Performing SSL/TLS Inspection Configuration

Overview

SSL/TLS inspection (also called SSL decryption, HTTPS inspection, or TLS break-and-inspect) intercepts encrypted traffic between clients and servers to inspect the cleartext content for malware, data exfiltration, policy violations, and command-and-control communications. The inspection device acts as a trusted man-in-the-middle, terminating the TLS session from the client, inspecting the plaintext content, and establishing a new TLS session to the destination server. With over 95% of web traffic now encrypted, organizations without TLS inspection have a massive blind spot. This guide covers configuring TLS inspection on next-generation firewalls, deploying trusted CA certificates, managing exemptions for certificate-pinned applications, and ensuring compliance with privacy regulations.

Prerequisites

Next-generation firewall or secure web gateway with TLS inspection capability
Internal Certificate Authority (CA) for signing inspection certificates
Endpoint certificate management (GPO, MDM, or manual deployment)
Privacy and legal review for TLS inspection scope
Understanding of PKI, X.509 certificates, and TLS handshake

Core Concepts

SSL/TLS Inspection Modes

Mode	Direction	Description
SSL Forward Proxy	Outbound	Intercepts client-to-internet HTTPS connections
SSL Inbound Inspection	Inbound	Decrypts traffic destined for internal servers
SSH Proxy	Both	Inspects SSH tunneled traffic

Forward Proxy Process

Client                  Firewall/Proxy              Web Server
  │                         │                          │
  │──TLS ClientHello──────→│                          │
  │                         │──TLS ClientHello───────→│
  │                         │←─TLS ServerHello────────│
  │                         │  (real server cert)      │
  │                         │                          │
  │                         │  [Validates server cert]  │
  │                         │  [Generates proxy cert   │
  │                         │   signed by internal CA]  │
  │                         │                          │
  │←─TLS ServerHello───────│                          │
  │  (proxy-signed cert)    │                          │
  │                         │                          │
  │──Encrypted data────────→│  [Decrypt, Inspect]      │
  │                         │──Encrypted data────────→│
  │←─Encrypted data─────────│  [Decrypt, Inspect]      │
  │                         │←─Encrypted data─────────│

Certificate Trust Chain

Enterprise Root CA
  └── Subordinate CA (SSL Inspection)
        └── Dynamically Generated Server Certificates
             (CN matches requested server)

Implementation Steps

Step 1: Generate Internal CA for SSL Inspection

# Create private key for SSL Inspection CA
openssl genrsa -aes256 -out ssl-inspect-ca.key 4096

# Create CA certificate (5 year validity)
openssl req -new -x509 -key ssl-inspect-ca.key \
  -sha256 -days 1825 \
  -out ssl-inspect-ca.crt \
  -subj "/C=US/ST=California/O=Corp Inc/OU=Network Security/CN=Corp SSL Inspection CA" \
  -extensions v3_ca \
  -config <(cat <<EOF
[req]
distinguished_name = req_dn
x509_extensions = v3_ca

[req_dn]

[v3_ca]
basicConstraints = critical,CA:TRUE,pathlen:0
keyUsage = critical,digitalSignature,keyCertSign,cRLSign
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always
EOF
)

# Verify certificate
openssl x509 -in ssl-inspect-ca.crt -text -noout

Step 2: Deploy CA Certificate to Endpoints

Windows (Group Policy):

# Import CA cert to trusted root store via GPO
# Computer Configuration > Policies > Windows Settings >
# Security Settings > Public Key Policies > Trusted Root CAs

# Or deploy via PowerShell
Import-Certificate -FilePath "\\server\share\ssl-inspect-ca.crt" `
  -CertStoreLocation "Cert:\LocalMachine\Root"

# Verify deployment
Get-ChildItem Cert:\LocalMachine\Root | Where-Object {
    $_.Subject -like "*SSL Inspection CA*"
}

macOS (MDM profile or manual):

# Install via command line
sudo security add-trusted-cert -d -r trustRoot \
  -k /Library/Keychains/System.keychain ssl-inspect-ca.crt

