3 * $Id: seal.c,v 1.2 2004/04/08 01:36:15 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 /*----- Header files ------------------------------------------------------*/
36 #include <mLib/bits.h>
45 /*----- Global variables --------------------------------------------------*/
47 const octet seal_keysz
[] = { KSZ_ANY
, SHA_HASHSZ
};
49 /*----- Main code ---------------------------------------------------------*/
53 * Arguments: @uint32 *p@ = output table
54 * @size_t sz@ = size of the output table
55 * @const void *k@ = pointer to key material
56 * @unsigned i@ = integer offset
60 * Use: Initializes a SEAL key table.
63 static void gamma(uint32
*p
, size_t sz
, const void *k
, unsigned i
)
65 uint32 buf
[80] = { 0 };
67 uint32 aa
= LOAD32(kk
);
68 uint32 bb
= LOAD32(kk
+ 4);
69 uint32 cc
= LOAD32(kk
+ 8);
70 uint32 dd
= LOAD32(kk
+ 12);
71 uint32 ee
= LOAD32(kk
+ 16);
73 unsigned skip
= i
% 5;
76 /* --- While there's hashing to do, do hashing --- */
79 uint32 a
= aa
, b
= bb
, c
= cc
, d
= dd
, e
= ee
;
82 /* --- Initialize and expand the buffer --- */
86 for (j
= 16; j
< 80; j
++) {
87 uint32 x
= buf
[j
- 3] ^ buf
[j
- 8] ^ buf
[j
- 14] ^ buf
[j
- 16];
91 /* --- Definitions for round functions --- */
93 #define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
94 #define G(x, y, z) ((x) ^ (y) ^ (z))
95 #define H(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
97 #define T(v, w, x, y, z, i, f, k) do { \
99 z = ROL32(v, 5) + f(w, x, y) + z + buf[i] + k; \
101 _x = v; v = z; z = y; y = x; x = w; w = _x; \
104 #define FF(v, w, x, y, z, i) T(v, w, x, y, z, i, F, 0x5a827999)
105 #define GG(v, w, x, y, z, i) T(v, w, x, y, z, i, G, 0x6ed9eba1)
106 #define HH(v, w, x, y, z, i) T(v, w, x, y, z, i, H, 0x8f1bbcdc)
107 #define II(v, w, x, y, z, i) T(v, w, x, y, z, i, G, 0xca62c1d6)
109 /* --- The main compression function --- *
111 * Since this isn't doing bulk hashing, do it the easy way.
114 for (j
= 0; j
< 20; j
++)
115 FF(a
, b
, c
, d
, e
, j
);
116 for (j
= 20; j
< 40; j
++)
117 GG(a
, b
, c
, d
, e
, j
);
118 for (j
= 40; j
< 60; j
++)
119 HH(a
, b
, c
, d
, e
, j
);
120 for (j
= 60; j
< 80; j
++)
121 II(a
, b
, c
, d
, e
, j
);
123 /* --- Do the chaining at the end --- */
125 a
+= aa
; b
+= bb
; c
+= cc
; d
+= dd
; e
+= ee
;
127 /* --- Write to the output buffer --- */
131 if (sz
) { *p
++ = a
; sz
--; }
133 if (sz
) { *p
++ = b
; sz
--; }
135 if (sz
) { *p
++ = c
; sz
--; }
137 if (sz
) { *p
++ = d
; sz
--; }
139 if (sz
) { *p
++ = e
; sz
--; }
145 /* --- @seal_initkey@ --- *
147 * Arguments: @seal_key *k@ = pointer to key block
148 * @const void *buf@ = pointer to key material
149 * @size_t sz@ = size of the key material
153 * Use: Initializes a SEAL key block. The key material may be any
154 * size, but if it's not 20 bytes long it's passed to SHA for
158 void seal_initkey(seal_key
*k
, const void *buf
, size_t sz
)
160 /* --- Hash the key if it's the wrong size --- */
162 if (sz
== SHA_HASHSZ
)
