Whitepaper SSL Decryption: Uncovering The New Infrastructure Blind Spot

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1 Whitepaper SSL Decryption: Uncovering The New Infrastructure Blind Spot Since the mid-90 s, users transacting on the internet have been assured of security by the lock icon displayed on their browser and URLs that begin with https. These indicate secure websites that support the Secure Sockets Layer (SSL) internet protocol. These SSL sessions protect sensitive information such as credit card numbers and login credentials for , e-commerce, voice-over-ip (VoIP), online banking, remote health, and other critical services, from unauthorized or malicious parties. Yet, the security stakes have been raised multiple fold with more organizations adopting cloud computing. In a Cloud Security Alliance survey 1, 73% of respondents indicated that security concerns held back cloud projects. Decisions concerning security of data in the cloud have also shifted from the IT room to the boardroom for 61% of companies. Indeed, top executives have seen the impact of high-profile data breaches on not only company reputation and balance sheets but also their jobs. Encryption Primer To ensure security in the cloud, SSL encrypts data in connections between a web server and a browser. When one connects to a secure website via a browser, data sent or received from the remote web server is encrypted by a public key infrastructure (PKI). In the PKI, a Certificate Authority (CA) issues a root certificate an unsigned public key certificate or a signed certificate. The web server has the public certificate or a public key. It also has sole access to a private key. Simply put, the public key is used to encrypt data while only the private key is used to decrypt data. The public keys are visible at the start of the transaction, but the administrator controls access to the private keys. Within SSL secure connections, a web browser uses root certificates to verify identities and establish trust. The ITU-T X.509 standard certificate, for example, includes a digital signature from a CA. SSL Vulnerabilities But high-profile vulnerabilities, such as the Heartbleed bug, which exposes web server memory protected by the OpenSSL software to theft, have stoked concerns and fuelled threats SSL was supposed to curb. The Heartbleed bug, which has been present since 2011, is a serious threat because OpenSSL is used by some 20% of the world s web servers. Such vulnerabilities enable cyber criminals to gain access to keys and certificates and bypass SSL protection based on encryption and signatures in the X.509 certificates. Moreover, another trend spells trouble ahead. According to an independent study by NSS Labs 2, 25% to 35% of enterprise traffic is currently being carried over encrypted connections, of which a growing proportion are within SSL. That traffic segment continues to grow every month. And hackers and cyber criminals are increasingly using these SSL sessions to dodge network security defenses. These threat actors exploits stem from inline and out-of-band security tools either lacking the ability to see inside the encrypted sessions or end up with performance degradation of up to 80% from processing SSL traffic. Gaps in Tool Capabilities Although inline devices such as application delivery controllers and firewalls integrate SSL support, out-of-band monitoring and security tools often do not have the ability to access decrypted traffic. 1 Coles, Cameron. (2015, Jan. 12) CSA Survey: Security of Cloud Data Now a Board-Level Concern. Cloud Security Alliance Industry Blog. 2 Pirc, John W. (2013) Analyst Brief: SSL Performance Problems. NSS Labs. 1

2 But even inline technologies such as SSL proxies and application load balancers that provide SSL decryption lack the scalability to handle traffic from multiple TAPs across the network or to filter and replicate decrypted traffic to multiple monitoring tools. With limited extensibility, increasing SSL throughput often requires hardware upgrades. In addition, these tools also lack visibility functionality or traffic intelligence for non-encrypted traffic. The situation will worsen as certificate authorities implement longer keys such as 256-bit SSL encryption based on a 2048-bit key which will increase the compute load for SSL decryption. Furthermore, not knowing which applications are running over the network hampers the ability to monitor application performance and network usage patterns. When SSL traffic is allowed to flow uninspected, this creates a potential security loophole. Hence, analysts at Gartner believe that more than half of the network attacks targeting enterprises will use encrypted traffic to bypass controls in 2017, up from less than 5% today. 3 Harm will come from hackers and nefarious actors hiding threats, such as the Zeus botnet, in SSL sessions that have been largely considered safe. This makes uncovering attacks hiding in threat sources like SSL sessions an essential component of enterprise security. Organizations must develop visibility into these sessions so network security and analytics tools can monitor encrypted traffic and detect threats hidden within them. Why SSL Decryption Organizations should analyze their architecture and environment to determine the security risks due to uninspected encrypted network traffic. As more of enterprise network traffic is encrypted, organizations have to identify and seal gaps in defense-in-depth effectiveness. Without a traffic decryption plan, organizations will not be able to see and stop malware activity that comes through encrypted connections. To alleviate critical blind spots created by encrypted traffic flowing through the IT infrastructure, organizations need innovative visibility solutions with the capability to decrypt SSL sessions