R
, k
->k
, c
->ri
);
213 B
= ROR32(n
, 8) ^ c
->r
[1];
214 C
= ROR32(n
, 16) ^ c
->r
[2];
215 D
= ROR32(n
, 24) ^ c
->r
[3];
219 /* --- Ensure that everything is sufficiently diffused --- */
221 p
= A
& 0x7fc; B
+= k
->t
[p
>> 2]; A
= ROR32(A
, 9);
222 p
= B
& 0x7fc; C
+= k
->t
[p
>> 2]; B
= ROR32(B
, 9);
223 p
= C
& 0x7fc; D
+= k
->t
[p
>> 2]; C
= ROR32(C
, 9);
224 p
= D
& 0x7fc; A
+= k
->t
[p
>> 2]; D
= ROR32(D
, 9);
225 p
= A
& 0x7fc; B
+= k
->t
[p
>> 2]; A
= ROR32(A
, 9);
226 p
= B
& 0x7fc; C
+= k
->t
[p
>> 2]; B
= ROR32(B
, 9);
227 p
= C
& 0x7fc; D
+= k
->t
[p
>> 2]; C
= ROR32(C
, 9);
228 p
= D
& 0x7fc; A
+= k
->t
[p
>> 2]; D
= ROR32(D
, 9);
230 /* --- Write out some context --- */
232 c
->n1
= D
; c
->n2
= B
; c
->n3
= A
; c
->n4
= C
;
234 /* --- Diffuse some more --- */
236 p
= A
& 0x7fc; B
+= k
->t
[p
>> 2]; A
= ROR32(A
, 9);
237 p
= B
& 0x7fc; C
+= k
->t
[p
>> 2]; B
= ROR32(B
, 9);
238 p
= C
& 0x7fc; D
+= k
->t
[p
>> 2]; C
= ROR32(C
, 9);
239 p
= D
& 0x7fc; A
+= k
->t
[p
>> 2]; D
= ROR32(D
, 9);
241 /* --- Write out the magic numbers --- */
243 c
->a
= A
; c
->b
= B
; c
->c
= C
; c
->d
= D
;
247 /* --- @seal_initctx@ --- *
249 * Arguments: @seal_ctx *c@ = pointer to a SEAL context
250 * @seal_key *k@ = pointer to a SEAL key
251 * @uint32 n@ = integer sequence number
255 * Use: Initializes a SEAL context which can be used for random
256 * number generation or whatever.
259 void seal_initctx(seal_ctx
*c
, seal_key
*k
, uint32 n
)
265 c
->ri
= 0x2000 + SEAL_R
;
270 /* --- @seal_encrypt@ --- *
272 * Arguments: @seal_ctx *c@ = pointer to a SEAL context
273 * @const void *src@ = pointer to source data
274 * @void *dest@ = pointer to destination data
275 * @size_t sz@ = size of the data
279 * Use: Encrypts a block of data using SEAL. If @src@ is zero,
280 * @dest@ is filled with SEAL output. If @dest@ is zero, the
281 * SEAL generator is just spun around for a bit. This shouldn't
282 * be necessary, because SEAL isn't RC4.
285 void seal_encrypt(seal_ctx
*c
, const void *src
, void *dest
, size_t sz
)
287 const octet
*s
= src
;
290 /* --- Expect a big dollop of bytes --- */
294 uint32 A
= c
->a
, B
= c
->b
, C
= c
->c
, D
= c
->d
;
295 uint32 n1
= c
->n1
, n2
= c
->n2
, n3
= c
->n3
, n4
= c
->n4
;
296 uint32 aa
, bb
, cc
, dd
;
299 /* --- Empty the queue first --- */
304 octet
*p
= c
->q
+ sizeof(c
->q
) - c
->qsz
;
305 for (i
= 0; i
< c
->qsz
; i
++)
306 *d
++ = (s ?
