Security Protocol Implementation

# Apache SSL configuration

    ServerName example.com
    DocumentRoot /var/www/html
    
    SSLEngine on
    SSLCertificateFile /etc/ssl/certs/example.com.crt
    SSLCertificateKeyFile /etc/ssl/private/example.com.key
    SSLCertificateChainFile /etc/ssl/certs/example.com.chain.crt
    
    # TLS 1.3 only
    SSLProtocol -all +TLSv1.3
    SSLCipherSuite TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256
    SSLHonorCipherOrder on
    
    # Security headers
    Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains"
    Header always set X-Content-Type-Options nosniff
    Header always set X-Frame-Options DENY

# Nginx SSL configuration
server {
    listen 443 ssl http2;
    server_name example.com;
    
    ssl_certificate /etc/ssl/certs/example.com.crt;
    ssl_certificate_key /etc/ssl/private/example.com.key;
    ssl_trusted_certificate /etc/ssl/certs/example.com.chain.crt;
    
    # TLS 1.3 only
    ssl_protocols TLSv1.3;
    ssl_ciphers TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256;
    ssl_prefer_server_ciphers off;
    
    # Security headers
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
    add_header X-Content-Type-Options nosniff always;
    add_header X-Frame-Options DENY always;
}

# Install Certbot
sudo apt install certbot python3-certbot-apache

# Obtain certificate
sudo certbot --apache -d example.com -d www.example.com

# Auto-renewal setup
sudo crontab -e
# Add: 0 12 * * * /usr/bin/certbot renew --quiet

# Manual renewal
sudo certbot renew

# Check certificate status
sudo certbot certificates

# Generate private key
openssl genrsa -out example.com.key 4096

# Generate certificate signing request
openssl req -new -key example.com.key -out example.com.csr

# Generate self-signed certificate
openssl x509 -req -days 365 -in example.com.csr -signkey example.com.key -out example.com.crt

# Verify certificate
openssl x509 -in example.com.crt -text -noout

# Install StrongSwan
sudo apt install strongswan strongswan-pki

# Generate CA certificate
ipsec pki --gen --type rsa --size 4096 --outform pem > ca-key.pem
ipsec pki --self --ca --lifetime 3652 --in ca-key.pem --dn "C=US, O=Company, CN=Company CA" --outform pem > ca-cert.pem

# Generate server certificate
ipsec pki --gen --type rsa --size 4096 --outform pem > server-key.pem
ipsec pki --req --in server-key.pem --dn "C=US, O=Company, CN=server.company.com" --outform pem > server-req.pem
ipsec pki --issue --cacert ca-cert.pem --cakey ca-key.pem --in server-req.pem --dn "C=US, O=Company, CN=server.company.com" --san="server.company.com" --flag serverAuth --outform pem > server-cert.pem

# Configure /etc/ipsec.conf
config setup
    charondebug="ike 1, knl 1, cfg 0"
    uniqueids=no

conn site-to-site
    authby=secret
    left=192.168.1.1
    leftsubnet=192.168.1.0/24
    right=192.168.2.1
    rightsubnet=192.168.2.0/24
    ike=aes256-sha256-modp2048
    esp=aes256-sha256
    keyingtries=0
    ikelifetime=1h
    lifetime=8h
    dpddelay=30
    dpdtimeout=120
    dpdaction=restart
    auto=start

# /etc/ipsec.conf for road warrior
conn roadwarrior
    auto=add
    compress=no
    type=tunnel
    keyexchange=ikev2
    fragmentation=yes
    forceencaps=yes
    dpdaction=clear
    dpddelay=300s
    rekey=no
    left=%any
    leftid=server.company.com
    leftcert=server-cert.pem
    leftsendcert=always
    leftsubnet=0.0.0.0/0
    right=%any
    rightid=%any
    rightauth=eap-mschapv2
    rightsourceip=10.10.10.0/24
    rightdns=8.8.8.8,8.8.4.4
    rightsendcert=never
    eap_identity=%identity

# /etc/ssh/sshd_config
Port 2222
Protocol 2
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_ecdsa_key
HostKey /etc/ssh/ssh_host_ed25519_key

# Authentication
LoginGraceTime 2m
PermitRootLogin no
StrictModes yes
MaxAuthTries 3
MaxSessions 10

# Key-based authentication
PubkeyAuthentication yes
AuthorizedKeysFile .ssh/authorized_keys
PasswordAuthentication no
PermitEmptyPasswords no
ChallengeResponseAuthentication no

# Security settings
X11Forwarding no
X11DisplayOffset 10
PrintMotd no
PrintLastLog yes
TCPKeepAlive yes
ClientAliveInterval 300
ClientAliveCountMax 2

# Ciphers and MACs
Ciphers chacha20-poly1305@openssh.com,aes256-gcm@openssh.com,aes128-gcm@openssh.com
MACs hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com
KexAlgorithms curve25519-sha256@libssh.org,ecdh-sha2-nistp521,ecdh-sha2-nistp384

