X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/e8ec97351e2296b1db2cd33bcb188dca51c431b1..621468d83b9305d85b36c27b6cbf8f4dac89d284:/safer.c?ds=sidebyside diff --git a/safer.c b/safer.c new file mode 100644 index 00000000..1c97eab7 --- /dev/null +++ b/safer.c @@ -0,0 +1,333 @@ +/* -*-c-*- + * + * $Id: safer.c,v 1.1 2001/04/29 17:37:35 mdw Exp $ + * + * The SAFER block cipher + * + * (c) 2001 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. + */ + +/*----- Revision history --------------------------------------------------* + * + * $Log: safer.c,v $ + * Revision 1.1 2001/04/29 17:37:35 mdw + * Added SAFER block cipher. + * + */ + +/*----- Header files ------------------------------------------------------*/ + +#include +#include + +#include + +#include "blkc.h" +#include "gcipher.h" +#include "paranoia.h" +#include "safer.h" +#include "safer-tab.h" + +/*----- Global variables --------------------------------------------------*/ + +const octet safer_keysz[] = { KSZ_SET, 8, 16, 0 }; + +/*----- Important tables --------------------------------------------------*/ + +static const octet s[265] = SAFER_S, si[256] = SAFER_SI; + +/*----- Main code ---------------------------------------------------------*/ + +/* --- @safer_setup@ --- * + * + * Arguments: @safer_ctx *k@ = pointer to context to initialize + * @unsigned r@ = number of rounds wanted + * @unsigned f@ = various other flags + * @const void *buf@ = pointer to key material + * @size_t sz@ = size of key material in bytes + * + * Returns: --- + * + * Use: Initializes an SAFER expanded key. A default number of + * rounds is chosen, based on the key length. + */ + +struct ksched { + unsigned i; + octet x[9]; +}; + +static void init(struct ksched *t, const octet *k) +{ + memcpy(t->x, k, 8); + t->i = 1; +} + +static void init_sk(struct ksched *t, const octet *k) +{ + unsigned i; + octet x; + memcpy(t->x, k, 8); + for (x = 0, i = 0; i < 8; x ^= k[i++]) + ; + t->x[8] = x; + t->i = 1; +} + +static void next(struct ksched *t, octet *k) +{ + unsigned i; + if (k) { + memcpy(k, t->x, 8); + if (t->i > 1) { + for (i = 0; i < 8; i++) + k[i] += s[s[U8(9*t->i + i + 1)]]; + } + } + for (i = 0; i < 8; i++) + t->x[i] = ROL8(t->x[i], 3); + t->i++; +} + +static void next_sk(struct ksched *t, octet *k) +{ + unsigned i; + i = (t->i - 1)%9; + if (k) { + if (i < 2) + memcpy(k, t->x + i, 8); + else { + memcpy(k, t->x + i, 9 - i); + memcpy(k + 9 - i, t->x, i - 1); + } + if (t->i > 1) { + for (i = 0; i < 8; i++) + k[i] += s[s[U8(9*t->i + i + 1)]]; + } + } + for (i = 0; i < 9; i++) + t->x[i] = ROL8(t->x[i], 3); + t->i++; +} + +void safer_setup(safer_ctx *k, unsigned r, unsigned f, + const void *buf, size_t sz) +{ + struct ksched ka, kb; + void (*in)(struct ksched *, const octet *); + void (*nx)(struct ksched *, octet *); + octet *kk; + + assert(r <= SAFER_MAXROUNDS); + KSZ_ASSERT(safer, sz); + + if (f & SAFER_SK) { + in = init_sk; + nx = next_sk; + } else { + in = init; + nx = next; + } + + in(&kb, buf); + in(&ka, sz == 8 ? buf : (const octet *)buf + 8); + + k->r = r; + kk = k->k; + while (r) { + nx(&ka, kk); nx(&kb, 0); kk += 8; + nx(&kb, kk); nx(&ka, 0); kk += 8; + r--; + } + nx(&ka, kk); kk += 8; +} + +/* --- @safer_init@, @safersk_init@ --- * + * + * Arguments: @safer_ctx *k@ = pointer to context to initialize + * @const void *buf@ = pointer to key material + * @size_t sz@ = size of key material in bytes + * + * Returns: --- + * + * Use: Initializes an SAFER expanded key. A default number of + * rounds is chosen, based on the key length. + */ + +void safer_init(safer_ctx *k, const void *buf, size_t sz) +{ + safer_setup(k, sz == 8 ? 6 : 10, 0, buf, sz); +} + +void safersk_init(safer_ctx *k, const void *buf, size_t sz) +{ + safer_setup(k, sz == 8 ? 