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  • /* camellia-set-encrypt-key.c
     *
     * Key setup for the camellia block cipher.
     */
    /*
     * Copyright (C) 2006,2007
     * NTT (Nippon Telegraph and Telephone Corporation).
     *
     * Copyright (C) 2010 Niels Mller
     *
     * This library is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 2.1 of the License, or (at your option) any later version.
     *
     * This library 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
     * Lesser General Public License for more details.
     *
     * You should have received a copy of the GNU Lesser General Public
     * License along with this library; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     */
    
    /*
     * Algorithm Specification 
     *  http://info.isl.ntt.co.jp/crypt/eng/camellia/specifications.html
     */
    
    /* Based on camellia.c ver 1.2.0, see
       http://info.isl.ntt.co.jp/crypt/eng/camellia/dl/camellia-LGPL-1.2.0.tar.gz.
     */
    #if HAVE_CONFIG_H
    # include "config.h"
    #endif
    
    #include <assert.h>
    
    #include <limits.h>
    
    
    #include "camellia-internal.h"
    
    #include "macros.h"
    
    /* key constants */
    
    #define SIGMA1 0xA09E667F3BCC908BULL
    #define SIGMA2 0xB67AE8584CAA73B2ULL
    #define SIGMA3 0xC6EF372FE94F82BEULL
    #define SIGMA4 0x54FF53A5F1D36F1CULL
    #define SIGMA5 0x10E527FADE682D1DULL
    #define SIGMA6 0xB05688C2B3E6C1FDULL
    
    #define CAMELLIA_SP1110(INDEX) (_nettle_camellia_table.sp1110[(int)(INDEX)])
    #define CAMELLIA_SP0222(INDEX) (_nettle_camellia_table.sp0222[(int)(INDEX)])
    #define CAMELLIA_SP3033(INDEX) (_nettle_camellia_table.sp3033[(int)(INDEX)])
    #define CAMELLIA_SP4404(INDEX) (_nettle_camellia_table.sp4404[(int)(INDEX)])
    
    #define CAMELLIA_F(x, k, y) do {		\
        uint32_t __yl, __yr;			\
        uint64_t __i = (x) ^ (k);			\
        __yl					\
          = CAMELLIA_SP1110( __i & 0xff)		\
          ^ CAMELLIA_SP0222((__i >> 24) & 0xff)	\
          ^ CAMELLIA_SP3033((__i >> 16) & 0xff)	\
          ^ CAMELLIA_SP4404((__i >> 8) & 0xff);	\
        __yr					\
          = CAMELLIA_SP1110( __i >> 56)		\
          ^ CAMELLIA_SP0222((__i >> 48) & 0xff)	\
          ^ CAMELLIA_SP3033((__i >> 40) & 0xff)	\
          ^ CAMELLIA_SP4404((__i >> 32) & 0xff);	\
        __yl ^= __yr;				\
        __yr = ROL32(24, __yr);			\
        __yr ^= __yl;				\
        (y) = ((uint64_t) __yl << 32) | __yr;	\
      } while (0)
    
    
    #if ! HAVE_NATIVE_64_BIT
    #define CAMELLIA_F_HALF_INV(x) do {            \
        uint32_t __t, __w;                         \
        __t = (x) >> 32;                           \
        __w = __t ^(x);                            \
        __w = ROL32(8, __w);                       \
        (x) = ((uint64_t) __w << 32) | (__t ^ __w);        \
      } while (0)
    #endif
    
    
    void
    camellia_set_encrypt_key(struct camellia_ctx *ctx,
    			 unsigned length, const uint8_t *key)
    {
    
      uint64_t k0, k1;
    
      uint64_t w, kw2, kw4;
    
      k0 = READ_UINT64(key);
      k1 = READ_UINT64(key +  8);
    
          /**
           * generate KL dependent subkeys
           */
          subkey[0] = k0; subkey[1] = k1;
          ROL128(15, k0, k1);
          subkey[4] = k0; subkey[5] = k1;
          ROL128(30, k0, k1);
          subkey[10] = k0; subkey[11] = k1;
          ROL128(15, k0, k1);
          subkey[13] = k1;
          ROL128(17, k0, k1);
          subkey[16] = k0; subkey[17] = k1;
          ROL128(17, k0, k1);
          subkey[18] = k0; subkey[19] = k1;
          ROL128(17, k0, k1);
          subkey[22] = k0; subkey[23] = k1;
    
