1#!/usr/local/bin/perl 2# 3# The inner loop instruction sequence and the IP/FP modifications are from 4# Svend Olaf Mikkelsen <svolaf@inet.uni-c.dk> 5# I've added the stuff needed for crypt() but I've not worried about making 6# things perfect. 7# 8 9push(@INC,"perlasm","../../perlasm"); 10require "x86asm.pl"; 11 12&asm_init($ARGV[0],"crypt586.pl"); 13 14$L="edi"; 15$R="esi"; 16 17&external_label("DES_SPtrans"); 18&fcrypt_body("fcrypt_body"); 19&asm_finish(); 20 21sub fcrypt_body 22 { 23 local($name,$do_ip)=@_; 24 25 &function_begin($name,"EXTRN _DES_SPtrans:DWORD"); 26 27 &comment(""); 28 &comment("Load the 2 words"); 29 $trans="ebp"; 30 31 &xor( $L, $L); 32 &xor( $R, $R); 33 34 # PIC-ification:-) 35 if ($cpp) { &picmeup("edx","DES_SPtrans"); } 36 else { &lea("edx",&DWP("DES_SPtrans")); } 37 &push("edx"); # becomes &swtmp(1) 38 # 39 &mov($trans,&wparam(1)); # reloaded with DES_SPtrans in D_ENCRYPT 40 41 &push(&DWC(25)); # add a variable 42 43 &set_label("start"); 44 for ($i=0; $i<16; $i+=2) 45 { 46 &comment(""); 47 &comment("Round $i"); 48 &D_ENCRYPT($i,$L,$R,$i*2,$trans,"eax","ebx","ecx","edx"); 49 50 &comment(""); 51 &comment("Round ".sprintf("%d",$i+1)); 52 &D_ENCRYPT($i+1,$R,$L,($i+1)*2,$trans,"eax","ebx","ecx","edx"); 53 } 54 &mov("ebx", &swtmp(0)); 55 &mov("eax", $L); 56 &dec("ebx"); 57 &mov($L, $R); 58 &mov($R, "eax"); 59 &mov(&swtmp(0), "ebx"); 60 &jnz(&label("start")); 61 62 &comment(""); 63 &comment("FP"); 64 &mov("edx",&wparam(0)); 65 66 &FP_new($R,$L,"eax",3); 67 &mov(&DWP(0,"edx","",0),"eax"); 68 &mov(&DWP(4,"edx","",0),$L); 69 70 &add("esp",8); # remove variables 71 72 &function_end($name); 73 } 74 75sub D_ENCRYPT 76 { 77 local($r,$L,$R,$S,$trans,$u,$tmp1,$tmp2,$t)=@_; 78 79 &mov( $u, &wparam(2)); # 2 80 &mov( $t, $R); 81 &shr( $t, 16); # 1 82 &mov( $tmp2, &wparam(3)); # 2 83 &xor( $t, $R); # 1 84 85 &and( $u, $t); # 2 86 &and( $t, $tmp2); # 2 87 88 &mov( $tmp1, $u); 89 &shl( $tmp1, 16); # 1 90 &mov( $tmp2, $t); 91 &shl( $tmp2, 16); # 1 92 &xor( $u, $tmp1); # 2 93 &xor( $t, $tmp2); # 2 94 &mov( $tmp1, &DWP(&n2a($S*4),$trans,"",0)); # 2 95 &xor( $u, $tmp1); 96 &mov( $tmp2, &DWP(&n2a(($S+1)*4),$trans,"",0)); # 2 97 &xor( $u, $R); 98 &xor( $t, $R); 99 &xor( $t, $tmp2); 100 101 &and( $u, "0xfcfcfcfc" ); # 2 102 &xor( $tmp1, $tmp1); # 1 103 &and( $t, "0xcfcfcfcf" ); # 2 104 &xor( $tmp2, $tmp2); 