163 memcpy(k
->k
, buf
, sizeof(k
->k
));
167 sha_hash(&c
, buf
, sz
);
171 /* --- Expand the key to fit the various tables --- */
173 gamma(k
->t
, 512, k
->k
, 0);
174 gamma(k
->s
, 256, k
->k
, 0x1000);
175 gamma(k
->r
, SEAL_R
, k
->k
, 0x2000);
178 /* --- @seal_reset@ --- *
180 * Arguments: @seal_ctx *c@ = pointer to a SEAL context
184 * Use: Resets the context so that more data can be extracted from
188 static void seal_reset(seal_ctx
*c
)
195 /* --- Initialize the new chaining variables --- */
197 if (c
->l
>= SEAL_R
) {
198 gamma(c
->rbuf
, SEAL_R
, k
->k
, c
->ri
);
205 B
= ROR32(n
, 8) ^ c
->r
[1];
206 C
= ROR32(n
, 16) ^ c
->r
[2];
207 D
= ROR32(n
, 24) ^ c
->r
[3];
211 /* --- Ensure that everything is sufficiently diffused --- */
213 p
= A
& 0x7fc; B
+= k
->t
[p
>> 2]; A
= ROR32(A
, 9);
214 p
= B
& 0x7fc; C
+= k
->t
[p
>> 2]; B
= ROR32(B
, 9);
215 p
= C
& 0x7fc; D
+= k
->t
[p
>> 2]; C
= ROR32(C
, 9);
216 p
= D
& 0x7fc; A
+= k
->t
[p
>> 2]; D
= ROR32(D
, 9);
217 p
= A
& 0x7fc; B
+= k
->t
[p
>> 2]; A
= ROR32(A
, 9);
218 p
= B
& 0x7fc; C
+= k
->t
[p
>> 2]; B
= ROR32(B
, 9);
219 p
= C
& 0x7fc; D
+= k
->t
[p
>> 2]; C
= ROR32(C
, 9);
220 p
= D
& 0x7fc; A
+= k
->t
[p
>> 2]; D
= ROR32(D
, 9);
222 /* --- Write out some context --- */
224 c
->n1
= D
; c
->n2
= B
; c
->n3
= A
; c
->n4
= C
;
226 /* --- Diffuse some more --- */
228 p
= A
& 0x7fc; B
+= k
->t
[p
>> 2]; A
= ROR32(A
, 9);
229 p
= B
& 0x7fc; C
+= k
->t
[p
>> 2]; B
= ROR32(B
, 9);
230 p
= C
& 0x7fc; D
+= k
->t
[p
>> 2]; C
= ROR32(C
, 9);
231 p
= D
& 0x7fc; A
+= k
->t
[p
>> 2]; D
= ROR32(D
, 9);
233 /* --- Write out the magic numbers --- */
235 c
->a
= A
; c
->b
= B
; c
->c
= C
; c
->d
= D
;
239 /* --- @seal_initctx@ --- *
241 * Arguments: @seal_ctx *c@ = pointer to a SEAL context
242 * @seal_key *k@ = pointer to a SEAL key
243 * @uint32 n@ = integer sequence number
247 * Use: Initializes a SEAL context which can be used for random
248 * number generation or whatever.
251 void seal_initctx(seal_ctx
*c
, seal_key
*k
, uint32 n
)
257 c
->ri
= 0x2000 + SEAL_R
;
262 /* --- @seal_encrypt@ --- *
264 * Arguments: @seal_ctx *c@ = pointer to a SEAL context
265 * @const void *src@ = pointer to source data
266 * @void *dest@ = pointer to destination data
267 * @size_t sz@ = size of the data
271 * Use: Encrypts a block of data using SEAL. If @src@ is zero,
272 * @dest@ is filled with SEAL output. If @dest@ is zero, the
273 * SEAL generator is just spun around for a bit. This shouldn't
274 * be necessary, because SEAL isn't RC4.
277 void seal_encrypt(seal_ctx
*c
, const void *src
, void *dest
, size_t sz
)
279 const octet
*s
= src
;
282 /* --- Expect a big dollop of bytes --- */
286 uint32 A
= c
->a
, B
= c
->b
, C
= c
->c
, D
= c
->d
;
287 uint32 n1
= c
->n1
, n2
= c
->n2
, n3
= c
->n3
, n4
= c
->n4
;
288 uint32 aa
, bb
, cc
, dd
;
291 /* --- Empty the queue first --- */
296 octet
*p
= c
->q
+ sizeof(c
->q
) - c
->qsz
;
297 for (i
= 0; i
< c
->qsz
; i
++)
298 *d
++ = (s ?