# Generate ED25519 key pair
ssh-keygen -t ed25519 -C "user@company.com" -f ~/.ssh/id_ed25519

# Generate RSA key pair (4096 bits)
ssh-keygen -t rsa -b 4096 -C "user@company.com" -f ~/.ssh/id_rsa

# Copy public key to server
ssh-copy-id -i ~/.ssh/id_ed25519.pub user@server.com

# Test key-based authentication
ssh -i ~/.ssh/id_ed25519 user@server.com

# Add key to SSH agent
ssh-add ~/.ssh/id_ed25519

# List SSH agent keys
ssh-add -l

# Remove key from SSH agent
ssh-add -d ~/.ssh/id_ed25519

# Install OpenVPN
sudo apt install openvpn easy-rsa

# Setup PKI
make-cadir ~/openvpn-ca
cd ~/openvpn-ca

# Edit vars file
nano vars
# Set KEY_COUNTRY, KEY_PROVINCE, KEY_CITY, KEY_ORG, KEY_EMAIL

# Build CA
source vars
./clean-all
./build-ca

# Build server certificate
./build-key-server server

# Build client certificate
./build-key client1

# Generate Diffie-Hellman parameters
./build-dh

# Generate TLS auth key
openvpn --genkey --secret keys/ta.key

# Copy files to OpenVPN directory
sudo cp keys/ca.crt keys/server.crt keys/server.key keys/dh2048.pem keys/ta.key /etc/openvpn/

# Server configuration
sudo nano /etc/openvpn/server.conf

# /etc/openvpn/server.conf
port 1194
proto udp
dev tun

ca ca.crt
cert server.crt
key server.key
dh dh2048.pem
tls-auth ta.key 0

server 10.8.0.0 255.255.255.0
ifconfig-pool-persist ipp.txt

push "redirect-gateway def1 bypass-dhcp"
push "dhcp-option DNS 8.8.8.8"
push "dhcp-option DNS 8.8.4.4"

keepalive 10 120
cipher AES-256-GCM
auth SHA256
user nobody
group nogroup
persist-key
persist-tun

status openvpn-status.log
verb 3
explicit-exit-notify 1

# Install WireGuard
sudo apt install wireguard

# Generate server keys
cd /etc/wireguard
sudo wg genkey | tee server_private_key | wg pubkey > server_public_key

# Generate client keys
sudo wg genkey | tee client1_private_key | wg pubkey > client1_public_key

# Server configuration
sudo nano /etc/wireguard/wg0.conf

# /etc/wireguard/wg0.conf
[Interface]
PrivateKey = SERVER_PRIVATE_KEY
Address = 10.0.0.1/24
ListenPort = 51820
PostUp = iptables -A FORWARD -i %i -j ACCEPT; iptables -A FORWARD -o %i -j ACCEPT; iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
PostDown = iptables -D FORWARD -i %i -j ACCEPT; iptables -D FORWARD -o %i -j ACCEPT; iptables -t nat -D POSTROUTING -o eth0 -j MASQUERADE

[Peer]
PublicKey = CLIENT1_PUBLIC_KEY
AllowedIPs = 10.0.0.2/32

// OAuth 2.0 server implementation
const express = require('express');
const oauth2Server = require('oauth2-server');
const { Request, Response } = oauth2Server;

const app = express();

// OAuth 2.0 model
const model = {
  getAccessToken: async (token) => {
    // Return access token from database
    return await db.accessTokens.findOne({ token });
  },
  
  getClient: async (clientId, clientSecret) => {
    // Return client from database
    return await db.clients.findOne({ clientId, clientSecret });
  },
  
  saveToken: async (token, client, user) => {
    // Save token to database
    return await db.accessTokens.create({
      accessToken: token.accessToken,
      clientId: client.clientId,
      userId: user.id,
      expires: token.accessTokenExpiresAt
    });
  },
  
  getUser: async (username, password) => {
    // Return user from database
    return await db.users.findOne({ username, password });
  }
};

// OAuth 2.0 server
const oauth = new oauth2Server({ model });

// Authorization endpoint
app.get('/oauth/authorize', (req, res) => {
  const request = new Request(req);
  const response = new Response(res);
  
  oauth.authorize(request, response)
    .then(() => {
      res.redirect(response.headers.location);
    })
    .catch(err => {
      res.status(400).json(err);
    });
});

// Token endpoint
app.post('/oauth/token', (req, res) => {
  const request = new Request(req);
  const response = new Response(res);
  
  oauth.token(request, response)
    .then(() => {
      res.json(response.body);
    })
    .catch(err => {
      res.status(400).json(err);
    });
});

# SAML SP configuration (Python)
from saml2 import BINDING_HTTP_POST
from saml2.client import Saml2Client
from saml2.config import Config as Saml2Config