at high performance. A traffic decryption strategy can bolster protection of endpoints and DMZ servers from threats in outbound and inbound traffic. SSL decryption can be applied to: Malware detection It prevents malware from exploiting a host using SSL transactions Data loss prevention (DLP) It prevents confidential data and files from being encrypted and leaked via malware or a malicious insider using SSL connections Application performance monitoring (APM) It enables proper monitoring of data and allows business applications to use SSL for authentication Cloud services monitoring It helps to differentiate and monitor secure services running in the cloud, including web applications Two types of traffic have to be decrypted so security tools can examine them: Inbound traffic from an external or remote client computer on the internet to an internal server Outbound traffic from an internal client computer to an external server on the internet Decrypting Inbound Traffic When a client device accesses a web server in a data center via the internet, an end-to-end, SSL-encrypted connection is established between the device s browser and the web server. If this link is invisible to network security tools deployed in the data center, the traffic has to be decrypted using two steps: 1. Place a copy of the web server s private key on a decryptioncapable device 2. Store a copy of the data in the decryption-capable device End-to-end data encryption must be maintained to prevent data theft or leakage. Decrypting Outbound Traffic Decrypting outbound traffic requires a different approach. When the server sends its certificate to a browser, the browser decides whether or not it trusts the certificate based on a list of trusted CAs loaded in the device. 3 D Hoinne, Jeremy and Hils, Adam. Security Leaders Must Address Threats From Rising SSL Traffic. Gartner report, 9 Dec

3 However, cyber criminals can exploit decryption of outbound traffic by setting up a decryption device as a CA with the ability to sign certificates and configuring the browser to trust certificates from the decryption device. With the decryption device placed inline between users and the internet, it is ready to intercept any request from users who browse to an encrypted website and pretend to be the web server. At the other end, the decryption device establishes its own connection to the actual web server and controls requests between the user and the server. Protecting Data Confidentiality Many organizations and countries are required to meet strict regulations to protect data privacy. While SSL decryption is critical for security and performance analysis, capabilities must be in place to prevent misuse of decrypted data. SSL decryption can stop outbound malware connections or leakage of sensitive information. But privacy-related laws, regulations, and employee issues can derail an outbound web traffic decryption project. At the workplace, organizations have to manage employees expectations of privacy on the corporate network or help employees understand the importance of SSL decryption in protecting the business. At the same time, existing privacy and network usage policy has to be reviewed and updated, if necessary, to facilitate SSL decryption. Privacy Concerns The critical task is to ensure that sensitive user data contained in SSL traffic remains secure. For example, decrypted packets can be sliced to remove irrelevant or private payload data, or fields within the payload can be masked. By doing so, the monitoring and security tools do not store, read, or analyze private data. This simplifies the auditing process for organizations challenged to maintain user privacy and comply with rigorous regulatory compliance imposed by PCI-DSS, HIPAA, SOX, and the GLB Act. Security Compliance To maintain security compliance in cloud environments, proper handling of private encryption keys is just as vital as data protection and encryption. Whenever a user accesses a cloud service or application, the public and private keys are used and put at risk. These challenges have driven Gigamon to introduce the industry s first and only visibility solution with integrated SSL support. Gigamon s innovative GigaSMART traffic intelligence application features are built into hardware to decrypt SSL sessions at high performance. This serves the demand for deeper insight into the critical blind spots to help expose hidden security threats or network performance issues. The GigaSMART Difference Unlike what other visibility solutions offer, the GigaSMART application delivers SSL decryption as a common service to connected security and performance management tools so the tools can function at full performance. The offloading of SSL decryption also eliminates the need to have multiple decryption licenses for multiple tools. After all, a security appliance with integrated SSL decryption, for example, does not benefit other tools, such as application performance monitoring. Gigamon can supply decrypted traffic to multiple tools simultaneously, maximizing the overall efficiency, security, and performance of the infrastructure. An associated benefit of this approach is that the private keys can now be securely uploaded to just the visibility infrastructure instead of sharing it with multiple tools. It also delivers to IT and security administrators the right level of visibility into traffic, including SSL-encrypted segments that are at the heart of today s cloud infrastructures. GigaSMART decrypts the packets and sends the traffic to multiple out-of-band tools, including intrusion detection (IDS), data loss prevention, and application performance monitoring for analysis. High-performance Engine Hardware accelerators drive the GigaSMART modules highperformance compute engines when handling SSL traffic. Another