When implementing SSL/TLS for internal applications, the fundamental difference lies in trust chain management. A self-signed certificate acts as its own root authority, while an internal CA-signed certificate establishes a hierarchical trust model.

Consider this OpenSSL command to generate a self-signed cert:

openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes

For a CA-signed certificate, you'd first need to establish your CA:

# Generate CA private key
openssl genrsa -out ca.key 4096

# Create CA certificate
openssl req -new -x509 -days 365 -key ca.key -out ca.crt

For a Windows Server CA environment, the certificate enrollment process differs significantly:

# PowerShell command to request cert from Windows CA
$cert = Get-Certificate -Template "WebServer" -Url "ldap:///CN=CA01,CN=Enrollment"

Self-signed certificates require manual trust establishment on each client:

# Linux client trust import
sudo cp cert.pem /usr/local/share/ca-certificates/
sudo update-ca-certificates

Internal CA certificates only need the root CA installed once.

Internal CAs support CRL/OCSP for revocation:

# Checking certificate revocation status
openssl verify -CAfile ca.crt -crl_check -crl_download cert.pem

Self-signed certificates lack this capability entirely.

For production environments with multiple services, an internal CA provides:

• Centralized certificate lifecycle management
• Automated renewal processes
• Consistent security policies
• Audit capabilities

For Windows environments with AD integration, setting up Certificate Services provides seamless authentication:

# Install AD CS role
Install-WindowsFeature Adcs-Cert-Authority -IncludeManagementTools

# Configure CA
Install-AdcsCertificationAuthority -CAType EnterpriseRootCA

When implementing SSL/TLS in internal networks, the fundamental difference lies in trust chain management. A self-signed certificate acts as its own root authority, while a private CA-signed certificate establishes a proper certificate hierarchy that can be centrally managed.

# Generating a self-signed certificate with OpenSSL
openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365 -nodes -subj "/CN=internal.example.com"

# Generating CSR for CA signing
openssl req -new -newkey rsa:4096 -nodes -keyout server.key -out server.csr -subj "/CN=sensitiveapp.internal"

A Windows Server CA provides several advantages for enterprise environments:

• Centralized certificate lifecycle management
• Automatic renewal capabilities
• Template-based certificate issuance
• Integration with Active Directory

For .NET applications, the certificate validation approach differs significantly:

// Bypassing validation for self-signed (NOT recommended for production)
ServicePointManager.ServerCertificateValidationCallback += 
    (sender, cert, chain, errors) => true;

// Proper validation with private CA
X509Store store = new X509Store(StoreName.Root, StoreLocation.LocalMachine);
store.Open(OpenFlags.ReadOnly);
var certs = store.Certificates.Find(X509FindType.FindByThumbprint, "THUMBPRINT", false);

When using a private CA:

1. Secure the CA server with strict access controls
2. Implement certificate revocation (CRL/OCSP)
3. Use appropriate key lengths (minimum 2048-bit RSA)
4. Establish clear certificate expiration policies

While both approaches have similar SSL/TLS handshake overhead, private CA-signed certificates enable:

• Faster deployment through auto-enrollment
• Reduced maintenance from automatic renewals
• Better security through managed revocation