shc 加密与解密
党俊健
一、shc加密文件
Shc可以用来对shell脚本进行加密，可以将shell脚本转换为一个可执行的二进制文件。经过shc对shell脚本进行加密后，会同时生成两种个新的文件，一个是加密后的可执行的二进制文件（文件名以.x结束），另一个是C语言的原文件（文件名以.x.c结束）。
下面就说明一下shc的安装,参数，以及使用示例：
(官网下载地址: http://www.datsi.fi.upm.es/~frosal/sources/)
安装命令(前提先安装gcc)：
# wget http://www.datsi.fi.upm.es/~frosal/sources/shc-3.8.9.tgz
# tar zxf shc-3.8.9.tgz
# cd shc-3.8.9
#make test
# make strings
# make install
*** Installing shc and shc.1 on /usr/local
*** Do you want to continue? <输入y> y
install -c -s shc /usr/local/bin/
install -c -m 644 shc.1 /usr/local/man/man1/
(仅用make就可以完成安装，运行shc时要指出绝对路径；用make install，将shc安装到/usr/local/bin下，可以直接运行）
常用参数：
-e date （指定过期日期）
-m message （指定过期提示的信息）
-f script_name（指定要编译的shell的路径及文件名）
-r Relax security. （可以相同操作系统的不同系统中执行）
-v Verbose compilation（编译的详细情况）
使用方法：
# shc -v -f abc.sh
-v 是现实加密过程
-f 后面跟需要加密的文件
运行后会生成两个文件:
abc.sh.x 和 abc.sh.x.c
abc.sh.x为二进制文件，赋予执行权限后，可直接执行。更改名字mv abc.sh.x a.sh
abc.sh.x.c 是c源文件。基本没用，可以删除
二、加密unshc
#!/bin/bash
###################
# Author: Luiz Otavio Duarte a.k.a. (LOD)
# 11/03/08 - v0.1
# Updated: Yann CAM v0.2 - yann.cam@gmail.com | www.asafety.fr
# 06/27/13 - v0.2
# -- Adding new objdump format (2.22) to retrieve data (especially on Ubuntu distribution)
# -- Patch few regex with sorted address list
# Updated: Yann CAM v0.3 - yann.cam@gmail.com | www.asafety.fr
# 18/11/15 - v0.3
# -- Adapt script for new architecture
# -- Clean and optimize functions
# -- Add an (unsigned long) cast in shc C source code
# Updated: Yann CAM v0.4 - yann.cam@gmail.com | www.asafety.fr
# 14/12/15 - v0.4
# -- Comment specific return statement in C source
# Updated: Yann CAM v0.5 - yann.cam@gmail.com | www.asafety.fr
# 15/12/15 - v0.5
# -- Patch extract arc4 function to keep the latest offset only
# Updated: Yann CAM v0.6 - yann.cam@gmail.com | www.asafety.fr
# 16/12/15 - v0.6
# -- Add bash script options (getopts)
# Updated: Yann CAM v0.7 - yann.cam@gmail.com | www.asafety.fr
# 07/28/16 - v0.7
# -- Add support of multiple ARC4 offsets auto-retrieved by script (iterate over each one), specialy for huge bash file encrypted
# -- Force .sh extension to decrypted file, for initial file without extension (prevent rewrite of original file)
# Updated: Yann CAM v0.8 - yann.cam@gmail.com | www.asafety.fr
# 01/23/17 - v0.8
# -- Adjust grep for retrieve PWD_SIZE in OBJDUMP to ignore movb instruction (https://github.com/yanncam/UnSHc/issues/12)
###################
# Tested on :
# Ubuntu 14.04.3 LTS x86_64
# Linux server 3.13.0-61-generic #100-Ubuntu SMP Wed Jul 29 11:21:34 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
# Linux version 3.13.0-61-generic (buildd@lgw01-50) (gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) ) #100-Ubuntu SMP Wed Jul 29 11:21:34 UTC 2015
#
# CentOS release 6.6 (Final) x86_64
# Linux server 2.6.32-504.23.4.el6.x86_64 #1 SMP Tue Jun 9 20:57:37 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
# Linux version 2.6.32-504.23.4.el6.x86_64 (mockbuild@c6b9.bsys.dev.centos.org) (gcc version 4.4.7 20120313 (Red Hat 4.4.7-11) (GCC) ) #1 SMP Tue Jun 9 20:57:37 UTC 2015
#
# Debian 7.8 i686
# Linux server 3.2.0-4-686-pae #1 SMP Debian 3.2.68-1+deb7u2 i686 GNU/Linux
# Linux version 3.2.0-4-686-pae (debian-kernel@lists.debian.org) (gcc version 4.6.3 (Debian 4.6.3-14) ) #1 SMP Debian 3.2.68-1+deb7u2
###################
