More Tricks for Defeating SSL in Practice
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Universidad Pol Facultad D Trabajo
UNIVERSIDAD POLITÉCNICA DE MADRID FACULTAD DE INFORMÁTICA TRABAJO FINAL DE CARRERA ESTUDIO DEL PROTOCOLO XMPP DE MESAJERÍA ISTATÁEA, DE SUS ATECEDETES, Y DE SUS APLICACIOES CIVILES Y MILITARES Autor: José Carlos Díaz García Tutor: Rafael Martínez Olalla Madrid, Septiembre de 2008 2 A mis padres, Francisco y Pilar, que me empujaron siempre a terminar esta licenciatura y que tanto me han enseñado sobre la vida A mis abuelos (q.e.p.d.) A mi hijo icolás, que me ha dejado terminar este trabajo a pesar de robarle su tiempo de juego conmigo Y muy en especial, a Susana, mi fiel y leal compañera, y la luz que ilumina mi camino Agradecimientos En primer lugar, me gustaría agradecer a toda mi familia la comprensión y confianza que me han dado, una vez más, para poder concluir definitivamente esta etapa de mi vida. Sin su apoyo, no lo hubiera hecho. En segundo lugar, quiero agradecer a mis amigos Rafa y Carmen, su interés e insistencia para que llegara este momento. Por sus consejos y por su amistad, les debo mi gratitud. Por otra parte, quiero agradecer a mis compañeros asesores militares de Nextel Engineering sus explicaciones y sabios consejos, que sin duda han sido muy oportunos para escribir el capítulo cuarto de este trabajo. Del mismo modo, agradecer a Pepe Hevia, arquitecto de software de Alhambra Eidos, los buenos ratos compartidos alrrededor de nuestros viejos proyectos sobre XMPP y que encendieron prodigiosamente la mecha de este proyecto. A Jaime y a Bernardo, del Ministerio de Defensa, por haberme hecho descubrir las bondades de XMPP. -
Openfire Service Level Agreement
Service Level Agreement Technical Services — Communications Service University Technology Services 1. Overview This Service Level Agreement (SLA) is between University Technology Services (UTS) and either departments or groups choosing to utilize the internal Oakland University instant messaging (OUIM) service. The OUIM service is currently referenced by talk.oakland.edu and runs XMPP/Jabber software called Openfire. Under this SLA, UTS agrees to provide specific information technology (IT) services. This SLA also covers performance and reliability targets and objectives. Section 7 requires the signature and contact information of the group coordinator as an agreement to the SLA. OUIM is an online service that is available on campus and off campus. The requirements to utilize the service are a NetID, an XMPP client, and an Internet connection. XMPP clients are available online. The UTS Helpdesk supports the XMPP clients Spark, Pidgin, and Adium. Instructions are available on the UTS Web site at http://www.oakland.edu/?id=13849&sid=70. 2. Purpose The purpose of this SLA is to establish a cooperative partnership between UTS staff members with the community of customers who may opt into its use by clarifying roles, setting expectations, and providing service objectives and limitations. 3. Terms of Agreement This service is provided on an ongoing basis. From time to time, it may be reviewed and modified by UTS. Modifications to this agreement will be done at the sole discretion of UTS and the Technical Support and Services team (TSS). 4. Service Hours Regularly scheduled maintenance will be scheduled during low-use hours as much as possible; such work will be done either before 8:00 A.M. -
The Double Ratchet Algorithm
The Double Ratchet Algorithm Trevor Perrin (editor) Moxie Marlinspike Revision 1, 2016-11-20 Contents 1. Introduction 3 2. Overview 3 2.1. KDF chains . 3 2.2. Symmetric-key ratchet . 5 2.3. Diffie-Hellman ratchet . 6 2.4. Double Ratchet . 13 2.6. Out-of-order messages . 17 3. Double Ratchet 18 3.1. External functions . 18 3.2. State variables . 19 3.3. Initialization . 19 3.4. Encrypting messages . 20 3.5. Decrypting messages . 20 4. Double Ratchet with header encryption 22 4.1. Overview . 22 4.2. External functions . 26 4.3. State variables . 26 4.4. Initialization . 26 4.5. Encrypting messages . 27 4.6. Decrypting messages . 28 5. Implementation considerations 29 5.1. Integration with X3DH . 29 5.2. Recommended cryptographic algorithms . 30 6. Security considerations 31 6.1. Secure deletion . 31 6.2. Recovery from compromise . 31 6.3. Cryptanalysis and ratchet public keys . 31 1 6.4. Deletion of skipped message keys . 32 6.5. Deferring new ratchet key generation . 32 6.6. Truncating authentication tags . 32 6.7. Implementation fingerprinting . 32 7. IPR 33 8. Acknowledgements 33 9. References 33 2 1. Introduction The Double Ratchet algorithm is used by two parties to exchange encrypted messages based on a shared secret key. Typically the parties will use some key agreement protocol (such as X3DH [1]) to agree on the shared secret key. Following this, the parties will use the Double Ratchet to send and receive encrypted messages. The parties derive new keys for every Double Ratchet message so that earlier keys cannot be calculated from later ones. -
Security Analysis of the Signal Protocol Student: Bc
