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Security for Web Services and Service Oriented Architectures


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Title: Security for Web Services and Service Oriented Architectures

Security for Web Services and Service Oriented
Bhavani Thuraisingham The University of Texas at
Dallas June 2013
  • Professors Elisa Bertino and Lorenzo Martino
    Purdue University for much of the information and
    charts on web services security standards and
    digital identity management
  • Others
  • Dr. Frederica Pacci University of Milan for
    ideas obtianed when serving on her thesis
    committee on reserach in web services security
  • Prof. I-Ling Yen and Wei-She University of Texas
    at Dallas for collaboration on web services
    security and the delegation model
  • Book by Thomas Erl on Service Oriented
    Architectures, Prentice Hall, 2005

Objective and Scope
  • The objective of this course is to provide an
    overview of the significant developments in SOA
    and Web Services Security Standards as well as
    directions for future developments
  • Current work on SOA security is focusing mainly
    on access control as well as confidentiality and
  • Solutions proposed for systems to address
    intrusion detection, denial of service and
    infrastructure attacks, insider threat analysis
    including data mining techniques for security
    applications are beyond the scope of this course.

  • SOA and Web services Overview
  • SOA and Web services security Overview
  • WS-Security and WS- Security

Service Oriented Architecture (SOA)
  • Service Oriented Architecture (SOA) is an
    architectural style that guides all aspects of
    creating and using business processes, packaged
    as services, throughout their lifecycle, as well
    as defining and provisioning the IT
    infrastructure that allows different applications
    to exchange data and participate in business
    processes loosely coupled from the operating
    systems and programming languages underlying
    those applications
  • SOA represents a model in which functionality is
    decomposed into distinct units (services), which
    can be distributed over a network and can be
    combined together and reused to create business
  • These services communicate with each other by
    passing data from one service to another, or by
    coordinating an activity between two or more
  • SOA concepts makes software development flexible
    and extensible
  • Service oriented analysis is becoming key to
    modeling and analyzing software
  • The concepts of Service Oriented Architecture are
    often seen as built upon, and the evolution of,
    the older concepts of distributed computing and
    modular programming
  • While object-orientation views the world as a
    collection of objects, service orientation views
    the world as a collection of services
  • SOA is technology independent however it is
    commonly realized using web services

Web service definition
  • A Web Service is a software system designed to
    support interoperable machine-to-machine
    interaction over a network. It has an interface
    described in a machine-processable format
    (specifically WSDL). Other systems interact with
    the Web service in a manner prescribed by its
    description using SOAP messages, typically
    conveyed using HTTP with an XML serialization in
    conjunction with other Web-related standards.
  • Source http//

Web Services (WS) Framework
  • An abstract (vendor neutral) existence defined by
    standards organizations and implemented by
    (proprietary) technology platforms
  • Core building blocks that include web sercices,
    service descriptions and messages
  • A communication agreement centered around service
    descriptions and WSDL
  • A messaging framework comprised of SOAP
    technology concepts
  • A service description registration and discovery
    architecture sometimes realized through UDDI
  • A well defined architecture that supports
    messaging patterns and compositions
  • A second generation of web services extensions
    (also known as WS- specifications) continually
    broadening its underlying feature-set
  • Concepts in WS- include Message Exchange
    Patterns (MEP), Service Activity, Coordination,
    Atomic Transaction, Business Activities,
    Orchestration (WS-BPEL), Choreography (WS-CDL)
  • Reference Service Oriented Architecture, Thomas
    Erl, Prentice Hall, 2005

Standardization bodies related to Web Services
SOA Security
  • Our approach is to implement SOA through web
    services therefore SOA security essentially is
    about web services security
  • Three core specifications
  • WS-Security, XML-Signature, XML-Encryption
  • WS-Security is the second generation of
    technologies for SOA security
  • Single sign-on (SSO) is a form of centralized
    security mechanism that complements the
    WS-Security extensions
  • Related specifications for SOA security
  • WS-Security, WS-SecurityPolicy, WS-Trust,

    WS-SecureConversation, WS-Federation, XACML,
    Extensibe Rights Markup Language, XML Key
    Management, XML, Signature, SAML, .NET Passport,
    Secure Socket Layer, WS-I Basic Security Profile

