Allow and instruct the web application to query an untrusted https URL

Https query from web application like JSON to the site that needs to add certification exception (the trust) manually. When the user use their own browser to launch a https query to a web site that its certificate is not supported by the standard authorities, the user will be prompted for a permission to accept the certificate as an exception.

For web application server to launch the query, there is no way to prompt the web application to accept the exception, and the default is to reject the untrusted certificate. The web server will complain that the certificate is not found from the keystore for the requested target.

javax.xml.ws.soap.SOAPFaultException
sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Now, we have to tell the web server to trust the certificate from the target.
1> Query the target URL by web browser.
2> Download and save the certificate <xxx.pem> from the target.
3> Append the certificate to the keystore

1. cd /usr/java/jdk1.6.0_33/jre/lib/security

2. /usr/java/jdk1.6.0_33/bin/keytool -import -v -trustcacerts -alias <Create your own> -file <filepath/xxx.pem> -keypass changeit -keystore ./cacerts -storepass changeit

Mounting file system, fstab, mtab

Basic format: mount -t <filesystem type> old_dir new_dir

1> Mounting a directory to another directory to let them access the same content
mount --bind old_dir<directory has content> new_dir<directory designed to access the content>

2> Mounting a device <like CDROM> with no -t parameter, it will let the OS to guess
mount /dev/cdrom /cd

3> NFS

• /etc/exports specifies the access control of the mounting directory.

/home vale(rw) vstout(rw) vlight(rw)
/usr/X11R6 vale(ro) vstout(ro) vlight(ro)
/usr/TeX vale(ro) vstout(ro) vlight(ro)
/ vale(rw,no_root_squash)
/home/ftp (ro) 

/var/myApp 172.16.95.17/255.255.255.255(rw,no_root_squash) 

Each line defines a directory and the hosts allowed to mount it. Wildcard is allowed (* ?).

Range of ip address / network mask can be used to specify the host. 

If no host is give, any host matches and is allowed to mount the directory.

• CLI form to mount NFS volume. 

  mount -t nfs nfs_volume local_dir options

• /etc/fstab entry of NFS

[root@localhost ~]# cat /etc/fstab
/dev/VolGroup00/LogVol00 /                       ext3    defaults        1 1
/dev/VolGroup00/LogVol01 /data                   ext3    defaults        1 2
LABEL=/boot1            /boot                   ext3    defaults        1 2
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
LABEL=SWAP-sda6         swap                    swap    defaults        0 0
172.16.95.93:/var/myApp    /logserver-1/var/myApp     nfs     hard,intr       0 0

4> fstab and mtab
[root@localhost ~]# cat /etc/fstab
/dev/VolGroup00/LogVol00 /                       ext3    defaults        1 1
LABEL=/boot             /boot                   ext3    defaults        1 2
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
/dev/VolGroup00/LogVol01 swap                    swap    defaults        0 0
/var/myApp /localserver-1/var/myApp none rw,bind 0 0

There are 3 ways of using fstab.
1> mount -a will cause all the filesystem listed on fstab to be mounted, except those noted as noauto. Adding the -F will make mount fork. Usually it is used by boot scripts.

2> To mount or umount the filesystem mentioned on the fstab, it is sufficed to give only the device or the mount point.

e.g In fstab, /tmp/a /tmp/b none rw,bind 0 0
mount /tmp/a or mount /tmp/b will suffice.

3>  Normally, only the superuser can mount  file  systems.   However, when  fstab  contains  the user option on a line, anybody can mount the corresponding system.