VERSION="0.8"
OBJDUMP=`which objdump`
GREP=`which grep`
CUT=`which cut`
SHRED=`which shred`
UNIQ=`which uniq`
SORT=`which sort`
GCC=`which gcc`
WC=`which wc`
AWK=`which awk`
SED=`which sed`
TR=`which tr`
HEAD=`which head`
TAIL=`which tail`
BINARY=""
TMPBINARY=$(mktemp /tmp/XXXXXX)
DUMPFILE=""
STRINGFILE=""
CALLFILE=$(mktemp /tmp/XXXXXX)
CALLADDRFILE=$(mktemp /tmp/XXXXXX)
CALLSIZEFILE=$(mktemp /tmp/XXXXXX)
declare -A LISTOFCALL
# Variable to know the index of variables.
# This var is to loop on each 14 arc4() call with ordered args.
j=0
# Simple usage help / man
function usage(){
printf "[*] Usage : $0 [OPTIONS] <file.sh.x>\n"
printf "\t -h | --help : print this help message\n"
printf "\t -a OFFSET | --arc4 OFFSET : specify the arc4() offset arbitrarily (without 0x prefix)\n"
printf "\t -d DUMPFILE | --dumpfile DUMPFILE : provide an object dump file (objdump -D script.sh.x > DUMPFILE)\n"
printf "\t -s STRFILE | --stringfile STRFILE : provide a string dump file (objdump -s script.sh.x > STRFILE)\n"
printf "\t -o OUTFILE | --outputfile OUTFILE : indicate the output file name\n\n"
printf "[*] e.g : \n"
printf "\t$0 script.sh.x\n"
printf "\t$0 script.sh.x -o script_decrypted.sh\n"
printf "\t$0 script.sh.x -a 400f9b\n"
printf "\t$0 script.sh.x -d /tmp/dumpfile -s /tmp/strfile\n"
printf "\t$0 script.sh.x -a 400f9b -d /tmp/dumpfile -s /tmp/strfile -o script_decrypted.sh\n"
}
# Clean all temp file created for this script
function clean(){
$SHRED -zu -n 1 $DUMPFILE $CALLFILE $CALLADDRFILE $CALLSIZEFILE $STRINGFILE $TMPBINARY ${TMPBINARY}.c >/dev/null 2>&1
}
# Clean error exit function after cleaning temp file
function exit_error(){
clean
exit 1;
}
# Check the availability of basic commands usefull for this script
function check_binaries() {
if [ ! -x ${OBJDUMP} ]; then
echo "[-] Error, cannot execute or find objdump binary"
exit_error
fi
if [ ! -x ${GREP} ]; then
echo "[-] Error, cannot execute or find grep binary"
exit_error
fi
if [ ! -x ${CUT} ]; then
echo "[-] Error, cannot execute or find cut binary"
exit_error
fi
if [ ! -x ${SHRED} ]; then
echo "[-] Error, cannot execute or find shred binary"
exit_error
fi
if [ ! -x ${UNIQ} ]; then
echo "[-] Error, cannot execute or find uniq binary"
exit_error
fi
if [ ! -x ${SORT} ]; then
echo "[-] Error, cannot execute or find sort binary"
exit_error
fi
if [ ! -x ${GCC} ]; then
echo "[-] Error, cannot execute or find gcc binary"
exit_error
fi
if [ ! -x ${WC} ]; then
echo "[-] Error, cannot execute or find wc binary"
exit_error
fi
}
# Create dump files of encrypted script
function generate_dump() {
# DUMPFILE dump to retrive arc4 address, address and size of each arc4 arguments and pwd
$OBJDUMP -D $BINARY > "$DUMPFILE"
# STRINGFILE dump to retrieve pwd and arc4 argument
$OBJDUMP -s $BINARY > "$STRINGFILE"
