Internet infrastructure - Prof. dr. ir. André Mariën
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Internet infrastructure
Prof. dr. ir. André Mariën
2020 - 2021 (c) A. Mariën 1Electronic mail 2020 - 2021 (c) A. Mariën 2
SMTP
• Simple Mail Transfer Protocol
• RFC 2821
• Successor of RFC 821 (and others)
• Objective:
transfer mail reliably and efficiently
2020 - 2021 (c) A. Mariën 3Basic structure
SMTP SMTP SMTP
User
Client Server Client
SMTP SMTP SMTP
User
Client Server Client
(c) A. Mariën
2020 - 2021 4Basic operation
• Determine postbox domain
– Postbox: postbox@domain
• Look up SMTP server
– DNS MX records (nslookup):
• Querytype=mx
• Search ‘domain’
• Set up TCP connection to server, port 25
• Transfer mail using SMTP protocol
2020 - 2021 (c) A. Mariën 5Look up SMTP server
• DNS contains Mail eXchange resource records
(MX RR records)
• MX records contain server and priority
– example:
smallcom.com MX mail.smallcom.com 10
smallcom.com MX mail.hoster.com 20
– “if possible, deliver to me (mail.smallcom.com), otherwise
my hosting company (mail.hoster.com)”
2020 - 2021 (c) A. Mariën 6Set up connection to server
• SMTP: typically on top of TCP/IP
• IANA assigned number SMTP port: 25
– To test:
• telnet host 25
• Note
– Typical end-node configuration: via a dedicated SMTP
gateway
– Configured in email client
– No DNS lookup, no direct connection
2020 - 2021 (c) A. Mariën 7Transfer mail using SMTP
HELO marien.com
MAIL FROM:andre@marien.com
RCPT TO:an@an.com
RCPT TO:bob@bob.com
…
DATA
ILOVEYOU
.
QUIT
2020 - 2021 (c) A. Mariën 8Mail object structure
• Mail envelop
– MAIL FROM
– RCPT TO
– DATA
• Mail content
– most often: RFC 822 (see next topic)
• header
• body
2020 - 2021 (c) A. Mariën 9SMTP reply • numeric completion code • 1yz: positive preliminary • 2yz: positive completion • 3yz: positive intermediate • 4yz: transient negative completion • 5yz: permanent negative completion 2020 - 2021 (c) A. Mariën 10
Additional commands
VERIFY EXPAND
• Verify: checking of • Expand : support for
mailbox existence mailing lists
• OK: 250 response • OK: (250- [name]
)* 250 [name]
• If ambiguous: (553-
[name] )* 553 • 500 / 502 : NOK
[name] • Often desactivated for
• 500 / 502 : NOK security reasons
• Often this functionality is • Alternatives
desactivated for security – User agent definitions
reasons (account – Server side group
expansion
enumeration)
2020 - 2021 (c) A. Mariën 11“Postmaster” address
• Mandatory: ‘postmaster’ must exist
• Used for:
– error reporting
– abuse reporting (SPAM)
• Exception: mail can be send without domain,
implies domain of SMTP server
2020 - 2021 (c) A. Mariën 12RFC822 structure
• Header format: “:”
From: x@y.com • Field names:
To: i@j.org HEADER – "Return-Path",
Cc: u@v.net "Received", "Date",
CR - LF "From", "Subject",
"Sender", "To", “Cc”,
Hello, “Bcc”
RTFM BODY – "Message-ID”,
Goodbye "References”,
"Keywords”, "Subject”
2020 - 2021 (c) A. Mariën 13SMTP envelop – RFC822 headers
SMTP envelope:
RCPT TO: d@x.com Conflicting data!
MAIL FROM: f@y.comp
So what?
RFC822 message
From: u@i.com How about Bcc: ?
To: d@x.com
Subject: all is discovered!
Run while you can...