ASSIGNMENT OF MASTER’S THESIS Title: Security Analysis of the Signal Protocol Student: Bc. Jan Rubín Supervisor: Ing. Josef Kokeš Study Programme: Informatics Study Branch: Computer Security Department: Department of Computer Systems Validity: Until the end of summer semester 2018/19 Instructions 1) Research the current instant messaging protocols, describe their properties, with a particular focus on security. 2) Describe the Signal protocol in detail, its usage, structure, and functionality. 3) Select parts of the protocol with a potential for security vulnerabilities. 4) Analyze these parts, particularly the adherence of their code to their documentation. 5) Discuss your findings. Formulate recommendations for the users. References Will be provided by the supervisor. prof. Ing. Róbert Lórencz, CSc. doc. RNDr. Ing. Marcel Jiřina, Ph.D. Head of Department Dean Prague January 27, 2018 Czech Technical University in Prague Faculty of Information Technology Department of Computer Systems Master’s thesis Security Analysis of the Signal Protocol Bc. Jan Rub´ın Supervisor: Ing. Josef Kokeˇs 1st May 2018 Acknowledgements First and foremost, I would like to express my sincere gratitude to my thesis supervisor, Ing. Josef Kokeˇs,for his guidance, engagement, extensive know- ledge, and willingness to meet at our countless consultations. I would also like to thank my brother, Tom´aˇsRub´ın,for proofreading my thesis. I cannot express enough gratitude towards my parents, Lenka and Jaroslav Rub´ınovi, who supported me both morally and financially through my whole studies. Last but not least, this thesis would not be possible without Anna who re- lentlessly supported me when I needed it most. Declaration I hereby declare that the presented thesis is my own work and that I have cited all sources of information in accordance with the Guideline for adhering to ethical principles when elaborating an academic final thesis. -
SSL/TLS Interception Proxies and Transitive Trust Jeff Jarmoc Dell Secureworks Counter Threat Unit℠ Threat Intelligence
SSL/TLS Interception Proxies and Transitive Trust Jeff Jarmoc Dell SecureWorks Counter Threat Unit℠ Threat Intelligence Presented at Black Hat Europe – March 14, 2012. Introduction Secure Sockets Layer (SSL) [1] and its successor Transport Layer Security (TLS) [2] have become key components of the modern Internet. The privacy, integrity, and authenticity [3] [4] provided by these protocols are critical to allowing sensitive communications to occur. Without these systems, e- commerce, online banking, and business-to-business exchange of information would likely be far less frequent. Threat actors have also recognized the benefits of transport security, and they are increasingly turning to SSL to hide their activities. Advanced Persistent Threat (APT) attackers [5], botnets [6], and even commodity web attacks can leverage SSL encryption to evade detection. To counter these tactics, organizations are increasingly deploying security controls that intercept end- to-end encrypted channels. Web proxies, data loss prevention (DLP) systems, specialized threat detection solutions, and network intrusion prevention systems (NIPS) offer functionality to intercept, inspect, and filter encrypted traffic. Similar functionality is present in lawful intercept systems and solutions enabling the broad surveillance of encrypted communications by governments. Broadly classified as “SSL/TLS interception proxies,” these solutions act as a “man in the middle,” violating the end-to-end security promises of SSL. This type of interception comes at a cost. Intercepting SSL-encrypted connections sacrifices a degree of privacy and integrity for the benefit of content inspection, often at the risk of authenticity and endpoint validation. Implementers and designers of SSL interception proxies should consider these risks and understand how their systems operate in unusual circumstances. -
Novell Messenger 3.0 May 2015
Novell Messenger 3.0 May 2015 1Overview The information in this Readme file pertains to Novell Messenger 3.0. Novell Messenger 3.0 offers enhanced functionality over prior Messenger versions: Mobile Applications: Novell Messenger 3.0 provides native applications for iOS, Android, and BlackBerry devices. For more information, see “Using Novell Messenger on Your Mobile Device” in the Novell Messenger 3.0 Client User Guide. For information about the administrative tasks associated with Messenger mobile applications, see “Managing Messenger Mobile Applications” in the Novell Messenger 3.0 Administration Guide. Simultaneous Client Connections: Novell Messenger 3.0 allows you to maintain simultaneous connections to your Messenger system from multiple workstations or devices. For example, you can be connected to Messenger on your workstation, and then connect to Messenger from a mobile device without being logged out of Messenger on your workstation. For more information about this feature, see “Limiting Physical Access to Client Workstations” in “Securing Novell Messenger” in the Novell Messenger 3.0 Administration Guide. Update Clients (Look and Feel): Novell Messenger 3.0 provides an updated look and feel for both the Windows and Linux/Mac client interfaces. The Messenger 3.0 release also contains the following changes: Removal of NetWare support: With Messenger 3.0 and later, NetWare is no longer supported. ConsoleOne download option: If you have not already installed ConsoleOne, it is available with the Messenger distribution. 2 System Requirements Novell Messenger 3.0 system requirements (including requirements for mobile devices) are listed in “Novell Messenger Hardware and Software Requirements” in the Novell Messenger 3.0 Installation Guide. -
Is Bob Sending Mixed Signals?
