X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/ba6e6b64033b1f9de49feccb5c9cd438354481f7..0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a:/rc4.c diff --git a/rc4.c b/rc4.c deleted file mode 100644 index 83b5104..0000000 --- a/rc4.c +++ /dev/null @@ -1,369 +0,0 @@ -/* -*-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 -#include -#include - -#include -#include - -#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 -#include - -#include -#include - -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 -------------------------------------------------*/