2020 - 2021 (c) A. Mariën 14MIME
Multipurpose Internet Mail
Extensions
2020 - 2021 (c) A. Mariën 15New Headers
• MIME-Version: 1.0 Content type:
• /
• Content-type *(;=)
– type := discrete-type /
• Content-Transfer- composite-type
– discrete-type := "text" /
Encoding "image" / "audio" / "video" /
"application"
– composite-type := "message" /
"multipart"
• The subtype specification is
MANDATORY
• The type, subtype, and
parameter names are not case
sensitive
2020 - 2021 (c) A. Mariën 16Encoding
• "Content-Transfer- • standard encoding
Encoding" Header Field mechanisms: 7bit, 8bit,
• RFC 821 (SMTP) restricts binary, quoted-printable,
mail messages base64
– to 7bit US-ASCII data
– lines"Quoted-Printable”
• What: • Rules
– Content-Transfer-Encoding: – White Space:
quoted-printable • c == 9 => US-ASCII TAB, c == 32 US-
ASCII SPACE
• When: – Line Breaks:
– data that largely consists of • a CRLF sequence in the text=> (RFC
822) line break: CRLF
printable characters (also) in • Sequences like "=0D", "=0A",
US-ASCII set "=0A=0D" and "=0D=0A" may appear
• How: Quoted-printable: rules in data
– General 8bit representation: • Soft line breaks
– lines "=" + 2 two digit
hexadecimal representation – longer lines: use "soft" line breaks:
"=" as last character on line
• example: US-ASCII "=", dec 61 => – example:
"=3D" Listen carefully, I will only say this once.
– Literal representation: Listen carefully, =
• 33Base64: encoding process
• 3 byte input => 4 encoded characters (bytes)
• Encoded is about 33 percent larger than un-encoded
• How:
– 3 8bit inputs => 24 bits => 4 * 6bit groups
– each: single digit in the base64 alphabet
– A 65-character subset of US-ASCII is used: 64 + special ("=")
• 0-25 => A-Z
• 26-51 => a-z
• 52-61 => 0-9
• 62 => +
• 63 => /
– "=", is used to signify a special processing function
• represented identically in all versions of ISO 646, including US-ASCII
& EBCDIC.
2020 - 2021 (c) A. Mariën 19Encoding/decoding
bbbbbbbb bbbbbbbb bbbbbbbb
bbbbbb bbbbbb bbbbbb bbbbbb
F(bbbbbb) F(bbbbbb) F(bbbbbb) F(bbbbbb)
2020 - 2021 (c) A. Mariën 20Encoding/decoding: end
bbbbbbbb bbbbbbbb ---
F(bbbbbb) F(bbbbbb) F(bbbb00) “=“
bbbbbbbb --- ---
F(bbbbbb) F(bb0000) “=“ “=“
2020 - 2021 (c) A. Mariën 21MIME: Media types
Basic: • Multipart:
• application: octet-stream, – multiple entities of
independent data types.
postscript, pdf • Multipart subtypes:
• audio: basic, mpeg – "mixed": a generic mixed
• image: jpeg, gif set
– "alternative": same data in
• message: rfc822, news multiple formats
• model: vrml – "parallel": to be viewed
simultaneously
• multipart: form-data, – "digest": default type of
signed, mixed, alternative each part is
"message/rfc822".
• text: plain, html, xml
• video: mpeg, quicktime
2020 - 2021 (c) A. Mariën 22Multipart body
must contain (MIME-typed) body parts:
– each one preceded by a boundary line
– followed by a closing boundary line
– Content-Type: multipart/xxx; boundary=""
– The boundary delimiter line:
– CRLF--
– Final boundary delimiter line:
– CRLF----
2020 - 2021 (c) A. Mariën 23Preamble and epilogue
• Problem in multipart Content-type:
multipart/mixed;
specification: two boundary="simple"
unused areas
This is the preamble.
• In general: not used: no --simple
proper semantics Content-type: text/plain;
• many implementations charset=us-ascii
insert an explanatory message
note for recipients who
read the message with --simple--
MIME-challenged This is the epilogue. It is also
software to be ignored.