Basic Components of SOA Security
  • Identification
  • For service requestor to acces a secure service
    provider it must first provide information that
    expresses its origin or owner. This is referred
    to as making a claim
  • Authentiaction
  • A message being delivered to a receipient must
    prove that the message is in fact from the sender
    that it claims
  • Authorization
  • Once authenticated, the receipient of a message
    may need to determine what the requestor is
    alowed to do
  • Singe sign on
  • It is supported by SAML, .NET Passport and XACML
  • Confidentiality and Integrity
  • Confidentiality is concerned with protecting the
    privacy of the message content, Integrity ensures
    that the message has not been altered
  • Transport level and Message level security
  • Transport level securiy is provided by SSL
    (securing HTTP), message level confidentiality
    and integrity are provied by XML-Encryption and

Web Services Security Requirements and Standards
  • Securing Web services mainly requires to
  • provide facilities for securing the integrity and
    confidentiality of the messages and
  • ensure that the service acts only on requests in
    messages that express the claims required by
  • Role of Standards
  • Providing a Web Services Security Framework that
    is an integral part of the Web Services
  • The framework is a layered and composable set of
    standard specifications

WS- security Standards framework
WS- security standards implementations
  • Microsoft .NET Framework 2.0 / WSE3.0
  • WS-Security (OASIS 2004 standard), WS-Policy,
    WS-SecurityPolicy, WS-Trust, WS-SecureConversation
    and WS-Addressing
  • SUN Web Services Interoperability Technology
  • IBM WebSphere
  • Open Software The Apache Software Foundation Web
    Services Project (http//

XML Encryption
  • XML Encryption Syntax and Processing
  • 10 December 2002
  • Status W3C Recommendation
  • Core standard
  • Goals
  • provide confidentiality for applications that
    exchange structured data by
  • Representing in a standard way digitally
    encrypted resources
  • separating encryption information from encrypted
    data, and supporting reference mechanisms for
    addressing encryption information from encrypted
    data sections and vice-versa
  • providing a mechanism for conveying encryption
    key information to a recipient
  • providing for the encryption of a part or
    totality of an XML document

XML Signature
  • XML-Signature Syntax and Processing
  • 12 February 2002
  • Status W3C Recommendation
  • Core standard XML Signature is a building block
    for many web services security standards (e.g.
    XKMS and WS-Security)
  • Goals
  • represent a digital signature as an XML element
  • Processing rules for creating this XML element
  • The signed data items can be of different types
    and granularity (XML documents, XML Elements,
    files containing any type of digital data)

Securing SOAP messagesWeb Services Security
SOAP Message Security 1.1
(WS-Security 2004)Status Approved OASIS
Standard Specification 1 February 2006
  • Goals
  • Provide single SOAP message integrity and
  • Using existing digital signature, encryption, and
    security token mechanisms
  • Provide mechanisms for associating security
    tokens with message content (header and body
  • Extensibility (i.e. support multiple security
    token format)

the recipient can trust the content of the
message and its sender
Security Token - a representation of
security-related information (e.g. X.509
certificate, Kerberos tickets and authenticators,
mobile device security tokens from SIM cards,
username, etc.). Signed Security Token - a
security token that contains a set of related
claims (assertions) cryptographically endorsed by
an issuer. Examples X.509 certificates and
Kerberos tickets.
What is WS-Security?
  • WS-Security enhances SOAP messaging to provide
    quality of protection through
  • message integrity,
  • message confidentiality, and
  • single message authentication.
  • These mechanisms can be used to accommodate a
    wide variety of security models and encryption
  • WS-Security also provides a general-purpose,
    extensible mechanism for associating security
    tokens with messages
  • No specific type of security token is required
  • support for multiple security token formats
  • WS-Security describes how to encode binary
    security tokens( X.509 certificates and Kerberos

  • Web Services Policy 1.2 - Framework (WS-Policy)
    W3C Member Submission 25 April 2006
  • Status public draft release for review and
    evaluation only
  • Main goal The WS-Policy and WS-PolicyAttachment
    aim to offer mechanisms to represent the
    capabilities and requirements of Web services as
  • Policy view in WS-Policy
  • A policy is used to convey conditions on an
    interaction between two Web service endpoints.
  • The provider of a Web service exposes a policy to
    convey conditions under which it provides the
  • A requester might use this policy to decide
    whether or not to use the service.

