Shulou(Shulou.com)06/01 Report--

This article mainly introduces the relevant knowledge of "how SHC encrypts Shell scripts". The editor shows you the operation process through an actual case. The operation method is simple, fast and practical. I hope this article "how SHC encrypts Shell scripts" can help you solve the problem.

Environment

Centos8

Install SEC [root @ localhost ~] # yum-y install shc to create a shell script

Create a script file below:

[root@localhost ~] # vim encrypt e.shrunk "Welcome to linux world" use shc to encrypt the script file

Use the shc encrypt. sh script as shown below.

[root@localhost scripts] # shc-v-f welcome.shshc shll=shshc [- I] =-cshc [- x] = exec'% s'"$@" shc [- l] = shc opts=shc: cc welcome.sh.x.c-o welcome.sh.xshc: strip welcome.sh.xshc: chmod ug=rwx,o=rx welcome.sh.xwelcome.sh is the original unencrypted shell script welcome.sh.x is in binary format encrypted shell script welcome.sh.x.c is the C source code of the welcome.sh file. Compile the C source code to create the encrypted welcome.sh.x file above.

You can use the file command to view the type of file:

[root@localhost scripts] # file welcome.shwelcome.sh: POSIX shell script, ASCII text executable [root@localhost scripts] # file welcome.sh.xwelcome.sh.x: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter / lib64/ld-linux-x86-64.so.2, for GNU/Linux 3.2.0, BuildID [sha1] = 35e0e2569eca90774e379d6fef51ad6fedf346f5, stripped [root@localhost scripts] # file welcome.sh.x.cwelcome.sh.x.c: C source, ASCII text [root@localhost scripts] #

Execute encrypted shell script

Now, let's execute the encrypted Shell script to make sure it runs:

[root@localhost scripts] #. / welcome.sh.xWelcome to linux world

Specify the expiration time of the Shell script

With shc, you can also specify an expiration date. That is, after this expiration date, when someone tries to execute the Shell script, they will receive an error message. Use the shc-e option to create a new encrypted Shell script that specifies the expiration date. The expiration date is specified in dd/mm/yyyy format.

# Delete the previously created .x, .x.c file [root@localhost scripts] # rm-rf welcome.sh.x*# create an encryption script with expiration time [root@localhost scripts] # shc-e 01ax 02b 2021-v-f welcome.shshc shll=shshc [- I] =-cshc [- x] = exec'% s'"$@" shc [- l] = shc opts=shc: cc welcome.sh.x.c-o welcome.sh.xshc: strip welcome.sh.xshc: chmod ug=rwx O=rx welcome.sh.x

In this example, if someone tries to execute a welcome.sh.x script file, it will be prompted that it has expired.

[root@localhost scripts] #. / welcome.sh.x./welcome.sh.x: has expired!Please contact your provider jahidulhamid@yahoo.com

If you want to specify a custom expiration message, you need to add the-m option.

[root@localhost scripts] # shc-e 01welcome.sh.xshc 02shc opts=shc 2021-m "Please contact admin@example.com!"-v-f welcome.shshc shll=shshc [- I] =-cshc [- x] = exec'% s'"$@" shc [- l] = shc opts=shc: cc welcome.sh.x.c-o welcome.sh.xshc: strip welcome.sh.xshc: chmod ug=rwx,o=rx welcome.sh.x, that's all for "how SHC encrypts Shell scripts". Thank you for reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.