*s
++ ^ *p
++ : *p
++);
311 /* --- Main sequence --- */
316 /* --- Reset if we've run out of steam on this iteration --- */
320 A
= c
->a
, B
= c
->b
, C
= c
->c
, D
= c
->d
;
321 n1
= c
->n1
, n2
= c
->n2
, n3
= c
->n3
, n4
= c
->n4
;
325 /* --- Make some new numbers --- */
327 P
= A
& 0x7fc; B
+= k
->t
[P
>> 2]; A
= ROR32(A
, 9); B
^= A
;
328 Q
= B
& 0x7fc; C
^= k
->t
[Q
>> 2]; B
= ROR32(B
, 9); C
+= B
;
329 P
= (P
+ C
) & 0x7fc; D
+= k
->t
[P
>> 2]; C
= ROR32(C
, 9); D
^= C
;
330 Q
= (Q
+ D
) & 0x7fc; A
^= k
->t
[Q
>> 2]; D
= ROR32(D
, 9); A
+= D
;
331 P
= (P
+ A
) & 0x7fc; B
^= k
->t
[P
>> 2]; A
= ROR32(A
, 9);
332 Q
= (Q
+ B
) & 0x7fc; C
+= k
->t
[Q
>> 2]; B
= ROR32(B
, 9);
333 P
= (P
+ C
) & 0x7fc; D
^= k
->t
[P
>> 2]; C
= ROR32(C
, 9);
334 Q
= (Q
+ D
) & 0x7fc; A
+= k
->t
[Q
>> 2]; D
= ROR32(D
, 9);
336 /* --- Remember the output and set up the next round --- */
338 aa
= B
+ k
->s
[j
+ 0];
339 bb
= C
^ k
->s
[j
+ 1];
340 cc
= D
+ k
->s
[j
+ 2];
341 dd
= A
^ k
->s
[j
+ 3];
345 A
+= n1
, B
+= n2
, C
^= n1
, D
^= n2
;
347 A
+= n3
, B
+= n4
, C
^= n3
, D
^= n4
;
349 /* --- Bail out here if we need to do buffering --- */
354 /* --- Write the next 16 bytes --- */
358 aa
^= LOAD32_L(s
+ 0);
359 bb
^= LOAD32_L(s
+ 4);
360 cc
^= LOAD32_L(s
+ 8);
361 dd
^= LOAD32_L(s
+ 12);
364 STORE32_L(d
+ 0, aa
);
365 STORE32_L(d
+ 4, bb
);
366 STORE32_L(d
+ 8, cc
);
367 STORE32_L(d
+ 12, dd
);
373 /* --- Write the new queue --- */
375 STORE32_L(c
->q
+ 0, aa
);
376 STORE32_L(c
->q
+ 4, bb
);
377 STORE32_L(c
->q
+ 8, cc
);
378 STORE32_L(c
->q
+ 12, dd
);
381 c
->a
= A
; c
->b
= B
; c
->c
= C
; c
->d
= D
;
385 /* --- Deal with the rest from the queue --- */
389 octet
*p
= c
->q
+ sizeof(c
->q
) - c
->qsz
;
391 for (i
= 0; i
< sz
; i
++)
392 *d
++ = (s ?
*s
++ ^ *p
++ : *p
++);
398 /*----- Generic cipher interface ------------------------------------------*/
400 typedef struct gctx
{
406 static const gcipher_ops gops
;
408 static gcipher
*ginit(const void *k
, size_t sz
)
410 gctx
*g
= S_CREATE(gctx
);
412 seal_initkey(&g
->k
, k
, sz
);
413 seal_initctx(&g
->cc
, &g
->k
, 0);
417 static void gencrypt(gcipher
*c
, const void *s
, void *t
, size_t sz
)
420 seal_encrypt(&g
->cc
, s
, t
, sz
);
423 static void gsetiv(gcipher
*c
, const void *iv
)
426 uint32 n
= *(const uint32
*)iv
;
427 seal_initctx(&g
->cc
, &g
->k
, n
);
430 static void gdestroy(gcipher
*c
)
437 static const gcipher_ops gops
= {
439 gencrypt
, gencrypt
, gdestroy
, gsetiv
, 0
442 const gccipher seal
= {
443 "seal", seal_keysz
, 0,
447 /*----- Generic random number generator interface -------------------------*/
449 typedef struct grctx
{
455 static void grdestroy(grand
*r
)
457 grctx
*g
= (grctx
*)r
;
462 static int grmisc(grand
*r
, unsigned op
, ...)
