Date post: | 16-Dec-2015 |
Category: |
Documents |
Upload: | payton-gladwin |
View: | 214 times |
Download: | 0 times |
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
11
Evaluation of Existing Voice over Internet Protocol Security
Mechanisms &
A Recommended Implementation for a SIP-based VoIP Phone
Brett WilsonBrett WilsonHakan EvecekHakan Evecek
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
22
OverviewOverview Basic Voice Over IP (VoIP) ArchitectureBasic Voice Over IP (VoIP) Architecture Basic VoIP Calling ProcedureBasic VoIP Calling Procedure VoIP Service IssuesVoIP Service Issues Call Setup and Management SecurityCall Setup and Management Security
Session Initiation Protocol (SIP) OverviewSession Initiation Protocol (SIP) Overview SIP Security MechanismsSIP Security Mechanisms Recommended minimum implementation to protect Recommended minimum implementation to protect
SIP call setup/managementSIP call setup/management Media Stream SecurityMedia Stream Security
Secure Real Time Protocol (SRTP), Multimedia Secure Real Time Protocol (SRTP), Multimedia Internet Keying (MIKEY)Internet Keying (MIKEY)
Recommended minimum implementation to protect Recommended minimum implementation to protect media streammedia stream
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
33
Basic VoIP ArchitectureBasic VoIP Architecture End UsersEnd Users
VoIP handsets, conferencing units, mobile VoIP handsets, conferencing units, mobile units, PC softphonesunits, PC softphones
Network ComponentsNetwork Components Network ProtocolsNetwork Protocols Public Switched Telephone Network (PSTN) Public Switched Telephone Network (PSTN)
gateways provide access to non-VoIP phonesgateways provide access to non-VoIP phones Call managers, routers, Network Address Call managers, routers, Network Address
Translations (NATs), firewalls, gatewaysTranslations (NATs), firewalls, gateways SIP Proxies/H.323 GatekeepersSIP Proxies/H.323 Gatekeepers
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
44
VoIP Calling ProcedureVoIP Calling Procedure Call setup/maintenanceCall setup/maintenance
H.323 or SIP used as the signaling protocolH.323 or SIP used as the signaling protocol Both are commonly used to establish contact and Both are commonly used to establish contact and
negotiate the media stream connection and negotiate the media stream connection and detailsdetails
SIP is newer and has several advantages over SIP is newer and has several advantages over H.323H.323
Media connectionMedia connection After calling session has been created a media After calling session has been created a media
connection is created for exchanging media packetsconnection is created for exchanging media packets A separate connection/protocolA separate connection/protocol
RTP is commonRTP is common
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
55
Link & Physical Layer
IP
UDP TCP
RTP
Voice CodecG.711, 723,
729, etc. RTCPH.225RAS
H.225 Call
SignalingH.245
Audio Application
Terminal Control & Management
H.323 Protocol StackH.323 Protocol Stack
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
66
Link & Physical Layer
IP
UDP TCP
RTP
Voice CodecG.711, 723,
729, etc. RTCP SIP SDP
Audio Application
Terminal Control & Management
SIP Protocol StackSIP Protocol Stack
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
77
SIP vs H.323SIP vs H.323 Distinct advantages to both protocolsDistinct advantages to both protocols SIPSIP
Many recent comparisons regard SIP as the Many recent comparisons regard SIP as the future for VoIPfuture for VoIP
However, H.323 use will continue due to However, H.323 use will continue due to existing implementations and its advantagesexisting implementations and its advantages
Currently receiving most attention from Currently receiving most attention from researchers and the VoIP implementersresearchers and the VoIP implementers
Our research focused on SIP Our research focused on SIP
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
88
Basic SIP OperationBasic SIP Operation Bob wants to place a call to AliceBob wants to place a call to Alice
Bob sends INVITE msg to Alice through his SIP Bob sends INVITE msg to Alice through his SIP proxy serverproxy server