}
# Find out the most called function. This function is arc4() and there are 14 calls.
# Update 27/06/2013 : Regexps updated to match new objdump format and retrieve the $CALLADDR from his number of call (bug initial with "sort")
# Update 16/11/2015 : Adding new architecture support
# Update 28/07/2016 : Adding multiple ARC4 offsets support (loop on each candidate)
function extract_arc4_call_addr(){
TAILNUMBER=$1
CALLADDRS=$($GREP -Eo "call.*[0-9a-f]{6,}" $DUMPFILE | $GREP -Eo "[0-9a-f]{6,}" | $SORT | $UNIQ -c | $SORT | $GREP -Eo "(14).*[0-9a-f]{6,}" | $GREP -Eo "[0-9a-f]{6,}")
TAILMAX=`wc -l <<< "$CALLADDRS"`
CALLADDR=$(echo $CALLADDRS | $SED "s/ /\n/g" | $TAIL -n $TAILNUMBER | $HEAD -n 1)
if [[ -z "$CALLADDR" || $TAILNUMBER -gt $TAILMAX ]]; then
echo "[-] Unable to define arc4() call address..."
exit_error
fi
echo "[+] ARC4 address call candidate : [0x$CALLADDR]"
}
# Extract each args values of arc4 calls
function extract_variables_from_binary(){
echo "[*] Extracting each args address and size for the 14 arc4() calls with address [0x$CALLADDR]..."
# Initialize the number of line before CALLADDR to looking for addresses of args
i=2
# Retrieve ordered list of address var and put it to $CALLADDRFILE
while [[ $($WC -l < $CALLADDRFILE) -ne 14 ]]; do
$GREP -B $i "call.*$CALLADDR" $DUMPFILE | $GREP -v "$CALLADDR" | $GREP -Eo "(0x[0-9a-f]{6,})" > $CALLADDRFILE
i=$(($i + 1))
if [ $i -eq 10 ]; then
echo "[-] Unable to extract addresses of 14 arc4 args with ARC4 address call [0x$CALLADDR]..."
return;
fi
done
# Initialize the number of line before CALLADDR to looking for sizes of args
i=3
# Retrieve ordered list of size var and append it to $CALLSIZEFILE
while [[ $($WC -l < $CALLSIZEFILE) -ne 14 ]]; do
$GREP -B $i "call.*$CALLADDR" $DUMPFILE | $GREP -v "$CALLADDR" | $GREP -Eo "(0x[0-9a-f]+,)" | $GREP -Eo "(0x[0-9a-f]+)" | $GREP -Ev "0x[0-9a-f]{6,}" > $CALLSIZEFILE
i=$(($i + 1))
if [ $i -eq 10 ]; then
echo "[-] Unable to extract sizes of 14 arc4 args with ARC4 address call [0x$CALLADDR]..."
return;
fi
done
# For each full address in $CALLADDRFILE and corresponding size in $CALLSIZEFILE
IFS=$'\n' read -d '' -r -a LISTOFADDR < $CALLADDRFILE
IFS=$'\n' read -d '' -r -a LISTOFSIZE < $CALLSIZEFILE
for (( x = 0; x < ${#LISTOFADDR[*]}; x = x+1 ))
do
i=${LISTOFADDR[$x]}
NBYTES=${LISTOFSIZE[$x]}
echo -e "\t[$x] Working with var address at offset [$i] ($NBYTES bytes)"