2020 - 2021 (c) A. Mariën 24MIME typing
• Content handled by application
• File recognition
– Magic numbers
– File extension
– Fingerprinting content
• Configuration
– Application – MIME type – file extension(s)
2020 - 2021 (c) A. Mariën 25References • RFC 2045: headers used to describe the structure of MIME messages • RFC 2046: general structure of the MIME media typing system and defines an initial set of media types • RFC 2047: to allow non-US-ASCII text data in header fields. • RFC 2049: conformance criteria & examples, acknowledgements, bibliography. 2020 - 2021 (c) A. Mariën 26
S/MIME
• RFC 2311, 2633: S/MIME S/MIME: not restricted to
Version 2&3 Message mail
Specification
• S/MIME provides the • can be used with any
following cryptographic transport mechanism
security services: that transports MIME
– authentication data
– message integrity
– non-repudiation of origin
• can be used in systems
(using digital signatures) that use cryptographic
– privacy security services that do
– data security (using not require (or support)
encryption).
any human intervention
2020 - 2021 (c) A. Mariën 27PKCS standards • "PKCS #1: RSA Encryption" • "PKCS #7: Cryptographic Message Syntax" • "PKCS #10: Certification Request Syntax" 2020 - 2021 (c) A. Mariën 28
Message structure: signed
• Single PKCS#7 signedData format
– MIME type:
• application/pkcs7-mime;smime-type=signed-data
• Composite message
– MIME type: multipart/signed
– Part1: text/plain, application/msword, ...
– Part2: application/pkcs7-signature
2020 - 2021 (c) A. Mariën 29PKCS #7 content types:
• “data”
– The data to be secured
• “signedData”
– to apply a digital signature to a message
– to convey certificates
• “envelopedData”
– To provide confidentiality
– Does not provide authentication
2020 - 2021 (c) A. Mariën 30application/pkcs7-mime
• MIME type used to carry PKCS #7 objects:
envelopedData, signedData
• general characteristics
– always carries a single PKCS #7 object.
– must always be BER encoding of the ASN.1 syntax
describing the object
2020 - 2021 (c) A. Mariën 31S/Mime type
• The application/pkcs7-mime content type defines
the optional "smime-type" parameter.
• The intent of this parameter: to convey details about
the security applied (signed or enveloped) along with
information about the contained content.
• S/MIME-types:
– enveloped-data: EnvelopedData
– signed-data: SignedData
– certs-only: SignedData
2020 - 2021 (c) A. Mariën 32Format for Signed-only Messages
• Choice:
– multipart/signed format can always be viewed by
the receiver whether they have S/MIME software
or not
– signedData format: cannot be viewed by a
recipient unless they have S/MIME facilities
2020 - 2021 (c) A. Mariën 33PKCS#7: SignedData
• ASN.1 structure for the SignedData content
type
– version
– digestAlgorithms
– contentInfo (or empty)
– certificates (OPTIONAL)
– crls (OPTIONAL)
– signerInfos (SET OF): multiple signers
2020 - 2021 (c) A. Mariën 34Example message
Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1;
boundary=boundary42
--boundary42
Content-Type: text/plain
This is a clear-signed message.
--boundary42
Content-Type: application/pkcs7-signature; name=smime.p7s
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p7s
ghyHhHUujhJhjH77n8HHGTrfvbnj756tbB9HG4VQpfyF467GhIGfHfYT6
4VQpfyF467GhIGfHfYT6jH77n8HHGghyHhHUujhJh756tbB9HGTrfvbnj
n8HHGTrfvhJhjH776tbB9HG4VQbnj7567GhIGfHfYT6ghyHhHUujpfyF4
7GhIGfHfYT64VQbnj756
--boundary42--
2020 - 2021 (c) A. Mariën 35References • RFC 1321: The MD5 Message Digest Algorithm" • RFC 2045: MIME Part 1: Format of Internet Message Bodies • RFC 2046: MIME Part 2: Media Types • RFC 1847: Security Multiparts for MIME: Multipart/Signed and Multipart/Encrypted • RFC 2313: PKCS #1: RSA Encryption Version 1.5 2020 - 2021 (c) A. Mariën 36
References • RFC 2315: PKCS #7: Cryptographic Message Syntax Version 1.5 • RFC 2314: PKCS #10: Certification Request Syntax Version 1.5 2020 - 2021 (c) A. Mariën 37
POP3 2020 - 2021 (c) A. Mariën 38
POP3
• Post Office Protocol version 3
• Protocol for maildrop (pick-up) service
• Simple protocol
– advanced requirements: use IMAP
– delivery: use SMTP
• RFC 1939, STD 53
2020 - 2021 (c) A. Mariën 39POP3 set-up
POP3
client
POP3 POP3 SMTP SMTP
client server server
POP3
client
POP3
2020 - 2021 (c) A. Mariën 40POP3 connection
• TCP/IP connection Example:
• Server assigned port number: 110 • telnet pop.somewhere.else 110
• Reply: two options – USER andre
– +OK – PASS andre
– -ERR – LIST
• Multi-line response: – RETR 1
– . terminated – DELE 1
– QUIT
2020 - 2021 (c) A. Mariën 41POP3 Commands
• Always: • Authorization
– QUIT – APOP name digest
• Authorization state: • Transaction
– USER name / PASS string
– TOP msg n
• Transaction state – UIDL [msg]
– STAT / LIST [msg] / RETR
msg / DELE msg / NOOP
/ RSET
where msg is the
message ordinal number
2020 - 2021 (c) A. Mariën 42POP3 commands
STAT • RETR
• Response:
• Reply: – +OK
– +OK number of messages, – Message
– .
