crypto/rc4/asm/rc4-586.pl

   1 #!/usr/local/bin/perl
   2
   3 # define for pentium pro friendly version
   4
   5 push(@INC,"perlasm","../../perlasm");
   6 require "x86asm.pl";
   7
   8 &asm_init($ARGV[0],"rc4-586.pl");
   9
  10 $x="eax";
  11 $y="ebx";
  12 $tx="ecx";
  13 $ty="edx";
  14 $in="esi";
  15 $out="edi";
  16 $d="ebp";
  17
  18 &RC4("RC4");
  19
  20 &asm_finish();
  21
  22 sub RC4_loop
  23         {
  24         local($n,$p,$char)=@_;
  25
  26         &comment("Round $n");
  27
  28         if ($char)
  29                 {
  30                 if ($p >= 0)
  31                         {
  32                          &mov($ty,      &swtmp(2));
  33                         &cmp($ty,       $in);
  34                          &jbe(&label("finished"));
  35                         &inc($in);
  36                         }
  37                 else
  38                         {
  39                         &add($ty,       8);
  40                          &inc($in);
  41                         &cmp($ty,       $in);
  42                          &jb(&label("finished"));
  43                         &mov(&swtmp(2), $ty);
  44                         }
  45                 }
  46         # Moved out
  47         # &mov( $tx,            &DWP(0,$d,$x,4)) if $p < 0;
  48
  49          &add(  $y,             $tx);
  50         &and(   $y,             0xff);
  51          &inc(  $x);                    # NEXT ROUND
  52         &mov(   $ty,            &DWP(0,$d,$y,4));
  53          # XXX
  54         &mov(   &DWP(-4,$d,$x,4),$ty);                  # AGI
  55          &add(  $ty,            $tx);
  56         &and(   $x,             0xff);  # NEXT ROUND
  57          &and(  $ty,            0xff);
  58         &mov(   &DWP(0,$d,$y,4),$tx);
  59          &nop();
  60         &mov(   $ty,            &DWP(0,$d,$ty,4));
  61          &mov(  $tx,            &DWP(0,$d,$x,4)) if $p < 1; # NEXT ROUND
  62          # XXX
  63
  64         if (!$char)
  65                 {
  66                 #moved up into last round
  67                 if ($p >= 1)
  68                         {
  69                         &add(   $out,   8)
  70                         }
  71                 &movb(  &BP($n,"esp","",0),     &LB($ty));
  72                 }
  73         else
  74                 {
  75                 # Note in+=8 has occured
  76                 &movb(  &HB($ty),       &BP(-1,$in,"",0));
  77                  # XXX
  78                 &xorb(&LB($ty),         &HB($ty));
  79                  # XXX
  80                 &movb(&BP($n,$out,"",0),&LB($ty));
  81                 }
  82         }
  83
  84
  85 sub RC4
  86         {
  87         local($name)=@_;
  88
  89         &function_begin_B($name,"");
  90
  91         &mov($ty,&wparam(1));           # len
  92         &cmp($ty,0);
  93         &jne(&label("proceed"));
  94         &ret();
  95         &set_label("proceed");
  96
  97         &comment("");
  98
  99         &push("ebp");
 100          &push("ebx");
 101         &push("esi");
 102          &push("edi");
 103         &mov(   $d,     &wparam(0));    # key
 104          &mov(  $in,    &wparam(2));
 105
 106         &mov(   $x,     &DWP(0,$d,"",1));
 107          &mov(  $y,     &DWP(4,$d,"",1));
 108
 109         &mov(   $out,   &wparam(3));
 110          &inc(  $x);
 111
 112         &stack_push(3); # 3 temp variables
 113          &add(  $d,     8);
 114         &and(   $x,             0xff);
 115
 116         # detect compressed schedule, see commentary section in rc4_skey.c...
 117         &cmp(&DWP(256,$d),-1);
 118         &je(&label("RC4_CHAR"));
 119
 120          &lea(  $ty,    &DWP(-8,$ty,$in));
 121
 122         # check for 0 length input
 123
 124          &mov(  &swtmp(2),      $ty);   # this is now address to exit at
 125         &mov(   $tx,    &DWP(0,$d,$x,4));
 126
 127          &cmp(  $ty,    $in);
 128         &jb(    &label("end")); # less than 8 bytes
 129
 130         &set_label("start");
 131
 132         # filling DELAY SLOT
 133         &add(   $in,    8);
 134
 135         &RC4_loop(0,-1,0);
 136         &RC4_loop(1,0,0);
 137         &RC4_loop(2,0,0);
 138         &RC4_loop(3,0,0);
 139         &RC4_loop(4,0,0);
 140         &RC4_loop(5,0,0);
 141         &RC4_loop(6,0,0);
 142         &RC4_loop(7,1,0);
 143
 144         &comment("apply the cipher text");
 145         # xor the cipher data with input
 146
 147         #&add(  $out,   8); #moved up into last round
 148
 149         &mov(   $tx,    &swtmp(0));
 150          &mov(  $ty,    &DWP(-8,$in,"",0));
 151         &xor(   $tx,    $ty);
 152          &mov(  $ty,    &DWP(-4,$in,"",0));
 153         &mov(   &DWP(-8,$out,"",0),     $tx);
 154          &mov(  $tx,    &swtmp(1));
 155         &xor(   $tx,    $ty);
 156          &mov(  $ty,    &swtmp(2));     # load end ptr;
 157         &mov(   &DWP(-4,$out,"",0),     $tx);
 158          &mov(  $tx,            &DWP(0,$d,$x,4));
 159         &cmp($in,       $ty);
 160          &jbe(&label("start"));
 161
 162         &set_label("end");
 163
 164         # There is quite a bit of extra crap in RC4_loop() for this
 165         # first round
 166         &RC4_loop(0,-1,1);
 167         &RC4_loop(1,0,1);
 168         &RC4_loop(2,0,1);
 169         &RC4_loop(3,0,1);
 170         &RC4_loop(4,0,1);
 171         &RC4_loop(5,0,1);
 172         &RC4_loop(6,1,1);
 173
 174         &jmp(&label("finished"));
 175
 176         &align(16);
 177         # this is essentially Intel P4 specific codepath, see rc4_skey.c...
 178         &set_label("RC4_CHAR");
 179
 180         &lea    ($ty,&DWP(0,$in,$ty));
 181         &mov    (&swtmp(2),$ty);
 182
 183         # strangely enough unrolled loop performs over 20% slower...
 184         &set_label("RC4_CHAR_loop");
 185                 &movz   ($tx,&BP(0,$d,$x));
 186                 &add    (&LB($y),&LB($tx));
 187                 &movz   ($ty,&BP(0,$d,$y));
 188                 &movb   (&BP(0,$d,$y),&LB($tx));
 189                 &movb   (&BP(0,$d,$x),&LB($ty));
 190                 &add    (&LB($ty),&LB($tx));
 191                 &movz   ($ty,&BP(0,$d,$ty));
 192                 &xorb   (&LB($ty),&BP(0,$in));
 193                 &movb   (&BP(0,$out),&LB($ty));
 194                 &inc    (&LB($x));
 195                 &inc    ($in);
 196                 &inc    ($out);
 197                 &cmp    ($in,&swtmp(2));
 198         &jb     (&label("RC4_CHAR_loop"));
 199
 200         &set_label("finished");
 201         &dec(   $x);
 202          &stack_pop(3);
 203         &mov(   &DWP(-4,$d,"",0),$y);
 204          &movb( &BP(-8,$d,"",0),&LB($x));
 205
 206         &function_end($name);
 207         }
 208