# Some diferences in assembly.
# We can have:
# mov <adr>,%eax
# push 0x<hex>
# push %eax
# call $CALLADDR
#
# or
#
# push 0x<hex>
# push 0x<adr>
# call $CALLADDR
#
# UPDATE 27/06/2013 :
# Adding support of objdump format
# New format supported (Debian 7 x86) :
#
# movl $0x<hex>,0x4(%esp)
#
# movl $0x<adr>,(%esp)
# call $CALLADDR
#
# UPDATE 18/11/2015 :
# Adding support of objdump format
# Ubuntu 14.04 LTS x86_64
#
# mov $0x<hex>,%esi
# mov $0x<adr>,%edi
# callq $CALLADDR <fork@plt+0x23b>
#
# Key is the address with the variable content.
KEY=$(echo $i | $CUT -d 'x' -f 2)
# A 2 bytes variable (NBYTES > 0) can be found like this: (in STRINGFILE)
# ---------------X
# X---------------
#
# So we need 2 lines from STRINGFILE to make it all correct. So:
NLINES=$(( ($NBYTES / 16) +2 ))
# All line in STRINGFILE starts from 0 to f. So LASTBIT tells me the index in the line to start recording.
let LASTBYTE="0x${KEY:$((${#KEY}-1))}"
# Grep all lines needed from STRINGFILE, merge lines.
STRING=$( $GREP -A $(($NLINES-1)) -E "^ ${KEY:0:$((${#KEY}-1))}0 " $STRINGFILE | $AWK '{ print $2$3$4$5}' | $TR '\n' 'T' | $SED -e "s:T::g")
# Change string to begin in the line index.
STRING=${STRING:$((2*$LASTBYTE))}
# Cut the string to the number off bytes of the variable.
STRING=${STRING:0:$(($NBYTES * 2))}
# We need to convert to a \x??\x?? structure so:
FINALSTRING=""
for ((i = 0; i < $((${#STRING} /2 )); i++)); do
FINALSTRING="${FINALSTRING}\x${STRING:$(($i * 2)):2}"
done
define_variable
done
}
# arc4 function is called 14 times in the C code.
# Each call is done with the same args sequence even if their declaration is randomized :
# msg1, date, shll, inlo, xecc, lsto, tst1, chk1, msg2, rlax, opts, text, tst2 and chk2.
function define_variable() {
case "$j" in
0) VAR_MSG1=$FINALSTRING
VAR_MSG1_Z=$NBYTES;;
1) VAR_DATE=$FINALSTRING
VAR_DATE_Z=$NBYTES;;
2) VAR_SHLL=$FINALSTRING
VAR_SHLL_Z=$NBYTES;;
3) VAR_INLO=$FINALSTRING
VAR_INLO_Z=$NBYTES;;
4) VAR_XECC=$FINALSTRING
VAR_XECC_Z=$NBYTES;;
5) VAR_LSTO=$FINALSTRING
VAR_LSTO_Z=$NBYTES;;
6) VAR_TST1=$FINALSTRING
VAR_TST1_Z=$NBYTES;;
7) VAR_CHK1=$FINALSTRING
VAR_CHK1_Z=$NBYTES;;
8) VAR_MSG2=$FINALSTRING
VAR_MSG2_Z=$NBYTES;;
9) VAR_RLAX=$FINALSTRING
VAR_RLAX_Z=$NBYTES;;
10) VAR_OPTS=$FINALSTRING
VAR_OPTS_Z=$NBYTES;;
11) VAR_TEXT=$FINALSTRING
VAR_TEXT_Z=$NBYTES;;
12) VAR_TST2=$FINALSTRING
VAR_TST2_Z=$NBYTES;;
13) VAR_CHK2=$FINALSTRING
VAR_CHK2_Z=$NBYTES;;
esac
j=$(($j + 1))
}
# The password is used in the key function right before first call to arc4.
# So we need the previous call just before the first "call ARC4_CALLADDR" and its args.
# Update 27/06/2013 : Add new objdump format
# Update 18/11/2015 : Simplify extraction
# Update 23/01/2017 : Ignore movb instruction
function extract_password_from_binary(){
echo "[*] Extracting password..."
KEY_ADDR=""
KEY_SIZE=""
# Initialize the number of line before CALLADDR to watch
i=5
while [[ ( -z "$KEY_ADDR" ) || ( -z "$KEY_SIZE" ) ]]; do
$GREP -B $i -m 1 "call.*$CALLADDR" $DUMPFILE | $GREP -v $CALLADDR > $CALLFILE
#cat $CALLFILE
# Adjust these two next line to grep right addr & size value (depending on your architecture)
KEY_ADDR=$($GREP -B 3 -m 1 "call" $CALLFILE | $GREP mov | $GREP -oE "0x[0-9a-z]{6,}+" | $HEAD -n 1)
KEY_SIZE=$($GREP -B 3 -m 1 "call" $CALLFILE | $GREP mov | $GREP -v $KEY_ADDR | $GREP -v movb | $GREP -oE "0x[0-9a-z]+" | $HEAD -n 1)
i=$(($i + 1))
if [ $i -eq 10 ]; then
echo "[-] Error, function call previous first call of arc4() hasn't been identified..."
