aes.c

openswan

}

// y = output word, x = input word, r = row, c = column
// for r = 0, 1, 2 and 3 = column accessed for row r

#if defined(ARRAYS)
#define s(x,c) x[c]
#else
#define s(x,c) x##c
#endif

// I am grateful to Frank Yellin for the following constructions
// which, given the column (c) of the output state variable that
// is being computed, return the input state variables which are
// needed for each row (r) of the state

// For the fixed block size options, compilers reduce these two 
// expressions to fixed variable references. For variable block 
// size code conditional clauses will sometimes be returned

#define unused  77  // Sunset Strip

#define fwd_var(x,r,c) \
 ( r==0 ?			\
    ( c==0 ? s(x,0) \
    : c==1 ? s(x,1) \
    : c==2 ? s(x,2) \
    : c==3 ? s(x,3) \
    : c==4 ? s(x,4) \
    : c==5 ? s(x,5) \
    : c==6 ? s(x,6) \
    : s(x,7))		\
 : r==1 ?			\
    ( c==0 ? s(x,1) \
    : c==1 ? s(x,2) \
    : c==2 ? s(x,3) \
    : c==3 ? nc==4 ? s(x,0) : s(x,4) \
    : c==4 ? s(x,5) \
    : c==5 ? nc==8 ? s(x,6) : s(x,0) \
    : c==6 ? s(x,7) \
    : s(x,0))		\
 : r==2 ?			\
    ( c==0 ? nc==8 ? s(x,3) : s(x,2) \
    : c==1 ? nc==8 ? s(x,4) : s(x,3) \
    : c==2 ? nc==4 ? s(x,0) : nc==8 ? s(x,5) : s(x,4) \
    : c==3 ? nc==4 ? s(x,1) : nc==8 ? s(x,6) : s(x,5) \
    : c==4 ? nc==8 ? s(x,7) : s(x,0) \
    : c==5 ? nc==8 ? s(x,0) : s(x,1) \
    : c==6 ? s(x,1) \
    : s(x,2))		\
 :					\
    ( c==0 ? nc==8 ? s(x,4) : s(x,3) \
    : c==1 ? nc==4 ? s(x,0) : nc==8 ? s(x,5) : s(x,4) \
    : c==2 ? nc==4 ? s(x,1) : nc==8 ? s(x,6) : s(x,5) \
    : c==3 ? nc==4 ? s(x,2) : nc==8 ? s(x,7) : s(x,0) \
    : c==4 ? nc==8 ? s(x,0) : s(x,1) \
    : c==5 ? nc==8 ? s(x,1) : s(x,2) \
    : c==6 ? s(x,2) \
    : s(x,3)))

#define inv_var(x,r,c) \
 ( r==0 ?			\
    ( c==0 ? s(x,0) \
    : c==1 ? s(x,1) \
    : c==2 ? s(x,2) \
    : c==3 ? s(x,3) \
    : c==4 ? s(x,4) \
    : c==5 ? s(x,5) \
    : c==6 ? s(x,6) \
    : s(x,7))		\
 : r==1 ?			\
    ( c==0 ? nc==4 ? s(x,3) : nc==8 ? s(x,7) : s(x,5) \
    : c==1 ? s(x,0) \
    : c==2 ? s(x,1) \
    : c==3 ? s(x,2) \
    : c==4 ? s(x,3) \
    : c==5 ? s(x,4) \
    : c==6 ? s(x,5) \
    : s(x,6))		\
 : r==2 ?			\
    ( c==0 ? nc==4 ? s(x,2) : nc==8 ? s(x,5) : s(x,4) \
    : c==1 ? nc==4 ? s(x,3) : nc==8 ? s(x,6) : s(x,5) \
    : c==2 ? nc==8 ? s(x,7) : s(x,0) \
    : c==3 ? nc==8 ? s(x,0) : s(x,1) \
    : c==4 ? nc==8 ? s(x,1) : s(x,2) \
    : c==5 ? nc==8 ? s(x,2) : s(x,3) \
    : c==6 ? s(x,3) \
    : s(x,4))		\
 :					\
    ( c==0 ? nc==4 ? s(x,1) : nc==8 ? s(x,4) : s(x,3) \
    : c==1 ? nc==4 ? s(x,2) : nc==8 ? s(x,5) : s(x,4) \
    : c==2 ? nc==4 ? s(x,3) : nc==8 ? s(x,6) : s(x,5) \
    : c==3 ? nc==8 ? s(x,7) : s(x,0) \
    : c==4 ? nc==8 ? s(x,0) : s(x,1) \
    : c==5 ? nc==8 ? s(x,1) : s(x,2) \
    : c==6 ? s(x,2) \
    : s(x,3)))

