+++ /dev/null
-/* -*-c-*-
- *
- * $Id: rc4.c,v 1.6 2004/04/08 01:36:15 mdw Exp $
- *
- * The alleged RC4 stream cipher
- *
- * (c) 1999 Straylight/Edgeware
- */
-
-/*----- Licensing notice --------------------------------------------------*
- *
- * This file is part of Catacomb.
- *
- * Catacomb is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Library General Public License as
- * published by the Free Software Foundation; either version 2 of the
- * License, or (at your option) any later version.
- *
- * Catacomb is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library General Public
- * License along with Catacomb; if not, write to the Free
- * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-#include <assert.h>
-#include <stdarg.h>
-#include <stdio.h>
-
-#include <mLib/bits.h>
-#include <mLib/sub.h>
-
-#include "arena.h"
-#include "gcipher.h"
-#include "grand.h"
-#include "paranoia.h"
-#include "rc4.h"
-
-/*----- Global variables --------------------------------------------------*/
-
-const octet rc4_keysz[] = { KSZ_RANGE, RC4_KEYSZ, 1, 255, 1 };
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @rc4_addkey@ --- *
- *
- * Arguments: @rc4_ctx *ctx@ = pointer to context to key
- * @const void *k@ = pointer to key data to use
- * @size_t sz@ = size of the key data
- *
- * Returns: ---
- *
- * Use: Mixes key data with an RC4 context. The RC4 context is not
- * reset before mixing. This may be used to mix new key
- * material with an existing RC4 context.
- */
-
-void rc4_addkey(rc4_ctx *ctx, const void *k, size_t sz)
-{
- unsigned i, j;
- const octet *p = k, *q = p + sz;
-
- KSZ_ASSERT(rc4, sz);
-
- for (i = j = 0; i < 256; i++) {
- unsigned si = ctx->s[i];
- j = (j + si + *p++) & 0xff;
- ctx->s[i] = ctx->s[j];
- ctx->s[j] = si;
- if (p == q)
- p = k;
- }
-
- ctx->i = ctx->j = 0;
-}
-
-/* --- @rc4_init@ --- *
- *
- * Arguments: @rc4_ctx *ctx@ = pointer to context to initialize
- * @const void *k@ = pointer to key data to use
- * @size_t sz@ = size of the key data
- *
- * Returns: ---
- *
- * Use: Initializes an RC4 context ready for use.
- */
-
-void rc4_init(rc4_ctx *ctx, const void *k, size_t sz)
-{
- unsigned i;
-
- for (i = 0; i < 256; i++)
- ctx->s[i] = i;
- ctx->f = 0;
- rc4_addkey(ctx, k, sz);
-}
-
-/* --- @rc4_encrypt@ --- *
- *
- * Arguments: @rc4_ctx *ctx@ = pointer to context to use
- * @const void *src@ = pointer to the source block
- * @void *dest@ = pointer to the destination block
- * @size_t sz@ = size of the block
- *
- * Returns: ---
- *
- * Use: Encrypts or decrypts a block of data. The destination may
- * be null to just grind the generator around for a while. It's
- * recommended that you say `@rc4_encrypt(&ctx, 0, 0, 1024)@'
- * after initializing a new context, to prevent keystream
- * guessing attacks. The source may be null to just extract a
- * big lump of data from the generator.
- */
-
-void rc4_encrypt(rc4_ctx *ctx, const void *src, void *dest, size_t sz)
-{
- const octet *s = src;
- octet *d = dest;
-
- if (!d)
- RC4_OPEN(ctx, while (sz) { unsigned x; RC4_BYTE(x); sz--; });
- else if (!s)
- RC4_OPEN(ctx, while (sz) { RC4_BYTE(*d++); sz--; });
- else
- RC4_OPEN(ctx,
- while (sz) { unsigned x; RC4_BYTE(x); *d++ = *s++ ^ x; sz--; });
-}
-
-/*----- Generic cipher interface ------------------------------------------*/
-
-typedef struct gctx {
- gcipher c;
- rc4_ctx rc4;
-} gctx;
-
-static const gcipher_ops gops;
-
-static gcipher *ginit(const void *k, size_t sz)
-{
- gctx *g = S_CREATE(gctx);
- g->c.ops = &gops;
- rc4_init(&g->rc4, k, sz);
- return (&g->c);
-}
-
-static void gencrypt(gcipher *c, const void *s, void *t, size_t sz)
-{
- gctx *g = (gctx *)c;
- rc4_encrypt(&g->rc4, s, t, sz);
-}
-
-static void gdestroy(gcipher *c)
-{
- gctx *g = (gctx *)c;
- BURN(*g);
- S_DESTROY(g);
-}
-
-static const gcipher_ops gops = {
- &rc4,
- gencrypt, gencrypt, gdestroy, 0, 0
-};
-
-const gccipher rc4 = {
- "rc4", rc4_keysz, 0,
- ginit
-};
-
-/*----- Generic random number generator interface -------------------------*/
-
-typedef struct grctx {
- grand r;
- rc4_ctx rc4;
-} grctx;
-
-static void grdestroy(grand *r)
-{
- grctx *g = (grctx *)r;
- BURN(*g);
- S_DESTROY(g);
-}
-
-static int grmisc(grand *r, unsigned op, ...)
