You can use following commands for the same:
Method 1 (md5, sha256, sha512)
openssl passwd -6 -salt xyz yourpass
Note: passing -1 will generate an MD5 password, -5 a SHA256 and -6 SHA512 (recommended)
Method 2 (md5, sha256, sha512)
mkpasswd --method=SHA-512 --stdin
The option --method accepts md5, sha-256 and sha-512
Method 3 (des, md5, sha256, sha512)
As @tink suggested, we can update the password using chpasswd using:
echo "username:password" | chpasswd
Or you can use the encrypted password with chpasswd. First generate it using this:
perl -e 'print crypt("YourPasswd", "salt", "sha512"),"\n"'
Then later you can use the generated password to update /etc/shadow:
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