DOCSLIB.ORG

TACACS+ Authentication

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
TACACS+ Authentication TACACS+ Authentication PacketShaper 11.10 TACACS+ Authentication PacketShaper 11.10 Legal Notice Copyright © 2019 Symantec Corp. All rights reserved. Symantec, the Symantec Logo, the Checkmark Logo, Blue Coat, and the Blue Coat logo are trademarks or registered trademarks of Symantec Corp. or its affiliates in the U.S. and other countries. Other names may be trademarks of their respective owners. This document is provided for informational purposes only and is not intended as advertising. All warranties relating to the information in this document, either express or implied, are disclaimed to the maximum extent allowed by law. The information in this document is subject to change without notice. THE DOCUMENTATION IS PROVIDED "AS IS" AND ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE DISCLAIMED, EXCEPT TO THE EXTENT THAT SUCH DISCLAIMERS ARE HELD TO BE LEGALLY INVALID. SYMANTEC CORPORATION SHALL NOT BE LIABLE FOR INCIDENTAL OR CONSEQUENTIAL DAMAGES IN CONNECTION WITH THE FURNISHING, PERFORMANCE, OR USE OF THIS DOCUMENTATION. THE INFORMATION CONTAINED IN THIS DOCUMENTATION IS SUBJECT TO CHANGE WITHOUT NOTICE. SYMANTEC CORPORATION PRODUCTS, TECHNICAL SERVICES, AND ANY OTHER TECHNICAL DATA REFERENCED IN THIS DOCUMENT ARE SUBJECT TO U.S. EXPORT CONTROL AND SANCTIONS LAWS, REGULATIONS AND REQUIREMENTS, AND MAY BE SUBJECT TO EXPORT OR IMPORT REGULATIONS IN OTHER COUNTRIES. YOU AGREE TO COMPLY STRICTLY WITH THESE LAWS, REGULATIONS AND REQUIREMENTS, AND ACKNOWLEDGE THAT YOU HAVE THE RESPONSIBILITY TO OBTAIN ANY LICENSES, PERMITS OR OTHER APPROVALS THAT MAY BE REQUIRED IN ORDER TO EXPORT, RE-EXPORT, TRANSFER IN COUNTRY OR IMPORT AFTER DELIVERY TO YOU. Symantec Corporation 350 Ellis Street Mountain View, CA 94043 www.symantec.com Friday, June 14, 2019 2 TACACS+ Authentication PacketShaper 11.10 Contents Configure TACACS+ 4 Configure Linux TACACS+ Servers using the Cisco TACACS+ Daemon 4 Configure TACACS+ Authentication Service 5 Configure TACACS+ Accounting Service 7 Log In and Out with TACACS+ 9 Logging In with TACACS+ 9 Logging Out 9 3 TACACS+ Authentication PacketShaper 11.10 Configure TACACS+ Terminal Access Controller Access-Control System Plus (TACACS+) is a protocol that provides access control via one or more centralized servers. TACACS+ provides separate authentication, authorization and accounting services. Steps: 1. First, configure the TACACS+ server with PacketShaper-specific attributes. 2. Configure the TACACS+ authentication service in PacketShaper. 3. Configure the TACACS+ accounting service in PacketShaper to have an audit trail of user logins. 4. Log into PacketShaper using TACACS+. Configure Linux TACACS+ Servers using the Cisco TACACS+ Daemon The PacketShaper TACACS+ client has been tested with the Cisco TACACS+ Daemon. This section includes instructions on configuring a Linux TACACS+ server with PacketShaper-specific information. These steps should be performed before you configure the TACACS+ authentication and TACACS+ accounting services via the PacketShaper browser or command-line interfaces. For more information on the general setup and configuration of your TACACS+ server, refer to the documentation included with the product. Note: This procedure only is recommended for users with previous Linux experience. Configure the TACACS+ Server 1. Install TACACS+ server from your Linux distribution. In Ubuntu: apt-get install tacacs+ 2. To configure the TACACS+ server, update the TACACS+ user configuration file tac_plus.conf with information for each TACACS+ user. The example configuration text below shows how to define TACACS+ users with look or touch access and a clear text password, and a touch access user with an encrypted password. Note: For additional details, refer to the users_guide file included with the Cisco TACACS+ files. # set the secret key 4 TACACS+ Authentication PacketShaper 11.10 key = "<key>" # where the accounting records should go accounting file = /var/log/tac_plus.acct # users accounts user = <username> { login = cleartext "<password>" before authorization "echo \"access=touch\"; exit 2" name = "<username> touch login" } user = <username> { login = cleartext "<password>" before