  • eXtensible Access Control Markup Language 2
    (XACML) Version 2.0 OASIS Standard, 1 Feb 2005
  • Status approved OASIS Standard within the OASIS
    Access 12 Control TC.
  • XACML is a general-purpose access control policy
    language for managing access to resources
  • It describes both a policy language and an access
    control decision request/response language
  • Fine access control grained control
  • Access control based on subject and object
  • Consistent with and building upon SAML

XACML Key Aspects
  • General-purpose authorization policy model and
    XML-based specification language
  • XACML is independent of SAML specification
  • Triple-based policy syntax ltObject, Subject,
  • Negative authorization is supported
  • Input/output to the XACML policy processor is
    clearly defined as XACML context data structure
  • Input data is referred by XACML-specific
    attribute designator as well as XPath expression
  • Extension points function, identifier, data
    type, rule-combining algorithm, policy-combining
    algorithm, etc.
  • A policy consists of multiple rules
  • A set of policies is combined by a higher level
    policy (PolicySet element)

XACML data flow model
Source oasis-access_control-xacml-2.0-core-spec-
XACML Protocol
XACML Request/ Response
XACML Protocol
  • When a client makes a resource request upon a
    server, the PEP is charged with AC
  • In order to enforce AC policies, the PEP will
    formalize the attributes describing the requester
    at the PIP and delegate the authorization
    decision to the PDP
  • Applicable policies are located in a policy
    store, managed by the PAP, and evaluated at the
    PDP, which then returns the authorization
  • Using this information, the PEP can deliver the
    appropriate response to the client
  • XACML Request
  • Subject
  • Object
  • Action
  • XACML Response
  • Permit
  • Permit with Obligations
  • Deny
  • NotApplicable (the PDP cannot locate a policy
    whose target matches the required resource)
  • Indeterminate (an error occurred or some required
    value was missing)

XACML Protocol
  • The Policy Administration Point (PAP) creates
    security policies and stores these policies in
    the appropriate repository.
  • The Policy Enforcement Point (PEP) performs
    access control by making decision requests and
    enforcing authorization decisions.
  • The Policy Information Point (PIP) serves as the
    source of attribute values, or the data required
    for policy evaluation.
  • The Policy Decision Point (PDP) evaluates the
    applicable policy and renders an authorization
  • Note The PEP and PDP might both be contained
    within the same application, or might be
    distributed across different servers

XACML policy
  • A Policy has four main components
  • A target
  • A rule-combining algorithm identifier
  • A set of rules
  • Obligations
  • The Rule is the elementary unit of a policy
  • Main components of a rule
  • A target
  • An effect permit or deny
  • A condition
  • Policy Language
  • A policy target specifies a set of
  • Resources
  • Subjects
  • Actions
  • Environment
  • to which it applies

Security Assertion Markup Language (SAML)
  • Developed by the OASIS XML-Based Security
    Services Technical Committee (SSTC)
  • Status SAML V2.0 OASIS Standard specification
    set was approved on 15 March 2005
  • Main goal authentication and authorization
  • promote interoperability between disparate
    authentication and authorization systems
  • How
  • defining an XML-based framework for communicating
    security and identity information (e.g.,
    authentication, entitlements, and attribute)
    between computing entities
  • using available different security
    infrastructures (e.g., PKI, Kerberos, LDAP, etc)

SAML basic concepts
  • Assertions The core concept
  • SAML Authority a system entity that makes SAML
    assertions (also called Identity Provider IdP
    and Asserting Party)
  • Service Provider a system entity making use of
    SAML assertions
  • Relying Party a system entity that uses received
    assertions (named also SAML requester)
  • SAML Bindings Bindings describe exactly how the
    SAML protocol maps onto the transport protocols.

SAML assertions
  • An assertion is constituted by one or more
    statements made by a SAML authority
  • Different kinds of assertion statement that can
    be created by a SAML authority
  • Authentication The specified subject was
    authenticated by a particular means at a
    particular time.
  • Attribute The specified subject is associated
    with the supplied attributes.
  • Authorization decision statements the specified
    subject is entitled to do a specified action

Martino authenticated with a password at 900am
Bill is an account manager with a 1000 spending
limit per one-day travel
John Doe is permitted to buy a specified item
SAML entities
SAML Authority makes SAML assertions
SAML Requester a system entity that uses received
Service Providers a system entity making use of
SAML assertions
Source Security Assertion Markup Language (SAML)
V2.0 Technical Overview Working Draft 08, 12
September 2005
SAML Federated Identity
  • SAML addresses one key aspect of identity
    management how identity information can be
    communicated from one domain to another
  • SAML 2.0 will be the basis on which Liberty
    Alliance builds additional federated identity
    applications (such as web service-enabled
    permissions-based attribute sharing).