#define si(y,x,k,c) s(y,c) = const_word_in(x + 4 * c) ^ k[c]
#define so(y,x,c)   word_out(y + 4 * c, s(x,c))

#if defined(FOUR_TABLES)
#define fwd_rnd(y,x,k,c)    s(y,c)= (k)[c] ^ four_tables(x,ft_tab,fwd_var,rf1,c)
#define inv_rnd(y,x,k,c)    s(y,c)= (k)[c] ^ four_tables(x,it_tab,inv_var,rf1,c)
#elif defined(ONE_TABLE)
#define fwd_rnd(y,x,k,c)    s(y,c)= (k)[c] ^ one_table(x,upr,ft_tab,fwd_var,rf1,c)
#define inv_rnd(y,x,k,c)    s(y,c)= (k)[c] ^ one_table(x,upr,it_tab,inv_var,rf1,c)
#else
#define fwd_rnd(y,x,k,c)    s(y,c) = fwd_mcol(no_table(x,s_box,fwd_var,rf1,c)) ^ (k)[c]
#define inv_rnd(y,x,k,c)    s(y,c) = inv_mcol(no_table(x,inv_s_box,inv_var,rf1,c) ^ (k)[c])
#endif

#if defined(FOUR_LR_TABLES)
#define fwd_lrnd(y,x,k,c)   s(y,c)= (k)[c] ^ four_tables(x,fl_tab,fwd_var,rf1,c)
#define inv_lrnd(y,x,k,c)   s(y,c)= (k)[c] ^ four_tables(x,il_tab,inv_var,rf1,c)
#elif defined(ONE_LR_TABLE)
#define fwd_lrnd(y,x,k,c)   s(y,c)= (k)[c] ^ one_table(x,ups,fl_tab,fwd_var,rf1,c)
#define inv_lrnd(y,x,k,c)   s(y,c)= (k)[c] ^ one_table(x,ups,il_tab,inv_var,rf1,c)
#else
#define fwd_lrnd(y,x,k,c)   s(y,c) = no_table(x,s_box,fwd_var,rf1,c) ^ (k)[c]
#define inv_lrnd(y,x,k,c)   s(y,c) = no_table(x,inv_s_box,inv_var,rf1,c) ^ (k)[c]
#endif

#if AES_BLOCK_SIZE == 16

#if defined(ARRAYS)
#define locals(y,x)     x[4],y[4]
#else
#define locals(y,x)     x##0,x##1,x##2,x##3,y##0,y##1,y##2,y##3
// the following defines prevent the compiler requiring the declaration
// of generated but unused variables in the fwd_var and inv_var macros
#define b04 unused
#define b05 unused
#define b06 unused
#define b07 unused
#define b14 unused
#define b15 unused
#define b16 unused
#define b17 unused
#endif
#define l_copy(y, x)    s(y,0) = s(x,0); s(y,1) = s(x,1); \
                        s(y,2) = s(x,2); s(y,3) = s(x,3);
#define state_in(y,x,k) si(y,x,k,0); si(y,x,k,1); si(y,x,k,2); si(y,x,k,3)
#define state_out(y,x)  so(y,x,0); so(y,x,1); so(y,x,2); so(y,x,3)
#define round(rm,y,x,k) rm(y,x,k,0); rm(y,x,k,1); rm(y,x,k,2); rm(y,x,k,3)

