Wireless Transport Layer Security (WTLS)

VOCAL's software library Wireless Transport Layer Security (WTLS) module provides communication security with the Wireless Application Protocol (WAP). WTLS is the security layer protocol that operates above the transport layer as shown in Figure 1. Contact us to discuss your wireless application requirements.WTLSThe primary job of WTLS is to provide privacy, data integrity and authentication between applications communicating using WAP. WTLS is based on and provides similar functionality to the Transport Layer Security (TLS) protocol but is optimized for low bandwidth mobile devices. The three major differences between TLS and WTLS are:Compressed Data Structures - Packet size was reduced by using bit-fields, discarding redundancy and truncating cryptographic elements when ever possibleCompressed Certificate Format - The format follows the X.509v3 certificate structure but uses smaller data structuresPacket Based Instead of Stream Based - TLS is designed to be used over a data stream and a significant part of the design of WTLS was to allow it to be used in a data packet environment so that protocols suchas Short Message Service (SMS) could be used as data transport.WTLS PrimitivesWTLS has seven service Primitives listed below with their description:Unitdata - Primitive for exchanging data between peers when there is an existing secureconnection between the peers transport addressesCreate - Primitive for initiation of the establishment of the secure connectionExchange - Primitive for public-key authentication or key exchange with the client in thecreation of a secure connectionCommit - Primitive for switching to the newly negotiated secure connection once the handshakeis completeTerminate - Primitive for terminating the connectionException - Primitive for information about warning level alertsCreate-Request - Primitive for the server to request the client to initiate a new handshakeThe service Primitives can be one of four different types listed below with their description:request - used when a higher layer is requesting a service from a lower layerindication - used by the service providing layer to notify the next higher layer of activities relatedto the request type of the peer or to the provider of the serviceresponse - used to acknowledge receipt of the indication type from the next lower layerconfirm - used by the service providing layer to report that activity has been completed successfullyWTLS ParametersThe matrix below lists the parameters with each service Primitive and defines the requirement of the parameterspresence in each parameter type. The entries under the types across from the parameters is defined in the list beforethe matrix.MUST - Presence of the parameter is mandatory and MUST be presentCONDITIONAL - Presence of the parameter is conditional depending on other parametersOPTION - Presence of the parameter is a user option and MAY be omitted - A blank space means the parameter is absentX - Primitive type is not possible for that service Primitive* - The value of the parameter is identical to the value of the corresponding parameterof the proceeding service PrimitiveWTLS uses algorithms for Key Exchange, Encryption, and Message Authentication Code (MAC) calculations. The tablesbelow list the specific algorithms along with needed parameter information.Service Primitive Types Parameter MatrixService PrimitiveParameterParameterDescriptionPrimitive TypesrequestindicationresponseconfirmUnitdataSource AddressIdentifies the originatorMUSTMUST*XXSource PortIdentifies the port the message is sent fromMUSTMUST*Destination AddressIdentifies the peer user data is sent toMUSTOPTION*Destination PortIdentifies the to which the data is sentMUSTOPTION*User DataThe data to be transmittedMUSTMUST*CreateSource AddressIdentifies the originatorMUSTMUST* Source PortIdentifies the port the message is sent fromMUSTMUST* Destination AddressIdentifies the peer user data is sent toMUSTOPTION* Destination PortIdentifies the to which the data is sentMUSTOPTION* Client IdentitiesIndependent originator identity, may be used by server to look up certificatesOPTIONCONDITIONAL* Proposed Key Exchange SuitesKey Exchange Suites proposed by clientMUSTMUST* Proposed Cipher SuitesCipher Suites proposed by clientMUSTMUST* Proposed Compression MethodsCompression Methods proposed by clientMUSTMUST* Sequence Number ModeDefines how the Sequence Number is used in a secure connectionOPTIONCONDITIONAL*MUSTMUST*Key RefreshDefines how often the encryption and protection keys are refreshed in a secure connectionOPTIONCONDITIONAL*MUSTMUST*Session IDIs unique per server and identifies the secure sessionOPTIONCONDITIONAL*MUSTMUST*Selected Key Exchange SuiteIdentifies the Key Exchange Suite selected by the server MUSTMUST*Selected Cipher SuiteIdentifies the Cipher Suite selected by the server MUSTMUST*Selected Compression MethodIdentifies the Compression Method selected by the server MUSTMUST*Server CertificatePublic-Key Certificate of the server OPTIONCONDITIONAL*ExchangeClient CertificatePublic-Key Certificate of the client MUSTMUST*Commit No parameters, just an empty packet TerminateAlert DescriptionIdentifies the reason for terminationMUSTMUST*XXAlert LevelDefines whether the session (fatal) or connection (critical) is terminatedMUSTMUST*ExceptionAlert DescriptionIdentifies what caused the warningMUSTMUST*XXCreate-RequestSource AddressIdentifies the originatorOPTIONCONDITIONAL*XXSource PortIdentifies the port the message is sent fromOPTIONCONDITIONAL*Destination AddressIdentifies the peer user data is sent toOPTIONCONDITIONAL*Destination