authorization "echo \"access=look\"; exit 2" name = "<username> look login" } user = <username> { login = des "<encrypt_pwd>" before authorization "echo \"access=touch\"; exit 2" name = "<username> touch login" } Variable Description <key> the TACACS+ secret key <username> User name of the TACACS+ user <password> Clear text password for a TACACS+ user <encrypt_ Encrypted password for a TACACS+ pwd> user Start the TACACS+ Server Once your user and password settings have been configured, issue the command to start the TACACS+ server. For example: /etc/init.d/tacacs_plus start Configure TACACS+ Authentication Service TACACS+ authentication is an optional method for users to log into the PacketShaper browser interface and command-line interface. Using third-party TACACS+ servers enables you to have central configuration of user accounts. In addition to configuring the server as described below, you need to do some configuration at the TACACS+ server so that it will work with PacketShaper. (See " Configure Linux TACACS+ Servers using the Cisco TACACS+ Daemon " on the previous pagefor an example.) Note that the server you configure for TACACS+ authentication will also be used for authorization. 5 TACACS+ Authentication PacketShaper 11.10 To configure PacketShaper to work with a TACACS+ authentication server: 1. Click the Setup tab. 2. From the Choose Setup Page list, choose TACACS+ Client. The TACACS+ Client Settings screen appears. 3. In the Authentication field, select on. 4. Select an Authentication method: n ASCII (American Standard Code for Information Interchange): With ASCII, the user name and password are transmitted in clear, unencrypted text. This is the default authentication method. n PAP (Password Authentication Protocol): With PAP, the user name and password are transmitted in clear, unencrypted text. If you select the PAP authentication method, Symantec recommends you increase security by logging into the PacketShaper browser interface via HTTPS. ASCII or PAP authentication is required for TACACS+ configurations that require access to clear text passwords (for example, when passwords are stored and maintained in a database external to the TACACS+ server). n CHAP (Challenge Handshake Authentication Protocol): In other environments, CHAP may be preferred for greater security. The TACACS+ server sends a challenge that consists of a session ID and an arbitrary challenge string, and the user name and password are encrypted before they are sent back to the server. n MS-CHAP (Microsoft Challenge Handshake Authentication Protocol): This protocol is similar to CHAP, but with MS-CHAP authentication, the TACACS+ server can store an encrypted version of a user password to validate the challenge response. Standard CHAP authentication requires that the server stores unencrypted passwords. If you select the MS-CHAP authentication method, Symantec recommends you increase security by logging into the PacketShaper browser interface via HTTPS. Note: MS-CHAP v1 and v2 are supported. PacketShaper attempts authentication with MS-CHAP v2 first. If the remote server doesn't support v2 or if authentication is denied, PacketShaper re-attempts 6 TACACS+ Authentication PacketShaper 11.10 authentication with MS-CHAP v1. When you change the TACACS+ authentication method for a PolicyCenter sharable configuration via the PolicyCenter browser interface, TACACS+ authentication returns to the default "off" setting for that configuration. If you change the authentication method via PolicyCenter browser interface, be sure to also reenable the TACACS+ authentication feature before you apply the changes. Limitation: PacketShaper SSH and serial console connections do not support the PAP, MS-CHAP, and CHAP authentication methods with TACACS+. Regardless of which method the PacketShaper is configured to use for TACACS+ authentication, ASCII will be used when logging in to the CLI with SSH or serial console. Note that this limitation does not apply when logging in to the web UI: the configured method will be used during authentication. 5. In the Primary Authentication Host field, enter the IP address or DNS name of the TACACS+ server. 6. Optional: To access the TACACS+ server with a specific port, enter a number in the Port field. If the field is left blank, the default port (49) will be used. 7. In the Shared Secret field, enter the designated secret. 