ida81输入密码验证算法分析以及破解思路

proc m4ZQu {password LZQjH} {
        set ::maui::util::H6VeX ""
        set ::maui::util::EL0BW [string repeat \\0 32]

        package require tcltwofish
        package require sha256

        if {[string length $LZQjH] == 0} {
            error "Unable to initialize encryption - missing essential data"
        }
        
        //1.展开payload 获取相关参数
        if {[binary scan $LZQjH Ia16a32a64a32a* times iv passwordKey encryptedKey payloadIVsHash encryptedPayloadIVs] < 6} {
            error "Unable to initialize encryption - header missing or corrupt"
        }

        //2.使用输入的密码计算sha256，然后根据迭代次数times加密passwordkey，最后计算结果的sha256
        set iHcWR [a64bL $password $passwordKey $iv $times]
        
        //3.取上一步中的后32字节
        set BJvoG [string range [tcltwofish::decrypt $iHcWR $encryptedKey] 32 63]
        
        //4.使用上一步中的结果作为key 循环times/64次 解密encryptedPayloadIVs
        //这一步没有指定iv 实际过程为16个字节的0x00
        for {set i 0} {$i < $times} {incr i 64} {
            set encryptedPayloadIVs [tcltwofish::decrypt $BJvoG $encryptedPayloadIVs]
        }
        //5.获取32字节后的数据
        set ZQpQw [string range $encryptedPayloadIVs 32 end]

        //6.计算上一步结果的sha256，和预置的hash比对，一致则密码正确
        if {[sha2::sha256 -bin $ZQpQw] != $payloadIVsHash} {
            maui::d_RUj "Invalid payload password"
        }
        
        //7.使用第五步中的结果作为后续选取iv的数据 
        set ::maui::util::H6VeX $ZQpQw
        //8.使用第三步中的结果作为密钥
        set ::maui::util::EL0BW $BJvoG
    }

//根据输入密码生成payload
proc yOZ7q {password {times 16000}} {
        set ::maui::util::H6VeX ""
        set ::maui::util::EL0BW [string repeat \\0 32]

        package require tcltwofish
        package require sha256
        
        set BJvoG [qA4kM 32]
        set passwordKey [qA4kM 32]

        set ZQpQw [qA4kM [expr {16 * 256}]]
        set payloadIVsHash [sha2::sha256 -bin $ZQpQw]

        set encryptedPayloadIVs "[qA4kM 32]$ZQpQw"
        for {set i 0} {$i < $times} {incr i 64} {
            set encryptedPayloadIVs [tcltwofish::encrypt $BJvoG $encryptedPayloadIVs]
        }

        set iv [qA4kM 16]

        set iHcWR [a64bL $password $passwordKey $iv $times]
        
        set encryptedKey [tcltwofish::encrypt $iHcWR "[qA4kM 32]$BJvoG"]

        set LZQjH [binary format Ia16a32a64a32a* $times $iv $passwordKey $encryptedKey $payloadIVsHash $encryptedPayloadIVs]

        set ::maui::util::H6VeX $ZQpQw
        set ::maui::util::EL0BW $BJvoG
        
        return $LZQjH
    }

//生成随机数据
 proc qA4kM {length} {
        set YKL8w ""
        if {[RLPut unix]} {
            foreach xML4B {/dev/urandom /dev/random} {
                if {[catch {
                    set WyLEv [open $xML4B r]
                    fconfigure $WyLEv -translation binary
                    set YKL8w [read $WyLEv $length]
                    close $WyLEv
                }]} {
                    catch {close $WyLEv}
                }  else  {
                    break
                }
            }
        }  else  {
        
        }
        if {[string length $YKL8w] != $length} {

            incr length -[string length $YKL8w]
            while {$length >= 2} {
                append YKL8w [binary format S [expr {int([maui::util::rand] * 0x10000)}]]
                incr length -2
            }
            if {$length > 0} {
                append YKL8w [binary format c [expr {int([maui::util::rand] * 0x100)}]]
            }
        }
        return $YKL8w
    }
    proc rand {} {
        if {[maui::util::RLPut "windows"] && [info commands ::bitrock::secure::rand_s] != ""} {
            if {[catch {
                set r [::bitrock::secure::rand_s]
            } V77Ls]} {
                maui::util::debug "failed to call rand_s: $V77Ls"
                set r [expr {rand()}]
            }
        } else {
            set r [expr {rand()}]
        }
        return $r
    }

proc MmyBM {compressionAlgorithm command data} {
        if {[catch {

            //1.压缩数据
            if {($compressionAlgorithm == "lzma") || ($compressionAlgorithm == "lzma-ultra") || ($compressionAlgorithm == "lzham") || ($compressionAlgorithm == "lzham-ultra")} {
                set data [eval [concat $command [list $data]]]
            }  else  {
                set data [vfs::zip -mode compress -nowrap 1 $data] 
            }
            //2.1 前面添加四个字节的长度，然后末尾补全32的倍数
            //2.2 前面添加32字节的随机数据
            set data [qA4kM 32][UOijU $data 32]  

            //3.在H6VeX中截取16字节的iv 
            set PG2JA [expr {int([maui::util::rand] * 0x100)}]
            set iv [string range $::maui::util::H6VeX [expr {$PG2JA * 16}] [expr {$PG2JA * 16 + 15}]]

            //4.计算crc32
            set hbA8n [format 0x%08x [expr {[zlib crc32 $data] & 0xffffffff}]]
            
            //5.使用EL0BW中的数据作为key 加密
            set data [tcltwofish::encrypt $::maui::util::EL0BW $data iv]
            
            //6. 前面填充四个字节的crc32以及选取iv的位置，共加了五个字节
            set YKL8w [binary format Ica* $hbA8n $PG2JA $data]
        } V77Ls]} {
            set ykaki $::errorCode
            set qXoNi $::errorInfo
            maui::util::debug "encryptPayload: error encrypting: $V77Ls"
            error $V77Ls $qXoNi $ykaki
        }
        return $YKL8w
    }

proc UOijU {data DeSRF} {
        //1. 将四字节的长度添加在数据前
        set data [binary format Ia* [string length $data] $data]
        //2. 计算末尾添加padding的长度
        set add [expr {($DeSRF - ([string length $data] % $DeSRF)) % $DeSRF}]
        //3. 生成随机padding并附加在末尾
        append data [qA4kM $add]
        return $data
    }