May require authentication to the proxyMay require authentication to the proxy Bob’s proxy server relays request to Alice’s Bob’s proxy server relays request to Alice’s
proxy serverproxy server Bob’s proxy finds Alice’s proxy using DNSBob’s proxy finds Alice’s proxy using DNS
Alice’s proxy server relays request to Alice’s Alice’s proxy server relays request to Alice’s locationlocation
Alice’s location is known only if she Alice’s location is known only if she “registers” her location with her proxy“registers” her location with her proxy
Typically done by the user agent on a Typically done by the user agent on a periodic basisperiodic basis
Alice replies with OK msg to Bob back through Alice replies with OK msg to Bob back through the proxiesthe proxies
Bob sends Alice an ACK directly to his locationBob sends Alice an ACK directly to his location
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
99
Basic SIP OperationBasic SIP Operation
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
1010
Example SIP INVITE messageExample SIP INVITE message
INVITE sip:[email protected] SIP/2.0INVITE sip:[email protected] SIP/2.0 Via: SIP/2.0/UDP Via: SIP/2.0/UDP
pc33.biloxi.com;branch=z9hG4bK776asdhdspc33.biloxi.com;branch=z9hG4bK776asdhds Max-Forwards: 70Max-Forwards: 70 To: Alice <sip:[email protected]>To: Alice <sip:[email protected]> From: Bob <sip:[email protected]>;tag=1928301774From: Bob <sip:[email protected]>;tag=1928301774 Call-ID: [email protected]: [email protected] CSeq: 314159 INVITECSeq: 314159 INVITE Contact: <sip:[email protected]>Contact: <sip:[email protected]> Content-Type: application/sdpContent-Type: application/sdp Content-Length: 142Content-Length: 142 (Bob's SDP not shown)(Bob's SDP not shown)
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
1111
Basic SIP Operation, cont’dBasic SIP Operation, cont’d
SIP does not establish media connection SIP does not establish media connection parametersparameters SIP body typically contains Session Description SIP body typically contains Session Description
Protocol (SDP) used to negotiate media Protocol (SDP) used to negotiate media parametersparameters
After call is established, SIP can be used to After call is established, SIP can be used to modify call (add more participants, etc) modify call (add more participants, etc) and to end the calland to end the call
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
1212
VoIP Service IssuesVoIP Service Issues QoSQoS
Can packet-switched networks provide the same Can packet-switched networks provide the same reliability/voice quality as the PSTN?reliability/voice quality as the PSTN?
Latency, jitter, echoLatency, jitter, echo SecuritySecurity
ConfidentialityConfidentiality Concealing signaling details as well as Concealing signaling details as well as
media streamsmedia streams IntegrityIntegrity
Ensuring message content is unalteredEnsuring message content is unaltered Providing a way to determine/authenticate Providing a way to determine/authenticate
message originmessage origin AvailabilityAvailability
Preventing denial or disruption of servicePreventing denial or disruption of service
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
1313
Disclaimers & Problems Protocol security is only a piece of the big
picture security of a system may always be compromised by naïve implementation or administration.
Security of a single protocol does not help all participating protocols have to be made secure.
Physical security counts as well. Security protocols cannot solve social layer
issues.
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
1414
Disclaimer #4Disclaimer #4
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
1515
SIP Issues with Network Address SIP Issues with Network Address Translation (NAT) traversalTranslation (NAT) traversal
NAT presents major difficultiesNAT presents major difficulties How to accurately register oneself from inside How to accurately register oneself from inside
NAT?NAT? Only know local private IPOnly know local private IP
How to receive incoming calls?How to receive incoming calls? Proxy only knows public IPs of NATProxy only knows public IPs of NAT
How to set up public NAT IP/ports for How to set up public NAT IP/ports for negotiated media stream?negotiated media stream?