8. Optional: Specify a Secondary Authentication Host to use in case the primary TACACS+ server is not accessible or failed to authenticate. Be sure to specify its Shared Secret as well. 9. If necessary, adjust the Timeout interval. By default, PacketShaper waits 10 seconds for a response from the TACACS+ server before the login fails. You can select a value between 1 and 60 seconds. 10. Click apply changes. After you have configured a TACACS+ authentication server, users will be prompted for a user name and password when logging into PacketShaper. For more information, see Log In and Out with TACACS+. Note: Starting in PS 11.10.3, if the TACACS+ primary server has an authentication failure, PacketShaper attempts to log onto a configured secondary server; in earlier versions, PacketShaper attempted to log onto the secondary server only when the primary server had a connection
Load more

Recommended publications
  • Extensible Authentication Protocol (EAP) and IEEE 802.1X: Tutorial and Empirical Experience
    CHEN LAYOUT 11/17/05 11:57 AM Page 52 Extensible Authentication Protocol (EAP) and IEEE 802.1x: Tutorial and Empirical Experience JYH-CHENG CHEN AND YU-PING WANG, NATIONAL TSING HUA UNIVERSITY Abstract oped WIRE1x to support various versions of MS Windows. As This article presents the technical details of the Extensible the name suggests, WIRE1x is an open-source implementa- Authentication Protocol (EAP) and IEEE 802.1x by using tion of IEEE 802.1x client (supplicant)1 developed by the WIRE1x, an open-source implementation of IEEE 802.1x Wireless Internet Research & Engineering (WIRE) Laborato- client (supplicant) and various EAP-based authentication ry.2 Both source code and executable code of WIRE1x can be mechanisms. By using a real implementation, 802.1x and EAP downloaded freely from http://wire.cs.nthu.edu.tw/wire1x/. should be easily understood. Essentially, 802.1x provides a framework for port-based access control. It can work with various authentication mecha- nisms to authenticate and authorize users. The Extensible Introduction Authentication Protocol (EAP, IETF RFC 2284) is a protocol Wireless local area networks (WLANs) have become increas- commonly used in 802.1x to authenticate users. Currently, ingly more prevalent in recent years. The IEEE 802.11 stan- WIRE1x provides various authentication mechanisms, includ- dard is one of the most widely adopted standards for ing EAP Message Digest 5 (EAP-MD5, IETF RFC 1321), broadband wireless Internet access. However, security consid- EAP Transport Layer Security (EAP-TLS, IETF RFC 2716), erations with regard to wireless environments are more com- EAP Tunneled TLS (EAP-TTLS) [5], and Protected Extensi- plicated than those in wired environments.
    [Show full text]
  • Kerberos: an Authentication Service for Computer Networks by Clifford Neuman and Theodore Ts’O
    Kerberos: An Authentication Service for Computer Networks by Clifford Neuman and Theodore Ts’o Presented by: Smitha Sundareswaran Chi Tsong Su Introduction z Kerberos: An authentication protocol based on cryptography z Designed at MIT under project Athena z Variation of Needham Schroeder protocol - Difference: Kerberos assumes all systems on the network to be synchronized z Similar function as its mythological namesake: “guards” the access to network protocols Contribution z Defines ideas of authentication, Integrity, confidentiality and Authorization z Working of Kerberos z Limitations z Utilities z How to obtain and use Kerberos z Other methods to improve security Why Kerberos? z Foils threats due to eavesdropping z More convenient than password based authentication { Allows user to avoid “authentication by assertion” z Authentication based on cryptography: attacker can’t impersonate a valid user How Kerberos Works z Distributed authentication service using a series of encrypted messages {Password doesn’t pass through the network z Timestamps to reduce the number of messages needed for authentication z “Ticket granting Service” for subsequent authentication Kerberos Authentication and Encryption zAuthentication proves that a client is running on behalf of a particular user zUses encryption key for authentication {Encryption key = Password zEncryption implemented using DES {Checksum included in message checksum and encryption provide integrity & confidentiality The Kerberos Ticket z Initially, client and Server don’t share an encryption