-{
- grctx *g = (grctx *)r;
- va_list ap;
- int rc = 0;
- uint32 i;
- octet buf[4];
- va_start(ap, op);
-
- switch (op) {
- case GRAND_CHECK:
- switch (va_arg(ap, unsigned)) {
- case GRAND_CHECK:
- case GRAND_SEEDINT:
- case GRAND_SEEDUINT32:
- case GRAND_SEEDBLOCK:
- case GRAND_SEEDRAND:
- rc = 1;
- break;
- default:
- rc = 0;
- break;
- }
- break;
- case GRAND_SEEDINT:
- i = va_arg(ap, unsigned);
- STORE32(buf, i);
- rc4_addkey(&g->rc4, buf, sizeof(buf));
- break;
- case GRAND_SEEDUINT32:
- i = va_arg(ap, uint32);
- STORE32(buf, i);
- rc4_addkey(&g->rc4, buf, sizeof(buf));
- break;
- case GRAND_SEEDBLOCK: {
- const void *p = va_arg(ap, const void *);
- size_t sz = va_arg(ap, size_t);
- rc4_addkey(&g->rc4, p, sz);
- } break;
- case GRAND_SEEDRAND: {
- grand *rr = va_arg(ap, grand *);
- octet buf[16];
- rr->ops->fill(rr, buf, sizeof(buf));
- rc4_addkey(&g->rc4, buf, sizeof(buf));
- } break;
- default:
- GRAND_BADOP;
- break;
- }
-
- va_end(ap);
- return (rc);
-}
-
-static octet grbyte(grand *r)
-{
- grctx *g = (grctx *)r;
- octet o;
- RC4_OPEN(&g->rc4, RC4_BYTE(o););
- return (o);
-}
-
-static uint32 grword(grand *r)
-{
- grctx *g = (grctx *)r;
- octet b[4];
- int i;
- RC4_OPEN(&g->rc4,
- for (i = 0; i < sizeof(b); i++)
- RC4_BYTE(b[i]););
- return (LOAD32(b));
-}
-
-static void grfill(grand *r, void *p, size_t sz)
-{
- grctx *g = (grctx *)r;
- rc4_encrypt(&g->rc4, 0, p, sz);
-}
-
-static const grand_ops grops = {
- "rc4",
- GRAND_CRYPTO, 0,
- grmisc, grdestroy,
- grword, grbyte, grword, grand_range, grfill
-};
-
-/* --- @rc4_rand@ --- *
- *
- * Arguments: @const void *k@ = pointer to key material
- * @size_t sz@ = size of key material
- *
- * Returns: Pointer to generic random number generator interface.
- *
- * Use: Creates a random number interface wrapper around an
- * OFB-mode block cipher.
- */
-
-grand *rc4_rand(const void *k, size_t sz)
-{
- grctx *g = S_CREATE(grctx);
- g->r.ops = &grops;
- rc4_init(&g->rc4, k, sz);
- return (&g->r);
-}
-
-/*----- Test rig ----------------------------------------------------------*/
-
-#ifdef TEST_RIG
-
-#include <stdio.h>
-#include <string.h>
-
-#include <mLib/quis.h>
-#include <mLib/testrig.h>
-
-static int v_encrypt(dstr *v)
-{
- rc4_ctx ctx;
- dstr d = DSTR_INIT;
- int ok = 1;
-
- rc4_init(&ctx, v[0].buf, v[0].len);
- dstr_ensure(&d, v[1].len);
- d.len = v[1].len;
- rc4_encrypt(&ctx, v[1].buf, d.buf, d.len);
-
- if (memcmp(v[2].buf, d.buf, d.len) != 0) {
- ok = 0;
- printf("\nfail encryption:"
- "\n\tkey = ");
- type_hex.dump(&v[0], stdout);
- printf("\n\tplaintext = "); type_hex.dump(&v[1], stdout);
- printf("\n\texpected = "); type_hex.dump(&v[2], stdout);
- printf("\n\tcalculated = "); type_hex.dump(&d, stdout);
- putchar('\n');
- }
-
- return (ok);
-}
-
-static int v_generate(dstr *v)
-{
- rc4_ctx ctx;
- dstr d = DSTR_INIT;
- int ok = 1;
-
- rc4_init(&ctx, v[0].buf, v[0].len);
- rc4_encrypt(&ctx, 0, 0, *(int *)v[1].buf);
- dstr_ensure(&d, v[2].len);
- d.len = v[2].len;
- rc4_encrypt(&ctx, 0, d.buf, d.len);
-
- if (memcmp(v[2].buf, d.buf, d.len) != 0) {
- ok = 0;
- printf("\nfail generation:"
- "\n\tkey = ");
- type_hex.dump(&v[0], stdout);
- printf("\n\tskip len = %i", *(int *)v[1].buf);
- printf("\n\texpected = "); type_hex.dump(&v[2], stdout);
- printf("\n\tcalculated = "); type_hex.dump(&d, stdout);
- putchar('\n');
- }
-
- return (ok);
-}
-
-static test_chunk defs[] = {
- { "rc4-encrypt", v_encrypt, { &type_hex, &type_hex, &type_hex, 0 } },
- { "rc4-generate", v_generate, { &type_hex, &type_int, &type_hex, 0 } },
- { 0, 0, { 0 } }
-};
-
-int main(int argc, char *argv[])
-{
- test_run(argc, argv, defs, SRCDIR"/tests/rc4");
- return (0);
-}
-
-#endif
-
-/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff