TEST SUITE DEVELOPMENT FOR CONFORMANCE TESTING OF EMAIL PROTOCOLS

TEST SUITE DEVELOPMENT TEST SUITE DEVELOPMENT FOR CONFORMANCE TESTING FOR CONFORMANCE TESTING

OF EMAIL PROTOCOLSOF EMAIL PROTOCOLS

Anastasia TugaenkoAnastasia Tugaenko

Scientific AdviserScientific Adviser::Nikolay Pakulin, PhDNikolay Pakulin, PhD

Institute for System Programming RAS, MoscowInstitute for System Programming RAS, Moscow

SYRCoSE 2010. 1-2 June, 2010. Nizhny Novgorod, Russia

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Conformance Testing

• Many implementations of protocols from different developers are functioning in the contemporary Internet

• The reliability of data transfer substantially depends on implementations compatibility

• The basic method of attesting implementations compatibility is conformance testing (testing to conform to the standard)

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Simple Mail Transfer Protocol

User agent (UA)

Local mail transfer agent (Local MTA)

Relay mail transfer agent (Relay MTA)

Relay mail transfer agent (Relay MTA)

Local mail transfer agent (Local MTA)

User agent (UA)

Internet

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Simple Mail Transfer ProtocolS: 220 foo.com Simple Mail Transfer Service Ready C: EHLO bar.com S: 250-foo.com greets bar.com S: 250-8BITMIME S: 250 HELP C: MAIL FROM:<[email protected]> S: 250 OK C: RCPT TO:<[email protected]> S: 250 OK C: RCPT TO:<[email protected]> S: 550 No such user here C: RCPT TO:<[email protected]> S: 250 OK C: DATA S: 354 Start mail input; end with <CRLF>.<CRLF> C: Blah blah blah... C: ...etc. etc. etc. C: . S: 250 OK C: QUIT S: 221 foo.com Service closing transmission channel

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Post Office Protocol (version 3)

UserUser

Agent MailboxPOP

server

commands

replies and data

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Post Office Protocol (version 3)S: +OK POP3 server readyC: USER mrose S: +OK mrose is a real hoopy frood C: PASS secret S: +OK mrose's maildrop has 2 messages (320 octets) C: LIST S: +OK 2 messages (320 octets) S: 1 120 S: 2 200 S: . C: RETR 1 S: +OK 120 octets S: <the POP3 server sends message 1> S: . C: DELE 3 S: -ERR no such message C: QUIT S: +OK dewey POP3 server signing off (maildrop empty)

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Mail Protocols Features

• Mail protocols are underspecified

• Mail protocols are nondeterministic

• Mail protocols requirements differ in the level of obligations (MUST, SHOULD, MAY, …)

• Protocol architecture is extensible

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Requirements for Test Suite

• Requirements traceability

• Availability of option defining the set of requirements supported by IUT

• Completeness in terms of requirements coverage

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Traditional Methodology of Conformance Testing

• Test suite consists of formal given tests which are not connected to the implementation

• Connections between requirements and test purposes and between test purposes and their tests are informal

• Test purposes describe situations to be tested. Test purpose is realized in one or several tests

• Implementation is considered to conform to the standard if all test purposes have been passed

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Testing with Mail Protocol Tester (James MPT)

S: 220.* -- expected response (pattern)C: HELO example.org -- test stimuliS: 250.*C: QUITS: 221.*

Connecting to localhost:25<-220 petr SMTP Server (JAMES SMTP Server 2.3.1) ready + <date>-> HELO example.org<-250 petr Hello example.org (localhost [127.0.0.1])-> QUIT<-221 2.0.0 petr Service closing transmission channelclosing

Script:

Result:

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UniTESK Technology

• Specifications formalize requirements as pre- and postconditions

From specifications test oracles are generated

• Test sequence is generated from test state machine traversal

Observable behavior is automatically verified by test oracles

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Method for Mail Protocols Conformance Testing

Creation of requirements catalogue

Designing of lite protocol model

Building test state machine with dedicated states

Requirements formalization

Enhancement of scenario and specification

Execution of test suites and analyzing the results

Developing of elementary tests

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Example: Generated Automaton for SMTP Protocol

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Example: Generated Report

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Results• Number of main requirements:

SMTP RFC 5321, 51 requirements POP3 RFC 1939, 58 requirements

• Size of the test suite: Specifications: SMTP 1400 lines, POP3 1600 lines Test scenarios: 7 scenarios, 2500 lines total Mediators: 3000 lines

• Implementations tested: James: 5 defects revealed HMail: 2 defects revealed

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Method Analysis: the Lows

• The absence of quick test suites updating ability (but after all preparations have done one got not a single test but a set of tests responsible for certain requirements class)

• Formal specification description is very laborious process

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Method Analysis: the Advantages

• High order of reusing test suite components Test oracles Test data iterators

• Automated generation of test sequences

• Automated calculation of reached test coverage

• Automated verdict pronouncement

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Conclusion• The method for test sequence generation for

email protocols implementation testing is presented

• Test suite for conformance testing of email protocols is constructed

• The following disagreements between email implementations and standards were detected:

Absence of required commands supporting Protocol rules violation Wrong reply codes to the protocol commands Cycling while redirecting mail

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Thank You!

Questions?

Anastasia Tugaenko

[email protected]

TEST SUITE DEVELOPMENT FOR CONFORMANCE TESTING OF EMAIL PROTOCOLS

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