qMail Message Transfer Agent

LinuxCBT qmail Edition - Module III

• qmail - Installation
  • Identify current Mail Transfer Agent (MTA) environment on Red Hat Enterprise box
  • Discuss system initialization environment
  • Disable current MTA in applicable run-levels
  • Identify qmail pre-requisites
  • Setup qmail source-tree hierarchy for build process
  • Discuss qmail's modular, component architecture - relevant binaries
  • Navigate to a close qmail mirror
  • Download qmail components
  • Extract primary qmail packaged and dicuss contents
  • Patch original qmail sources
  • Install ucspi-tcp - INETD/XINETD substitute
  • Install dameontools - daemon management for qmail daemons
  • Create requisite users and groups
  • Compile and install qmail
  • Define default qmail environment
  • Explore and discuss the important qmail directories, symlinks and binaries
  • Illustrate internal qmail communications required for local and remote deliveries
  • Identify initial qmail startup process
  • Define genersal startup scripts for qmail
  • Define supervise scripts for qmail delivery
  • Define supervise scripts for qmail logging
  • Backup default local queue-injection process (Sendmail)
  • Create Sendmail symlink to qmail-compatible binary for local queue-injection
  • Start qmail & confirm processes and network bindings
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• qmail - Local Mail
  • Define required system aliases using qmail files
  • Configure qmail rules to permit local relaying
  • Identify default mbox mail storage format
  • Use MUA mutt to deliver mail via qmail
  • Examine delivery via qmail logs
  • Identify mbox destination
  • Discuss local queue-injection logic - qmail-inject/Sendmail
  • Explain permissions used by qmail when delivering local mail
  • Update local user's environment variables and confirm message delivery
  • Identify variables used for local queue-injection
  • Explore and discuss the mbox mail storage format
  • Update global environment configuration to reflect new mbox storage location
  • Examine running qmail statistics
  • Inject messages into the queue of a downed MTA
  • Examine results
  • Explore a message's path throught the local queue
  • Resume message delivery
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• qmail - Mail Storage Formats
  • Switch qmail global configuration from mbox to Maildir storage format
  • Use maildirmake to create Maildir-compliant directory structure for users
  • Explore standard Maildir directory tree
  • Restart qmail and attempt delivery to Maildir mailbox
  • Confirm deliver of message to Maildir recipient
  • Discuss Maildir file nomenclature
  • Update environment variables to reflect Maildir mail storage format
  • Explore headers of delivered messages and discuss key components
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• qmail - Aliases
  • Explain the benefits of aliases
  • Explore traditional Sendmail-style aliases in /etc/aliases
  • Compare and contrast Sendmail-style aliases to qmail-style (.qmail) aliases
  • Discuss key qmail alias user
  • Explore system-wide qmail aliases
  • Test delivery to system-wide qmail aliases
  • Define an abuse qmail-style alias and confirm delivery
  • Deine one-to-many qmail-style abuse alias and confirm delivery
  • Attempt delivery to non-existing local user or alias using Sendmail and confirm results
  • Define a catch-all system-wide alias to handle non-existing local users or accounts
  • Test catch-all system-wide alias by injecting messages bound to non-existing mailboxes
  • Discuss sub-addresses/address extensions using qmail aliases
  • Define sub-address for non-privileged user and confirm delivery using MUA mutt
  • Forward defined non-privileged sub-address to other local user and examine results
  • Redirect the abuse alias to a Mailbox-style repository for evidence-collection
  • Confirm appended alias-redirection of messages destined to catch-all accounts
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• qmail - Remote Mail
  • Identify key qmail daemons and binaries responsible for remote delivery
  • Explain remote delivery logic using DNS
  • Connect (SSH) to remote Linux system to be used for initial remote delivery & explore
  • Attempt remote delivery using qmail and FQDN of remote box and examine the qmail queue
  • Alter remote Postfix environment to find Maildir mailbox and confirm delivery using mutt
  • Update remote Postfix configuration to handle messages destined to second-level domain
  • Alter remote Postfix transport (smtproutes) file to disable static delivery
  • Confirm DNS second-level Mail Exchanger (MX) configuration for linuxcbt.internal domain
  • Attempt MX-based delivery and confirm delivery on remote host
  • Discuss employed qmail logic
  • Switch primary Mail Exchanger (MX) from Postfix box to qmail box - adjusting distances
  • Confirm MX distances using Domain Information Groper (dig)
  • Attempt delivery to second-level domain from the qmail box & confirm delivery
  • Explore qmail log files for message-delivery information
  • Debug qmail-smtpd delivery issues and adjust to ensure delivery
  • Discuss a Backup MX configuration for a given domain
  • Update DNS configuration to reflect the ideal MX distances
  • Confirm DNS configuration from a tertiary Linux server
  • Purposely fail the primary Postfix server for the linuxcbt.external domain
  • Configure qmail to be a Backup MX server for a business partner's domain
  • Attempt delivery to the linuxcbt.external domain from the tertiary Linux server
  • Examine queued messages for the linuxcbt.external backup domain on the qmail box
  • Re-enable the primary domain's Postfix box
  • Flush the qmail queue and examine delivery to the primary MX host
•  
• qmail - Relay Control
  • Discuss Smart Host applications
  • Explore pre-Smart Host SMTP delivery of messages to Internet-based host
  • Configure qmail to use a remote Postfix SMTP Smart Host system
  • Disable Smart Host configuration
  • Discuss qmail's default relay policy
  • Identify key qmail configuration files related to relaying
  • Attempt to relay from a remote Windows 2003 Host through the open qmail MTA
  • Confirm delivery of message via qmail in open-relay mode to local and remote recipients
  • Secure open relay and confirm inability to relay messages to untrusted domains
  • Configure selective relaying based on individual host and subnet
  • Discuss the benefits of SMTP Auth
  • Explain qmail's SMTP Auth implementation
  • Identify SMTP Auth pre-requisites
  • Download, compile and install CheckPassword authentication application
  • Debug compilation-related errors
  • Download SMTP Auth patch
  • Patch qmail sources and recompile to produce modified qmail-smtpd binary
  • Install new qmail-smtpd binary and prepare run scripts for usage
  • Attempt to relay with tightened relay permissions and confirm failure
  • Confirm SMTP Auth from Windows 2003 Host using Outlook Express
  • Relay outbound messages using SMTP Auth from Outlook Express client
•  
• qmail - Network-based Mail Retrieval
  • Discuss Mail retrieval authentication framework using Courier
  • Identify pre-requisites
  • Download, compile and install Courier Authentication Daemon
  • Identify Courier Authentication key directories, binaries and configuration file
  • Download and install Courier IMAP Daemon
  • Explore Courier IMAP binary directory tree
  • Discuss Courier framework
  • Configure Courier for POP3 mail retrieval
  • Confirm retrieval using Windows 2003 - Outlook Express client
  • Identify POP3 Secure configuration files
  • Generate self-signed certificate for use with POP3 Secure communications
  • Confirm retrieval of messages using Outlook Expres and POP3 Secure
  • Establish run-level symbolic links for POP3 & POP3S services
  • Configure Courier for IMAP mail retrieval
  • Confirm retrieval using Windows 2003 - Outlook Express client
  • Generate self-signed certificate for use with IMAP Secure communications
  • Establish run-level symbolic links for IMAP & IMAPS services
•  
• qmail - Web-based Mail Retrieval
  • Discuss Web-based SquirrelMail pre-requisites
  • Enable Apache web server
  • Download and Install SquirrelMail into web-accessible location
  • Secure data and attachments directories
  • Configure SquirrelMail for initial use with Courier IMAP
  • Address PHP session-related issues
  • Explore SquirrelMail from the browser as various Linux users
  • Confirm deliver using multiple clients - (mutt/Outlook Express/SquirrelMail/Local Injection)
•  
• qmail - Virtual Domains
  • Discuss qmail virtual domains support via system-wide aliases
  • Configure basic/global virtual domains using .qmail files
  • Confirm delivery to users @ virtual domains
  • Configure individual virtual domains
  • Confirm delivery to individuals @ virtual domains
  • Ensure non-global delivery to virtual domains
  • Define non-privileged user-managed virtual domains
  • Confirm deliver to user-managed virtual domains
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• qmail - Malware Framework - OpenProtect, Bad Senders, TLS
  • Discus the OpenProtect Malware Framework
  • Identify pre-requisites
  • Download OpenProtect
  • Install Open Protect
  • Explore OpenProtect Configuration (MailScanner/ClamAV/SpamAssAssin)
  • Configure outbound signatures
  • Configure qmail to reject users based header information
  • Confirm rejection from Windows 2003 Host - Outlook Express
  • Discuss Transport Layer Security framework and requirements
  • Implement Transport Layer Security (TLS)
  • Configure Outlook Express client to use TLS & test outbound relaying
•  