          /* generate KA. D1 is k0, d2 is k1. */
          /* FIXME: Make notation match the spec better. */
          /* For the 128-bit case, KR = 0, the construction of KA reduces to:
    
    	 D1 = KL >> 64;
    	 W = KL & MASK64;
    	 D2 = F(D1, Sigma1);
    	 W = D2 ^ W
    	 D1 = F(W, Sigma2)
    	 D2 = D2 ^ F(D1, Sigma3);
    	 D1 = D1 ^ F(D2, Sigma4);
    	 KA = (D1 << 64) | D2;
          */
          k0 = subkey[0]; w = subkey[1];
          CAMELLIA_F(k0, SIGMA1, k1);
          w ^= k1;
          CAMELLIA_F(w, SIGMA2, k0);
          CAMELLIA_F(k0, SIGMA3, w);
          k1 ^= w;
          CAMELLIA_F(k1, SIGMA4, w);
          k0 ^= w;
    
          /* generate KA dependent subkeys */
          subkey[2] = k0; subkey[3] = k1;
          ROL128(15, k0, k1);
          subkey[6] = k0; subkey[7] = k1;
          ROL128(15, k0, k1);
          subkey[8] = k0; subkey[9] = k1;
          ROL128(15, k0, k1);
          subkey[12] = k0;
          ROL128(15, k0, k1);
          subkey[14] = k0; subkey[15] = k1;
          ROL128(34, k0, k1);
          subkey[20] = k0; subkey[21] = k1;
          ROL128(17, k0, k1);
          subkey[24] = k0; subkey[25] = k1;
    
          uint64_t k2, k3;
    
          k2 = READ_UINT64(key + 16);
    
    	k3 = ~k2;
    
    	  k3 = READ_UINT64(key + 24);
    
          /* generate KL dependent subkeys */
          subkey[0] = k0; subkey[1] = k1;
          ROL128(45, k0, k1);
          subkey[12] = k0; subkey[13] = k1;
          ROL128(15, k0, k1);
          subkey[16] = k0; subkey[17] = k1;
          ROL128(17, k0, k1);
          subkey[22] = k0; subkey[23] = k1;
          ROL128(34, k0, k1);
          subkey[30] = k0; subkey[31] = k1;
    
          /* generate KR dependent subkeys */
          ROL128(15, k2, k3);
          subkey[4] = k2; subkey[5] = k3;
          ROL128(15, k2, k3);
          subkey[8] = k2; subkey[9] = k3;
          ROL128(30, k2, k3);
          subkey[18] = k2; subkey[19] = k3;
          ROL128(34, k2, k3);
          subkey[26] = k2; subkey[27] = k3;
          ROL128(34, k2, k3);
    
          /* generate KA */
          /* The construction of KA is done as
    
    	 D1 = (KL ^ KR) >> 64
    	 D2 = (KL ^ KR) & MASK64
    	 W = F(D1, SIGMA1)
    	 D2 = D2 ^ W
    	 D1 = F(D2, SIGMA2) ^ (KR >> 64)
    	 D2 = F(D1, SIGMA3) ^ W ^ (KR & MASK64)
    	 D1 = D1 ^ F(W, SIGMA2)
    	 D2 = D2 ^ F(D1, SIGMA3)
    	 D1 = D1 ^ F(D2, SIGMA4)
          */
    
          k0 = subkey[0] ^ k2;
          k1 = subkey[1] ^ k3;
    
          CAMELLIA_F(k0, SIGMA1, w);
          k1 ^= w;
    
          CAMELLIA_F(k1, SIGMA2, k0);
          k0 ^= k2;
    
          CAMELLIA_F(k0, SIGMA3, k1);
          k1 ^= w ^ k3;
    
          CAMELLIA_F(k1, SIGMA4, w);
          k0 ^= w;
    
          /* generate KB */
          k2 ^= k0; k3 ^= k1;
          CAMELLIA_F(k2, SIGMA5, w);
          k3 ^= w;
          CAMELLIA_F(k3, SIGMA6, w);
          k2 ^= w;
    
          /* generate KA dependent subkeys */
          ROL128(15, k0, k1);
          subkey[6] = k0; subkey[7] = k1;
          ROL128(30, k0, k1);
          subkey[14] = k0; subkey[15] = k1;
          ROL128(32, k0, k1);
          subkey[24] = k0; subkey[25] = k1;
          ROL128(17, k0, k1);
          subkey[28] = k0; subkey[29] = k1;
    
