Step-by-Step Guide

1. Download Cisco AnyConnect for Linux

   To get started, you'll need to download the Cisco AnyConnect Secure Mobility Client from Cisco's official website. You can follow this link for detailed download instructions and ensure you have the correct version for your system.

2. Extract the AnyConnect Installation Files

   After downloading the tar file, extract it using the following command:

   bashCopy

   tar -xvf anyconnect-linux64-4.10.07061-k9.tar.gz
   cd anyconnect-linux64-4.10.07061-k9

   This command extracts the AnyConnect files and moves you into the extracted directory.

3. Install Cisco AnyConnect

   To install Cisco AnyConnect, run the installation script with sudo:

   bashCopy

   sudo ./vpn_install.sh

   Follow the on-screen prompts to complete the installation. This script will install AnyConnect on your system, allowing you to connect to VPNs securely.

4. Convert .pfx Certificate to .pem and .key Formats

   If you need to use certificate-based authentication with AnyConnect, you will likely have a .pfx file. You'll need to convert this .pfx file into separate .pem and .key files that AnyConnect can recognize. The following commands do this:

   bashCopy

   openssl pkcs12 -in certificate.pfx -out certificate.pem -nokeys
   openssl pkcs12 -in certificate.pfx -out certificate.key -nocerts

   • The first command extracts the public certificate (.pem).
   • The second command extracts the private key (.key).

   Be sure to save these files in a directory where you'll easily find them later, such as ~/certificates.

5. Place the Certificate Files in the Correct Directories

   AnyConnect checks various locations for certificates, including those used by web browsers. However, to ensure AnyConnect can find your certificates, you should manually create the required directories:

   bashCopy

   mkdir -p ~/.cisco/certificates/client
   mkdir -p ~/.cisco/certificates/client/private

   Now, copy or move the .pem and .key files into the respective directories:

   bashCopy

   cp ~/certificates/certificate.pem ~/.cisco/certificates/client/
   cp ~/certificates/certificate.key ~/.cisco/certificates/client/private/

   Make sure the certificate and key files have the correct access rights so that AnyConnect can read them.

6. Handling Multiple Certificates with a Script

   If you need to switch between multiple certificates for different VPN connections, you can automate the process using a simple Bash script. This script allows you to select and symlink the desired certificate pair into AnyConnect's directories before connecting to the VPN.

   First, create the following Bash script:

   bashCopy

   #!/bin/bash
   
   # Define your certificate directory
   CERT_DIR=~/certificates
   
   # List available certificates (.pem files only)
   echo "Available certificates:"
   select CERT in "$CERT_DIR"/*.pem; do
       if [ -z "$CERT" ]; then
           echo "Invalid selection. Please try again."
       else
           echo "You selected: $CERT"
   
           # Construct corresponding .key file path
           CERT_KEY="${CERT %.pem}.key"
   
           # Check if the key file exists
           if [ ! -f "$CERT_KEY" ]; then
               echo "Error: Corresponding key file not found for $CERT"
               exit 1
           fi
   
           echo "Using corresponding key: $CERT_KEY"
   
           # Symlink the selected certificate and key into Cisco directories
           ln -sf "$CERT" ~/.cisco/certificates/client/certificate.pem
           ln -sf "$CERT_KEY" ~/.cisco/certificates/client/private/certificate.key
   
           echo "Symlinks created for $CERT and $CERT_KEY"
           break
       fi
   done

   How to Use the Script:

   1. Save the script to a file, for example, switch-certificates.sh.
   2. Make the script executable:
      bashCopy

      chmod +x switch-certificates.sh

   3. Run the script:
      bashCopy

      ./switch-certificates.sh

   This script will present a list of available .pem files in your ~/certificates directory. Once you select a certificate, it will symlink the corresponding .pem and .key files into the AnyConnect directories, making them the active certificate for your next VPN connection.

7. Connect to the VPN Using Cisco AnyConnect

   Once you've set up the certificates, you can launch Cisco AnyConnect from your system's application menu. When you connect to the VPN, AnyConnect will ask you for the password you set for the .key file during the conversion process. After entering the correct credentials, you should be able to authenticate and connect to your VPN.