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#!/usr/bin/perl
# void des_ncbc_encrypt(input, output, length, schedule, ivec, enc)
# des_cblock (*input);
# des_cblock (*output);
# long length;
# des_key_schedule schedule;
# des_cblock (*ivec);
# int enc;
#
# calls
# des_encrypt((DES_LONG *)tin,schedule,DES_ENCRYPT);
#
#&cbc("des_ncbc_encrypt","des_encrypt",0);
#&cbc("BF_cbc_encrypt","BF_encrypt","BF_encrypt",
# 1,4,5,3,5,-1);
#&cbc("des_ncbc_encrypt","des_encrypt","des_encrypt",
# 0,4,5,3,5,-1);
#&cbc("des_ede3_cbc_encrypt","des_encrypt3","des_decrypt3",
# 0,6,7,3,4,5);
#
# When doing a cipher that needs bigendian order,
# for encrypt, the iv is kept in bigendian form,
# while for decrypt, it is kept in little endian.
sub cbc
{
local($name,$enc_func,$dec_func,$swap,$iv_off,$enc_off,$p1,$p2,$p3)=@_;
# name is the function name
# enc_func and dec_func and the functions to call for encrypt/decrypt
# swap is true if byte order needs to be reversed
# iv_off is parameter number for the iv
# enc_off is parameter number for the encrypt/decrypt flag
# p1,p2,p3 are the offsets for parameters to be passed to the
# underlying calls.
&function_begin_B($name,"");
&comment("");
$in="esi";
$out="edi";
$count="ebp";
&push("ebp");
&push("ebx");
&push("esi");
&push("edi");
$data_off=4;
$data_off+=4 if ($p1 > 0);
$data_off+=4 if ($p2 > 0);
$data_off+=4 if ($p3 > 0);
&mov($count, &wparam(2)); # length
&comment("getting iv ptr from parameter $iv_off");
&mov("ebx", &wparam($iv_off)); # Get iv ptr
&mov($in, &DWP(0,"ebx","",0));# iv[0]
&mov($out, &DWP(4,"ebx","",0));# iv[1]
&push($out);
&push($in);
&push($out); # used in decrypt for iv[1]
&push($in); # used in decrypt for iv[0]
&mov("ebx", "esp"); # This is the address of tin[2]
&mov($in, &wparam(0)); # in
&mov($out, &wparam(1)); # out
# We have loaded them all, how lets push things
&comment("getting encrypt flag from parameter $enc_off");
&mov("ecx", &wparam($enc_off)); # Get enc flag
if ($p3 > 0)
{
&comment("get and push parameter $p3");
if ($enc_off != $p3)
{ &mov("eax", &wparam($p3)); &push("eax"); }
else { &push("ecx"); }
}
if ($p2 > 0)
{
&comment("get and push parameter $p2");
if ($enc_off != $p2)
{ &mov("eax", &wparam($p2)); &push("eax"); }
else { &push("ecx"); }
}
if ($p1 > 0)
{
&comment("get and push parameter $p1");
if ($enc_off != $p1)
{ &mov("eax", &wparam($p1)); &push("eax"); }
else { &push("ecx"); }
}
&push("ebx"); # push data/iv
&cmp("ecx",0);
&jz(&label("decrypt"));
&and($count,0xfffffff8);
&mov("eax", &DWP($data_off,"esp","",0)); # load iv[0]
&mov("ebx", &DWP($data_off+4,"esp","",0)); # load iv[1]
&jz(&label("encrypt_finish"));
#############################################################
&set_label("encrypt_loop");
# encrypt start
# "eax" and "ebx" hold iv (or the last cipher text)
&mov("ecx", &DWP(0,$in,"",0)); # load first 4 bytes
&mov("edx", &DWP(4,$in,"",0)); # second 4 bytes
&xor("eax", "ecx");
&xor("ebx", "edx");
&bswap("eax") if $swap;
&bswap("ebx") if $swap;
&mov(&DWP($data_off,"esp","",0), "eax"); # put in array for call
&mov(&DWP($data_off+4,"esp","",0), "ebx"); #
&call($enc_func);
&mov("eax", &DWP($data_off,"esp","",0));
&mov("ebx", &DWP($data_off+4,"esp","",0));
&bswap("eax") if $swap;
&bswap("ebx") if $swap;
&mov(&DWP(0,$out,"",0),"eax");
&mov(&DWP(4,$out,"",0),"ebx");