exit_error
fi
done
echo -e "\t[+] PWD address found : [$KEY_ADDR]"
echo -e "\t[+] PWD size found : [$KEY_SIZE]"
# Defining the address without 0x.
KEY=$(echo $KEY_ADDR | $CUT -d 'x' -f 2)
# Like the other NLINES
NLINES=$(( ($KEY_SIZE / 16) +2 ))
# Like the other LASTBYTE
LASTBYTE="0x${KEY:$((${#KEY}-1))}"
# Extract PWD from STRINGFILE
STRING=$( $GREP -A $(($NLINES-1)) -E "^ ${KEY:0:$((${#KEY}-1))}0 " $STRINGFILE | $AWK '{ print $2$3$4$5}' | $TR '\n' 'T' | $SED -e "s:T::g")
STRING=${STRING:$((2*$LASTBYTE))}
STRING=${STRING:0:$(($KEY_SIZE * 2))}
# Encode / rewrite PWD in the \x??\x?? format
FINALSTRING=""
for ((i=0;i<$((${#STRING} /2 ));i++)); do
FINALSTRING="${FINALSTRING}\x${STRING:$(($i * 2)):2}"
done
VAR_PSWD=$FINALSTRING
}
# This function append a generic engine for decrypt from shc project. With out own new variables extracted.
# Rather than execute the source code decrypted, it's printed in stdout.
function generic_file(){
cat > ${TMPBINARY}.c << EOF
#define msg1_z $VAR_MSG1_Z
#define date_z $VAR_DATE_Z
#define shll_z $VAR_SHLL_Z
#define inlo_z $VAR_INLO_Z
#define xecc_z $VAR_XECC_Z
#define lsto_z $VAR_LSTO_Z
#define tst1_z $VAR_TST1_Z
#define chk1_z $VAR_CHK1_Z
#define msg2_z $VAR_MSG2_Z
#define rlax_z $VAR_RLAX_Z
#define opts_z $VAR_OPTS_Z
#define text_z $VAR_TEXT_Z
#define tst2_z $VAR_TST2_Z
#define chk2_z $VAR_CHK2_Z
#define pswd_z $KEY_SIZE
static char msg1 [] = "$VAR_MSG1";
static char date [] = "$VAR_DATE";
static char shll [] = "$VAR_SHLL";
static char inlo [] = "$VAR_INLO";
static char xecc [] = "$VAR_XECC";
static char lsto [] = "$VAR_LSTO";
static char tst1 [] = "$VAR_TST1";
static char chk1 [] = "$VAR_CHK1";
static char msg2 [] = "$VAR_MSG2";
static char rlax [] = "$VAR_RLAX";
static char opts [] = "$VAR_OPTS";
static char text [] = "$VAR_TEXT";
static char tst2 [] = "$VAR_TST2";
static char chk2 [] = "$VAR_CHK2";
static char pswd [] = "$VAR_PSWD";
#define hide_z 4096
/* rtc.c */
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
/* 'Alleged RC4' */
static unsigned char stte[256], indx, jndx, kndx;
/*
* Reset arc4 stte.
*/
void stte_0(void)
{
indx = jndx = kndx = 0;
do {
stte[indx] = indx;
} while (++indx);
}
/*
* Set key. Can be used more than once.
*/
void key(void * str, int len)
{
unsigned char tmp, * ptr = (unsigned char *)str;
while (len > 0) {
do {
tmp = stte[indx];
kndx += tmp;
kndx += ptr[(int)indx % len];
stte[indx] = stte[kndx];
stte[kndx] = tmp;
} while (++indx);
ptr += 256;
len -= 256;
}
}
/*
* Crypt data.
*/
void arc4(void * str, int len)
{
unsigned char tmp, * ptr = (unsigned char *)str;
while (len > 0) {
indx++;
tmp = stte[indx];
jndx += tmp;
stte[indx] = stte[jndx];
stte[jndx] = tmp;
tmp += stte[indx];
*ptr ^= stte[tmp];
ptr++;
len--;
}
}
/* End of ARC4 */
/*
* Key with file invariants.
