http://www.aychedee.com/2012/03/14/etc_shadow-password-hash-formats/From the above article I can see the password can be encrypt in abot 6 different ways to genereate the hash in the format of $1$ ...However, when I read the shadow file of my machine, I get something like this root:l2tdfsoZQxobQ:15743:0:99999:7:::bin:*:13653:0:99999:7:::daemon:*:13653:0:99999:7:::adm:*:13653:0:99999:7:::lp:*:13653:0:99999:7:::sync:*:13653:0:99999:7:::shutdown:*:13653:0:99999:7:::halt:*:13653:0:99999:7:::mail:*:13653:0:99999:7:::news:*:13653:0:99999:7:::uucp:*:13653:0:99999:7:::operator:*:13653:0:99999:7:::games:*:13653:0:99999:7:::gopher:*:13653:0:99999:7:::ftp:*:13653:0:99999:7:::nobody:*:13653:0:99999:7:::dbus:!!:13653:0:99999:7:::vcsa:!!:13653:0:99999:7:::rpm:!!:13653:0:99999:7:::haldaemon:!!:13653:0:99999:7:::pcap:!!:13653:0:99999:7:::nscd:!!:13653:0:99999:7:::named:!!:13653:0:99999:7:::netdump:!!:13653:0:99999:7:::sshd:!!:13653:0:99999:7:::rpc:!!:13653:0:99999:7:::mailnull:!!:13653:0:99999:7:::smmsp:!!:13653:0:99999:7:::rpcuser:!!:13653:0:99999:7:::nfsnobody:!!:13653:0:99999:7:::apache:!!:13653:0:99999:7:::squid:!!:13653:0:99999:7:::webalizer:!!:13653:0:99999:7:::xfs:!!:13653:0:99999:7:::ntp:!!:13653:0:99999:7:::mysql:!!:13653:0:99999:7:::For the root password, it is like l2tdfsoZQxobQ, so what encryption method did the system use for this password? 
/etc/shadow encryption method
shadow
If the hashing algorithm isn't listed in the password field, it's usually because it's in traditional DES-based crypt form. The hash you've provided even looks like a crypt hash.Examples of what other DES hashes look like:[root@xxx601 ~]# openssl passwd -crypt myPass7BQrU5yVqiGqU[root@xxx601 ~]# openssl passwd -crypt newPassMbq6MsDxJOsow[root@xxx601 ~]#Crypt hashes are typically the weakest possible hashes for a variety of reasons. Not the least of which is that it can only support passwords up to eight characters so all characters after the eighth are just ignored.