Linux:

# Ubuntu/Debian
sudo cp ssl-inspect-ca.crt /usr/local/share/ca-certificates/
sudo update-ca-certificates

# RHEL/CentOS
sudo cp ssl-inspect-ca.crt /etc/pki/ca-trust/source/anchors/
sudo update-ca-trust

Step 3: Configure Palo Alto SSL Forward Proxy

# Import CA certificate to firewall
# Device > Certificate Management > Certificates > Import

# Set as Forward Trust CA
set shared certificate SSL-Inspect-CA forward-trust-certificate yes

# Create Decryption Profile
set profiles decryption Corporate-Decrypt ssl-forward-proxy block-expired-certificate yes
set profiles decryption Corporate-Decrypt ssl-forward-proxy block-untrusted-issuer yes
set profiles decryption Corporate-Decrypt ssl-forward-proxy block-unknown-cert yes
set profiles decryption Corporate-Decrypt ssl-forward-proxy restrict-cert-exts yes
set profiles decryption Corporate-Decrypt ssl-forward-proxy strip-alpn no

# Minimum TLS version
set profiles decryption Corporate-Decrypt ssl-protocol-settings min-version tls1-2
set profiles decryption Corporate-Decrypt ssl-protocol-settings max-version max

# Decryption policy - decrypt outbound HTTPS
set rulebase decryption rules Decrypt-Outbound from Trust to Untrust
set rulebase decryption rules Decrypt-Outbound source any
set rulebase decryption rules Decrypt-Outbound destination any
set rulebase decryption rules Decrypt-Outbound service any
set rulebase decryption rules Decrypt-Outbound action decrypt
set rulebase decryption rules Decrypt-Outbound type ssl-forward-proxy
set rulebase decryption rules Decrypt-Outbound profile Corporate-Decrypt

Step 4: Configure Exemptions

Certain applications and categories must be excluded from TLS inspection:

# Exempt certificate-pinned applications
set rulebase decryption rules No-Decrypt-Pinned from Trust to Untrust
set rulebase decryption rules No-Decrypt-Pinned application [ apple-update microsoft-update dropbox-base ]
set rulebase decryption rules No-Decrypt-Pinned action no-decrypt

# Exempt privacy-sensitive categories
set rulebase decryption rules No-Decrypt-Privacy from Trust to Untrust
set rulebase decryption rules No-Decrypt-Privacy category [ health-and-medicine financial-services ]
set rulebase decryption rules No-Decrypt-Privacy action no-decrypt

# Exempt specific high-trust domains
set rulebase decryption rules No-Decrypt-Trusted from Trust to Untrust
set rulebase decryption rules No-Decrypt-Trusted destination [ bank-of-america.com chase.com healthcare.gov ]
set rulebase decryption rules No-Decrypt-Trusted action no-decrypt

Step 5: Configure Inbound Inspection for Internal Servers

# Import server certificate and private key
# Device > Certificate Management > Certificates > Import

# Inbound inspection policy
set rulebase decryption rules Inspect-WebServers from Untrust to DMZ
set rulebase decryption rules Inspect-WebServers destination [ 10.0.20.10 10.0.20.11 ]
set rulebase decryption rules Inspect-WebServers service service-https
set rulebase decryption rules Inspect-WebServers action decrypt
set rulebase decryption rules Inspect-WebServers type ssl-inbound-inspection
set rulebase decryption rules Inspect-WebServers profile Corporate-Decrypt

Step 6: Validate SSL Inspection

# Test from client - verify certificate issuer is internal CA
openssl s_client -connect www.google.com:443 -servername www.google.com 2>/dev/null | \
  openssl x509 -noout -issuer -subject

# Expected output (with inspection active):
# issuer= /C=US/O=Corp Inc/OU=Network Security/CN=Corp SSL Inspection CA
# subject= /CN=www.google.com

# Verify no certificate errors in browser
# Check firewall decryption logs for errors

# Test with curl
curl -v https://www.example.com 2>&1 | grep "issuer"

# Check decryption statistics on firewall
show system setting ssl-decrypt memory
show system setting ssl-decrypt certificate-cache
show counter global filter category ssl