Real Time Protocol (RTP)/RTCP require Real Time Protocol (RTP)/RTCP require sequential portssequential ports
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
1616
Solutions for SIP NAT traversalSolutions for SIP NAT traversal Application Layer Gateways/MIDCOMApplication Layer Gateways/MIDCOM
Allow control of NAT IP/port assignmentsAllow control of NAT IP/port assignments Con - Someone at home can’t control ISP’s NATCon - Someone at home can’t control ISP’s NAT
New “Translate” SIP headerNew “Translate” SIP header Requires registration server to associate translated Requires registration server to associate translated
IP/port with given contact nameIP/port with given contact name Registration connection must be maintainedRegistration connection must be maintained
Use of Simple Traversal of User Datagram Protocol Use of Simple Traversal of User Datagram Protocol (STUN)/Traversal Using Relay NAT (TURN)(STUN)/Traversal Using Relay NAT (TURN) STUN allows NAT discovery/type determination and public STUN allows NAT discovery/type determination and public
IP/port assignmentsIP/port assignments TURN allows external connection requests to reach TURN allows external connection requests to reach
application behind NATapplication behind NAT Acts as relay server between external and internal Acts as relay server between external and internal
hostshosts
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
1717
SIP vulnerabilitiesSIP vulnerabilities RegistrationRegistration
Prevent unauthorized registration modificationPrevent unauthorized registration modification Impersonation of Registration ServerImpersonation of Registration Server
Prevent attacker from impersonating a valid registration Prevent attacker from impersonating a valid registration serverserver
Protecting SIP message bodiesProtecting SIP message bodies End-to-End securityEnd-to-End security
Prevent attackers from interfering with call setup Prevent attackers from interfering with call setup negotiationnegotiation
Session securitySession security Ensuring attackers can not alter sessionsEnsuring attackers can not alter sessions Protecting SIP headersProtecting SIP headers
Denial of ServiceDenial of Service Protect against numerous attack strategies that can Protect against numerous attack strategies that can
generate large volume of SIP msgs at target hostgenerate large volume of SIP msgs at target host
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
1818
Considerations for securing SIPConsiderations for securing SIP
Entire SIP message can not be encrypted Entire SIP message can not be encrypted end-to-endend-to-end SIP relies on proxies to modify/insert header SIP relies on proxies to modify/insert header
fieldsfields SIP transport mechanisms are specified on SIP transport mechanisms are specified on
a hop-by-hop basisa hop-by-hop basis User has no control over how proxy server User has no control over how proxy server
relays requestrelays request Firewalls/NATs present major challengesFirewalls/NATs present major challenges
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
1919
Securing SIPSecuring SIP HTTP AuthenticationHTTP Authentication
Digest authentication allows for one-way Digest authentication allows for one-way authentication and replay-attack preventionauthentication and replay-attack prevention
Network/Transport LayerNetwork/Transport Layer IPSecIPSec
Can provide hop-by-hop security for UDP, TCP SCTPCan provide hop-by-hop security for UDP, TCP SCTP An IPsec profile detailing protocols/mechanisms for An IPsec profile detailing protocols/mechanisms for
securing SIP would be neededsecuring SIP would be needed Key management issuesKey management issues
TLSTLS Can not be applied to UDP-based SIP (only TCP or Can not be applied to UDP-based SIP (only TCP or
other reliable transport protocol)other reliable transport protocol) Applied hop-by-hopApplied hop-by-hop All SIP proxies required to implementAll SIP proxies required to implement
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
2020
Securing SIP, cont’dSecuring SIP, cont’d
S/MIMES/MIME Use for public key distribution, authentication, Use for public key distribution, authentication,
integrity, and confidentiality of SIP signaling integrity, and confidentiality of SIP signaling datadata
Protect SIP header fields through tunneling Protect SIP header fields through tunneling entire SIP message as an S/MIME bodyentire SIP message as an S/MIME body
SIP Authenticated Identity BodySIP Authenticated Identity Body Basically same as S/MIME tunneling, but Basically same as S/MIME tunneling, but