key advantage is that SSL decryption is not limited to specific ingress ports or where the GigaSMART engine is located. The out-of-band Gigamon Visibility Fabric can deliver the decrypted traffic by GigaSMART from the production network to the tools required to monitor and manage IT infrastructure. Any traffic received on any network port of the Gigamon visibility nodes can be decrypted and sent to any tool port in the cluster. This is an important attribute because not every node in the cluster needs to have the SSL decryption capability. It also avoids the need to unnecessarily install SSL decryption appliances at various points in the infrastructure, saving cost and bringing efficiency. The cluster provides the necessary reach of the visibility infrastructure and SSL decryption can then be selectively applied to any traffic that enters the visibility infrastructure. 3

4 More GigaSMART modules can be added to the cluster to scale SSL decryption throughput up, allowing inspection to grow as SSL processing needs increase. The Steps to SSL Decryption Privacy Measures After traffic within the SSL session is decrypted, other GigaSMART applications are available to modify, manipulate, transform, and transport traffic from the network to connected management, monitoring, and security tools. A combination of these applications can be applied to different traffic profiles to maximize security. For example, SSL traffic can be decrypted and then masked so confidential information like passwords, financial accounts, or medical data can be hidden in compliance with SOX, HIPAA, PCI and other regulations. Security Compliance The key capabilities of Gigamon s holistic platform-based approach are designed to harness SSL decryption to solve visibility challenges. With access to bidirectional traffic, Gigamon s Visibility Fabric observes the exchange of public keys at the start of a transaction. Once the administrator loads the private keys, they are securely stored on the system. These private server keys are encrypted and protected by role-based access controls. Tap the network and connect it to Gigamon s Visibility Fabric. Select which flows to monitor and the GigaSMART engine will identify the exchange of public keys at the start of the transaction. The private keys, which have been uploaded by the administrator, are encrypted and stored under tight password and role-based access controls. GigaSMART then uses the private and public keys to decrypt the SSL traffic. The clear packets can be sent directly to your monitoring tools or additional Flow Mapping and GigaSMART operations can be applied. 1 That means Gigamon only allows keys to be uploaded, changed or deleted by users designated by the administrator. The keys are encrypted using a special password, which is distinct from the generic system admin password. 3 2 Visibility Fabric 4 Steps to SSL Decryption and Active Visibility Figure 1 shows the steps describing how SSL decryption is carried out via GigaSMART technology: In the final step, network managers can apply a combination of GigaSMART operations or use Gigamon s Flow Mapping technology to finely filter and forward traffic to specific monitoring tools. The latter is done through thousands of map rules or criteria based on over 30 predefined Layer 2, Layer 3 and Layer 4 parameters including IPv4/IPv6 addresses, application port numbers, VLAN IDs and MAC addresses, as well as custom rules that match specific bit sequences in the traffic streams. Additional filter criteria can be set up based on user defined attributes or even based on content inspection for specific patterns. Leveraging GigaSMART traffic intelligence is also a key step toward Gigamon s Active Visibility for Multi-tiered Security architecture. As part of the Gigamon Visibility Fabric, GigaSMART technology extends the intelligence and value of the architecture with expanded visibility; high-precision NetFlow-generated data on traffic flows and usage patterns across systems; improved tool performance; privacy protection; and easier regulatory compliance. The Steps to SSL Decryption 1. Tap the network and connect it to Gigamon s Figure Visibility 1: The Fabric. steps to SSL decryption 2. Select which flows to monitor and the GigaSMART engine will identify the exchange The architecture s Fabric Manager centrally administers these of public keys at the start of the transaction. capabilities across the Visibility Fabric. Traffic bound for out-of-band 3. The private keys, which have been uploaded monitoring by the administrator, tools can benefit are encrypted from GigaSMART and stored intelligence regardless under tight of where password it entered and role-based the Visibility access Fabric. controls. 4. GigaSMART then uses the private and public keys to decrypt the SSL traffic. 5. The clear packets can be sent directly to your monitoring tools or additional Flow Mapping and GigaSMART operations can be applied. 5 4

5 REST API Closed Loop Monitoring GigaVUE-FM Multi-tiered security appliances (inline or out-of-band) NGFW Core Core Inline Bypass SSL Decryption Generation NetFlow IPS WAF Spine Spine ANTI-MALWARE Leaf Leaf VM VM HYPERVISOR GigaVUE-VM Visibility Fabric IDS DLP NETWORK FORENSICS APT Figure 2: Multi-tiered security supported by Gigamon s Visibility Fabric architecture Key Benefits for the Cloud The growing adoption of cloud computing be it public, private, or hybrid as an alternative deployment strategy for IT systems disrupts traditional notions of data security. Data center managers have typically secured the entire core infrastructure and the perimeter. Cloud computing and mobility have blurred that perimeter. Meanwhile, a dynamic cloud-based environment calls for agile and efficient allocation of IT resources and investments. For instance, security plans have to