Performance Considerations

Factor	Impact	Mitigation
CPU overhead	50-80% increase per session	Hardware SSL acceleration, dedicated decrypt appliance
Throughput reduction	40-60% typical	Size decryption hardware for peak encrypted traffic
Latency increase	1-5ms additional	Place inspection close to users
TLS 1.3 0-RTT	Cannot inspect 0-RTT data	Block 0-RTT or accept risk
Certificate pinning	Inspection fails	Add to exemption list
QUIC/HTTP3	Bypasses traditional proxy	Block QUIC, force HTTP/2

Compliance and Privacy

Employee Notice - Notify users that network traffic is subject to inspection
Privacy Exemptions - Exclude healthcare, financial, and legally privileged traffic
Data Handling - Inspected cleartext must not be logged or stored unnecessarily
GDPR Compliance - Document lawful basis for processing encrypted personal data
Certificate Pinning - Maintain exemption list for applications using HPKP or built-in pins

Best Practices

Start with Logging - Deploy in detect-only mode first to identify certificate-pinned applications
Maintain Exemption List - Keep a curated list of applications requiring decryption bypass
Block QUIC - Block UDP/443 to force HTTP/2 through TLS inspection
Monitor Certificate Errors - Track decryption errors in firewall logs
TLS 1.2 Minimum - Enforce TLS 1.2 as minimum version; block SSLv3 and TLS 1.0/1.1
Key Protection - Store inspection CA private key in HSM for production environments
Regular CA Rotation - Plan for CA certificate rotation before expiration

Verification Criteria

Confirm successful execution by validating:

[ ] All prerequisite tools and access requirements are satisfied
[ ] Each workflow step completed without errors
[ ] Output matches expected format and contains expected data
[ ] No security warnings or misconfigurations detected
[ ] Results are documented and evidence is preserved for audit

Compliance Framework Mapping

This skill supports compliance evidence collection across multiple frameworks:

SOC 2: CC6.6 (System Boundaries), CC6.7 (Restriction on Transmission)
ISO 27001: A.13.1 (Network Security), A.13.2 (Information Transfer)
NIST 800-53: SC-7 (Boundary Protection), AC-17 (Remote Access), SI-4 (System Monitoring)
NIST CSF: PR.AC (Access Control), PR.PT (Protective Technology)

Claw GRC Tip: When this skill is executed by a registered agent, compliance evidence is automatically captured and mapped to the relevant controls in your active frameworks.

Deploying This Skill with Claw GRC

Agent Execution

# Install via CLI
npx claw-grc skills add performing-ssl-tls-inspection-configuration

# Or load dynamically via MCP
grc.load_skill("performing-ssl-tls-inspection-configuration")

Audit Trail Integration

When executed through Claw GRC, every step of this skill generates tamper-evident audit records:

SHA-256 chain hashing ensures no step can be modified after execution
Evidence artifacts (configs, scan results, logs) are automatically attached to relevant controls
Trust score impact — successful execution increases your agent's trust score

Continuous Compliance

Schedule this skill for recurring execution to maintain continuous compliance posture. Claw GRC monitors for drift and alerts when re-execution is needed.

References

Performing SSL/TLS Inspection Configuration

Overview

Prerequisites

Next-generation firewall or secure web gateway with TLS inspection capability
Internal Certificate Authority (CA) for signing inspection certificates
Endpoint certificate management (GPO, MDM, or manual deployment)
Privacy and legal review for TLS inspection scope
Understanding of PKI, X.509 certificates, and TLS handshake

Core Concepts

SSL/TLS Inspection Modes

Mode	Direction	Description
SSL Forward Proxy	Outbound	Intercepts client-to-internet HTTPS connections
SSL Inbound Inspection	Inbound	Decrypts traffic destined for internal servers
SSH Proxy	Both	Inspects SSH tunneled traffic