Sums

• Various Tools
• Remote Confirmations
• File Metadata
• File Fragments
• Compress Content
• Archive Content
• DIR Hierarchy
• Password Sums
• Shared Secret
• Restrict History
• Downloaded Content
• Encrypt Content
• Site Credentials
• Site COOKIE
• Site COOKIE - Unique

CentOS9x Stream Administration

• Initial Environment
• ls, pwd, cd, cp, mv, rm, mkdir, rmdir, whoami
• alias, cat, file, chmod, chown, history
• STD(IN|OUT), Pipes, Redirection, Command Chaining
• ps, df, top, free
• Pagers, W-Commands
• Checksums
• Awk | Sed | Grep Usage
• BASH SHELL Environment
• Compression | Archival Tools
• SSH Equivalence
• SHELL Quoting
• Propagate Environment
• Secure Clients

• Identify Standard File Types
• Standard File Permissions
• Symbolic Links
• Transfer Permissions

• Identify SWAP environment
• Provision dedicated SWAP partitions
• Add | Remove SWAP from pool as needed
• Provision File System-based SWAP
• SWAP Share
• SWAP Persistence
• Identify default storage configuration
• Provision new storage as needed
• XFS - File System
• XFS - Grow File System
• Identify LVM defaults
• Add new partitions to LVM management
• Allocate storage to LVM Volume Groups
• Create Logical Volumes (LVs) as needed
• Overlay File System and mount where applicables
• LVM - Resize
• LVM - Mixed FS
• LVM - SWAP