*/
int key_with_file(char * file)
{
struct stat statf[1];
struct stat control[1];
if (stat(file, statf) < 0)
return -1;
/* Turn on stable fields */
memset(control, 0, sizeof(control));
control->st_ino = statf->st_ino;
control->st_dev = statf->st_dev;
control->st_rdev = statf->st_rdev;
control->st_uid = statf->st_uid;
control->st_gid = statf->st_gid;
control->st_size = statf->st_size;
control->st_mtime = statf->st_mtime;
control->st_ctime = statf->st_ctime;
key(control, sizeof(control));
return 0;
}
void rmarg(char ** argv, char * arg)
{
for (; argv && *argv && *argv != arg; argv++);
for (; argv && *argv; argv++)
*argv = argv[1];
}
// Update 18/11/2015 : Update "mask" casting from "unsigned" to "unsigned long".
int chkenv(int argc)
{
char buff[512];
unsigned mask, m;
int l, a, c;
char * string;
extern char ** environ;
mask = (unsigned long)chkenv;
mask ^= (unsigned)getpid() * ~mask;
sprintf(buff, "x%x", mask);
string = getenv(buff);
l = strlen(buff);
if (!string) {
/* 1st */
sprintf(&buff[l], "=%u %d", mask, argc);
putenv(strdup(buff));
return 0;
}
c = sscanf(string, "%u %d%c", &m, &a, buff);
if (c == 2 && m == mask) {
/* 3rd */
rmarg(environ, &string[-l - 1]);
return 1 + (argc - a);
}
return -1;
}
char * xsh(int argc, char ** argv)
{
char * scrpt;
int ret, i, j;
char ** varg;
stte_0();
key(pswd, pswd_z);
arc4(msg1, msg1_z);
arc4(date, date_z);
//if (date[0] && date[0]<time(NULL))
// return msg1;
arc4(shll, shll_z);
arc4(inlo, inlo_z);
arc4(xecc, xecc_z);
arc4(lsto, lsto_z);
arc4(tst1, tst1_z);
key(tst1, tst1_z);
arc4(chk1, chk1_z);
if ((chk1_z != tst1_z) || memcmp(tst1, chk1, tst1_z))
return tst1;
ret = chkenv(argc);
arc4(msg2, msg2_z);
if (ret < 0)
return msg2;
varg = (char **)calloc(argc + 10, sizeof(char *));
if (!varg)
return 0;
if (ret) {
arc4(rlax, rlax_z);
if (!rlax[0] && key_with_file(shll))
return shll;
arc4(opts, opts_z);
arc4(text, text_z);
printf("%s",text);
return 0;
/*arc4(tst2, tst2_z);
key(tst2, tst2_z);
arc4(chk2, chk2_z);
if ((chk2_z != tst2_z) || memcmp(tst2, chk2, tst2_z))
return tst2;
if (text_z < hide_z) {
scrpt = malloc(hide_z);
if (!scrpt)
return 0;
memset(scrpt, (int) ' ', hide_z);
memcpy(&scrpt[hide_z - text_z], text, text_z);
} else {
scrpt = text;
}*/
} else {
if (*xecc) {
scrpt = malloc(512);
if (!scrpt)
return 0;
sprintf(scrpt, xecc, argv[0]);
} else {
scrpt = argv[0];
}
}
j = 0;
varg[j++] = argv[0]; /* My own name at execution */
if (ret && *opts)
varg[j++] = opts; /* Options on 1st line of code */
if (*inlo)
varg[j++] = inlo; /* Option introducing inline code */
varg[j++] = scrpt; /* The script itself */
if (*lsto)
varg[j++] = lsto; /* Option meaning last option */
i = (ret > 1) ? ret : 0; /* Args numbering correction */
while (i < argc)
varg[j++] = argv[i++]; /* Main run-time arguments */
varg[j] = 0; /* NULL terminated array */
execvp(shll, varg);
return shll;
}
int main(int argc, char ** argv)
{
argv[1] = xsh(argc, argv);
return 1;
}
EOF
}
##########################################
## Starting
echo " _ _ _____ _ _ "
echo "| | | | / ___| | | | "
echo "| | | |_ __ \ \`--.| |_| | ___ "
echo "| | | | '_ \ \`--. \ _ |/ __|"
echo "| |_| | | | /\__/ / | | | (__ "
echo " \___/|_| |_\____/\_| |_/\___|"
echo
echo "--- UnSHc - The shc decrypter."
