Decrypting Cambium router config passwords

In the cambium cloud you can retrieve a config from a router, modify it and reapply it or make a template from it. All the passwords are “encrypted” so you can’t read what the WiFi password is for example.

Example config line looks like

WPAPSK1=[c760ba8ffe65c669]

Looks like it uses some sort of des3 hex encryption.

Fortunately there is a utility on the routers we can use to decrypt the encrypted string.

First we need a router that we can SSH into.

Info on the encryption

The Cambium router uses the 3des_hex utility to decrypt and encrypt strings

It is located /sbin/3des_hex

Decrypting a password

Decrypting is super easy.

3des_hex -d "c760ba8ffe65c669"

Replace the key with the key you want to decrypt.

Encrypting a password

Not really sure if this would ever be needed, but you can use the -e option to encrypt a string

3des_hex -e "12345678"

More info.

It looks like it needs the lib file “/lib/libuClibc-0.9.33.2.so”

/sbin/3des_hex is where the main file is stored though.

The config_manager.sh script in /sbin has the functions that encrypt and decrypt the config lines.

TMP_FILE="/tmp/tmp_cfg"
TMP_FILE2="/tmp/tmp_cfg2"
TMP_FILE_DECRYPT="/tmp/tmp_cfg_decrypt"
TMP_MFK_FILE="/tmp/multi_function_key.cfg"
decrypt_key="asdfghjkl";
SNMP_DECRYPT_FILE="/etc/cambium/cambium_default.decrypt"
DotFactoryFile="/etc_ro/DoNotFactory.name"

# when security encrypt enable , decrypt.
handle_file_dec()
{
        local enc_enable=`dev_manage_stat_get has_config_enc`
        if [ "$enc_enable" != "1" ]; then
                return 0
        fi
        SecParamListFile="/etc_ro/ConfigFileSecParam"
        [ -x "/sbin/3des_hex" ] || return 0
        [ -f $SecParamListFile ] || return 0
        [ -z "$1" ] && return 1
        awk -F '=' 'ARGIND==1{pname[$0]}ARGIND>1&&($1 in pname){print $0}' $SecParamListFile $1 > $1.tmp
        awk '{if($0~/.+\=\[.*\]/){sub("\=","\|");print $0;}else{print $0}}' $1.tmp > $1.tmp1
        rm -f $1.tmp
        awk -F'|' '{if($2~/\[.*\]/){len=length($2);value=substr($2,2,len-2);while(("3des_hex -d \""value"\""|getline line)>0){printf("%s=%s\n",$1,line);}close("3des_hex -d \""value"\"");}else{print $0}}' $1.tmp1 > $1.tmp2
        rm -f $1.tmp1
        echo "" >> $1
        cat $1.tmp2 >> $1
        rm -f $1.tmp2
}

LibreNMS – Setting up Alerts to monitor Voltage on Mikrotik Routers

Create Alert Rule

Go to “Alerts -> Alert Rules” Then “Create rule from Collection”

Search for “Sensor under limit” and Select

Setup Sensor under limit

Configure Alert Rule

Add another rule to limit to just the Voltage Sensors by using the “sensors.sensor_class = Voltage”

Select your Groups and Transports and Save.

Modify Alert Rule

Disable Alerts for Unused Ports

You may get some alerts because there are some ports that do not have any any voltage on them. You can disable them on a per device basis by going to the “device -> Edit -> Health” and turning alerts off

Turn off voltage alerts on port that has no PoE