Summary Points
  • SOA concept based on service orientation is now a
    significant method for software development and
    promotes extensibility and flexibility Service
    oriented analysis has now become a standard way
    to model software
  • Web Services is just one way to realize SOA
  • Security for SOA is crucial as SOA is being used
    in numerous sectors since web services realize
    SOA, web services security is critical
  • SOA and SOA Security Standards are being
    developed by W3C and OASIS WS-Security,
    WS-Security Framework, and XACML are some of the
    key standards
  • SOA security currently focuses mainly on access
    control. SOA-specific techniques to address
    intrusion detection, denial of service and
    insider threat analysis need attention

Bhavani Thuraisingham The University of Texas at
Securing the network traffic SSL/TLS and IPsec
  • Secure Socket Layer SSL and Transport Layer
    Security are used to provide transport level
    security for web services applications.
  • Security features
  • authentication
  • data integrity
  • data confidentiality
  • SSL/TLS enables point-to-point secure sessions.
  • IP security (IPsec) security features
  • secure sessions with host authentication
  • data integrity
  • data confidentiality

WS-Policy Policy model
  • Policy
  • A potentially empty collection of policy
    alternatives. Alternatives are not ordered
  • Policy Alternative
  • A potentially empty collection of policy
  • An alternative with zero assertions indicates no
  • Alternatives are mutually exclusive (exclusive
  • Policy Assertion
  • Identifies a a requirement (or capability) of a
    policy subject.
  • Assertions indicate domain-specific (e.g.,
    security, transactions) semantics and are
    expected to be defined in separate,
    domain-specific specifications

WS-Policy example
ltwspPolicygt ltwspExactlyOnegt
ltwsseSecurityTokengt ltwsseTokenTypegtwsseKe
rberosv5TGT lt/wsseTokenTypegt
lt/wsseSecurityTokengt ltwsseSecurityTokengt
lt/wsseTokenTypegt lt/wsseSecurityTokengt
lt/wspExactlyOnegt lt/wspPolicygt Which security
token we want to use among the various tokens
such as Kerberos and X509
  • WS-Policy
  • is an extensible model for expressing all types
    of domain-specific policy models transport-level
    security, resource usage policy, even end-to-end
    business-process level policy. It Define basic
    policy, policy statement, and policy assertion
    models. WSPolicy is also able to incorporate
    other policy models such as SAML and XACML
  • WS-PolicyAssertions
  • Defines a few generic policy assertions
  • WS-Policy Attachment
  • Defines how to associate a policy with a service,
    either by directly embedding it in the WSDL
    definition or by indirectly associating it
    through UDDI
  • WS-SecurityPolicy
  • Defines security policy assertions corresponding
    to the security claims defined by WS-Security
    message integrity assertion, message
    confidentiality assertion, and message security
    token assertion
  • The only policy assertions standardized so far
    are those defined in WS-SecurityPolicy (specific
    assertions that describe how messages are
    secured) and WS-PolicyAssertions.

WS-Security mechanisms and considerations
  • Mechanism(s)
  • Mechanisms for message integrity digital
    signatures and certificates
  • Mechanism for confidentiality encryption (XML
  • Digital signatures alone do not provide message
    authentication. To prevent replay attack (one can
    record a signed message and resend it), digital
    signatures must be combined with timestamps or
    sequence numbers to ensure the uniqueness of the
  • When digital signatures are used for verifying
    the identity of the sending party, the sender
    must prove the possession of the private key. One
    way to achieve this is to use a
    challenge-response type of protocol.
  • The combination of signing and encryption over a
    common data item may introduce some cryptographic
  • For example, encrypting digitally signed data,
    while leaving the digital signature in the clear,
    may allow plain text guessing attacks