#elif AES_BLOCK_SIZE == 24

#if defined(ARRAYS)
#define locals(y,x)     x[6],y[6]
#else
#define locals(y,x)     x##0,x##1,x##2,x##3,x##4,x##5, \
                        y##0,y##1,y##2,y##3,y##4,y##5
#define b06 unused
#define b07 unused
#define b16 unused
#define b17 unused
#endif
#define l_copy(y, x)    s(y,0) = s(x,0); s(y,1) = s(x,1); \
                        s(y,2) = s(x,2); s(y,3) = s(x,3); \
                        s(y,4) = s(x,4); s(y,5) = s(x,5);
#define state_in(y,x,k) si(y,x,k,0); si(y,x,k,1); si(y,x,k,2); \
                        si(y,x,k,3); si(y,x,k,4); si(y,x,k,5)
#define state_out(y,x)  so(y,x,0); so(y,x,1); so(y,x,2); \
                        so(y,x,3); so(y,x,4); so(y,x,5)
#define round(rm,y,x,k) rm(y,x,k,0); rm(y,x,k,1); rm(y,x,k,2); \
                        rm(y,x,k,3); rm(y,x,k,4); rm(y,x,k,5)
#else

#if defined(ARRAYS)
#define locals(y,x)     x[8],y[8]
#else
#define locals(y,x)     x##0,x##1,x##2,x##3,x##4,x##5,x##6,x##7, \
                        y##0,y##1,y##2,y##3,y##4,y##5,y##6,y##7
#endif
#define l_copy(y, x)    s(y,0) = s(x,0); s(y,1) = s(x,1); \
                        s(y,2) = s(x,2); s(y,3) = s(x,3); \
                        s(y,4) = s(x,4); s(y,5) = s(x,5); \
                        s(y,6) = s(x,6); s(y,7) = s(x,7);

#if AES_BLOCK_SIZE == 32

#define state_in(y,x,k) si(y,x,k,0); si(y,x,k,1); si(y,x,k,2); si(y,x,k,3); \
                        si(y,x,k,4); si(y,x,k,5); si(y,x,k,6); si(y,x,k,7)
#define state_out(y,x)  so(y,x,0); so(y,x,1); so(y,x,2); so(y,x,3); \
                        so(y,x,4); so(y,x,5); so(y,x,6); so(y,x,7)
#define round(rm,y,x,k) rm(y,x,k,0); rm(y,x,k,1); rm(y,x,k,2); rm(y,x,k,3); \
                        rm(y,x,k,4); rm(y,x,k,5); rm(y,x,k,6); rm(y,x,k,7)
#else

#define state_in(y,x,k) \
switch(nc) \
{   case 8: si(y,x,k,7); si(y,x,k,6); \
    case 6: si(y,x,k,5); si(y,x,k,4); \
    case 4: si(y,x,k,3); si(y,x,k,2); \
            si(y,x,k,1); si(y,x,k,0); \
}

#define state_out(y,x) \
switch(nc) \
{   case 8: so(y,x,7); so(y,x,6); \
    case 6: so(y,x,5); so(y,x,4); \
    case 4: so(y,x,3); so(y,x,2); \
            so(y,x,1); so(y,x,0); \
}

#if defined(FAST_VARIABLE)

#define round(rm,y,x,k) \
switch(nc) \
{   case 8: rm(y,x,k,7); rm(y,x,k,6); \
            rm(y,x,k,5); rm(y,x,k,4); \
            rm(y,x,k,3); rm(y,x,k,2); \
            rm(y,x,k,1); rm(y,x,k,0); \
            break; \
    case 6: rm(y,x,k,5); rm(y,x,k,4); \
            rm(y,x,k,3); rm(y,x,k,2); \
            rm(y,x,k,1); rm(y,x,k,0); \
            break; \
    case 4: rm(y,x,k,3); rm(y,x,k,2); \
            rm(y,x,k,1); rm(y,x,k,0); \
            break; \
}
#else

#define round(rm,y,x,k) \
switch(nc) \
{   case 8: rm(y,x,k,7); rm(y,x,k,6); \
    case 6: rm(y,x,k,5); rm(y,x,k,4); \
    case 4: rm(y,x,k,3); rm(y,x,k,2); \
            rm(y,x,k,1); rm(y,x,k,0); \
}

#endif

#endif
#endif

void aes_encrypt(const aes_context *cx, const unsigned char in_blk[], unsigned char out_blk[])
{   u_int32_t        locals(b0, b1);
    const u_int32_t  *kp = cx->aes_e_key;

#if !defined(ONE_TABLE) && !defined(FOUR_TABLES)
    u_int32_t        f2;
#endif

    state_in(b0, in_blk, kp); kp += nc;