total number of bytes
• DELE
LIST • Response
– +OK
• LIST [message ordinal • Note
number] – Message is only marked for
deletion
• Response: – Subsequent LIST or RETR
commands fail
– +OK – Actual removal: after QUIT
command ONLY
– – RSET: clears all deletion markings
– ...
– .
2020 - 2021 (c) A. Mariën 43POP commands
• TOP
• Response
– +OK
– Header
– First lines of the message
– .
• UIDL []
• Response
– +OK
– 1 jdkodoiezjfrj
– 2 uikjendsiojdj
– 3 jdsoioizehjkl
– .
2020 - 2021 (c) A. Mariën 44POP cmd APOP
• APOP
• Response: +OK or –ERR
• The greeting banner must contain the
challenge
• The client computes md5(challenge+secret)
• Challenge has msg-id format
– +OK POP3 server ready
2020 - 2021 (c) A. Mariën 45Mail client
• Multi-protocol client
– SMTP: sending mail
– POP3: receiving mail
• But possibly also
– DNS
• Mail relay name to IP
• SMTP with target servers
– LDAP: user and group look-up
2020 - 2021 (c) A. Mariën 46Free software
• UNIX systems:
– Qpopper: http://qpopper.sourceforge.net/
• All
– Xmail: http://xmailserver.org/
• Smtp server
• Pop3 server
2020 - 2021 (c) A. Mariën 47Mail message formats • RFC (2)822 • MIME • S/MIME 2020 - 2021 (c) A. Mariën 48
IMAP4 2020 - 2021 (c) A. Mariën 49
IMAP4 • Internet Message Access Protocol version 4 • Extensive, comprehensive protocol for post office access • Richer but more complicated than POP • RFC 2060 2020 - 2021 (c) A. Mariën 50
Connection oriented
• TCP/IP connection
• server port number: 143
• reply: OK or NO or BAD or BYE
• Reply:
– tagged (tag of request)
– untagged
• request/reply, but also unsolicited
• Asynchronous operation possible
2020 - 2021 (c) A. Mariën 51Tags in the reply Request ID: Tag usage: • In response to a request, the > Request007 “command” request ID is repeated in the reply “*”: < * ... • untagged server message < * ... • Not a reply; for instance quota < Request007 OK “command notifications completed” “+”: • continuation required (for instance: authentication) 2020 - 2021 (c) A. Mariën 52
Message attributes
• Numbers
– Unique ID
– Sequential ID
• Flags
• IMAP server reception timestamp
• RFC822 size
• RFC822 Envelope structure
• Body structure (MIME)
2020 - 2021 (c) A. Mariën 53Message flags: system • \seen: Message has been “read” • \answered: Message has been answered • \flagged: Message is flagged • \deleted: Message is marked ‘to-be-deleted’ • \draft: message partially composed • \recent: new message notification flag 2020 - 2021 (c) A. Mariën 54
State diagram (from RFC 2060)
Initial connection and server greeting
1
Non-authenticated 2
4
Authenticated 3
7 6
5
7 Selected
7
Logout and close connection
2020 - 2021 (c) A. Mariën 55Commands
Any state: non-authenticated state
• CAPABILITY: which • AUTHENTICATE
authentication “authentication
mechanisms? mechanism”
• NOOP:
• LOGIN “user name”
– polling command to
trigger unsolicited (!) “password”
status info
– Session keep-alive
(against time-out)
• LOGOUT: end session
2020 - 2021 (c) A. Mariën 56Example from RFC222:
AUTHENTICATE
• S: * OK IMAP4 Server
• C: A001 AUTHENTICATE SKEY