          /* generate KB dependent subkeys */
          subkey[2] = k2; subkey[3] = k3;
          ROL128(30, k2, k3);
          subkey[10] = k2; subkey[11] = k3;
          ROL128(30, k2, k3);
          subkey[20] = k2; subkey[21] = k3;
          ROL128(51, k2, k3);
          subkey[32] = k2; subkey[33] = k3;
    
      /* At this point, the subkey array contains the subkeys as described
         in the spec, 26 for short keys and 34 for large keys. */
    
    
      /* absorb kw2 to other subkeys */
    
      subkey[3] ^= kw2;
      subkey[5] ^= kw2;
      subkey[7] ^= kw2;
    
      for (i = 8; i < ctx->nkeys; i += 8)
    
        {
          /* FIXME: gcc for x86_32 is smart enough to fetch the 32 low bits
    	 and xor the result into the 32 high bits, but it still generates
    	 worse code than for explicit 32-bit operations. */
          kw2 ^= (kw2 & ~subkey[i+1]) << 32;
          dw = (kw2 & subkey[i+1]) >> 32; kw2 ^= ROL32(1, dw); 
    
          subkey[i+3] ^= kw2;
          subkey[i+5] ^= kw2;
          subkey[i+7] ^= kw2;
    
      /* absorb kw4 to other subkeys */  
    
      kw4 = subkey[ctx->nkeys + 1];
    
      for (i = ctx->nkeys - 8; i > 0; i -= 8)
    
          subkey[i+6] ^= kw4;
          subkey[i+4] ^= kw4;
          subkey[i+2] ^= kw4;
          kw4 ^= (kw4 & ~subkey[i]) << 32;
          dw = (kw4 & subkey[i]) >> 32; kw4 ^= ROL32(1, dw);      
    
        }
    
      subkey[6] ^= kw4;
      subkey[4] ^= kw4;
      subkey[2] ^= kw4;
      subkey[0] ^= kw4;
    
      /* key XOR is end of F-function */
    
      ctx->keys[0] = subkey[0] ^ subkey[2];
    
      ctx->keys[2] = subkey[2] ^ subkey[4];
      ctx->keys[3] = subkey[3] ^ subkey[5];
      ctx->keys[4] = subkey[4] ^ subkey[6];
      ctx->keys[5] = subkey[5] ^ subkey[7];
    
      for (i = 8; i < ctx->nkeys; i += 8)
    
          tl = (subkey[i+2] >> 32) ^ (subkey[i+2] & ~subkey[i]);
          dw = tl & (subkey[i] >> 32);
          tr = subkey[i+2] ^ ROL32(1, dw);
    
          ctx->keys[i-2] = subkey[i-2] ^ ( ((uint64_t) tl << 32) | tr);
    
          ctx->keys[i-1] = subkey[i];
          ctx->keys[i] = subkey[i+1];
    
    
          tl = (subkey[i-1] >> 32) ^ (subkey[i-1] & ~subkey[i+1]);
          dw = tl & (subkey[i+1] >> 32);
          tr = subkey[i-1] ^ ROL32(1, dw);
    
          ctx->keys[i+1] = subkey[i+3] ^ ( ((uint64_t) tl << 32) | tr);
    
          ctx->keys[i+2] = subkey[i+2] ^ subkey[i+4];
          ctx->keys[i+3] = subkey[i+3] ^ subkey[i+5];
          ctx->keys[i+4] = subkey[i+4] ^ subkey[i+6];
          ctx->keys[i+5] = subkey[i+5] ^ subkey[i+7];
    
      ctx->keys[i-2] = subkey[i-2];
      ctx->keys[i-1] = subkey[i] ^ subkey[i-1];
    
    
    #if !HAVE_NATIVE_64_BIT
      for (i = 0; i < ctx->nkeys; i += 8)
        {
          /* apply the inverse of the last half of F-function */
          CAMELLIA_F_HALF_INV(ctx->keys[i+1]);
          CAMELLIA_F_HALF_INV(ctx->keys[i+2]);
          CAMELLIA_F_HALF_INV(ctx->keys[i+3]);
          CAMELLIA_F_HALF_INV(ctx->keys[i+4]);
          CAMELLIA_F_HALF_INV(ctx->keys[i+5]);
          CAMELLIA_F_HALF_INV(ctx->keys[i+6]);
        }
    #endif