Is Bob Sending Mixed Signals? Michael Schliep Ian Kariniemi Nicholas Hopper University of Minnesota University of Minnesota University of Minnesota [email protected] [email protected] [email protected] ABSTRACT Demand for end-to-end secure messaging has been growing rapidly and companies have responded by releasing applications that imple- ment end-to-end secure messaging protocols. Signal and protocols based on Signal dominate the secure messaging applications. In this work we analyze conversational security properties provided by the Signal Android application against a variety of real world ad- versaries. We identify vulnerabilities that allow the Signal server to learn the contents of attachments, undetectably re-order and drop messages, and add and drop participants from group conversations. We then perform proof-of-concept attacks against the application to demonstrate the practicality of these vulnerabilities, and suggest mitigations that can detect our attacks. The main conclusion of our work is that we need to consider more than confidentiality and integrity of messages when designing future protocols. We also stress that protocols must protect against compromised servers and at a minimum implement a trust but verify model. 1 INTRODUCTION (a) Alice’s view of the conversa-(b) Bob’s view of the conversa- Recently many software developers and companies have been inte- tion. tion. grating end-to-end encrypted messaging protocols into their chat applications. Some applications implement a proprietary protocol, Figure 1: Speaker inconsistency in a conversation. such as Apple iMessage [1]; others, such as Cryptocat [7], imple- ment XMPP OMEMO [17]; but most implement the Signal protocol or a protocol based on Signal, including Open Whisper Systems’ caching. -
A User Study of Off-The-Record Messaging
A User Study of Off-the-Record Messaging Ryan Stedman Kayo Yoshida Ian Goldberg University of Waterloo 200 University Avenue West Waterloo, Ontario, Canada N2L 3G1 {rstedman@cs, k2yoshid@math, iang@cs}.uwaterloo.ca ABSTRACT Keywords Instant messaging is a prevalent form of communication ac- OTR, Usable Security, Instant Messaging, Think Aloud ross the Internet, yet most instant messaging services pro- vide little security against eavesdroppers or impersonators. 1. INTRODUCTION There are a variety of existing systems that aim to solve There has been much research into creating privacy-en- this problem, but the one that provides the highest level hancing technologies, especially since the Internet has started of privacy is Off-the-Record Messaging (OTR), which aims to play an essential role in everyday life. However, not many to give instant messaging conversations the level of privacy of these technologies have seen widespread adoption. One available in a face-to-face conversation. In the most recent of the reasons for this is that many of these technologies redesign of OTR, as well as increasing the security of the provide insufficient usability [8]. protocol, one of the goals of the designers was to make OTR The process of evaluating and enhancing usability is im- easier to use, without users needing to understand details of portant in order for a privacy-enhancing technology to pro- computer security such as keys or fingerprints. vide benefits to ordinary users. Since privacy is not just To determine if this design goal has been met, we con- intended for computer scientists or cryptographers, but for ducted a user study of the OTR plugin for the Pidgin in- everyone, these technologies should be accessible to the gen- stant messaging client using the think aloud method. -
A Survey of Open Source Products for Building a SIP Communication Platform
Hindawi Publishing Corporation Advances in Multimedia Volume 2011, Article ID 372591, 21 pages doi:10.1155/2011/372591 Research Article A Survey of Open Source Products for Building a SIP Communication Platform Pavel Segec and Tatiana Kovacikova Department of InfoCom Networks, University of Zilina, Univerzitna 8215/1, 010 26 Zilina, Slovakia Correspondence should be addressed to Tatiana Kovacikova, [email protected] Received 29 July 2011; Revised 31 October 2011; Accepted 15 November 2011 Academic Editor: T. Turletti Copyright © 2011 P. Segec and T. Kovacikova. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Session Initiation Protocol (SIP) is a multimedia signalling protocol that has evolved into a widely adopted communication standard. The integration of SIP into existing IP networks has fostered IP networks becoming a convergence platform for both real- time and non-real-time multimedia communications. This converged platform integrates data, voice, video, presence, messaging, and conference services into a single network that offers new communication experiences for users. The open source community has contributed to SIP adoption through the development of open source software for both SIP clients and servers. In this paper, we provide a survey on open SIP systems that can be built using publically available software. We identify SIP features for service deve- lopment and programming, services and applications of a SIP-converged platform, and the most important technologies support- ing SIP functionalities. We propose an advanced converged IP communication platform that uses SIP for service delivery. -
Implementing Reliable Instant Messaging at Your Library