# SAML configuration
saml_config = {
    'entityid': 'https://sp.company.com/metadata',
    'description': 'Company Service Provider',
    'service': {
        'sp': {
            'name': 'Company SP',
            'endpoints': {
                'assertion_consumer_service': [
                    ('https://sp.company.com/acs', BINDING_HTTP_POST)
                ],
                'single_logout_service': [
                    ('https://sp.company.com/sls', BINDING_HTTP_POST)
                ]
            },
            'required_attributes': ['uid', 'mail', 'cn'],
            'optional_attributes': ['displayName'],
            'idp': {
                'https://idp.company.com/metadata': {
                    'single_sign_on_service': {
                        BINDING_HTTP_POST: 'https://idp.company.com/sso'
                    },
                    'single_logout_service': {
                        BINDING_HTTP_POST: 'https://idp.company.com/slo'
                    }
                }
            }
        }
    },
    'key_file': '/path/to/sp.key',
    'cert_file': '/path/to/sp.crt',
    'xmlsec_binary': '/usr/bin/xmlsec1',
    'metadata': {
        'local': ['/path/to/idp-metadata.xml']
    }
}

# Initialize SAML client
saml_client = Saml2Client(config=Saml2Config(saml_config))

# Encrypt file with AES-256-GCM
openssl enc -aes-256-gcm -salt -in sensitive_file.txt -out sensitive_file.txt.enc -k password

# Decrypt file
openssl enc -aes-256-gcm -d -in sensitive_file.txt.enc -out sensitive_file.txt -k password

# Encrypt with password file
openssl enc -aes-256-gcm -salt -in sensitive_file.txt -out sensitive_file.txt.enc -pass file:password.txt

# Generate random password
openssl rand -base64 32 > password.txt

# Encrypt with public key
openssl rsautl -encrypt -pubin -inkey public_key.pem -in sensitive_file.txt -out sensitive_file.txt.enc

# Enable encryption for InnoDB tables
# my.cnf configuration
[mysqld]
innodb_encrypt_tables = ON
innodb_encryption_threads = 4
innodb_encryption_rotate_key_age = 1

# Create encrypted table
CREATE TABLE sensitive_data (
    id INT PRIMARY KEY,
    data VARBINARY(255) NOT NULL
) ENGINE=InnoDB ENCRYPTION='Y';

# Encrypt data in application
INSERT INTO sensitive_data (id, data) VALUES (1, AES_ENCRYPT('sensitive data', 'encryption_key'));

# Decrypt data
SELECT id, AES_DECRYPT(data, 'encryption_key') as decrypted_data FROM sensitive_data;

# Nginx HTTPS configuration
server {
    listen 443 ssl http2;
    server_name api.company.com;
    
    ssl_certificate /etc/ssl/certs/api.company.com.crt;
    ssl_certificate_key /etc/ssl/private/api.company.com.key;
    
    # TLS 1.3 only
    ssl_protocols TLSv1.3;
    ssl_ciphers TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256;
    
    # HSTS
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
    
    # API endpoints
    location /api/ {
        proxy_pass http://backend;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

# /etc/rsyslog.d/50-security.conf
# Security events
:programname, isequal, "sshd" /var/log/security/ssh.log
:programname, isequal, "sudo" /var/log/security/sudo.log
:programname, isequal, "su" /var/log/security/su.log

# Failed login attempts
:msg, contains, "Failed password" /var/log/security/failed_logins.log
:msg, contains, "Invalid user" /var/log/security/invalid_users.log

# Firewall events
:programname, isequal, "ufw" /var/log/security/firewall.log

# SSL/TLS events
:programname, isequal, "nginx" /var/log/security/ssl.log
& stop

#!/bin/bash
# security_monitor.sh

LOG_FILE="/var/log/security_monitor.log"
ALERT_EMAIL="security@company.com"

# Function to log and alert
log_and_alert() {
    echo "$(date): $1" >> $LOG_FILE
    echo "$1" | mail -s "Security Alert" $ALERT_EMAIL
}

# Check for failed SSH attempts
FAILED_SSH=$(grep "Failed password" /var/log/auth.log | grep "$(date +%b\ %d)" | wc -l)
if [ $FAILED_SSH -gt 10 ]; then
    log_and_alert "High number of failed SSH attempts: $FAILED_SSH"
fi

# Check for invalid users
INVALID_USERS=$(grep "Invalid user" /var/log/auth.log | grep "$(date +%b\ %d)" | wc -l)
if [ $INVALID_USERS -gt 5 ]; then
    log_and_alert "High number of invalid user attempts: $INVALID_USERS"
fi

# Check for root login attempts
ROOT_LOGINS=$(grep "root" /var/log/auth.log | grep "$(date +%b\ %d)" | wc -l)
if [ $ROOT_LOGINS -gt 0 ]; then
    log_and_alert "Root login attempts detected: $ROOT_LOGINS"
fi

# Check SSL certificate expiration
SSL_CERT=$(echo | openssl s_client -servername api.company.com -connect api.company.com:443 2>/dev/null | openssl x509 -noout -dates)
EXPIRY_DATE=$(echo "$SSL_CERT" | grep "notAfter" | cut -d= -f2)
EXPIRY_EPOCH=$(date -d "$EXPIRY_DATE" +%s)
CURRENT_EPOCH=$(date +%s)
DAYS_UNTIL_EXPIRY=$(( (EXPIRY_EPOCH - CURRENT_EPOCH) / 86400 ))

if [ $DAYS_UNTIL_EXPIRY -lt 30 ]; then
    log_and_alert "SSL certificate expires in $DAYS_UNTIL_EXPIRY days"
fi