Author: Jason

The hidden and all powerful link that all NUS students need.

How to unsubscribe from NUS mailing lists:

1. Go to https://groups.nus.edu.sg/NUSgroups/
2. Login with your NUSNET account
3. Uncheck all boxes on the mailing list option
4. Enjoy life

Notes on updating edgerouter lite. Especially important since Ubiquiti does not provide an easy disaster recovery procedure to follow if anyone messes up the update.

Update

Where to download updates: Ubiquiti Web Site

How to update:

• Use the Upgrade System Image in the System Tab.

• When updating, if the render error message occurs, do not panic. This is normal behaviour. Continue to wait for another 1 minute before refreshing.

Disaster Recovery

Use the image below and dump it to a fresh flashdrive. Then use it to replace the existing flashdrive in the edgerouter lite.
Link

A quick lookup page for me to install softether vpn server on Ubuntu 16.04 since the apt version no longer work properly (17-01-2020)

Original apt version
https://launchpad.net/~paskal-07/+archive/ubuntu/softethervpn

Requirements

apt-get install -y build-essential make gcc

Download

wget -O /tmp/softether-vpnserver.tar.gz https://github.com/SoftEtherVPN/SoftEtherVPN_Stable/releases/download/v4.32-9731-beta/softether-vpnserver-v4.32-9731-beta-2020.01.01-linux-x64-64bit.tar.gz

Extract

tar xfz /tmp/softether-vpnserver.tar.gz -C /usr/local

Compile

cd /usr/local/vpnserver
make

Method 1: Non-root User

Note that local bridge setting will not work, so you will need to use SecureNAT

Adding a service account for softether

sudo useradd --system --no-create-home softether

Permissions

chown -R softether:softether /usr/local/vpnserver

find /usr/local/vpnserver -type f -exec chmod 600 {} \;
find /usr/local/vpnserver -type d -exec chmod 700 {} \;

chmod +x /usr/local/vpnserver/vpncmd 
chmod +x /usr/local/vpnserver/vpnserver

Create /etc/systemd/system/softether.service

[Unit]
Description=SoftEther VPN Server
After=network.target auditd.service
ConditionPathExists=!/usr/local/vpnserver/do_not_run

[Service]
Type=forking
TasksMax=16777216
User=softether
Group=softether
ExecStart=/usr/local/vpnserver/vpnserver start
ExecStop=/usr/local/vpnserver/vpnserver stop
KillMode=process
Restart=on-failure

# Hardening
PrivateTmp=yes
ProtectHome=yes
ProtectSystem=full
ReadOnlyDirectories=/
ReadWriteDirectories=/usr/local/vpnserver
CapabilityBoundingSet=CAP_NET_ADMIN CAP_NET_BIND_SERVICE CAP_NET_BROADCAST CAP_NET_RAW CAP_SYS_NICE CAP_SYSLOG CAP_SETUID

[Install]
WantedBy=multi-user.target

Allow vpnserver to bind to local ports despite being run by softether user (non-root)

sudo setcap CAP_NET_BIND_SERVICE=+eip /usr/local/vpnserver/vpnserver

Start service

systemctl daemon-reload
systemctl start softether.service
systemctl enable softether.service

Method 2: Root User

Permissions

chown -R root:root /usr/local/vpnserver

find /usr/local/vpnserver -type f -exec chmod 600 {} \;
find /usr/local/vpnserver -type d -exec chmod 700 {} \;

chmod +x /usr/local/vpnserver/vpncmd 
chmod +x /usr/local/vpnserver/vpnserver

Create /etc/systemd/system/softether.service

cat > /lib/systemd/system/softether.service << EOF
[Unit]
Description=SoftEther VPN Server
After=network.target auditd.service
ConditionPathExists=!/usr/local/vpnserver/do_not_run

[Service]
Type=forking
ExecStart=/usr/local/vpnserver/vpnserver start
ExecStop=/usr/local/vpnserver/vpnserver stop
KillMode=process
Restart=on-failure

[Install]
WantedBy=multi-user.target
EOF

Run

Enable and start the Service

systemctl daemon-reload
systemctl start softether.service
systemctl enable softether.service

Clean up

rm -f /tmp/softether-vpnserver.tar.gz 

Full Script

apt-get update
apt-get install -y build-essential make gcc

curl -s https://api.github.com/repos/SoftEtherVPN/SoftEtherVPN_Stable/releases/latest \
| grep "softether-vpnserver.*linux-x64-64bit.tar.gz" \
| cut -d : -f 2,3 \
| tr -d \" \
| wget -O /tmp/softether-vpnserver.tar.gz  -i -

tar xfz /tmp/softether-vpnserver.tar.gz -C /usr/local
cd /usr/local/vpnserver
make

chown -R root:root /usr/local/vpnserver

find /usr/local/vpnserver -type f -exec chmod 600 {} \;
find /usr/local/vpnserver -type d -exec chmod 700 {} \;

chmod +x /usr/local/vpnserver/vpncmd 
chmod +x /usr/local/vpnserver/vpnserver

cat > /lib/systemd/system/softether.service << EOF
[Unit]
Description=SoftEther VPN Server
After=network.target auditd.service
ConditionPathExists=!/usr/local/vpnserver/do_not_run

[Service]
Type=forking
ExecStart=/usr/local/vpnserver/vpnserver start
ExecStop=/usr/local/vpnserver/vpnserver stop
KillMode=process
Restart=on-failure

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload
systemctl start softether.service
systemctl enable softether.service
rm -f /tmp/softether-vpnserver.tar.gz 

You can find the script in https://github.com/adjscent/softether_installer.

Huawei E1750 3G Modem has the ability to call, but the feature is disabled by default.

Most online solutions on enabling the voice feature do not work, including manual AT commands, the cracked version of dc unlocker or huawei unlocker.
I am not sure what the actual dc unlocker voice activation (4 credits) does, but it successfully activated the voice feature.

This video is just me trying out the dc unlocker voice activation (with credits T_T) in a virtual machine.

After this, the raspbx chan_dongle works 😀

Damage: 4 credits

Video Tutorial and Walkthrough

Some of the important openssl commands to create certificates

Configuration Issues

Environment Variables for Windows Openssl

set OpenSSL_HOME=C:\OpenSSL-Win64
set OPENSSL_CONF=C:\OpenSSL-Win64\bin\openssl.cfg

Certificate Creation

Create self-sign certificates short method

openssl req -x509 -nodes -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365

Create self-sign certificates long method

openssl genrsa -out helloeb.com.key 4096
openssl req -new -sha256 -key helloeb.com.key -out helloeb.com.csr
openssl x509 -req -nodes -days 365 -in helloeb.com.csr -CAkey helloeb.com.key -out sha1.crt -sha256