• S: +
• C: bW9yZ2Fu
• S: + OTUgUWE1ODMwOA==
• C: Rk9VUiBNQU5OIFNPT04[...]TUFTSA==
• S: A001 OK S/Key authentication successful
2020 - 2021 (c) A. Mariën 57Commands: authenticated:
Managing mailboxes Browsing
• CREATE “mailbox name” • LIST “reference name”
• DELETE “mailbox “wildcard mailbox
name” name”
• RENAME “existing – Browsing + metainfo
(hierarchy separator)
mailbox name” “new
mailbox name” • STATUS “mailbox name”
( “status data item
names” )
– Number of messages
2020 - 2021 (c) A. Mariën 58Commands: authenticated:
selecting current mailbox
• SELECT “mailbox name”:
– open read/write
– Responses: untagged
• * FLAGS (...)
• * EXISTS
• * RECENT
• * OK [UNSEEN 134]
• EXAMINE “mailbox name”:
– open read-only, rest: see SELECT
2020 - 2021 (c) A. Mariën 59Commands: selected state
• CLOSE
– Remove (silently) all messages marked for
deletion
• EXPUNGE
– Remove (silently) all messages marked for
deletion; unmarked responses:
• * EXPUNGE
• ...
2020 - 2021 (c) A. Mariën 60FETCH command
• Fetch Data item names:
• BODY [][]
– : RFC822
• Message set decomposition
– :
– Items: “”
• • Example, first 100 bytes:
• “*” (highest number) Sections:
• : • BODY[HEADER]
• , • BODY[TEXT]
– Examples: • BODY[HEADER.FIELDS (field-
• 7 name field-name)]
• 5:100 • BODY[HEADER.FIELDS (DATE
• 7,5:100,120,130:* FROM)]
2020 - 2021 (c) A. Mariën 61FETCH command: RFC822
decomposition
• Top-level: HEADER & TEXT
• MIME: multipart/*
– 1.HEADER & 1.TEXT & 1.MIME
– 2.HEADER & 2.TEXT & 2.MIME
– ...
2020 - 2021 (c) A. Mariën 62FETCH command example • X007 FETCH 2:8 (FLAGS BODY[HEADER.FIELDS (DATE FROM)] BODY[TEXT]) • * 2 FETCH ... • ... • * 8 FETCH ... • X007 OK Fetch completed 2020 - 2021 (c) A. Mariën 63
SEARCH command
• Conditions: examples:
– ; ALL;
– To ; BCC ; Cc
– BODY ; SUBJECT
– Before ; sentbefore ; sentsince ;
senton
– Answered; Deleted; ...
– Unanswered; Undeleted; ...
– Smaller
2020 - 2021 (c) A. Mariën 64Search reply • X007 search From student unanswered • * search 5 8 12 45 77 123 453 • X007 OK search completed 2020 - 2021 (c) A. Mariën 65
IMAP URLs • URL type: IMAP • imap://imaphost?imap command 2020 - 2021 (c) A. Mariën 66
Mail infrastructure
• Mailbox servers
– POP/IMAP connectivity
• SMTP gateways
– Send/receive
• SPAM gateways
– Filtering (ex: messagelabs)
• Anti Virus solutions
– Server solutions
• Webmail
– Web - email gateway
• Mobile mail
– Blackberry, ActiveSync
• Exchange & OWA
2020 - 2021 (c) A. Mariën 67Security • No open relay • No email spoofing • Relay only for other Mail Relays • Refuse SMTP connections from any unknown client • Use *s variant of the protocols: smtps, imaps, … • Ensure proper authentication of senders • Distinguish internal/external senders • Use s/mime • In- & outgoing traffic filtering • Use host hardening, firewall • Use malware detection 2020 - 2021 (c) A. Mariën 68
Professional Service
• Server doesn’t look like a spam exploder
– Configure reverse DNS properly
– Handle abuse reports promptly and properly
– Look “legitimate”
• Concern: availability
– Volume: spam, attachments
– Disk space!