WS-Security request example
1 ltsoapEnvelopegt 2 ltsoapHeadergt 3
ltwsSecuritygt 4 ltwsBinarySecurityToken
id"X509token" ValueType"X.509"gt 5
sdfOIDFKLSoidefsdflk 6 lt/wsBinarySecurityTo
kengt 7 ltdsSignaturegt 8 ltdsReferencegt 9
ltdsRef URI"PO"/gt 10 lt/dsReferencegt 11
egt 12 ltdsKeyInfogt 13 ltwsBinarySecurityTok
enReference URI"X509token"/gt 14
lt/dsKeyInfogt 15 lt/dsSignaturegt 16
lt/wsSecuritygt 17 lt/soapHeadergt 18 ltsoapBodygt
19 ltpoPurchaseOrder ID"PO"/gt 20 lt/soapBodygt
21 lt/soapEnvelopegt
  • Conversations focus on the public processes in
    which the participants of a Web service engage
    WSCL is Web Services Conversation Language.
  • Web Services Secure Conversation Language
    (WS-SecureConversation) February 2005
  • Status revised public draft release provided for
    review and evaluation only
  • Main goal provide secure communication across
    one or more messages.
  • Extends WS-Security mechanisms
  • Allows to authenticate a series of SOAP messages
  • by establishing and sharing between two endpoints
    a security context for a message conversation
    using a series of derived keys to increase
  • The security context is defined as a new token
    type that is obtained using a binding of WS-Trust
  • This allows for exchange in a potentially more
    efficient way keys or new key material
  • Security Context
  • A security context is an abstract concept that
    refers to an established authentication state and
    negotiated key(s) that may have additional
    security-related properties.
  • A security context token (SCT) is a
    representation of that security context abstract
    concept, which allows a context to be named by a
    URI and used with WS-Security.

Security policies for Web Services
  • The concept of Policy Guiding principles and
  • Security policy might mean different things to
    different people
  • Firewall filtering rules
  • Access control policy
  • Privacy policy
  • Standards for Web Services Policies
  • WS-Policy
  • XACML profile for Web Services
  • Approaches specialized models languages vs.
    one-size-fits-all framework

XACML Profile for Web-Services
  • OASIS XACML Profile for Web-Services XACML
    Working draft 04, 29 Sep 2003
  • Status working draft
  • Main goal extending XACML to deal with the
    specific characteristics of Web services
  • Two main extensions to XACML
  • define in a precise way the various aspects to
    which a security policy applies to, for example
    for distinguishing the security policy that must
    be applied to the message level from the access
    control policy applied to a Web service or to an
    operation of the Web service
  • use of the policy combination mechanisms defined
    in XACML in order to combine the
    preference/requirements policy of the Web service
    client with the access control policy of the Web
    service provider
  • Note XACML profile is not getting as much
    attention as it used to

SAML profiles
  • Defines constraints and/or extensions of the core
    protocols and assertions in support of the usage
    of SAML for a particular application.
  • Achieve interoperability.
  • Stipulates how particular statements are
    communicated using appropriate protocol messages
    over specified bindings.
  • E.g. Web Browser SSO Profile specifies how SAML
    authentication assertions are communicated using
    the Authentication Query and Response messages
    over a number of different bindings in order to
    enable Single Sign-On for a browser user
  • By agreeing to support a particular SAML profile
    (as opposed to the complete specification set),
    parties who wish to exchange SAML messages have a
    much simpler job of achieving interoperability.

Policies and PolicySet
  • The key top-level element is the ltPolicySetgt
    which aggregates other ltPolicySetgt elements or
    ltPolicygt elements
  • The ltPolicygt element is composed principally of
    ltTargetgt, ltRuleSetgt and ltObligationgt elements and
    is evaluated at the PDP to yield and access
  • Since multiple policies may be found applicable
    to an access decision, (and since a single policy
    can contain multiple Rules) Combining Algorithms
    are used to reconcile multiple outcomes into a
    single decision
  • The ltTargetgt element is used to associate a
    requested resource with an applicable Policy. It
    contains conditions that the requesting Subject,
    Resource, or Action must meet for a Policy Set,
    Policy, or Rule to be applicable to the resource.
  • The Target includes a build-in scheme for
    efficient indexing/lookup of Policies.
  • Rules provide the conditions which test the
    relevant attributes within a Policy. Any number
    of Rule elements may be used each of which
    generates a true or false outcome. Combining
    these outcomes yields a single decision for the
    Policy, which may be "Permit", "Deny",
    "Indeterminate", or a "NotApplicable" decision.