# eax and ebx are the next iv.
&add($in, 8);
&add($out, 8);
&sub($count, 8);
&jnz(&label("encrypt_loop"));
###################################################################3
&set_label("encrypt_finish");
&mov($count, &wparam(2)); # length
&and($count, 7);
&jz(&label("finish"));
&xor("ecx","ecx");
&xor("edx","edx");
&mov($count,&DWP(&label("cbc_enc_jmp_table"),"",$count,4));
&jmp_ptr($count);
&set_label("ej7");
&xor("edx", "edx") if $ppro; # ppro friendly
&movb(&HB("edx"), &BP(6,$in,"",0));
&shl("edx",8);
&set_label("ej6");
&movb(&HB("edx"), &BP(5,$in,"",0));
&set_label("ej5");
&movb(&LB("edx"), &BP(4,$in,"",0));
&set_label("ej4");
&mov("ecx", &DWP(0,$in,"",0));
&jmp(&label("ejend"));
&set_label("ej3");
&movb(&HB("ecx"), &BP(2,$in,"",0));
&xor("ecx", "ecx") if $ppro; # ppro friendly
&shl("ecx",8);
&set_label("ej2");
&movb(&HB("ecx"), &BP(1,$in,"",0));
&set_label("ej1");
&movb(&LB("ecx"), &BP(0,$in,"",0));
&set_label("ejend");
&xor("eax", "ecx");
&xor("ebx", "edx");
&bswap("eax") if $swap;
&bswap("ebx") if $swap;
&mov(&DWP($data_off,"esp","",0), "eax"); # put in array for call
&mov(&DWP($data_off+4,"esp","",0), "ebx"); #
&call($enc_func);
&mov("eax", &DWP($data_off,"esp","",0));
&mov("ebx", &DWP($data_off+4,"esp","",0));
&bswap("eax") if $swap;
&bswap("ebx") if $swap;
&mov(&DWP(0,$out,"",0),"eax");
&mov(&DWP(4,$out,"",0),"ebx");
&jmp(&label("finish"));
#############################################################
#############################################################
&set_label("decrypt",1);
# decrypt start
&and($count,0xfffffff8);
# The next 2 instructions are only for if the jz is taken
&mov("eax", &DWP($data_off+8,"esp","",0)); # get iv[0]
&mov("ebx", &DWP($data_off+12,"esp","",0)); # get iv[1]
&jz(&label("decrypt_finish"));
&set_label("decrypt_loop");
&mov("eax", &DWP(0,$in,"",0)); # load first 4 bytes
&mov("ebx", &DWP(4,$in,"",0)); # second 4 bytes
&bswap("eax") if $swap;
&bswap("ebx") if $swap;
&mov(&DWP($data_off,"esp","",0), "eax"); # put back
&mov(&DWP($data_off+4,"esp","",0), "ebx"); #
&call($dec_func);
&mov("eax", &DWP($data_off,"esp","",0)); # get return
&mov("ebx", &DWP($data_off+4,"esp","",0)); #
&bswap("eax") if $swap;
&bswap("ebx") if $swap;
&mov("ecx", &DWP($data_off+8,"esp","",0)); # get iv[0]
&mov("edx", &DWP($data_off+12,"esp","",0)); # get iv[1]
&xor("ecx", "eax");
&xor("edx", "ebx");
&mov("eax", &DWP(0,$in,"",0)); # get old cipher text,
&mov("ebx", &DWP(4,$in,"",0)); # next iv actually
&mov(&DWP(0,$out,"",0),"ecx");
&mov(&DWP(4,$out,"",0),"edx");
&mov(&DWP($data_off+8,"esp","",0), "eax"); # save iv
&mov(&DWP($data_off+12,"esp","",0), "ebx"); #
&add($in, 8);
&add($out, 8);
&sub($count, 8);
&jnz(&label("decrypt_loop"));
############################ ENDIT #######################3
&set_label("decrypt_finish");
&mov($count, &wparam(2)); # length
&and($count, 7);
&jz(&label("finish"));
&mov("eax", &DWP(0,$in,"",0)); # load first 4 bytes
&mov("ebx", &DWP(4,$in,"",0)); # second 4 bytes
&bswap("eax") if $swap;
&bswap("ebx") if $swap;
&mov(&DWP($data_off,"esp","",0), "eax"); # put back
&mov(&DWP($data_off+4,"esp","",0), "ebx"); #
&call($dec_func);
&mov("eax", &DWP($data_off,"esp","",0)); # get return
&mov("ebx", &DWP($data_off+4,"esp","",0)); #
&bswap("eax") if $swap;
&bswap("ebx") if $swap;
&mov("ecx", &DWP($data_off+8,"esp","",0)); # get iv[0]
&mov("edx", &DWP($data_off+12,"esp","",0)); # get iv[1]
&xor("ecx", "eax");
&xor("edx", "ebx");
# this is for when we exit
&mov("eax", &DWP(0,$in,"",0)); # get old cipher text,
&mov("ebx", &DWP(4,$in,"",0)); # next iv actually
&set_label("dj7");
&rotr("edx", 16);
&movb(&BP(6,$out,"",0), &LB("edx"));
&shr("edx",16);
&set_label("dj6");
&movb(&BP(5,$out,"",0), &HB("edx"));
&set_label("dj5");
&movb(&BP(4,$out,"",0), &LB("edx"));
&set_label("dj4");
&mov(&DWP(0,$out,"",0), "ecx");
&jmp(&label("djend"));
&set_label("dj3");
&rotr("ecx", 16);
&movb(&BP(2,$out,"",0), &LB("ecx"));
&shl("ecx",16);
&set_label("dj2");
&movb(&BP(1,$in,"",0), &HB("ecx"));
&set_label("dj1");
&movb(&BP(0,$in,"",0), &LB("ecx"));
&set_label("djend");
# final iv is still in eax:ebx
&jmp(&label("finish"));
############################ FINISH #######################3
&set_label("finish",1);
&mov("ecx", &wparam($iv_off)); # Get iv ptr
#################################################
$total=16+4;
$total+=4 if ($p1 > 0);
$total+=4 if ($p2 > 0);
$total+=4 if ($p3 > 0);
&add("esp",$total);
&mov(&DWP(0,"ecx","",0), "eax"); # save iv
&mov(&DWP(4,"ecx","",0), "ebx"); # save iv
&function_end_A($name);
&set_label("cbc_enc_jmp_table",1);
&data_word("0");
&data_word(&label("ej1"));
&data_word(&label("ej2"));
&data_word(&label("ej3"));
&data_word(&label("ej4"));
&data_word(&label("ej5"));
&data_word(&label("ej6"));
&data_word(&label("ej7"));
&set_label("cbc_dec_jmp_table",1);
&data_word("0");
&data_word(&label("dj1"));
&data_word(&label("dj2"));
&data_word(&label("dj3"));
&data_word(&label("dj4"));
&data_word(&label("dj5"));
&data_word(&label("dj6"));
&data_word(&label("dj7"));
&function_end_B($name);
}
1;
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