– A policy for
• removing unread mail from mailboxes after some time
• refusing more mail to mailboxes which are already too full
2020 - 2021 (c) A. Mariën 69SPAM
• Netiquette • Refuse some hosts:
– ? – When reverse DNS not
• Appropriate use policy OK
– Required to have clear – Blacklists
rules
• blackholes.mail-abuse.org
• correct reactions • dialups.mail-abuse.org
– ignore • relays.mail-abuse.org
– reply to postmaster only
• Examine message bodies
– Products exist
– More expensive
2020 - 2021 (c) A. Mariën 70Blacklist
RSS – RBL DNS-based
• Relay Spam Stopper • queryable DNS-based
(RSS) database
– http://work-rss.mail- • Lookup host:
abuse.org/rss/ – $4.$3.$2.$1.blackholes.
• Realtime Blackhole List mail-abuse.org.
(RBL) • With $1.$2.$3.$4 the IP
– http://www.mail- address of the possible
abuse.org/rbl/ offender
2020 - 2021 (c) A. Mariën 71Build-in anti-spam
• White listing / blacklisting
– http://mail-abuse.org/ (paying)
– http://www.spamcop.net/bl.shtml
– http://www.spamhaus.org/SBL/
• RFC 2822 adherence
• Remove some SMTP commands
• Reverse DNS checks
2020 - 2021 (c) A. Mariën 72Electronic mail
Alternatives
2020 - 2021 (c) A. Mariën 73Electronic mail
• Asynchronous communication via a message
oriented system
– Message: any data
– Asynchronous:
• Sending a message without waiting for confirmation
• No handshake
• Note: individual communication may be synchronous,
or do a handshake (or even authentication)
2020 - 2021 (c) A. Mariën 74Context
• Communication mode
– Talk, chat: interactive
– SMS, e-mail: asynchronous
• Other systems
– May be able to work with internet standards
– Work with proprietary mechanisms
– Major “other” systems
• Webmail
• Lotus Notes
• Microsoft exchange
• X.400
2020 - 2021 (c) A. Mariën 75X.400 MAIL 2020 - 2021 (c) A. Mariën 76
Genesis of X.400
• Quest: acceptable global mail standard by CCITT and
ISO to solve incompatibility problems
• Result: X.400 Series Recommendations
– a superset of the existing systems
– Idea behind this: easier integration later on
• October 1984, CCITT X.400 series recommendations:
X.400(84)
• This was the first CCITT recommendation for a
network application.
2020 - 2021 (c) A. Mariën 77X.400
• Some features of X.400
– The store-and-forward mechanism
– The hierarchical address space
– The possibility of combining different types of body
parts into one message body.
• X.400 adapted best in Europe
– There was not much equipment in place yet
– Use X.400 as much as possible right from the
beginning.
– But: the expected success of X.400: disappointing
2020 - 2021 (c) A. Mariën 78Components
• Components:
– User Agent (UA)
– Message Transfer System (MTS)
– Message Transfer Agent (MTA)
• UA:
– “A process that makes the services of the MTS available to the user”
– A program that provides utilities to create, send, receive and perhaps
archive messages.
• MTS:
– Transfers messages from an originating UA to a recipient UA.
• MTA:
– Data that is sent from UA to UA may be stored temporarily in several
intermediate MTAs
– A store-and- forward mechanism: MTA forwards received messages to
a next MTA or to the recipient UA.