Policies and Policy Sets
  • Policy
  • Smallest element PDP can evaluate
  • Contains Description, Defaults, Target, Rules,
    Obligations, Rule Combining Algorithm
  • Policy Set
  • Allows Policies and Policy Sets to be combined
  • Use not required
  • Contains Description, Defaults, Target,
    Policies, Policy Sets, Policy References, Policy
    Set References, Obligations, Policy Combining
  • Combining Algorithms Deny-overrides,
    Permit-overrides, First-applicable,

Overview of the Policy Element
ltPolicygt ltTargetgt ltResourcesgt
ltSubjectsgt ltActionsgt ltRuleSet
ruleCombiningAlgId DenyOverridesgt
ltRule ruleIdR1gt ltRule ruleIdR2gt
ltRuleSetgt lt/Policygt
ltRule RuleIdR2 EffectDenygt
ltTargetgt ltResourcesgt ltSubjectsgt
ltActionsgt ltConditiongt lt/Rulegt
ltRule RuleIdR1 EffectPermitgt
ltTargetgt ltResourcesgt ltSubjectsgt
ltActionsgt ltConditiongt lt/Rulegt
Standards for security management XKMS (XML Key
Management Standard)
  • XML Key Management Specification (XKMS 2.0)
    Version 2.0 5 April 2004
  • Status W3C Candidate Recommendation
  • XKMS provides a Web-based interface to existing
    public key infrastructure (PKI)
  • XKMS specifies protocols for
  • Distributing
  • Registering public keys
  • The protocol is suitable for use in conjunction
    with the standard for XML Signatures XML-SIG
    and companion standard for XML Encryption
  • The XML Key Management Specification (XKMS)
    defines two services
  • the XML Key Information Service Specification
    (X-KISS) and
  • the XML Key Registration Service Specification

XKMS services
XKMS protocol
XML Key Information Service (X-KISS)
XML Key Registration Service (X-KRSS)
- register - reissue - revoke - recover
- locate a public key - validate a public key
Standards for security management WS-TRUST
  • Security (confidentiality integrity) is
    achieved through encryption, digital signatures
    and certificates
  • Ultimately, security depends on the secure
    management of cryptographic keys and security
  • Key/security token issuance
  • Key/security token transmission
  • Key/security token storage
  • Key/security token exchange

  • Web Services Trust Language (WS-Trust) February
  • Status Initial public draft release provided for
    review and evaluation only
  • Main goal to enable the issuance and
    dissemination of credentials among different
    trust domains
  • WS-Trust defines extensions to WS-Security that
  • Methods for issuing, renewing, and validating
    security tokens.
  • Ways to establish, assess the presence of, and
    broker trust relationships.
  • Motivation The recipient of a WS-Security-protect
    ed SOAP message has three potential issues with
    the security token contained within the Security
  • Format the format or syntax of the token is not
    known to the recipient
  • Trust -- the recipient may be unable to build a
    chain-of-trust from its own trust anchors (e.g.
    its X.509 Certificate Authority, a local Kerberos
    KDC, or a SAML Authority) to the issuer or signer
    of the token
  • Namespace -- the recipient may be unable to
    directly comprehend the set of claims within the
    token because of syntactical differences

WS-Trust trust model
WS-Trust example
NO previouos trust relationship
The Client uses X.509 certificate
WS-Security SOAP msg
The Provider understands Kerberos certificate
STS Service
WS- Security standards and security
  • WS- security standard specifications address
    interoperability aspects
  • Each standard specification provides a specific
    section describing security threats that are not
    addressed by that specification
  • When using implementations of the specifications,
    the above warnings must be carefully analyzed

WS- Security standards and interoperability
  • Theory
  • The framework mandates for a layered approach
  • every upper layer standard could/should re-use
    and extend the specification of lower-layer
  • Practice
  • Specifications issued by different bodies are not
    always compatible, but
  • Adherence to profiles improves interoperability
  • Implementations of different vendors are not
    always interoperable

WS- Security standards and performance
  • XML induces overhead
  • Efficient ways of packaging and transmitting
    binary data in SOAP messages are needed
  • XML-binary Optimized Packaging (XOP)
  • SOAP Message Transmission Optimization Mechanism
  • Resource Representation SOAP Header Block (RRSHB)
  • Processing of WS- security compliant messages
    require encryption/decryption and eventually
    signature management capabilities
  • XML accelerators and the XML firewalls try to
    solve those problems

XML Accelerators and Firewalls
  • Accelerators A customized hardware and software
    performing the following processing tasks
  • XML/SOAP parsing,
  • XML schema validation,
  • XPath processing and XSLT transformation
  • Firewalls Also known as XML gateways
  • Perform functions of a XML accelerator
  • Support WS-Security standard
  • Additional functionalities
  • content or metadata-based XML/SOAP filtering
  • XML messages encryption/decryption at the message
    or element level
  • XML signatures verification and XML message
    signing according to XML Encryption standard
  • Authentication and authorization functions (that
    in some XML appliance can be based on local or on
    off-board repositories)
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