*s
++ ^ *p
++ : *p
++);
303 /* --- Main sequence --- */
308 /* --- Reset if we've run out of steam on this iteration --- */
312 A
= c
->a
, B
= c
->b
, C
= c
->c
, D
= c
->d
;
313 n1
= c
->n1
, n2
= c
->n2
, n3
= c
->n3
, n4
= c
->n4
;
317 /* --- Make some new numbers --- */
319 P
= A
& 0x7fc; B
+= k
->t
[P
>> 2]; A
= ROR32(A
, 9); B
^= A
;
320 Q
= B
& 0x7fc; C
^= k
->t
[Q
>> 2]; B
= ROR32(B
, 9); C
+= B
;
321 P
= (P
+ C
) & 0x7fc; D
+= k
->t
[P
>> 2]; C
= ROR32(C
, 9); D
^= C
;
322 Q
= (Q
+ D
) & 0x7fc; A
^= k
->t
[Q
>> 2]; D
= ROR32(D
, 9); A
+= D
;
323 P
= (P
+ A
) & 0x7fc; B
^= k
->t
[P
>> 2]; A
= ROR32(A
, 9);
324 Q
= (Q
+ B
) & 0x7fc; C
+= k
->t
[Q
>> 2]; B
= ROR32(B
, 9);
325 P
= (P
+ C
) & 0x7fc; D
^= k
->t
[P
>> 2]; C
= ROR32(C
, 9);
326 Q
= (Q
+ D
) & 0x7fc; A
+= k
->t
[Q
>> 2]; D
= ROR32(D
, 9);
328 /* --- Remember the output and set up the next round --- */
330 aa
= B
+ k
->s
[j
+ 0];
331 bb
= C
^ k
->s
[j
+ 1];
332 cc
= D
+ k
->s
[j
+ 2];
333 dd
= A
^ k
->s
[j
+ 3];
337 A
+= n1
, B
+= n2
, C
^= n1
, D
^= n2
;
339 A
+= n3
, B
+= n4
, C
^= n3
, D
^= n4
;
341 /* --- Bail out here if we need to do buffering --- */
346 /* --- Write the next 16 bytes --- */
350 aa
^= LOAD32_L(s
+ 0);
351 bb
^= LOAD32_L(s
+ 4);
352 cc
^= LOAD32_L(s
+ 8);
353 dd
^= LOAD32_L(s
+ 12);
356 STORE32_L(d
+ 0, aa
);
357 STORE32_L(d
+ 4, bb
);
358 STORE32_L(d
+ 8, cc
);
359 STORE32_L(d
+ 12, dd
);
365 /* --- Write the new queue --- */
367 STORE32_L(c
->q
+ 0, aa
);
368 STORE32_L(c
->q
+ 4, bb
);
369 STORE32_L(c
->q
+ 8, cc
);
370 STORE32_L(c
->q
+ 12, dd
);
373 c
->a
= A
; c
->b
= B
; c
->c
= C
; c
->d
= D
;
377 /* --- Deal with the rest from the queue --- */
381 octet
*p
= c
->q
+ sizeof(c
->q
) - c
->qsz
;
383 for (i
= 0; i
< sz
; i
++)
384 *d
++ = (s ?
*s
++ ^ *p
++ : *p
++);
390 /*----- Generic cipher interface ------------------------------------------*/
392 typedef struct gctx
{
398 static const gcipher_ops gops
;
400 static gcipher
*ginit(const void *k
, size_t sz
)
402 gctx
*g
= S_CREATE(gctx
);
404 seal_initkey(&g
->k
, k
, sz
);
405 seal_initctx(&g
->cc
, &g
->k
, 0);
409 static void gencrypt(gcipher
*c
, const void *s
, void *t
, size_t sz
)
412 seal_encrypt(&g
->cc
, s
, t
, sz
);
415 static void gsetiv(gcipher
*c
, const void *iv
)
418 uint32 n
= *(const uint32
*)iv
;
419 seal_initctx(&g
->cc
, &g
->k
, n
);
422 static void gdestroy(gcipher
*c
)
429 static const gcipher_ops gops
= {
431 gencrypt
, gencrypt
, gdestroy
, gsetiv
, 0
434 const gccipher seal
= {
435 "seal", seal_keysz
, 0,
439 /*----- Generic random number generator interface -------------------------*/
441 typedef struct grctx
{
447 static void grdestroy(grand
*r
)
449 grctx
*g
= (grctx
*)r
;
454 static int grmisc(grand
*r
, unsigned op
, ...)
