I need to manually edit
/etc/shadow to change the root password inside of a virtual machine image.
Is there a command-line tool that takes a password and generates an
/etc/shadow compatible password hash on standard out?
You can use the following commands for the same
Method 1 (md5, sha256, sha512)
openssl passwd -6 -salt xyz yourpass
-1 will generate an MD5 password,
-5 a SHA256 and
-6 SHA512 (recommended)
Method 2 (md5, sha256, sha512)
mkpasswd --method=SHA-512 --stdin
Method 3 (des, md5, sha256, sha512)
As @tink suggested, we can update the password using
echo "username:password" | chpasswd
Or you can use the encrypted password with
chpasswd . We'll first create it using this
perl -e 'print crypt("YourPasswd", "salt", "sha512"),"\n"'
Then later you can use the generated password to update
echo "username:encryptedPassWd" | chpasswd -e
The encrypted password we can also use to create a new user with this password, for example.
useradd -p 'encryptedPassWd' username