    [Show full text]
  • PUF Based Authentication Protocol for Iot
    S S symmetry Article PUF Based Authentication Protocol for IoT An Braeken Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussel, Belgium; [email protected]; Tel.: +32-468-104-767 Received: 11 July 2018; Accepted: 11 August 2018; Published: 20 August 2018 Abstract: Key agreement between two constrained Internet of Things (IoT) devices that have not met each other is an essential feature to provide in order to establish trust among its users. Physical Unclonable Functions (PUFs) on a device represent a low cost primitive exploiting the unique random patterns in the device and have been already applied in a multitude of applications for secure key generation and key agreement in order to avoid an attacker to take over the identity of a tampered device, whose key material has been extracted. This paper shows that the key agreement scheme of a recently proposed PUF based protocol, presented by Chatterjee et al., for Internet of Things (IoT) is vulnerable for man-in-the-middle, impersonation, and replay attacks in the Yao–Dolev security model. We propose an alternative scheme, which is able to solve these issues and can provide in addition a more efficient key agreement and subsequently a communication phase between two IoT devices connected to the same authentication server. The scheme also offers identity based authentication and repudiation, when only using elliptic curve multiplications and additions, instead of the compute intensive pairing operations. Keywords: physical unclonable function; authentication; elliptic curve cryptography; internet of things 1. Introduction Internet of Things (IoT) is experiencing worldwide growth. Not only classical computing and communication devices are connected, but also a whole range of other gadgets that are used in our daily life, such as thermostats, light switches, door locks, refrigerators, etc.
    [Show full text]
  • Recommendation for EAP Methods
    Archived NIST Technical Series Publication The attached publication has been archived (withdrawn), and is provided solely for historical purposes. It may have been superseded by another publication (indicated below). Archived Publication Series/Number: NIST Special Publication 800-120 Title: Recommendation for EAP Methods Used in Wireless Network Access Authentication Publication Date(s): September 2009 Withdrawal Date: October 19, 2018 Withdrawal Note: This publication is out of date. Refer to relevant standards from the Internet Engineering Task Force (IETF), http://www.ietf.org/ . Superseding Publication(s) The attached publication has been superseded by the following publication(s): Series/Number: Title: Author(s): Publication Date(s): URL/DOI: Additional Information (if applicable) Contact: Computer Security Division (Information Technology Laboratory) Latest revision of the attached publication: Related information: https://csrc.nist.gov https://csrc.nist.gov/publications/detail/sp/800-120/archive/2009-09-17 Withdrawal N/A announcement (link): Date updated: October 19, 2018 NIST Special Publication 800-120 Recommendation for EAP Methods Used in Wireless Network Access Authentication Katrin Hoeper and Lily Chen Computer Security Division Information Technology Laboratory C O M P U T E R S E C U R I T Y September 2009 U.S. Department of Commerce Gary Locke, Secretary National Institute of Standards and Technology Patrick Gallagher, Deputy Director Abstract This Recommendation specifies security requirements for authentication methods with key establishment supported by the Extensible Authentication Protocol (EAP) defined in IETF RFC 3748 for wireless access authentications to federal networks. KEY WORDS: EAP methods, authentication, key establishment. SP 800-120: Recommendation for EAP Methods Used in Wireless Network Access Authentication Acknowledgments The authors, Katrin Hoeper and Lily Chen, wish to thank their colleagues who reviewed drafts of this document and contributed to its technical content.