456 grctx
*g
= (grctx
*)r
;
463 switch (va_arg(ap
, unsigned)) {
466 case GRAND_SEEDUINT32
:
467 case GRAND_SEEDBLOCK
:
477 seal_initctx(&g
->cc
, &g
->k
, va_arg(ap
, int));
479 case GRAND_SEEDUINT32
:
480 seal_initctx(&g
->cc
, &g
->k
, va_arg(ap
, uint32
));
482 case GRAND_SEEDBLOCK
: {
483 const void *p
= va_arg(ap
, const void *);
484 size_t sz
= va_arg(ap
, size_t);
489 octet buf
[4] = { 0 };
493 seal_initctx(&g
->cc
, &g
->k
, n
);
495 case GRAND_SEEDRAND
: {
496 grand
*rr
= va_arg(ap
, grand
*);
497 seal_initctx(&g
->cc
, &g
->k
, rr
->ops
->word(rr
));
508 static octet
grbyte(grand
*r
)
510 grctx
*g
= (grctx
*)r
;
512 seal_encrypt(&g
->cc
, 0, &o
, 1);
516 static uint32
grword(grand
*r
)
518 grctx
*g
= (grctx
*)r
;
520 seal_encrypt(&g
->cc
, 0, b
, 4);
524 static void grfill(grand
*r
, void *p
, size_t sz
)
526 grctx
*g
= (grctx
*)r
;
527 seal_encrypt(&g
->cc
, 0, p
, sz
);
530 static const grand_ops grops
= {
534 grword
, grbyte
, grword
, grand_range
, grfill
537 /* --- @seal_rand@ --- *
539 * Arguments: @const void *k@ = pointer to key material
540 * @size_t sz@ = size of key material
541 * @uint32 n@ = sequence number
543 * Returns: Pointer to generic random number generator interface.
545 * Use: Creates a random number interface wrapper around a SEAL
546 * pseudorandom function.
549 grand
*seal_rand(const void *k
, size_t sz
, uint32 n
)
551 grctx
*g
= S_CREATE(grctx
);
553 seal_initkey(&g
->k
, k
, sz
);
554 seal_initctx(&g
->cc
, &g
->k
, n
);
558 /*----- Test rig ----------------------------------------------------------*/
564 #include <mLib/testrig.h>
566 static int verify(dstr
*v
)
570 uint32 n
= *(uint32
*)v
[1].buf
;
576 DENSURE(&d
, v
[2].len
);
577 DENSURE(&z
, v
[2].len
);
578 memset(z
.buf
, 0, v
[2].len
);
579 z
.len
= d
.len
= v
[2].len
;
580 seal_initkey(&k
, v
[0].buf
, v
[0].len
);
582 for (i
= 0; i
< v
[2].len
; i
++) {
583 seal_initctx(&c
, &k
, n
);
584 seal_encrypt(&c
, 0, d
.buf
, i
);
585 seal_encrypt(&c
, z
.buf
, d
.buf
+ i
, d
.len
- i
);
586 if (memcmp(d
.buf
, v
[2].buf
, d
.len
) != 0) {
588 printf("*** seal failure\n");
589 printf("*** k = "); type_hex
.dump(&v
[0], stdout
); putchar('\n');
590 printf("*** n = %08lx\n", (unsigned long)n
);
591 printf("*** i = %i\n", i
);
592 printf("*** expected = "); type_hex
.dump(&v
[2], stdout
); putchar('\n');
593 printf("*** computed = "); type_hex
.dump(&d
, stdout
); putchar('\n');
603 static test_chunk defs
[] = {
604 { "seal", verify
, { &type_hex
, &type_uint32
, &type_hex
, 0 } },
608 int main(int argc
, char *argv
[])
610 test_run(argc
, argv
, defs
, SRCDIR
"/tests/seal");
616 /*----- That's all, folks -------------------------------------------------*/