echo "--- Version: $VERSION"
echo "------------------------------"
echo "UnSHc is used to decrypt script encrypted with SHc"
echo "Original idea from Luiz Octavio Duarte (LOD)"
echo "Updated and modernized by Yann CAM"
echo "- SHc : [http://www.datsi.fi.upm.es/~frosal/]"
echo "- UnSHc : [https://www.asafety.fr/unshc-the-shc-decrypter/]"
echo "------------------------------"
echo
if [ $# -lt 1 ]; then
echo "[?] Type -h or --help for how to use it"
clean
exit 0
fi
# Check the availability of each command needed in this script.
check_binaries
OPTS=$( getopt -o h,a:,d:,s:,o: -l help,arc4:,dumpfile:,stringfile:,outputfile: -- "$@" )
if [ $? != 0 ]; then
exit_error;
fi
while [ "$#" -gt 0 ] ; do
case "$1" in
-h|--help)
usage;
clean;
exit 0;;
-a|--arc4)
echo "[+] ARC4() offset function call address specified [0x$2]";
CALLADDR=$2;
shift 2;;
-d|--dumpfile)
echo "[+] Object dump file specified [$2]";
DUMPFILE=$2;
shift 2;;
-s|--stringfile)
echo "[+] String dump file specified [$2]";
STRINGFILE=$2;
shift 2;;
-o|--outputfile)
echo "[+] Output file name specified [$2]";
OUTPUTFILE=$2;
shift 2;;
-*)
echo "[-] Unknown option: [$1]" >&2;
exit_error;;
--)
shift;
break;;
*)
echo "[*] Input file name to decrypt [$1]";
BINARY=$1
shift 1;;
esac
done
if [ ! -e $BINARY ]; then
echo "[-] Error, File [$BINARY] not found."
exit_error
fi
if [ -z "$DUMPFILE" ]; then
DUMPFILE=$(mktemp /tmp/XXXXXX)
else
if [ ! -e $DUMPFILE ]; then
echo "[-] Object dump file [$DUMPFILE] not found."
exit_error;
fi
fi
if [ -z "$STRINGFILE" ]; then
STRINGFILE=$(mktemp /tmp/XXXXXX)
else
if [ ! -e $STRINGFILE ]; then
echo "[-] String dump file [$STRINGFILE] not found."
exit_error;
fi
fi
# Fill DUMPFILE and STRINGFILE from objdump of the *.sh.x encrypted script
generate_dump
# Find out the most called function. This function is arc4() and there are 14 calls.
# Then retrieve the data used in each CALLADDR call
c=1
if [ -z "$CALLADDR" ]; then
# Case when ARC4 offset is unknown and there are multiple candidate
while [[ $($WC -l < $CALLSIZEFILE) -ne 14 ]]; do
extract_arc4_call_addr "$c"
extract_variables_from_binary
c=$(($c + 1))
done
else
# Case when the ARC4 address is already defined and passed throught args
extract_variables_from_binary
fi
# Retrieve PWD from function call just before the first CALLADDR call
extract_password_from_binary
# Create a C source code to decrypt *.sh.x file with previously extracted data
generic_file
# Compile C source code to decrypt *.sh.x file
$GCC -o $TMPBINARY ${TMPBINARY}.c >/dev/null 2>&1
echo "[*] Executing [$TMPBINARY] to decrypt [${BINARY}]"
chmod +x $TMPBINARY
if [ -z "$OUTPUTFILE" ]; then
echo "[*] Retrieving initial source code in [${BINARY%.sh.x}.sh]"
$TMPBINARY > ${BINARY%.sh.x}.sh
else
echo "[*] Retrieving initial source code in [$OUTPUTFILE]"
$TMPBINARY > $OUTPUTFILE
fi
echo "[*] All done!"
clean
exit 0给文件进行授权
chmod +x unshc
解密：./unshc file1.x -o file1
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