Forward Proxy Process

Client                  Firewall/Proxy              Web Server
  │                         │                          │
  │──TLS ClientHello──────→│                          │
  │                         │──TLS ClientHello───────→│
  │                         │←─TLS ServerHello────────│
  │                         │  (real server cert)      │
  │                         │                          │
  │                         │  [Validates server cert]  │
  │                         │  [Generates proxy cert   │
  │                         │   signed by internal CA]  │
  │                         │                          │
  │←─TLS ServerHello───────│                          │
  │  (proxy-signed cert)    │                          │
  │                         │                          │
  │──Encrypted data────────→│  [Decrypt, Inspect]      │
  │                         │──Encrypted data────────→│
  │←─Encrypted data─────────│  [Decrypt, Inspect]      │
  │                         │←─Encrypted data─────────│

Certificate Trust Chain

Enterprise Root CA
  └── Subordinate CA (SSL Inspection)
        └── Dynamically Generated Server Certificates
             (CN matches requested server)

Implementation Steps

Step 1: Generate Internal CA for SSL Inspection

# Create private key for SSL Inspection CA
openssl genrsa -aes256 -out ssl-inspect-ca.key 4096

# Create CA certificate (5 year validity)
openssl req -new -x509 -key ssl-inspect-ca.key \
  -sha256 -days 1825 \
  -out ssl-inspect-ca.crt \
  -subj "/C=US/ST=California/O=Corp Inc/OU=Network Security/CN=Corp SSL Inspection CA" \
  -extensions v3_ca \
  -config <(cat <<EOF
[req]
distinguished_name = req_dn
x509_extensions = v3_ca

[req_dn]

[v3_ca]
basicConstraints = critical,CA:TRUE,pathlen:0
keyUsage = critical,digitalSignature,keyCertSign,cRLSign
subjectKeyIdentifier = hash
authorityKeyIdentifier = keyid:always
EOF
)

# Verify certificate
openssl x509 -in ssl-inspect-ca.crt -text -noout

Step 2: Deploy CA Certificate to Endpoints

Windows (Group Policy):

# Import CA cert to trusted root store via GPO
# Computer Configuration > Policies > Windows Settings >
# Security Settings > Public Key Policies > Trusted Root CAs

# Or deploy via PowerShell
Import-Certificate -FilePath "\\server\share\ssl-inspect-ca.crt" `
  -CertStoreLocation "Cert:\LocalMachine\Root"

# Verify deployment
Get-ChildItem Cert:\LocalMachine\Root | Where-Object {
    $_.Subject -like "*SSL Inspection CA*"
}

macOS (MDM profile or manual):

# Install via command line
sudo security add-trusted-cert -d -r trustRoot \
  -k /Library/Keychains/System.keychain ssl-inspect-ca.crt

Linux:

# Ubuntu/Debian
sudo cp ssl-inspect-ca.crt /usr/local/share/ca-certificates/
sudo update-ca-certificates

# RHEL/CentOS
sudo cp ssl-inspect-ca.crt /etc/pki/ca-trust/source/anchors/
sudo update-ca-trust

Step 3: Configure Palo Alto SSL Forward Proxy

# Import CA certificate to firewall
# Device > Certificate Management > Certificates > Import

# Set as Forward Trust CA
set shared certificate SSL-Inspect-CA forward-trust-certificate yes

# Create Decryption Profile
set profiles decryption Corporate-Decrypt ssl-forward-proxy block-expired-certificate yes
set profiles decryption Corporate-Decrypt ssl-forward-proxy block-untrusted-issuer yes
set profiles decryption Corporate-Decrypt ssl-forward-proxy block-unknown-cert yes
set profiles decryption Corporate-Decrypt ssl-forward-proxy restrict-cert-exts yes
set profiles decryption Corporate-Decrypt ssl-forward-proxy strip-alpn no

# Minimum TLS version
set profiles decryption Corporate-Decrypt ssl-protocol-settings min-version tls1-2
set profiles decryption Corporate-Decrypt ssl-protocol-settings max-version max

