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, $R); 33 34 # PIC-ification:-) 35 &picmeup("edx","DES_SPtrans"); 36 #if ($cpp) { &picmeup("edx","DES_SPtrans"); } 37 #else { &lea("edx",&DWP("DES_SPtrans")); } 38 &push("edx"); # becomes &swtmp(1) 39 # 40 &mov($trans,&wparam(1)); # reloaded with DES_SPtrans in D_ENCRYPT 41 42 &push(&DWC(25)); # add a variable 43 44 &set_label("start"); 45 for ($i=0; $i<16; $i+=2) 46 { 47 &comment(""); 48 &comment("Round $i"); 49 &D_ENCRYPT($i,$L,$R,$i*2,$trans,"eax","ebx","ecx","edx"); 50 51 &comment(""); 52 &comment("Round ".sprintf("%d",$i+1)); 53 &D_ENCRYPT($i+1,$R,$L,($i+1)*2,$trans,"eax","ebx","ecx","edx"); 54 } 55 &mov("ebx", &swtmp(0)); 56 &mov("eax", $L); 57 &dec("ebx"); 58 &mov($L, $R); 59 &mov($R, "eax"); 60 &mov(&swtmp(0), "ebx"); 61 &jnz(&label("start")); 62 63 &comment(""); 64 &comment("FP"); 65 &mov("edx",&wparam(0)); 66 67 &FP_new($R,$L,"eax",3); 68 &mov(&DWP(0,"edx","",0),"eax"); 69 &mov(&DWP(4,"edx","",0),$L); 70 71 &add("esp",8); # remove variables 72 73 &function_end($name); 74 } 75 76sub D_ENCRYPT 77 { 78 local($r,$L,$R,$S,$trans,$u,$tmp1,$tmp2,$t)=@_; 79 80 &mov( $u, &wparam(2)); # 2 81 &mov( $t, $R); 82 &shr( $t, 16); # 1 83 &mov( $tmp2, &wparam(3)); # 2 84 &xor( $t, $R); # 1 85 86 &and( $u, $t); # 2 87 &and( $t, $tmp2); # 2 88 89 &mov( $tmp1, $u); 90 &shl( $tmp1, 16); # 1 91 &mov( $tmp2, $t); 92 &shl( $tmp2, 16); # 1 93 &xor( $u, $tmp1); # 2 94 &xor( $t, $tmp2); # 2 95 &mov( $tmp1, &DWP(&n2a($S*4),$trans,"",0)); # 2 96 &xor( $u, $tmp1); 97 &mov( $tmp2, &DWP(&n2a(($S+1)*4),$trans,"",0)); # 2 98 &xor( $u, $R); 99 &xor( $t, $R); 100 &xor( $t, $tmp2); 101 102 &and( $u, "0xfcfcfcfc" ); # 2 103 &xor( $tmp1, $tmp1); # 1 104 &and( $t, "0xcfcfcfcf" ); # 2 105 &xor( $tmp2, $tmp2); 106 &movb( &LB($tmp1), &LB($u) ); 107 &movb( &LB($tmp2), &HB($u) ); 108 &rotr( $t, 4 ); 109 &mov( $trans, &swtmp(1)); 110 &xor( $L, &DWP(" ",$trans,$tmp1,0)); 111 &movb( &LB($tmp1), &LB($t) ); 112 &xor( $L, &DWP("0x200",$trans,$tmp2,0)); 113 &movb( &LB($tmp2), &HB($t) ); 114 &shr( $u, 16); 115 &xor( $L, &DWP("0x100",$trans,$tmp1,0)); 116 &movb( &LB($tmp1), &HB($u) ); 117 &shr( $t, 16); 118 &xor( $L, &DWP("0x300",$trans,$tmp2,0)); 119 &movb( &LB($tmp2), &HB($t) ); 120 &and( $u, "0xff" ); 121 &and( $t, "0xff" ); 122 &mov( $tmp1, &DWP("0x600",$trans,$tmp1,0)); 123 &xor( $L, $tmp1); 124 &mov( $tmp1, &DWP("0x700",$trans,$tmp2,0)); 125 &xor( $L, $tmp1); 126 &mov( $tmp1, &DWP("0x400",$trans,$u,0)); 127 &xor( $L, $tmp1); 128 &mov( $tmp1, &DWP("0x500",$trans,$t,0)); 129 &xor( $L, $tmp1); 130 &mov( $trans, &wparam(1)); 131 } 132 133sub n2a 134 { 135 sprintf("%d",$_[0]); 136 } 137 138# now has a side affect of rotating $a by $shift 139sub R_PERM_OP 140 { 141 local($a,$b,$tt,$shift,$mask,$last)=@_; 142 143 &rotl( $a, $shift ) if ($shift != 0); 144 &mov( $tt, $a ); 145 &xor( $a, $b ); 146 &and( $a, $mask ); 147 if ($notlast eq $b) 148 { 149 &xor( $b, $a ); 150 &xor( $tt, $a ); 151 } 152 else 153 { 154 &xor( $tt, $a ); 155 &xor( $b, $a ); 156 } 157 &comment(""); 158 } 159 160sub IP_new 161 { 162 local($l,$r,$tt,$lr)=@_; 163 164 &R_PERM_OP($l,$r,$tt, 4,"0xf0f0f0f0",$l); 165 &R_PERM_OP($r,$tt,$l,20,"0xfff0000f",$l); 166 &R_PERM_OP($l,$tt,$r,14,"0x33333333",$r); 167 &R_PERM_OP($tt,$r,$l,22,"0x03fc03fc",$r); 168 &R_PERM_OP($l,$r,$tt, 9,"0xaaaaaaaa",$r); 169 170 if ($lr != 3) 171 { 172 if (($lr-3) < 0) 173 { &rotr($tt, 3-$lr); } 174 else { &rotl($tt, $lr-3); } 175 } 176 if ($lr != 2) 177 { 178 if (($lr-2) < 0) 179 { &rotr($r, 2-$lr); } 180 else { &rotl($r, $lr-2); } 181 } 182 } 183 184sub FP_new 185 { 186 local($l,$r,$tt,$lr)=@_; 187 188 if ($lr != 2) 189 { 190 if (($lr-2) < 0) 191 { &rotl($r, 2-$lr); } 192 else { &rotr($r, $lr-2); } 193 } 194 if ($lr != 3) 195 { 196 if (($lr-3) < 0) 197 { &rotl($l, 3-$lr); } 198 else { &rotr($l, $lr-3); } 199 } 200 201 &R_PERM_OP($l,$r,$tt, 0,"0xaaaaaaaa",$r); 202 &R_PERM_OP($tt,$r,$l,23,"0x03fc03fc",$r); 203 &R_PERM_OP($l,$r,$tt,10,"0x33333333",$l); 204 &R_PERM_OP($r,$tt,$l,18,"0xfff0000f",$l); 205 &R_PERM_OP($l,$tt,$r,12,"0xf0f0f0f0",$r); 206 &rotr($tt , 4); 207 } 208 209