|
Secure Network Layer | Support
for Standards | Key Management | Automatic
Key Negotiation | Security Associations | Tunnel
and Transport Mode
V-IPSecure is a high-performance, lean and flexible implementation
of the IPSec protocols which provide IP extensions needed for security services
at the network level. Unlike other protocols that secure individual network applications,
IPSec protocols secure the network layer connection, thus automatically and transparently
securing all network applications that use it.
V-IPSecure’s implementation of these protocols provides
a high-quality cryptography-based communication channel setup on embedded systems.
Its end-to-end securing of IP datagrams prevents access or modification of any
information from above the IP layer, when passing through intermediate nodes in
a public network. This enables secure virtual private networks (VPN) to be carved
out of a public and/or insecure network. Designed exclusively for embedded use,
V-IPSecure’s robust and configurable implementation makes it an ideal fit for
embedded devices such as Internet appliances, VPNs, gateways, secure terminals
and routers.
While the TCP/IP suite of protocols has become very popular among embedded systems
with an explosion in connected devices, security is not part of its design. Hence
any embedded application with security requirements needs to implement security
at the application, transport, network or link layer. Placing security at the
network layer has several advantages, when security requirements affect all data
going through the stack. Transmission security is transparent to the applications
which use the network stack. Further, the security architecture is independent
of the network type or topology to which the embedded device is connected and
encrypted packets can be routed and switched on any network that supports IP traffic.
 V-IPSecure
implements a secure network layer (IPSec) that provides data integrity, origin
authentication, data confidentiality, access control, partial sequence integrity,
and limited traffic flow confidentiality services for communications between any
two networks or hosts. Replay-detection as defined by the IPSec standard is also
performed by using sequence numbers combined with authentication.
 Top
V-IPSecure includes a complete set of standards-based protocols for IPSec-enabling
a standard TCP/IP (V4 or V6) network stack.
Authentication Header (AH) Protocol: attaches a strong
crypto-checksum to packets for a guarantee of authenticity, and ties data in each
packet to a verifiable signature. This allows communicating parties to verify
that data was not modified in transit (connectionless integrity) and that it genuinely
came from its apparent source. Optionally, it can contain protections against
anti-replay attacks.
Encapsulating Security Payload (ESP) Protocol: encrypts
data using symmetric keys, to secure it against eavesdropping during transit.
It provides a guarantee of confidentiality and optionally provides for integrity
and authentication as well.
Internet Key Exchange (IKE): is a powerful and flexible
negotiation protocol that allows communicating parties to negotiate the methods
and parameters of the secure communication channel, such as the sharing of secret
keys between peers.
V-IPSecure seamlessly integrates with any IPV4 or IPV6
based TCP/IP stack, leveraging features such as PMTU support if the native stack
provides it.
Top
The flexibility and power of V-IPSecure is complemented by a highly configurable
framework for policy and secure channel management. It allows for a flexible set
of rules to decide when to apply the security policies and when to skip them,
and provides different levels of security setup. For example, a secure communication
channel to one network node may consist of a simple authentication scheme for
traffic in both directions, while a highly secure authentication and encryption
scheme may be setup for other hosts. The management control for such flexibility
is provided through a set of user friendly APIs to access and modify the Security
Policy Database (SPD) and APIs for configuration commands. APIs are also included
for starting and shutting down SA negotiations. These APIs may be called programatically,
or manually from a host or target-resident shell during development. This interface
may also be used to pre-share secret keys for encryption between network nodes.
Top
To use any encryption in a network environment, communicating peers must first
exchange keys. While manually sharing keys is a possibility and is fully supported
in V-IPSecure, it can become intractable as the number of IPSec hosts increases.
For this reason, V-IPSecure includes an implementation of a mechanism for automatic
key negotiation, called Internet Key Exchange (IKE). IKE is based on the Diffie-Hellman
key exchange and provides mechanisms for automatic generation and frequent renewal
of the crypto keys for the high security without increasing key-lengths which
may slow down the encryption process.
IKE integrates the Internet Security Association and Key Management
Protocol (ISAKMP) with a subset of the Oakley key exchange scheme. ISAKMP defines
a standardized framework to support negotiation of security associations (SA),
initial generation of all cryptographic keys, and subsequent refresh of these
keys. Oakley is the mandatory key management protocol that is used within the
ISAKMP framework. ISAKMP supports automated negotiation of security associations,
and automated generation and refresh of cryptographic keys.
Top
A Security Association (SA) is a one-way association between a sender and a receiver
of security services. Each SA represents one direction of traffic. The security
association separates the key management and the security mechanisms from each
other. Each V-IPSecure SA defines a set of parameters including the sequence number
for anti-replay service, the protocol mode, the lifetime of the SA, the path MTU
and other implementation details. For authentication services in AH or ESP, and
for encryption services in ESP, each SA also defines parameters such as the choice
of cryptographic algorithm, keys in use, key lifetimes, initial values etc. In
this way, V-IPSecure makes it possible to bundle SAs to achieve the desired level
of security in a fine-grained manner.
Top
Depending on the mechanism of secure IP packet transmission, V-IPSecure supports
two types of SAs, which define the IPSec protocol mode in use:
Transport mode SA: A security association between two hosts used to secure
the traffic of upper layer protocols.
Tunnel mode SA: A security association modeled similar
to an IP-in-IP tunnel, by encapsulating IP packets into new packets, which is
suitable for secure connections between security gateways.
Based on application requirements, V-IPSecure may be configured
in either mode or a mix of the two modes for different connections. ESP in transport
mode allows for lower processing overhead but provides neither authentication
nor encryption for the IP header, making it vulnerable to spoofing. In ESP in
tunnel mode, the original datagram becomes the payload data for the new ESP packet,
hence protection is total if both encryption and authentication are selected,
but has a higher overhead. Further, tunneling allows for the passing of illegal
IP addresses through a public network, which may be required in certain applications.
Tunneling with the ESP also has the advantage of hiding the original source and
destination addresses from users on the public network — defeating or at
least reducing the power of traffic analysis attacks.
Top
|