    [Show full text]
  • Diameter-Based Protocol in the IP Multimedia Subsystem
    International Journal of Soft Computing and Engineering (IJSCE) ISSN: 2231 – 2307, Volume- 1 Issue- 6, January 2012 Diameter-Based Protocol in the IP Multimedia Subsystem Vinay Kumar.S.B, Manjula N Harihar Abstract— The Diameter protocol was initially developed by II. ROLE OF DIAMETER IN IMS the Internet Engineering Task Force (IETF) as an Authentication, Authorization, and Accounting (AAA) framework The IMS is based on a horizontally layered architecture, intended for applications such as remote network access and IP consisting of three layers, namely, Service Layer, Control mobility. Diameter was further embraced by the Third Generation Layer, and Connectivity Layer. Service Layer comprises Partnership Project (3GPP) as the key protocol for AAA and application and content servers to execute value-added mobility management in 3G networks. The paper discusses the use services for the user. Control layer comprises network control of Diameter in the scope of the IP Multimedia Subsystem (IMS) as servers for managing call or session set-up, modification and specified by 3GPP. This paper presents a solution for the problem release. The most important of these is the Call Session of how to provide authentication, authorization and accounting Control Function (CSCF). Connectivity Layer comprises of (AAA) for multi-domain interacting services by referring open routers and switches, for both the backbone and the access diameter. We have studied the case of ‘FoneFreez’, a service that provides interaction between different basic services, like network telephony and television. The involvement of several parties like A. IMS functions television provider, telephony provider etc., secure interaction between multiple domains must be assured.
    [Show full text]
  • Formal Analysis of Combinations of Secure Protocols Elliott Blot, Jannik Dreier, Pascal Lafourcade
    Formal Analysis of Combinations of Secure Protocols Elliott Blot, Jannik Dreier, Pascal Lafourcade To cite this version: Elliott Blot, Jannik Dreier, Pascal Lafourcade. Formal Analysis of Combinations of Secure Protocols. FPS 2017 - 10th International Symposium on Foundations & Practice of Security, Oct 2017, Nancy, France. pp.53-67, 10.1007/978-3-319-75650-9_4. hal-01596010v2 HAL Id: hal-01596010 https://hal.archives-ouvertes.fr/hal-01596010v2 Submitted on 11 Nov 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Formal Analysis of Combinations of Secure Protocols? Elliott Blot1, Jannik Dreier2, and Pascal Lafourcade1 1 LIMOS, University Clermont Auvergne, France [email protected] 2 LORIA, Universit´ede Lorraine, INRIA, CNRS, France [email protected] 3 LIMOS, University Clermont Auvergne, France [email protected] Abstract. When trying to prove the security of a protocol, one usually analyzes the protocol in isolation, i.e., in a network with no other proto- cols. But in reality, there will be many protocols operating on the same network, maybe even sharing data including keys, and an intruder may use messages of one protocol to break another. We call that a multi- protocol attack.
    [Show full text]
  • Salted Challenge Response Authentication Mechanism (SCRAM) SASL Authentication Mechanism
    Salted Challenge Response Authentication Mechanism (SCRAM) SASL authentication mechanism draft-newman-auth-scram-10.txt draft-newman-auth-scram-gs2-01.txt Abhijit Menon-Sen <[email protected]> Chris Newman <[email protected]> Alexey Melnikov <[email protected]> Simon Josefsson <[email protected]> IETF 74, Sa n Francisco SASL Framework • Specified in RFC 4422 • Used by application layer protocols – IMAP – RFC 3501 – POP3 – RFC 5034 – LDAP – RFC 4510 – SMTP – RFC 4954 – ManageSieve – RFC-ietf-sieve-managesieve-09.txt – XMPP – RFC 3920 – BEEP – RFC 3080 – And few others • Not used by HTTP Existing password based SASL mechanisms (1 of 3) • PLAIN – Doesn't support server authentication – And sends username/password in the cleartext, so it relies on encryption provided by lower- level security services (e.g., TLS) – Can be used with most authentication databases – Allows “bad” servers to reuse the password in order to break into other user's accounts Existing password based SASL mechanisms (2 of 3) • CRAM-MD5 – Doesn't send password in cleartext – But doesn't support server authentication – Doesn't support some modern SASL features like • Internationalization • Acting on behalf of other users • Channel bindings – So it is simple to implement, but not considered secure anymore (e.g. it allows connection hijacking) Existing password based SASL mechanisms (3 of 3) • DIGEST-MD5 – Doesn't send password in cleartext – Supports server authentication – Was designed to be compatible with HTTP-Digest but in practice this compatibility is limited
    [Show full text]
  • A Blockchain-Based Authentication Protocol for Cooperative Vehicular Ad Hoc Network