instead of “tunneling” the entire message, only instead of “tunneling” the entire message, only a specific subset of headers are signeda specific subset of headers are signed
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
2121
AIB Minimum ContentAIB Minimum Content
Content-Type: message/sipfragContent-Type: message/sipfrag
Content-Disposition: aib; handling=optionalContent-Disposition: aib; handling=optional
From: Alice <sip:[email protected]>From: Alice <sip:[email protected]>
To: Bob <sip:[email protected]>To: Bob <sip:[email protected]>
Contact: <sip:[email protected]>Contact: <sip:[email protected]>
Date: Thu, 21 Feb 2002 13:02:03 GMTDate: Thu, 21 Feb 2002 13:02:03 GMT
Call-ID: a84b4c76e66710Call-ID: a84b4c76e66710
CSeq: 314159 INVITE CSeq: 314159 INVITE
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
2222
AIB ExampleAIB ExampleINVITE sip:[email protected] SIP/2.0INVITE sip:[email protected] SIP/2.0 Via: SIP/2.0/UDP pc33.example.com;branch=z9hG4bKnashds8Via: SIP/2.0/UDP pc33.example.com;branch=z9hG4bKnashds8 To: Bob <sip:[email protected]>To: Bob <sip:[email protected]> From: Alice <sip:[email protected]>;tag=1928301774From: Alice <sip:[email protected]>;tag=1928301774 Call-ID: a84b4c76e66710Call-ID: a84b4c76e66710 CSeq: 314159 INVITECSeq: 314159 INVITE Max-Forwards: 70Max-Forwards: 70 Date: Thu, 21 Feb 2002 13:02:03 GMTDate: Thu, 21 Feb 2002 13:02:03 GMT Contact: <sip:[email protected]>Contact: <sip:[email protected]> Content-Type: multipart/mixed; boundary=unique-boundary-1Content-Type: multipart/mixed; boundary=unique-boundary-1 --unique-boundary-1--unique-boundary-1 Content-Type: application/sdpContent-Type: application/sdp Content-Length: 147Content-Length: 147 v=0v=0 o=UserA 2890844526 2890844526 IN IP4 example.como=UserA 2890844526 2890844526 IN IP4 example.com s=Session SDPs=Session SDP c=IN IP4 pc33.example.comc=IN IP4 pc33.example.com t=0 0t=0 0 m=audio 49172 RTP/AVP 0m=audio 49172 RTP/AVP 0 a=rtpmap:0 PCMU/8000a=rtpmap:0 PCMU/8000
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
2323
AIB Example, cont’dAIB Example, cont’d--unique-boundary-1--unique-boundary-1 Content-Type: multipart/signed;Content-Type: multipart/signed; protocol="application/pkcs7-signature";protocol="application/pkcs7-signature"; micalg=sha1; boundary=boundary42micalg=sha1; boundary=boundary42 Content-Length: 608Content-Length: 608 --boundary42--boundary42 Content-Type: message/sipfragContent-Type: message/sipfrag Content-Disposition: aib; handling=optionalContent-Disposition: aib; handling=optional From: Alice <sip:[email protected]>From: Alice <sip:[email protected]> To: Bob <sip:[email protected]>To: Bob <sip:[email protected]> Contact: <sip:[email protected]>Contact: <sip:[email protected]> Date: Thu, 21 Feb 2002 13:02:03 GMTDate: Thu, 21 Feb 2002 13:02:03 GMT Call-ID: a84b4c76e66710Call-ID: a84b4c76e66710 CSeq: 314159 INVITECSeq: 314159 INVITE --boundary42--boundary42 Content-Type: application/pkcs7-signature; name=smime.p7sContent-Type: application/pkcs7-signature; name=smime.p7s Content-Transfer-Encoding: base64Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename=smime.p7s;Content-Disposition: attachment; filename=smime.p7s; handling=requiredhandling=required ghyHhHUujhJhjH77n8HHGTrfvbnj756tbB9HG4VQpfyF467GhIGfHfYT6ghyHhHUujhJhjH77n8HHGTrfvbnj756tbB9HG4VQpfyF467GhIGfHfYT6 4VQpfyF467GhIGfHfYT6jH77n8HHGghyHhHUujhJh756tbB9HGTrfvbnj4VQpfyF467GhIGfHfYT6jH77n8HHGghyHhHUujhJh756tbB9HGTrfvbnj n8HHGTrfvhJhjH776tbB9HG4VQbnj7567GhIGfHfYT6ghyHhHUujpfyF4n8HHGTrfvhJhjH776tbB9HG4VQbnj7567GhIGfHfYT6ghyHhHUujpfyF4 7GhIGfHfYT64VQbnj7567GhIGfHfYT64VQbnj756 --boundary42----boundary42-- --unique-boundary-1----unique-boundary-1--
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
2424
Securing SIP, cont’dSecuring SIP, cont’d SIP Authenticated Identity ManagementSIP Authenticated Identity Management
Proposes that each SIP proxy provide Proposes that each SIP proxy provide authentication services and then sign such authentication services and then sign such authentication with a trusted certificateauthentication with a trusted certificate
Insert into new “Identity” headerInsert into new “Identity” header Addresses the fact that most end users don’t Addresses the fact that most end users don’t
have their own certificatehave their own certificate ““Signs” the assertion that the user in the Signs” the assertion that the user in the
“from” field has the authority to use that “from” field has the authority to use that Address of RecordAddress of Record
