Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 1 | #!/usr/local/bin/perl |
| 2 | |
| 3 | push(@INC,"perlasm","../../perlasm"); |
| 4 | require "x86asm.pl"; |
| 5 | require "cbc.pl"; |
| 6 | |
| 7 | &asm_init($ARGV[0],"bf-686.pl"); |
| 8 | |
| 9 | $BF_ROUNDS=16; |
| 10 | $BF_OFF=($BF_ROUNDS+2)*4; |
| 11 | $L="ecx"; |
| 12 | $R="edx"; |
| 13 | $P="edi"; |
| 14 | $tot="esi"; |
| 15 | $tmp1="eax"; |
| 16 | $tmp2="ebx"; |
| 17 | $tmp3="ebp"; |
| 18 | |
| 19 | &des_encrypt("BF_encrypt",1); |
| 20 | &des_encrypt("BF_decrypt",0); |
| 21 | &cbc("BF_cbc_encrypt","BF_encrypt","BF_decrypt",1,4,5,3,-1,-1); |
| 22 | |
| 23 | &asm_finish(); |
| 24 | |
| 25 | &file_end(); |
| 26 | |
| 27 | sub des_encrypt |
| 28 | { |
| 29 | local($name,$enc)=@_; |
| 30 | |
| 31 | &function_begin($name,""); |
| 32 | |
| 33 | &comment(""); |
| 34 | &comment("Load the 2 words"); |
| 35 | &mov("eax",&wparam(0)); |
| 36 | &mov($L,&DWP(0,"eax","",0)); |
| 37 | &mov($R,&DWP(4,"eax","",0)); |
| 38 | |
| 39 | &comment(""); |
| 40 | &comment("P pointer, s and enc flag"); |
| 41 | &mov($P,&wparam(1)); |
| 42 | |
| 43 | &xor( $tmp1, $tmp1); |
| 44 | &xor( $tmp2, $tmp2); |
| 45 | |
| 46 | # encrypting part |
| 47 | |
| 48 | if ($enc) |
| 49 | { |
| 50 | &xor($L,&DWP(0,$P,"",0)); |
| 51 | for ($i=0; $i<$BF_ROUNDS; $i+=2) |
| 52 | { |
| 53 | &comment(""); |
| 54 | &comment("Round $i"); |
| 55 | &BF_ENCRYPT($i+1,$R,$L,$P,$tot,$tmp1,$tmp2,$tmp3); |
| 56 | |
| 57 | &comment(""); |
| 58 | &comment("Round ".sprintf("%d",$i+1)); |
| 59 | &BF_ENCRYPT($i+2,$L,$R,$P,$tot,$tmp1,$tmp2,$tmp3); |
| 60 | } |
| 61 | &xor($R,&DWP(($BF_ROUNDS+1)*4,$P,"",0)); |
| 62 | |
| 63 | &mov("eax",&wparam(0)); |
| 64 | &mov(&DWP(0,"eax","",0),$R); |
| 65 | &mov(&DWP(4,"eax","",0),$L); |
| 66 | &function_end_A($name); |
| 67 | } |
| 68 | else |
| 69 | { |
| 70 | &xor($L,&DWP(($BF_ROUNDS+1)*4,$P,"",0)); |
| 71 | for ($i=$BF_ROUNDS; $i>0; $i-=2) |
| 72 | { |
| 73 | &comment(""); |
| 74 | &comment("Round $i"); |
| 75 | &BF_ENCRYPT($i,$R,$L,$P,$tot,$tmp1,$tmp2,$tmp3); |
| 76 | &comment(""); |
| 77 | &comment("Round ".sprintf("%d",$i-1)); |
| 78 | &BF_ENCRYPT($i-1,$L,$R,$P,$tot,$tmp1,$tmp2,$tmp3); |
| 79 | } |
| 80 | &xor($R,&DWP(0,$P,"",0)); |
| 81 | |
| 82 | &mov("eax",&wparam(0)); |
| 83 | &mov(&DWP(0,"eax","",0),$R); |
| 84 | &mov(&DWP(4,"eax","",0),$L); |
| 85 | &function_end_A($name); |
| 86 | } |
| 87 | |
| 88 | &function_end_B($name); |
| 89 | } |
| 90 | |
| 91 | sub BF_ENCRYPT |
| 92 | { |
| 93 | local($i,$L,$R,$P,$tot,$tmp1,$tmp2,$tmp3)=@_; |
| 94 | |
| 95 | &rotr( $R, 16); |
| 96 | &mov( $tot, &DWP(&n2a($i*4),$P,"",0)); |
| 97 | |
| 98 | &movb( &LB($tmp1), &HB($R)); |
| 99 | &movb( &LB($tmp2), &LB($R)); |
| 100 | |
| 101 | &rotr( $R, 16); |
| 102 | &xor( $L, $tot); |
| 103 | |
| 104 | &mov( $tot, &DWP(&n2a($BF_OFF+0x0000),$P,$tmp1,4)); |
| 105 | &mov( $tmp3, &DWP(&n2a($BF_OFF+0x0400),$P,$tmp2,4)); |
| 106 | |
| 107 | &movb( &LB($tmp1), &HB($R)); |
| 108 | &movb( &LB($tmp2), &LB($R)); |
| 109 | |
| 110 | &add( $tot, $tmp3); |
| 111 | &mov( $tmp1, &DWP(&n2a($BF_OFF+0x0800),$P,$tmp1,4)); # delay |
| 112 | |
| 113 | &xor( $tot, $tmp1); |
| 114 | &mov( $tmp3, &DWP(&n2a($BF_OFF+0x0C00),$P,$tmp2,4)); |
| 115 | |
| 116 | &add( $tot, $tmp3); |
| 117 | &xor( $tmp1, $tmp1); |
| 118 | |
| 119 | &xor( $L, $tot); |
| 120 | # delay |
| 121 | } |
| 122 | |
| 123 | sub n2a |
| 124 | { |
| 125 | sprintf("%d",$_[0]); |
| 126 | } |
| 127 | |