#if defined(UNROLL)

    switch(cx->aes_Nrnd)
    {
    case 14:    round(fwd_rnd,  b1, b0, kp         ); 
                round(fwd_rnd,  b0, b1, kp + nc    ); kp += 2 * nc;
    case 12:    round(fwd_rnd,  b1, b0, kp         ); 
                round(fwd_rnd,  b0, b1, kp + nc    ); kp += 2 * nc;
    case 10:    round(fwd_rnd,  b1, b0, kp         );             
                round(fwd_rnd,  b0, b1, kp +     nc);
                round(fwd_rnd,  b1, b0, kp + 2 * nc); 
                round(fwd_rnd,  b0, b1, kp + 3 * nc);
                round(fwd_rnd,  b1, b0, kp + 4 * nc); 
                round(fwd_rnd,  b0, b1, kp + 5 * nc);
                round(fwd_rnd,  b1, b0, kp + 6 * nc); 
                round(fwd_rnd,  b0, b1, kp + 7 * nc);
                round(fwd_rnd,  b1, b0, kp + 8 * nc);
                round(fwd_lrnd, b0, b1, kp + 9 * nc);
    }

#elif defined(PARTIAL_UNROLL)
    {   u_int32_t    rnd;

        for(rnd = 0; rnd < (cx->aes_Nrnd >> 1) - 1; ++rnd)
        {
            round(fwd_rnd, b1, b0, kp); 
            round(fwd_rnd, b0, b1, kp + nc); kp += 2 * nc;
        }

        round(fwd_rnd,  b1, b0, kp);
        round(fwd_lrnd, b0, b1, kp + nc);
    }
#else
    {   u_int32_t    rnd;

        for(rnd = 0; rnd < cx->aes_Nrnd - 1; ++rnd)
        {
            round(fwd_rnd, b1, b0, kp); 
            l_copy(b0, b1); kp += nc;
        }

        round(fwd_lrnd, b0, b1, kp);
    }
#endif

    state_out(out_blk, b0);
}

void aes_decrypt(const aes_context *cx, const unsigned char in_blk[], unsigned char out_blk[])
{   u_int32_t        locals(b0, b1);
    const u_int32_t  *kp = cx->aes_d_key;

#if !defined(ONE_TABLE) && !defined(FOUR_TABLES)
    u_int32_t        f2, f4, f8, f9; 
#endif

    state_in(b0, in_blk, kp); kp += nc;

#if defined(UNROLL)

    switch(cx->aes_Nrnd)
    {
    case 14:    round(inv_rnd,  b1, b0, kp         );
                round(inv_rnd,  b0, b1, kp + nc    ); kp += 2 * nc;
    case 12:    round(inv_rnd,  b1, b0, kp         );
                round(inv_rnd,  b0, b1, kp + nc    ); kp += 2 * nc;
    case 10:    round(inv_rnd,  b1, b0, kp         );             
                round(inv_rnd,  b0, b1, kp +     nc);
                round(inv_rnd,  b1, b0, kp + 2 * nc); 
                round(inv_rnd,  b0, b1, kp + 3 * nc);
                round(inv_rnd,  b1, b0, kp + 4 * nc); 
                round(inv_rnd,  b0, b1, kp + 5 * nc);
                round(inv_rnd,  b1, b0, kp + 6 * nc); 
                round(inv_rnd,  b0, b1, kp + 7 * nc);
                round(inv_rnd,  b1, b0, kp + 8 * nc);
                round(inv_lrnd, b0, b1, kp + 9 * nc);
    }

#elif defined(PARTIAL_UNROLL)
    {   u_int32_t    rnd;

        for(rnd = 0; rnd < (cx->aes_Nrnd >> 1) - 1; ++rnd)
        {
            round(inv_rnd, b1, b0, kp); 
            round(inv_rnd, b0, b1, kp + nc); kp += 2 * nc;
        }

        round(inv_rnd,  b1, b0, kp);
        round(inv_lrnd, b0, b1, kp + nc);
    }
#else
    {   u_int32_t    rnd;

        for(rnd = 0; rnd < cx->aes_Nrnd - 1; ++rnd)
        {
            round(inv_rnd, b1, b0, kp); 
            l_copy(b0, b1); kp += nc;
        }

        round(inv_lrnd, b0, b1, kp);
    }
#endif

    state_out(out_blk, b0);
}