2020 - 2021 (c) A. Mariën 79Mapping service elements
Internet X.400
Reply-To IPMS.Heading.reply-recipients
Subject IPMS.Heading.subject
In-Reply-To IPMS.Heading.replied-to-ipm
To IPMS.Heading.primary-recipients
Cc IPMS.Heading.copy-recipients
2020 - 2021 (c) A. Mariën 80Mapping rules
RFC 822 -> X.400: X.400 -> RFC 822
• If Sender: is present • If
– Sender: is mapped to IPMS.Heading.authorizing
IPMS.Heading.originator -users is present
– From: is mapped to – IPMS.Heading.originator is
mapped to Sender:
IPMS.Heading.authorizin
g-users – IPMS.Heading.authorizing-
users is mapped to From:
• If not
• If not
– From: is mapped to
– IPMS.Heading.originator is
IPMS.Heading.originator mapped to From:
2020 - 2021 (c) A. Mariën 81Human readable notations: • C=zz • ADMD=ade • PRMD=fhbo • O=a bank • S=plork • G=mary 2020 - 2021 (c) A. Mariën 82
X.400 addresses
• X.400 address: a set of attributes
• attributes: mandatory or optional
• attribute: type and a value
– example: Surname has type IA5text
• Standard Attributes
– attributes that all X.400 installations are supposed to
'understand'
– example: 'country name', 'given name' or 'organizational
unit'
2020 - 2021 (c) A. Mariën 83Most important attributes
(see LDAP!)
• surName (S)
• givenName (G)
• initials (I*) (Zero or more)
• generationQualifier (GQ)
• OrganizationalUnits (OU1 OU2 OU3 OU4)
• OrganizationName (O)
• PrivateDomainName (PRMD)
• AdministrationDomainName (ADMD)
• CountryName (C)
• Common Name (CN)
• Combination of S, G, I* and GQ : the PersonalName (PN).
2020 - 2021 (c) A. Mariën 84X.400 address notation styles
• JTC:
– G=jo; S=plork; O=a bank; OU1=owe; OU2=you; P=fhbo; A=ade;
C=zz- DFN-EAN software:
– G=jo; S=plork; OU=you; OU=owe; O=a bank; PRMD=fhbo;
ADMD=ade; C=zz
• RARE Working Group on Mail and Messaging:
– C=zz; ADMD=ade; PRMD=fhbo; O=a bank; OU=owe; OU=you;
S=plork; G=jo
• RFC 1327:
– /G=jo/S=plork/OU=you/OU=owe/O=a
bank/P=fhbo/A=ade/C=zz/
– OU$you.OU$owe.O$a bank.P$fhbo.A$ade.C$zz
2020 - 2021 (c) A. Mariën 85LOTUS NOTES E-MAIL 2020 - 2021 (c) A. Mariën 86
Lotus Notes: basis
• Notes stores information in databases
– Files with extension .nsf
• Each database contains information about a
particular subject
• Examples:
– Company Policies
– Product Information
2020 - 2021 (c) A. Mariën 87Database organization
• many documents: search problem
• A view is a way for Notes to display
documents in a database.
• A view often shows documents
– in a particular order
– only a portion of the documents
2020 - 2021 (c) A. Mariën 88Designing a database
• A database can contains many documents.
– Example:Company Policies database
• a topic about parking
• one about sick days
• Decide on the type of information the database will contain.
• Databases can contain reports for to complete
• Examples:
– attendance reports
– expense reports
• Document creation
– How: filling in a form of the database
– forms contain
• Fields
• Buttons
• ...
2020 - 2021 (c) A. Mariën 89Mail transfer
• Actually: not done with mail protocols
• Uses database synchronization
– Server and client have database
– Database can be consulted locally or remotely
– Databases can be synchronized: exact replica
– Allows for off-line and on-line working (road
warriors)
2020 - 2021 (c) A. Mariën 90From proprietary to standards • Currently: supports internet standards • Example: migration from notes ID files to certificates (X.503v3) • Example: LDAP queries for address book • Supports access to POP3 and IMAP4 servers 2020 - 2021 (c) A. Mariën 91
Short note MAPI 2020 - 2021 (c) A. Mariën 92
MAPI • MAPI = Messaging Application Programming Interface • API: programmatic interface • Originally (and mainly): Microsoft only solution • Now some other mail clients like Eudora support it too 2020 - 2021 (c) A. Mariën 93
Simple MAPI Functions • MAPIAddress • MAPIDeleteMail • MAPIDetails • MAPIFindNext • MAPIFreeBuffer • MAPILogon • MAPILogoff • MAPIReadMail • MAPIResolveName • MAPISaveMail • MAPISendDocuments • MAPISendMail 2020 - 2021 (c) A. Mariën 94
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