105 &movb( &LB($tmp1), &LB($u) ); 106 &movb( &LB($tmp2), &HB($u) ); 107 &rotr( $t, 4 ); 108 &mov( $trans, &swtmp(1)); 109 &xor( $L, &DWP(" ",$trans,$tmp1,0)); 110 &movb( &LB($tmp1), &LB($t) ); 111 &xor( $L, &DWP("0x200",$trans,$tmp2,0)); 112 &movb( &LB($tmp2), &HB($t) ); 113 &shr( $u, 16); 114 &xor( $L, &DWP("0x100",$trans,$tmp1,0)); 115 &movb( &LB($tmp1), &HB($u) ); 116 &shr( $t, 16); 117 &xor( $L, &DWP("0x300",$trans,$tmp2,0)); 118 &movb( &LB($tmp2), &HB($t) ); 119 &and( $u, "0xff" ); 120 &and( $t, "0xff" ); 121 &mov( $tmp1, &DWP("0x600",$trans,$tmp1,0)); 122 &xor( $L, $tmp1); 123 &mov( $tmp1, &DWP("0x700",$trans,$tmp2,0)); 124 &xor( $L, $tmp1); 125 &mov( $tmp1, &DWP("0x400",$trans,$u,0)); 126 &xor( $L, $tmp1); 127 &mov( $tmp1, &DWP("0x500",$trans,$t,0)); 128 &xor( $L, $tmp1); 129 &mov( $trans, &wparam(1)); 130 } 131 132sub n2a 133 { 134 sprintf("%d",$_[0]); 135 } 136 137# now has a side affect of rotating $a by $shift 138sub R_PERM_OP 139 { 140 local($a,$b,$tt,$shift,$mask,$last)=@_; 141 142 &rotl( $a, $shift ) if ($shift != 0); 143 &mov( $tt, $a ); 144 &xor( $a, $b ); 145 &and( $a, $mask ); 146 if ($notlast eq $b) 147 { 148 &xor( $b, $a ); 149 &xor( $tt, $a ); 150 } 151 else 152 { 153 &xor( $tt, $a ); 154 &xor( $b, $a ); 155 } 156 &comment(""); 157 } 158 159sub IP_new 160 { 161 local($l,$r,$tt,$lr)=@_; 162 163 &R_PERM_OP($l,$r,$tt, 4,"0xf0f0f0f0",$l); 164 &R_PERM_OP($r,$tt,$l,20,"0xfff0000f",$l); 165 &R_PERM_OP($l,$tt,$r,14,"0x33333333",$r); 166 &R_PERM_OP($tt,$r,$l,22,"0x03fc03fc",$r); 167 &R_PERM_OP($l,$r,$tt, 9,"0xaaaaaaaa",$r); 168 169 if ($lr != 3) 170 { 171 if (($lr-3) < 0) 172 { &rotr($tt, 3-$lr); } 173 else { &rotl($tt, $lr-3); } 174 } 175 if ($lr != 2) 176 { 177 if (($lr-2) < 0) 178 { &rotr($r, 2-$lr); } 179 else { &rotl($r, $lr-2); } 180 } 181 } 182 183sub FP_new 184 { 185 local($l,$r,$tt,$lr)=@_; 186 187 if ($lr != 2) 188 { 189 if (($lr-2) < 0) 190 { &rotl($r, 2-$lr); } 191 else { &rotr($r, $lr-2); } 192 } 193 if ($lr != 3) 194 { 195 if (($lr-3) < 0) 196 { &rotl($l, 3-$lr); } 197 else { &rotr($l, $lr-3); } 198 } 199 200 &R_PERM_OP($l,$r,$tt, 0,"0xaaaaaaaa",$r); 201 &R_PERM_OP($tt,$r,$l,23,"0x03fc03fc",$r); 202 &R_PERM_OP($l,$r,$tt,10,"0x33333333",$l); 203 &R_PERM_OP($r,$tt,$l,18,"0xfff0000f",$l); 204 &R_PERM_OP($l,$tt,$r,12,"0xf0f0f0f0",$r); 205 &rotr($tt , 4); 206 } 207 208