8 : 10, SAFER_SK, buf, sz); +} + +/* --- @safer_eblk@, @safer_dblk@ --- * + * + * Arguments: @const safer_ctx *k@ = pointer to SAFER context + * @const uint32 s[2]@ = pointer to source block + * @const uint32 d[2]@ = pointer to destination block + * + * Returns: --- + * + * Use: Low-level block encryption and decryption. + */ + +#define UNPACK(src, a, b, c, d, e, f, g, h) do { \ + a = U8(src[0] >> 24); b = U8(src[0] >> 16); \ + c = U8(src[0] >> 8); d = U8(src[0] >> 0); \ + e = U8(src[1] >> 24); f = U8(src[1] >> 16); \ + g = U8(src[1] >> 8); h = U8(src[1] >> 0); \ +} while (0) + +#define PACK(dst, a, b, c, d, e, f, g, h) do { \ + dst[0] = (U8(a) << 24) | (U8(b) << 16) | (U8(c) << 8) | U8(d); \ + dst[1] = (U8(e) << 24) | (U8(f) << 16) | (U8(g) << 8) | U8(h); \ +} while (0) + +#define F(x, y) y += x, x += y +#define G(x, y) x -= y, y -= x + +#define PHT(a, b, c, d, e, f, g, h) do { \ + F(a, b); F(c, d); F(e, f); F(g, h); \ + F(a, c); F(e, g); F(b, d); F(f, h); \ + F(a, e); F(b, f); F(c, g); F(d, h); \ +} while (0) + #define IPHT(a, b, c, d, e, f, g, h) do { \ + G(a, e); G(b, f); G(c, g); G(d, h); \ + G(a, c); G(e, g); G(b, d); G(f, h); \ + G(a, b); G(c, d); G(e, f); G(g, h); \ +} while (0) + +#define KXA(k, a, b, c, d, e, f, g, h) do { \ + a ^= *k++; b += *k++; c += *k++; d ^= *k++; \ + e ^= *k++; f += *k++; g += *k++; h ^= *k++; \ +} while (0) +#define SUB(a, b, c, d, e, f, g, h) do { \ + a = s[U8(a)]; b = si[U8(b)]; c = si[U8(c)]; d = s[U8(d)]; \ + e = s[U8(e)]; f = si[U8(f)]; g = si[U8(g)]; h = s[U8(h)]; \ +} while (0) +#define KAX(k, a, b, c, d, e, f, g, h) do { \ + a += *k++; b ^= *k++; c ^= *k++; d += *k++; \ + e += *k++; f ^= *k++; g ^= *k++; h += *k++; \ +} while (0) + +#define KXS(k, a, b, c, d, e, f, g, h) do { \ + h ^= *--k; g -= *--k; f -= *--k; e ^= *--k; \ + d ^= *--k; c -= *--k; b -= *--k; a ^= *--k; \ +} while (0) +#define ISUB(a, b, c, d, e, f, g, h) do { \ + a = si[U8(a)]; b = s[U8(b)]; c = s[U8(c)]; d = si[U8(d)]; \ + e = si[U8(e)]; f = s[U8(f)]; g = s[U8(g)]; h = si[U8(h)]; \ +} while (0) +#define KSX(k, a, b, c, d, e, f, g, h) do { \ + h -= *--k; g ^= *--k; f ^= *--k; e -= *--k; \ + d -= *--k; c ^= *--k; b ^= *--k; a -= *--k; \ +} while (0) + +#define EROUND(k, a, b, c, d, e, f, g, h) do { \ + KXA(k, a, b, c, d, e, f, g, h); \ + SUB(a, b, c, d, e, f, g, h); \ + KAX(k, a, b, c, d, e, f, g, h); \ + PHT(a, b, c, d, e, f, g, h); \ +} while (0) + +#define DROUND(k, a, b, c, d, e, f, g, h) do { \ + IPHT(a, b, c, d, e, f, g, h); \ + KSX(k, a, b, c, d, e, f, g, h); \ + ISUB(a, b, c, d, e, f, g, h); \ + KXS(k, a, b, c, d, e, f, g, h); \ +} while (0) + + +void safer_eblk(const safer_ctx *k, const uint32 *src, uint32 *dst) +{ + octet a, b, c, d, e, f, g, h; + unsigned r = k->r; + const octet *kk = k->k; + + UNPACK(src, a, b, c, d, e, f, g, h); + while (r >= 3) { + EROUND(kk, a, b, c, d, e, f, g, h); + EROUND(kk, a, e, b, f, c, g, d, h); + EROUND(kk, a, c, e, g, b, d, f, h); + r -= 3; + } + switch (r) { + case 0: + KXA(kk, a, b, c, d, e, f, g, h); + PACK(dst, a, b, c, d, e, f, g ,h); + break; + case 1: + EROUND(kk, a, b, c, d, e, f, g, h); + KXA(kk, a, e, b, f, c, g, d, h); + PACK(dst, a, e, b, f, c, g, d, h); + break; + case 2: + EROUND(kk, a, b, c, d, e, f, g, h); + EROUND(kk, a, e, b, f, c, g, d, h); + KXA(kk, a, c, e, g, b, d, f, h); + PACK(dst, a, c, e, g, b, d, f, h); + break; + } +} + +void safer_dblk(const safer_ctx *k, const uint32 *src, uint32 *dst) +{ + octet a, b, c, d, e, f, g, h; + unsigned r = k->r; + const octet *kk = k->k + 16 * r + 8; + switch (r%3) { + default: + case 0: + UNPACK(src, a, b, c, d, e, f, g, h); + KXS(kk, a, b, c, d, e, f, g, h); + break; + case 1: + UNPACK(src, a, e, b, f, c, g, d, h); + KXS(kk, a, e, b, f, c, g, d, h); + r--; + goto one_round; + case 2: + UNPACK(src, a, c, e, g, b, d, f, h); + KXS(kk, a, c, e, g, b, d, f, h); + r -= 2; + DROUND(kk, a, e, b, f, c, g, d, h); + one_round: + DROUND(kk, a, b, c, d, e, f, g, h); + break; + } + while (r) { + DROUND(kk, a, c, e, g, b, d, f, h); + DROUND(kk, a, e, b, f, c, g, d, h); + DROUND(kk, a, b, c, d, e, f, g, h); + r -= 3; + } + PACK(dst, a, b, c, d, e, f, g, h); +} + +BLKC_TEST(SAFER, safer) + +/*----- That's all, folks -------------------------------------------------*/