PortIdentifies the to which the data is sentOPTIONCONDITIONAL*WTLS uses algorithms for Key Exchange, Encryption, and Message Authentication Code (MAC) calculations. The tablesbelow list the specific algorithms along with needed parameter information.WTLS Key Exchange SuitesKey Exchange SuiteAssigned NumberDescriptionKey SizeLimit(bits)NULL0No key exchange is doneN/ASHARED_SECRET1Symmetric-key based handshakeNoneDH_anon2Diffie-Hellman (DH) Key Exchange without authenticationNoneDH_anon_5123Diffie-Hellman (DH) Key Exchange without authentication512DH_anon_7684Diffie-Hellman (DH) Key Exchange without authentication768RSA_anon5RSA Key Exchange without authenticationNoneRSA_anon_5126RSA Key Exchange without authentication512RSA_anon_7687RSA Key Exchange without authentication768RSA8RSA Key Exchange withRSA based certificatesNoneRSA_5129RSA Key Exchange withRSA based certificates512RSA_76810RSA Key Exchange withRSA based certificates768ECDH_anon11Elliptical Curve Diffie-Hellman (ECDH) Key Exchangewithout authenticationNoneECDH_anon_11312Elliptical Curve Diffie-Hellman (ECDH) Key Exchangewithout authentication113ECDH_anon_13113Elliptical Curve Diffie-Hellman (ECDH) Key Exchangewithout authentication131ECDH_ECDSA14Elliptical Curve Diffie-Hellman (ECDH) Key ExchangewithElliptical Curve Digital Signature Algorithm (ECDSA) CertificatesNoneECDH_anon_uncomp15Elliptical Curve Diffie-Hellman (ECDH) Key Exchangewithout authentication where all Public keys MUST be uncompressed pointsNoneECDH_anon_uncomp_11316Elliptical Curve Diffie-Hellman (ECDH) Key Exchangewithout authentication where all Public keys MUST beuncompressed points113ECDH_anon_uncomp_13117Elliptical Curve Diffie-Hellman (ECDH) Key Exchangewithout authentication where all Public keys MUST be uncompressed points131ECDH_ECDSA_uncomp18Elliptical Curve Diffie-Hellman (ECDH) Key ExchangewithElliptical Curve Digital Signature Algorithm (ECDSA) Certificateswhere all Public keys MUST be uncompressed pointsNoneWTLS Bulk Cipher SuitesCipherAssignedNumberDescriptionTypeKeyMaterial(bytes)ExpandedKeyMaterial(bytes)EffectiveKey Bits(bits)IV Size(bytes)Block Size(bytes)NULL0No encryptionStream0000N/ARC5_CBC_401RC5 in CBC modeBlock5164088RC5_CBC_562RC5 in CBC modeBlock7165688RC5_CBC3RC5 in CBC modeBlock161612888DES_CBC_404Data Encryption Standard (DES) in CBC modeBlock584088DES_CBC5Data Encryption Standard (DES) in CBC modeBlock8856883DES_CBC_EDE63 key TripleDES in CBC modeBlock242416888IDEA_CBC_407IDEA in CBC modeBlock5164088IDEA_CBC_568IDEA in CBC modeBlock7165688IDEA_CBC9IDEA in CBC modeBlock161612888RC5_CBC_6410RC5 in CBC modeBlock8166488IDEA_CBC_6411IDEA in CBC modeBlock8166488WTLS Keyed Message Authentication Code (MAC) AlgorithmsHashFunctionAssignedNumberDescriptionKeySize(bytes)MACSize(bytes)SHA_00No keyed MAC is calculated00SHA_401Keyed MAC calculated with SHA-1 butonly 1st 5 bytes of output are used205SHA_802Keyed MAC calculated with SHA-1 butonly 1st half (10 bytes) of output are used2010SHA3Keyed MAC calculated with SHA-12020MD5_405Keyed MAC calculated with MD5 butonly 1st 5 bytes of output are used165MD5_806Keyed MAC calculated with MD5 butonly 1st half (10 bytes) of output are used1610MD57Keyed MAC calculated with MD51616 Service Primitive Parameter Parameter Description Primitive Types Request Indication Response Confirm Unidata Source Address Identifies the originator MUST MUST* × × Source Port Identifies the port the message is sent from MUST MUST* Destination Address Identifies the peer user data is sent to MUST OPTION* Destination Port Identifies the to which the data is sent MUST OPTION* User Data The data to be transmitted MUST OPTION* Create Source Address Identifies the originator MUST MUST* Source Port Identifies the port the message is sent from MUST MUST* Destination Address Identifies the peer user data is sent to MUST OPTION* Destination Port Identifies the to which the data is sent MUST OPTION* Client Identities Independent originator identity, may be used by server to look up certificates OPTION CONDITIONAL* Proposed Key Exchange Suites Key Exchange Suites proposed by client MUST MUST* Proposed Cipher Suites Cipher Suites proposed by client MUST MUST* Proposed Compression Methods Compression Methods proposed by client MUST MUST* Sequence Number Mode Defines how the Sequence Number is used in a secure connection OPTION CONDITIONAL* MUST MUST* Session ID Is unique per server and identifies the secure session OPTION CONDITIONAL* MUST MUST* Key Refresh Defines how often the encryption and protection keys are refreshed in a secure connection OPTION CONDITIONAL* MUST MUST* Selected Key Exchange Suite Identifies the Key Exchange Suite selected by the server MUST MUST* Selected Cipher Suite Identifies the Cipher Suite selected by the server MUST MUST* Selected Compression Method Identifies the Compression Method selected by the server MUST MUST* Server Certificate Public-Key Certificate of the server OPTION CONDITIONAL* Exchange Client Certificate Public-Key Certificate of the client MUST MUST* Commit No parameters, just an empty packet Terminate Alert Description Identifies the reason for termination MUST MUST* × × Alert Level Defines whether the session (fatal) or connection (critical) is terminated MUST MUST* Exception Alert Description Identifies what caused the warning MUST MUST* × × Create Request Source Address Identifies the originator OPTION CONDITIONAL* × × Source Port Identifies the port the message is sent from OPTION CONDITIONAL* Destination Address Identifies the peer user data is sent to OPTION CONDITIONAL* Destination Port Identifies the to which the data is sent OPTION CONDITIONAL*