464 grctx
*g
= (grctx
*)r
;
471 switch (va_arg(ap
, unsigned)) {
474 case GRAND_SEEDUINT32
:
475 case GRAND_SEEDBLOCK
:
485 seal_initctx(&g
->cc
, &g
->k
, va_arg(ap
, int));
487 case GRAND_SEEDUINT32
:
488 seal_initctx(&g
->cc
, &g
->k
, va_arg(ap
, uint32
));
490 case GRAND_SEEDBLOCK
: {
491 const void *p
= va_arg(ap
, const void *);
492 size_t sz
= va_arg(ap
, size_t);
497 octet buf
[4] = { 0 };
501 seal_initctx(&g
->cc
, &g
->k
, n
);
503 case GRAND_SEEDRAND
: {
504 grand
*rr
= va_arg(ap
, grand
*);
505 seal_initctx(&g
->cc
, &g
->k
, rr
->ops
->word(rr
));
516 static octet
grbyte(grand
*r
)
518 grctx
*g
= (grctx
*)r
;
520 seal_encrypt(&g
->cc
, 0, &o
, 1);
524 static uint32
grword(grand
*r
)
526 grctx
*g
= (grctx
*)r
;
528 seal_encrypt(&g
->cc
, 0, b
, 4);
532 static void grfill(grand
*r
, void *p
, size_t sz
)
534 grctx
*g
= (grctx
*)r
;
535 seal_encrypt(&g
->cc
, 0, p
, sz
);
538 static const grand_ops grops
= {
542 grword
, grbyte
, grword
, grand_range
, grfill
545 /* --- @seal_rand@ --- *
547 * Arguments: @const void *k@ = pointer to key material
548 * @size_t sz@ = size of key material
549 * @uint32 n@ = sequence number
551 * Returns: Pointer to generic random number generator interface.
553 * Use: Creates a random number interface wrapper around a SEAL
554 * pseudorandom function.
557 grand
*seal_rand(const void *k
, size_t sz
, uint32 n
)
559 grctx
*g
= S_CREATE(grctx
);
561 seal_initkey(&g
->k
, k
, sz
);
562 seal_initctx(&g
->cc
, &g
->k
, n
);
566 /*----- Test rig ----------------------------------------------------------*/
572 #include <mLib/testrig.h>
574 static int verify(dstr
*v
)
578 uint32 n
= *(uint32
*)v
[1].buf
;
584 DENSURE(&d
, v
[2].len
);
585 DENSURE(&z
, v
[2].len
);
586 memset(z
.buf
, 0, v
[2].len
);
587 z
.len
= d
.len
= v
[2].len
;
588 seal_initkey(&k
, v
[0].buf
, v
[0].len
);
590 for (i
= 0; i
< v
[2].len
; i
++) {
591 seal_initctx(&c
, &k
, n
);
592 seal_encrypt(&c
, 0, d
.buf
, i
);
593 seal_encrypt(&c
, z
.buf
, d
.buf
+ i
, d
.len
- i
);
594 if (memcmp(d
.buf
, v
[2].buf
, d
.len
) != 0) {
596 printf("*** seal failure\n");
597 printf("*** k = "); type_hex
.dump(&v
[0], stdout
); putchar('\n');
598 printf("*** n = %08lx\n", (unsigned long)n
);
599 printf("*** i = %i\n", i
);
600 printf("*** expected = "); type_hex
.dump(&v
[2], stdout
); putchar('\n');
601 printf("*** computed = "); type_hex
.dump(&d
, stdout
); putchar('\n');
611 static test_chunk defs
[] = {
612 { "seal", verify
, { &type_hex
, &type_uint32
, &type_hex
, 0 } },
616 int main(int argc
, char *argv
[])
618 test_run(argc
, argv
, defs
, SRCDIR
"/tests/seal");
624 /*----- That's all, folks -------------------------------------------------*/