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 $tx="eax";
  11 $ty="ebx";
  12 $x="ecx";
  13 $y="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,       $in);
  34                          &jle(&label("finished"));
  35                         &inc($in);
  36                         }
  37                 else
  38                         {
  39                         &add($ty,       8);
  40                          &inc($in);
  41                         &cmp($ty,       $in);
  42                          &jl(&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         &comment("");
  92
  93         &push("ebp");
  94          &push("ebx");
  95         &mov(   $d,     &wparam(0));    # key
  96          &mov(  $ty,    &wparam(1));    # num
  97         &push("esi");
  98          &push("edi");
  99
 100         &mov(   $x,     &DWP(0,$d,"",1));
 101          &mov(  $y,     &DWP(4,$d,"",1));
 102
 103         &mov(   $in,    &wparam(2));
 104          &inc(  $x);
 105
 106         &stack_push(3); # 3 temp variables
 107          &add(  $d,     8);
 108         &and(   $x,             0xff);
 109
 110          &lea(  $ty,    &DWP(-8,$ty,$in));
 111
 112         # check for 0 length input
 113
 114         &mov(   $out,   &wparam(3));
 115          &mov(  &swtmp(2),      $ty);   # this is now address to exit at
 116         &mov(   $tx,    &DWP(0,$d,$x,4));
 117
 118          &cmp(  $ty,    $in);
 119         &jl(    &label("end")); # less than 8 bytes
 120
 121         &set_label("start");
 122
 123         # filling DELAY SLOT
 124         &add(   $in,    8);
 125
 126         &RC4_loop(0,-1,0);
 127         &RC4_loop(1,0,0);
 128         &RC4_loop(2,0,0);
 129         &RC4_loop(3,0,0);
 130         &RC4_loop(4,0,0);
 131         &RC4_loop(5,0,0);
 132         &RC4_loop(6,0,0);
 133         &RC4_loop(7,1,0);
 134
 135         &comment("apply the cipher text");
 136         # xor the cipher data with input
 137
 138         #&add(  $out,   8); #moved up into last round
 139
 140         &mov(   $tx,    &swtmp(0));
 141          &mov(  $ty,    &DWP(-8,$in,"",0));
 142         &xor(   $tx,    $ty);
 143          &mov(  $ty,    &DWP(-4,$in,"",0));
 144         &mov(   &DWP(-8,$out,"",0),     $tx);
 145          &mov(  $tx,    &swtmp(1));
 146         &xor(   $tx,    $ty);
 147          &mov(  $ty,    &swtmp(2));     # load end ptr;
 148         &mov(   &DWP(-4,$out,"",0),     $tx);
 149          &mov(  $tx,            &DWP(0,$d,$x,4));
 150         &cmp($in,       $ty);
 151          &jle(&label("start"));
 152
 153         &set_label("end");
 154
 155         # There is quite a bit of extra crap in RC4_loop() for this
 156         # first round
 157         &RC4_loop(0,-1,1);
 158         &RC4_loop(1,0,1);
 159         &RC4_loop(2,0,1);
 160         &RC4_loop(3,0,1);
 161         &RC4_loop(4,0,1);
 162         &RC4_loop(5,0,1);
 163         &RC4_loop(6,1,1);
 164
 165         &set_label("finished");
 166         &dec(   $x);
 167          &stack_pop(3);
 168         &mov(   &DWP(-4,$d,"",0),$y);
 169          &movb( &BP(-8,$d,"",0),&LB($x));
 170
 171         &function_end($name);
 172         }
 173