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
2525
Recommended Implementation to Recommended Implementation to Secure SIPSecure SIP
Ability to establish and maintain a TLS connection for Ability to establish and maintain a TLS connection for registration and requestsregistration and requests Provides complete confidentiality, authenticity, integrityProvides complete confidentiality, authenticity, integrity
Ability to respond to digest authentication challengesAbility to respond to digest authentication challenges Authenticate with proxy for registration/serviceAuthenticate with proxy for registration/service
Ability to use AIB to protect SIP body and headersAbility to use AIB to protect SIP body and headers In absence of TLS anywhere along route will still provide In absence of TLS anywhere along route will still provide
authentication and integrity of original SIP requestauthentication and integrity of original SIP request Ability to handle receipt of an AIB payload and correctly Ability to handle receipt of an AIB payload and correctly
deduce whether security violations have occurred in transitdeduce whether security violations have occurred in transit Must be able to determine whether changes in SIP Must be able to determine whether changes in SIP
headers are legitimate (due to intermediaries) or headers are legitimate (due to intermediaries) or represent a security breachrepresent a security breach
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
2626
Securing the Media StreamSecuring the Media Stream
Encryption of media content May take place either at IP or RTP layer Performance overhead considerable New established solutions for keying –
Multimedia Internet Keying (MIKEY) protocol
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
2727
The Secure Real – Time Transport The Secure Real – Time Transport Protocol (SRTP)Protocol (SRTP)
The security goals for SRTP are to ensure:The security goals for SRTP are to ensure:· · The confidentiality of the RTP and RTCP payloads, The confidentiality of the RTP and RTCP payloads, · The integrity of the entire RTP and RTCP packets, · The integrity of the entire RTP and RTCP packets,
together with protection against replayed packets.together with protection against replayed packets.
Goals for the protocol are: Goals for the protocol are: A framework that permits upgrading with new A framework that permits upgrading with new
cryptographic transforms, A low computational cost, cryptographic transforms, A low computational cost, Low bandwidth cost, a framework preserving RTP header Low bandwidth cost, a framework preserving RTP header
compression efficiency, and, asserted by the pre-defined compression efficiency, and, asserted by the pre-defined transforms, A small footprint (i.e., small code size and transforms, A small footprint (i.e., small code size and data memory for keying information and replay lists),data memory for keying information and replay lists),
Independence from the underlying transport, network, Independence from the underlying transport, network, and physical layers used by RTP, in particular high and physical layers used by RTP, in particular high tolerance to packet loss and re-ordering. tolerance to packet loss and re-ordering.
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
2828
Key Management for SRTP – MIKEY Key Management for SRTP – MIKEY A key management scheme that addresses real-time A key management scheme that addresses real-time
multimedia scenarios (e.g. SIP calls and RTSP sessions, multimedia scenarios (e.g. SIP calls and RTSP sessions, streaming, unicast, groups, multicast). streaming, unicast, groups, multicast).
MIKEY uses a 160-bit authentication tag, generated by MIKEY uses a 160-bit authentication tag, generated by HMAC with SHA-1HMAC with SHA-1
MIKEY defines three options for the user authentication MIKEY defines three options for the user authentication and negotiation of the master keys all as 2 way-and negotiation of the master keys all as 2 way-handshakes. They are: handshakes. They are:
Symmetric key distribution (pre-shared keys, MAC for Symmetric key distribution (pre-shared keys, MAC for integrity protection· integrity protection·
Asymmetric key distribution public keys Asymmetric key distribution public keys Diffie-Hellman key agreement protected by digital Diffie-Hellman key agreement protected by digital
signatures; needs a certificate like in the public key case. signatures; needs a certificate like in the public key case.