# Decryption policy - decrypt outbound HTTPS
set rulebase decryption rules Decrypt-Outbound from Trust to Untrust
set rulebase decryption rules Decrypt-Outbound source any
set rulebase decryption rules Decrypt-Outbound destination any
set rulebase decryption rules Decrypt-Outbound service any
set rulebase decryption rules Decrypt-Outbound action decrypt
set rulebase decryption rules Decrypt-Outbound type ssl-forward-proxy
set rulebase decryption rules Decrypt-Outbound profile Corporate-Decrypt

Step 4: Configure Exemptions

Certain applications and categories must be excluded from TLS inspection:

# Exempt certificate-pinned applications
set rulebase decryption rules No-Decrypt-Pinned from Trust to Untrust
set rulebase decryption rules No-Decrypt-Pinned application [ apple-update microsoft-update dropbox-base ]
set rulebase decryption rules No-Decrypt-Pinned action no-decrypt

# Exempt privacy-sensitive categories
set rulebase decryption rules No-Decrypt-Privacy from Trust to Untrust
set rulebase decryption rules No-Decrypt-Privacy category [ health-and-medicine financial-services ]
set rulebase decryption rules No-Decrypt-Privacy action no-decrypt

# Exempt specific high-trust domains
set rulebase decryption rules No-Decrypt-Trusted from Trust to Untrust
set rulebase decryption rules No-Decrypt-Trusted destination [ bank-of-america.com chase.com healthcare.gov ]
set rulebase decryption rules No-Decrypt-Trusted action no-decrypt

Step 5: Configure Inbound Inspection for Internal Servers

# Import server certificate and private key
# Device > Certificate Management > Certificates > Import

# Inbound inspection policy
set rulebase decryption rules Inspect-WebServers from Untrust to DMZ
set rulebase decryption rules Inspect-WebServers destination [ 10.0.20.10 10.0.20.11 ]
set rulebase decryption rules Inspect-WebServers service service-https
set rulebase decryption rules Inspect-WebServers action decrypt
set rulebase decryption rules Inspect-WebServers type ssl-inbound-inspection
set rulebase decryption rules Inspect-WebServers profile Corporate-Decrypt

Step 6: Validate SSL Inspection

# Test from client - verify certificate issuer is internal CA
openssl s_client -connect www.google.com:443 -servername www.google.com 2>/dev/null | \
  openssl x509 -noout -issuer -subject

# Expected output (with inspection active):
# issuer= /C=US/O=Corp Inc/OU=Network Security/CN=Corp SSL Inspection CA
# subject= /CN=www.google.com

# Verify no certificate errors in browser
# Check firewall decryption logs for errors

# Test with curl
curl -v https://www.example.com 2>&1 | grep "issuer"

# Check decryption statistics on firewall
show system setting ssl-decrypt memory
show system setting ssl-decrypt certificate-cache
show counter global filter category ssl

Performance Considerations

Factor	Impact	Mitigation
CPU overhead	50-80% increase per session	Hardware SSL acceleration, dedicated decrypt appliance
Throughput reduction	40-60% typical	Size decryption hardware for peak encrypted traffic
Latency increase	1-5ms additional	Place inspection close to users
TLS 1.3 0-RTT	Cannot inspect 0-RTT data	Block 0-RTT or accept risk
Certificate pinning	Inspection fails	Add to exemption list
QUIC/HTTP3	Bypasses traditional proxy	Block QUIC, force HTTP/2

Compliance and Privacy

Employee Notice - Notify users that network traffic is subject to inspection
Privacy Exemptions - Exclude healthcare, financial, and legally privileged traffic
Data Handling - Inspected cleartext must not be logged or stored unnecessarily
GDPR Compliance - Document lawful basis for processing encrypted personal data
Certificate Pinning - Maintain exemption list for applications using HPKP or built-in pins

Best Practices

Start with Logging - Deploy in detect-only mode first to identify certificate-pinned applications
Maintain Exemption List - Keep a curated list of applications requiring decryption bypass
Block QUIC - Block UDP/443 to force HTTP/2 through TLS inspection
Monitor Certificate Errors - Track decryption errors in firewall logs
TLS 1.2 Minimum - Enforce TLS 1.2 as minimum version; block SSLv3 and TLS 1.0/1.1
Key Protection - Store inspection CA private key in HSM for production environments
Regular CA Rotation - Plan for CA certificate rotation before expiration

