How to check if the password entered by user is correct (in the command encrypted with OpenSSL)?-CodePudding

How to find out if the password entered by user is correct (in the command encrypted with OpenSSL)? I want to run another command if the password is successful. Voila my code :

#!/bin/bash
#decryption operation
openssl aes-128-cbc -d -in config.py.aes128 -out config.py
#run another command if password is correct
./doSomething.py

CodePudding user response：

Yes you catch the exit code if openssl fail to decrypt the file .

OPTION 1 : you can use $?

#!/bin/bash
# create a temporary file for output errors
ERR_OUTPUT=$(mktemp)
openssl aes-128-cbc -d  -in config.py.aes128 -out  config.py    >"${ERR_OUTPUT}" 2>&1
EXIT_CODE=$?
if [  ${EXIT_CODE} -ne 0 ]
then
    echo ERROR decryption failed
    cat "${ERR_OUTPUT}"
    rm -f "${ERR_OUTPUT}"
    exit ${EXIT_CODE}
fi
rm -f "${ERR_OUTPUT}"
./doSomething.py

OPTION 2 : you can embed the execution of the command in the if clause

#!/bin/bash
# create a temporary file for output errors
ERR_OUTPUT=$(mktemp)
if ( ! openssl aes-128-cbc -d  -in config.py.aes128 -out  config.py  >"${ERR_OUTPUT}" 2>&1 )
then
    echo ERROR decryption failed
    cat "${ERR_OUTPUT}"
    rm -f "${ERR_OUTPUT}"
    exit 1
fi
rm -f "${ERR_OUTPUT}"
./doSomething.py

OPTION 3 : you can use || between openssl and a block that will executed only if openssl generate a error

#!/bin/bash
# create a temporary file for output errors
ERR_OUTPUT=$(mktemp)
openssl aes-128-cbc -d  -in config.py.aes128 -out  config.py  >"${ERR_OUTPUT}" 2>&1 || (
    echo ERROR decryption failed
    cat "${ERR_OUTPUT}"
    rm -f "${ERR_OUTPUT}"
    exit ${EXIT_CODE}
)
rm -f "${ERR_OUTPUT}"
./doSomething.py

CodePudding user response：

With all respect for the @EchoMike44 suggestion, have you tried this?

#!/bin/bash
openssl aes-128-cbc -d -in config.py.aes128 -out config.py && \
  ./doSomething.py || \
    exit 1

If you don't need detailed messages in the output, so this will work with the same logic but in short syntax.

I mean if the ExitCode of the openssl ... command was 0 (successful) then will run ./doSomething.py otherwise it will exit from the bash script with the ExitCode of 1.