Implementing Reliable Instant Messaging at Your Library Karen McCoy Adult Services Librarian Farmington Public Library, NM Some background… More libraries are communicating with patrons in real time over the internet “Online real-time chat reference services have become increasingly prevalent in many types and sizes of libraries” (1). BUT… “Because no IM technology standard has been approved by all the major players, IM has long been problematic to libraries… but newer IM products can help resolve these dilemmas.”(2). 1. Kwon, Nahyun, & Gregory, Vicki L. (2007). The effects of librarians' behavioral performance on user satisfaction in chat reference services. Reference & User Services Quarterly. 47, 137-148, 137. 2. Rethlefsen, Melissa L. (Summer 2007). Product Pipeline. Netconnect, 14-16 Instant Messaging vs. Chat Software What’s the difference? Chat Software: fee-based, usually only used in businesses and libraries (usually part of a consortium to reduce cost) also referred to as “virtual reference” or “chat reference.” Instant Messaging: FREE to libraries and patrons, more often used by people in their daily lives, generally not platform dependent (1), more compatible in a Web 2.0 environment A recent trend in reference service seems to be a move from use of chat reference software to use of IM (2). 1. Johnson, Kris. “Pros & Cons of IM/SMS Virtual Reference.” NMLA/MPLA Presentation. March, 2007 2. Naylor, Sharon, Stoffel, Bruce, & Van Der Laan, Sharon (2008). Why isn't our chat reference used more? Reference & User Services Quarterly. -
The Most Dangerous Code in the World: Validating SSL Certificates In
The Most Dangerous Code in the World: Validating SSL Certificates in Non-Browser Software Martin Georgiev Subodh Iyengar Suman Jana The University of Texas Stanford University The University of Texas at Austin at Austin Rishita Anubhai Dan Boneh Vitaly Shmatikov Stanford University Stanford University The University of Texas at Austin ABSTRACT cations. The main purpose of SSL is to provide end-to-end security SSL (Secure Sockets Layer) is the de facto standard for secure In- against an active, man-in-the-middle attacker. Even if the network ternet communications. Security of SSL connections against an is completely compromised—DNS is poisoned, access points and active network attacker depends on correctly validating public-key routers are controlled by the adversary, etc.—SSL is intended to certificates presented when the connection is established. guarantee confidentiality, authenticity, and integrity for communi- We demonstrate that SSL certificate validation is completely bro- cations between the client and the server. Authenticating the server is a critical part of SSL connection es- ken in many security-critical applications and libraries. Vulnerable 1 software includes Amazon’s EC2 Java library and all cloud clients tablishment. This authentication takes place during the SSL hand- based on it; Amazon’s and PayPal’s merchant SDKs responsible shake, when the server presents its public-key certificate. In order for transmitting payment details from e-commerce sites to payment for the SSL connection to be secure, the client must carefully verify gateways; integrated shopping carts such as osCommerce, ZenCart, that the certificate has been issued by a valid certificate authority, Ubercart, and PrestaShop; AdMob code used by mobile websites; has not expired (or been revoked), the name(s) listed in the certifi- Chase mobile banking and several other Android apps and libraries; cate match(es) the name of the domain that the client is connecting Java Web-services middleware—including Apache Axis, Axis 2, to, and perform several other checks [14, 15]. -
Release Notes 2021 Firmware Version Pcs21ba
Spectralink DECT Server 2500 and 8000 Release Notes 2021 Firmware Version PCS21Ba Release Notes Spectralink Europe ApS, 2021 – R2 Bygholm Søpark 21E Stuen, Horsens, DK-8700, Denmark DECT Server 2500 and 8000 Release Notes Table of Contents Introduction ...................................................... 3 Changes ............................................................................. 5 Version PCS21Ba, 2021 – R2 ................................................................................................ 5 Version PCS21Ae, 2021 – R1 ................................................................................................ 5 Version PCS20Cd, 2020 – R3 ................................................................................................ 7 Version PCS20Ab, 2020 – R1 ................................................................................................ 8 Version PCS19Cb, 2019 – R3 .............................................................................................. 10 Version PCS19Bb, 2019 – R2 .............................................................................................. 12 Version PCS19Ab, 2019 – Q1 .............................................................................................. 13 Version PCS18Kb, 2018 – Q4 .............................................................................................. 14 Version PCS18Ka, 2018 (never released) ........................................................................... 15 Version PCS18Ea, 2018 – Q3 .............................................................................................