• Features
• Install
• Defaults
• General Usage
• Update Accounts

• Defaults
• Shared PASS Gen
• Unique PASS Gen
• Encrypted PASS Gen
• Update Accounts
• Groups

• Discuss features | limitations
• Identify default system-wide schedule
• Peruse various default Cron Jobs
• Schedule simple job and monitor recurrence
• Evaluate results

• Peruse Default CONF
• Discuss Syslog Rules
• Explore Log Rotate defaults
• Ensure rotated logs are compressed
• Extend default retention scheme
• Force Log Rotation as needed

• Explore Default environment
• Install PKGs
• Dump important metadata from packages
• Apply Updates

• Default CONF
• Add | Confirm IPs as needed

• Install
• Copy Configuration
• SELinux - Confirm
• TLS | SSL Services
• cURL Client Tests
• Virtual Hosts
• ENC Sites Only

• SFTP Only USER
• SFTP Only USER - NOLOGIN
• SFTP Only Group - Control
• NMap Intro

SysLOG with rSysLogD

• Discuss Features
• Default Environment
• Kernel Firewall LOG
• Split LOGs by Priorities
• UDP | TCP Logging
• Dual L4 Logging
• Multiple Hosts
• Basic Queueing
• Reliable Event Logging Protocol (RELP)
• RELP - Remote Only
• RELP Only
• Traditional to RELP
• SysLOG Clear-Text - Confirm
• Property Filters
• Expression Filters
• Relay Chain

Netfilter Tables

• Features
• SSHGuard
• Ruleset Basics
• Persistence
• Sample Rules
• Inbound Filtering
• Dormant Table
• Manage Tables | Chains | Rules
• Counters
• Sets
• LOG Basics
• LOG with Sets
• Closed-Port LOGs
• LOG Options
• Re-Route LOGs
• Jump Targets
• Chain Jumping
• GoTo Chains
• Meta Selectors

Debian 12x Administration

• Features
• Download
• Graphical Install
• Text Install
• Post-Install Tweaks

• Explore usage of the following useful commands
• tty | /dev/pts | w | whoami | who
• set | env | export | unset
• cat | echo | touch | rm
• pwd | ls | cd | mkdir | alias | umask
• head | tail
• dd
• find
• history
• STDIN, STDOUT, STDERR, UNIX Pipes, Redirection, Command Chaining
• ps, df, free, top, dd
• stat, which, w, who
• tar | gzip | bzip2 | xz
• ZSH Setup

• Network Tools | IP Configuration
• Examine default IP configuration
• Extend IP configuration to facilitate additional addresses
• Static IP Config
• Dual: Dynamic | Static Config
• Multiple Interfaces
• Dual Network Services
• Confirm communications

PHP One-Liners

• General Usage
• Count Lines
• Word Count
• Count Chars
• Split Lines into ARRAY
• Count Instances of Fields
• Transform Delimiters
• Anonymize LOGs
• Extract Unique SRCs
• Lines by Error Code
• LOG By Code
• Summarize Error Codes
• Pre-Seed Error Codes
• Random Strings
• Varied Passwords
• Expose Undefined Passwords
• Outdated Passwords
• Hash | Un-Hash

Cloud Storage with GlusterFS

• Discuss Features:
• Default Volume Type
• Common Volume Types
• Transport Types
• File System Support
• Storage Model

• Features
• Provision Storage
• Allocate GlusterFS Brick
• Persistence
• Generate IO
• Multiple File Systems
• Various Sizes
• Stop | Remove Volume
• Reconstitute Volume
• Server Mount
• Evaluate

OpenPGP with GPG

• Discuss Features:
• Primary Tool
• Private | Public Keys
• Public Key Cryptography Standards (PKCS)
• Encryption | Decryption
• Signing | Verification

• Features
• General Usage
• Create Content
• Encrypt
• PassPhrase Protect
• Binary | Text Encryption
• Share
• Decrypt

SSL-TLS with OpenSSL

• Discuss Features:
• Primary Tool
• Private | Public Keys
• Certificate Signing Requests (CSRs)
• Self-Signed Certificates
• Public Key Cryptography Standards (PKCS)
• Encryption | Decryption
• Random String Generation
• Message Digests
• SSL-TLS Client

• Features
• General Usage
• Retrieve Site Certificates
• Determine OCSP Configuration
• Probe supported TLS Versions
• Extract Certificate for local usage
• Retrieve Certificate with NMap
• Retrieve Certificate Chain

• Discuss
• Generate Private Keys
• Generate Correlating CSRs
• Confirm Keys | CSRs
• Self-Signed Certificates

SSH Variables

• Discuss Features
• Bare VARs
• SSH Client
• Double Quotes
• Single Quotes
• SSH Environment

SHELL Variables

• Discuss Features
• Terminal (TTY)
• CLI Arguments
• Process ID
• Backgrounded
• SHELL Local
• Environment
• Persistence
• Aliases
• Command Substitution
• Increment | Decrement
• Dynamism