clearly distinguish between sensitive and non-sensitive data and how to store and secure them. But while cloud computing has radically changed the way IT services are delivered and managed, the responsibility of securing sensitive data and ensuring compliance to security regulations has to remain with data owners. In essence, the Gigamon Visibility Fabric, built on the GigaSMART traffic intelligence engine and GigaVUE fabric nodes or servers, delivers the very benefits that give data owners the visibility and control to make sound security decisions while fulfilling regulatory compliance. Visibility into encrypted traffic facilitates malware detection, intrusion detection, data loss prevention, and network forensics while at the same time feeds traffic to application performance, monitoring, and customer experience management tools. Integrated SSL inspection in a multi-tiered security solution exposes malware within SSL sessions, forwards traffic that does not match known flows to GigaSMART for decryption, and decrypts traffic from the cloud and/or remote sites. Improved tool performance from offloading SSL decryption to the Visibility Fabric frees tool resources for packet analysis; decryption has to be applied only once for all tools. This method also increases secure management of private keys. A wide array of GigaSMART applications enable IT organizations to apply both Flow Mapping and SSL decryption; obscure private data with packet slicing or masking; use Adaptive Packet Filtering for L7-based packet forwarding; and more. Summary The changing threat landscape, amid growing volumes, velocity, and variety of data and evolving cloud-based infrastructure, are forcing organizations to rethink their approach to security. SSL has become a vital technology for cloud-based services. It has a strong track record for encrypting and authenticating data online but it might not be the silver bullet for cloud security. It severely limits visibility for both performance and security monitoring. The risk around the growing security threat posed by uninspected SSL sessions increases the urgency for inspecting SSL traffic. The ultimate objective is to build trusted cloud services and SSL connections. By supplying clear, decrypted SSL traffic to multiple tools, Gigamon provides immediate value and return on investment in capital expenditure, licensing fees, and management costs. 5

6 Coupled with the full capabilities of Flow Mapping and GigaSMART traffic intelligence, the Gigamon Visibility Fabric allows enterprises to be much more efficient in security management and to view and monitor the traffic that really matters. About the Visibility Fabric The Gigamon Visibility Fabric is a distributed system of nodes that provides pervasive visibility across physical, virtual, and future SDN production networks. The fabric delivers traffic from the production network to inline or out-of-band tools required to monitor and manage IT infrastructure such as security, application and network performance, and user experience monitoring tools. A Visibility Fabric is very different from a traditional network. The Visibility Fabric taps into the production network (be it SDN or traditional) or connects to the SPAN/mirror ports of the network es (white box or otherwise) to receive a copy of the traffic traversing the production network. That traffic is then forwarded to the tools based on the type of traffic that is relevant to the tools. There is a fundamental difference between how network es and Visibility Fabric nodes forward traffic. Traffic within the Visibility Fabric is forwarded based on the content that is relevant to the tools. both physical and virtual environments without affecting the performance or stability of the production network. Through patented technologies, centralized management and a portfolio of high availability and high density fabric nodes, network traffic is intelligently delivered to management, monitoring and security systems. Gigamon solutions have been deployed globally across enterprise, data centers and service providers, including over half of the Fortune 100 and many government and federal agencies. For more information about the Gigamon Unified Visibility Fabric visit: Traditional network es are highly optimized for addressbased forwarding where traffic is forwarded based on address information in the headers of the packets. Within the Visibility Fabric, traffic is forwarded based on the content of the packets, as well as based on correlated traffic flows that straddle multiple packets. And furthermore, those traffic streams may need to be replicated within the Visibility Fabric so as to deliver them to multiple sets of tools. That packet replication is also based on the content of the packet, as well as based on correlated traffic streams, so as to ensure that just the relevant traffic is delivered to the tools. This makes the Visibility Fabric a highly specialized function that is very unique and different from traditional network es. As we look to the future, this specialized capability of the Visibility Fabric will make it an integral but distinct component in ensuring the successful deployment of SDN solutions. About Gigamon Gigamon provides an intelligent Unified Visibility Fabric to enable the management of increasingly complex networks. Gigamon technology empowers infrastructure architects, managers and operators with pervasive visibility and control of traffic across Gigamon and the Gigamon logo are trademarks of Gigamon in the United States and/or other countries. Gigamon trademarks can be found at All other trademarks are the trademarks of their respective owners. Gigamon reserves the right to change, modify, transfer, or otherwise revise this publication without notice / Olcott Street, Santa Clara, CA USA +1 (408)