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
2929
Recommended Implementation to Recommended Implementation to Secure VoIP Media StreamSecure VoIP Media Stream
Support for SRTPSupport for SRTP AES – Counter Mode EncryptionAES – Counter Mode Encryption Support for MIKEYSupport for MIKEY
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
3030
ConclusionConclusion VoIP security is complexVoIP security is complex
Numerous protocolsNumerous protocols NAT/firewall traversal issuesNAT/firewall traversal issues QoS issuesQoS issues
Technologies are in place to secure VoIPTechnologies are in place to secure VoIP Solutions we’ve discussedSolutions we’ve discussed However, no “standard” approach is being However, no “standard” approach is being
usedused Current VoIP providers do not secure callsCurrent VoIP providers do not secure calls
http://www.vonage.com/help_knowledgeBase_ahttp://www.vonage.com/help_knowledgeBase_article.php?article=841rticle.php?article=841
Searches of AT&T and Earthlink turned up no Searches of AT&T and Earthlink turned up no info on secure VoIPinfo on secure VoIP
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
3131
Future Research/TestsFuture Research/Tests Evaluate the effects of the Evaluate the effects of the
recommended security systems on recommended security systems on different VoIP platforms. different VoIP platforms.
PC-to-Phone or PC-to-PC quality testing PC-to-Phone or PC-to-PC quality testing with security measures setup.with security measures setup.
Evaluate new mechanisms for Firewall/NAT problems.
How Advanced Services (transfer,conferencing, instant messaging) are affected with these security parameters.
5/3/055/3/05 Hakan Evecek and Brett Wilson - UCCHakan Evecek and Brett Wilson - UCCS CS691 Spring '05S CS691 Spring '05
3232
ReferencesReferences Dorgham Sisalem, Jiri Kuthan: Dorgham Sisalem, Jiri Kuthan: Understanding SIPUnderstanding SIP D. Richard Kuhn, Thomas J. Walsh, Steffen Fries: D. Richard Kuhn, Thomas J. Walsh, Steffen Fries:
Security Considerations for Voice Over IP SystemsSecurity Considerations for Voice Over IP Systems Daniel Collins: Carrier Grade Voice over IP, 2002 Daniel Collins: Carrier Grade Voice over IP, 2002 Using AES Counter Mode With IPsec ESP, Jan 2004Using AES Counter Mode With IPsec ESP, Jan 2004 RFC 3686RFC 3686 M. Baugher [Cisco Systems, Inc.], D. McGrew [Cisco M. Baugher [Cisco Systems, Inc.], D. McGrew [Cisco
Systems, Inc.], M. Naslund [Ericsson Research], E. Carrara Systems, Inc.], M. Naslund [Ericsson Research], E. Carrara [Ericsson Research], K. Norrman [Ericsson Research],[Ericsson Research], K. Norrman [Ericsson Research], The Secure Real-Time Transport Protocol (SRTP)The Secure Real-Time Transport Protocol (SRTP)
Tim Greene, Phil Hochmuth, Tim Greene, Phil Hochmuth, VoIP security a Moving TargetVoIP security a Moving Target Colin Perkins: RTP Audio and Video for Internet, 2003Colin Perkins: RTP Audio and Video for Internet, 2003 RFC 3329, Security Mechanism Agreement for the Session RFC 3329, Security Mechanism Agreement for the Session
Initiation Protocol (SIP) Initiation Protocol (SIP) http://www.http://www.ietfietf.org/.org/rfcrfc/rfc3686.txt?number=3686/rfc3686.txt?number=3686
RFC 3893, SIP Authenticated Identity Body (AIB) Format, RFC 3893, SIP Authenticated Identity Body (AIB) Format, http://www.http://www.ietfietf.org/.org/rfcrfc/rfc3686.txt?number=3686/rfc3686.txt?number=3686
Useful links: Useful links: VoIP-WLAN-VoIP-WLAN-QoSQoS Useful Links Useful Links