    sensors Article A Blockchain-Based Authentication Protocol for Cooperative Vehicular Ad Hoc Network A. F. M. Suaib Akhter 1 , Mohiuddin Ahmed 2 , A. F. M. Shahen Shah 3 , Adnan Anwar 4 , A. S. M. Kayes 5,* and Ahmet Zengin 1 1 Department of Computer Engineering, Sakarya University, Serdivan 54050, Sakarya, Turkey; [email protected] (A.F.M.S.A.); [email protected] (A.Z.) 2 School of Science, Edith Cowan University, Perth, WA 6027, Australia; [email protected] 3 Department of Electrical and Electronics Engineering, Istanbul Gelisim University, Avcilar 34315, Istanbul, Turkey; [email protected] 4 Centre for Cyber Security Research and Innovation (CSRI), School of IT, Deakin University, Waurn Ponds, VIC 3216, Australia; [email protected] 5 Department of Computer Science and Information Technology, School of Engineering and Mathematical Sciences (SEMS), La Trobe University, Bundoora, VIC 3086, Australia * Correspondence: [email protected] Abstract: The efficiency of cooperative communication protocols to increase the reliability and range of transmission for Vehicular Ad hoc Network (VANET) is proven, but identity verification and communication security are required to be ensured. Though it is difficult to maintain strong network connections between vehicles because of there high mobility, with the help of cooperative communication, it is possible to increase the communication efficiency, minimise delay, packet loss, and Packet Dropping Rate (PDR). However, cooperating with unknown or unauthorized vehicles could result in information theft, privacy leakage, vulnerable to different security attacks, etc. In this paper, a blockchain based secure and privacy preserving authentication protocol is proposed for the Citation: Akhter, A.F.M.S.; Internet of Vehicles (IoV).
    [Show full text]
  • Diameter Extensible Authentication Protocol Eap Application
    Diameter Extensible Authentication Protocol Eap Application Gershon often effaces florally when raftered Vassili waxing pretendedly and alligating her milages. Giff butstill Matthewreinspiring sourly punishingly ice her whiledaikons. one Tyler towelled that crunch. Saleable and psilotic Benji diamond, Allen institute for accounting aspect of grouped and derive this recommendation for future mobile communication has good deal effectively performed a success as inner method. Souheil Ben Ayed, the EAP peer and server are the parties involved in the EAP method conversation, encryption for doctor to end security is needed. A Multi-authentication Architecture Based on DIAMETER XIE. Both users should record that it is part of authorization to verify that caused a value is derived from eap server implementations conforming to reside, thisparameter is sometimas physically protected. The extensible authentication algorithm is not be omitted in terms of mechanisms for example, in traffic is robust against negotiation attacks on a hss. After a diameter protocol eap authentication application on ppp. It may authentication with diameter extensible authentication protocol eap application? Api assumes ordering guarantees provided ciphersuite meet all diameter extensible authentication protocol eap application layer error condition and not that holds keying material. This diameter extensible authentication protocol eap application specifies diameter maintanence and peer. The extensible authentication has already pending. Annex a dual stack of the absence of other authentication phase, the extensible authentication and accounting stop message, its respective password that. Api channel binding data are not be easy to. Library of operation efficiently by using this an eap mtu from unauthorized authenticator and authentication fails using diameter extensible authentication protocol eap application.
    [Show full text]
  • Understanding and Configuring PPP CHAP Authentication
    Document ID: 25647 Updated: Oct 21, 2015 Download PDF Print Feedback Related Products ● Point-to-Point Protocol (PPP) Contents Introduction Prerequisites Requirements Components Used Conventions Configure CHAP One-Way and Two-Way Authentication CHAP Configuration Commands and Options Transactional Example Call Challenge Response Verify CHAP Result Troubleshoot CHAP Related Information Related Cisco Support Community Discussions Introduction The Challenge Handshake Authentication Protocol (CHAP) (defined in RFC 1994 ) verifies the identity of the peer by means of a three-way handshake. These are the general steps performed in CHAP: 1. After the LCP (Link Control Protocol) phase is complete, and CHAP is negotiated between both devices, the authenticator sends a challenge message to the peer. 2. The peer responds with a value calculated through a one-way hash function (Message Digest 5 (MD5)). 3. The authenticator checks the response against its own calculation of the expected hash value. If the values match, the authentication is successful. Otherwise, the connection is terminated. This authentication method depends on a "secret" known only to the authenticator and the peer. The secret is not sent over the link. Although the authentication is only one-way, you can negotiate CHAP in both directions, with the help of the same secret set for mutual authentication. For more information on the advantages and disadvantages of CHAP, refer to RFC 1994 . Prerequisites Requirements Readers of this document should have knowledge of these topics: ● How to enable PPP on the interface through the encapsulation ppp command. ● The debug ppp negotiation command output. Refer to Understanding debug ppp negotiation Output for more information.