Verification Criteria

Confirm successful execution by validating:

[ ] All prerequisite tools and access requirements are satisfied
[ ] Each workflow step completed without errors
[ ] Output matches expected format and contains expected data
[ ] No security warnings or misconfigurations detected
[ ] Results are documented and evidence is preserved for audit

Compliance Framework Mapping

This skill supports compliance evidence collection across multiple frameworks:

SOC 2: CC6.6 (System Boundaries), CC6.7 (Restriction on Transmission)
ISO 27001: A.13.1 (Network Security), A.13.2 (Information Transfer)
NIST 800-53: SC-7 (Boundary Protection), AC-17 (Remote Access), SI-4 (System Monitoring)
NIST CSF: PR.AC (Access Control), PR.PT (Protective Technology)

Claw GRC Tip: When this skill is executed by a registered agent, compliance evidence is automatically captured and mapped to the relevant controls in your active frameworks.

Deploying This Skill with Claw GRC

Agent Execution

# Install via CLI
npx claw-grc skills add performing-ssl-tls-inspection-configuration

# Or load dynamically via MCP
grc.load_skill("performing-ssl-tls-inspection-configuration")

Audit Trail Integration

When executed through Claw GRC, every step of this skill generates tamper-evident audit records:

SHA-256 chain hashing ensures no step can be modified after execution
Evidence artifacts (configs, scan results, logs) are automatically attached to relevant controls
Trust score impact — successful execution increases your agent's trust score

Continuous Compliance

Schedule this skill for recurring execution to maintain continuous compliance posture. Claw GRC monitors for drift and alerts when re-execution is needed.

Prerequisites

Performing SSL/TLS Inspection Configuration

Overview

Prerequisites

Core Concepts

SSL/TLS Inspection Modes

Forward Proxy Process

Certificate Trust Chain

Implementation Steps

Step 1: Generate Internal CA for SSL Inspection

Step 2: Deploy CA Certificate to Endpoints

Step 3: Configure Palo Alto SSL Forward Proxy

Step 4: Configure Exemptions

Step 5: Configure Inbound Inspection for Internal Servers

Step 6: Validate SSL Inspection

Performance Considerations

Compliance and Privacy

Best Practices

Verification Criteria

Compliance Framework Mapping

Deploying This Skill with Claw GRC

Agent Execution

Audit Trail Integration

Continuous Compliance

References

Use with Claw GRC Agents

Tags

Related Skills

Detecting ARP Poisoning in Network Traffic

Analyzing Network Traffic with Wireshark

Conducting Man in the Middle Attack Simulation

Configuring Network Segmentation with Vlans

Configuring Pfsense Firewall Rules

Configuring Snort IDS for Intrusion Detection

Prerequisites

Performing SSL/TLS Inspection Configuration

Overview

Prerequisites

Core Concepts

SSL/TLS Inspection Modes

Forward Proxy Process

Certificate Trust Chain

Implementation Steps

Step 1: Generate Internal CA for SSL Inspection

Step 2: Deploy CA Certificate to Endpoints

Step 3: Configure Palo Alto SSL Forward Proxy

Step 4: Configure Exemptions

Step 5: Configure Inbound Inspection for Internal Servers

Step 6: Validate SSL Inspection

Performance Considerations

Compliance and Privacy

Best Practices

Verification Criteria

Compliance Framework Mapping

Deploying This Skill with Claw GRC

Agent Execution

Audit Trail Integration

Continuous Compliance

References

Use with Claw GRC Agents

Tags

Related Skills

Detecting ARP Poisoning in Network Traffic

Analyzing Network Traffic with Wireshark

Conducting Man in the Middle Attack Simulation

Configuring Network Segmentation with Vlans

Configuring Pfsense Firewall Rules

Configuring Snort IDS for Intrusion Detection