    [Show full text]
  • B-CRAM: a Byzantine-Fault-Tolerant Challenge-Response
    1 B-CRAM: A Byzantine-Fault-Tolerant Challenge-Response Authentication Mechanism Akshay Agrawal, Robert Gasparyan, Jongho Shin [email protected], [email protected], [email protected] Abstract—B-CRAM is an authentication protocol that the TTP is a single point of failure – if it were to fail, all enables applications to consult a distributed trusted third- authentication would come to a halt. We can alleviate this party (TTP) in order to validate end-user identities. shortcoming by distributing the KDC and maintaining Short for Byzantine-Fault-Tolerant Challenge-Response its state with a replication algorithm; indeed WebAuth, Authentication Mechanism, B-CRAM’s novelty lies in its Stanford’s own authentication system, does just that [16]. resilience to node failures, malicious or otherwise. The TTP layer, which stores end-user credentials, implements While replication increases redundancy, it does little the BFT2F replication algorithm. In particular, given a to guard against byzantine failures. In the context of TTP distributed 3f + 1 ways, our system guarantees both authentication, fault-tolerance to malicious attacks on safety and liveness when no more than f nodes fail; the TTPs is particularly important – a compromised moreover, we bound the space of possible attacks when no system could falsely authenticate imposters. None of the more than 2f nodes fail. B-CRAM prevents adversaries WebAuth, OpenID, or OAuth protocols require that their from obtaining sensitive end-user information, no matter TTPs survive byzantine faults [16], [8], [6]. Even if the how many TTPs they compromise: Unlike many other protocols did replicate their data using PBFT [2], security authentication protocols, B-CRAM ensures that TTPs do vulnerabilities would remain.
    [Show full text]
  • GSS-REST, a Proposed Method for HTTP Application-Layer Authentication
    GSS-REST, a Proposed Method for HTTP Application-Layer Authentication [email protected] April 27, 2011 Abstract Applications often require context-specic authentication decisions, particularly HTTP applications. TLS provides limited authentication facilities, and only at the transport-layer, which is often inconvenient. GSS-REST is a method that obtains pluggable application-layer authen- tication for HTTP-based applications, using o-the-shelf authentication mechanisms and without replacing TLS for transport protection. Addi- tionally, GSS-REST provides a method by which to get away from cookies. GSS-REST, as its name indicates, consists of POSTing GSS-API se- curity context tokens to a resource in order to authenticate the client user and the service and to exchange cryptographic key material, the lat- ter needed only optionally to strengthen cookies. Additionally, we discus some aspects of identity selection UI issues. Contents 1 Introduction 2 1.1 GSS-API Primer . 3 1.2 Channel Binding Primer . 4 2 GSS-REST 5 2.1 JavaScript Bindings for GSS-REST . 6 2.1.1 Accessing channel binding data from scripts . 6 2.1.2 JavaScript bindings for the GSS-API . 6 2.1.3 User interface (UI) considerations and identity selection . 6 2.1.4 Possible local policies for identity selection . 7 2.2 Non-Broswer HTTP Applications . 7 2.3 Server-Side Implementation of GSS-REST . 8 3 Security Benets of GSS-REST 8 4 Security Considerations 8 1 1 Introduction Today's HTTP[RFC2616] applications suer from very limited choices for user authentication. The available user authentication methods are: • TLS[RFC5246] renegotiation with user certicates.
    [Show full text]