While you can certainly create your own CA and generate self-signed certificates, Extended Validation (EV) certificates operate under a completely different paradigm. The green address bar and organization name display in browsers require strict validation processes that go beyond technical certificate generation.

To achieve EV status, you must:

• Be a legally registered business entity
• Pass rigorous verification by a Certificate Authority (CA) approved by browser vendors
• Follow the EV Guidelines from the CA/Browser Forum
• Have your root certificate included in browser trust stores

Browsers maintain hard-coded lists of CAs authorized to issue EV certificates. Even if you mimic all the technical aspects:

# Example openssl config that won't make a true EV cert
[ v3_ca ]
basicConstraints = critical,CA:TRUE
keyUsage = critical,keyCertSign,cRLSign
certificatePolicies = 2.23.140.1.1

The policy OID (2.23.140.1.1) indicates EV, but without browser recognition, it's meaningless.

For internal systems, you can:

1. Create your CA
2. Distribute the root certificate to all client machines
3. Configure applications to recognize your certs with special treatment

Example Firefox preference to force EV-like display (about:config):

// Not real EV but can show organization name
lockPref("security.enterprise_roots.enabled", true);

Major browsers use compiled-in lists of trusted root CAs with specific policy constraints. Chrome's list comes from the Chromium project, Firefox uses Mozilla's CA Certificate Program, and Edge/IE use Microsoft's root program.

EV certificates exist primarily for e-commerce and financial institutions needing maximum user trust. For most development purposes, standard OV or DV certificates from Let's Encrypt provide sufficient security without the EV overhead.

While developers can easily create self-signed certificates through their own Certificate Authority (CA), Extended Validation (EV) certificates operate under entirely different rules. The green address bar and organization name display require meeting strict validation criteria established by the CA/Browser Forum.

# This won't give you EV status
openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -days 365

The fundamental limitations include:

• EV certificates must be issued by a CA included in Microsoft's and Mozilla's root programs
• Requires legal business verification including government registration checks
• Physical address verification and operational existence confirmation
• Extended validation process typically takes 5-10 business days

For a certificate to trigger EV treatment in browsers:

Certificate must contain:
1. Certificate Policies extension with OID 2.23.140.1.1
2. CA must be in Microsoft/Mozilla root stores
3. Subject Organization fields must match legal registration
4. SHA-256 or stronger signature algorithm

For internal enterprise use, Microsoft provides specific guidance:

Windows Server AD CS can issue EV-like certificates when:
- Deployed with specific certificate templates
- Clients have the issuing CA in their Trusted Root store
- Using specific OIDs (1.3.6.1.4.1.311.47.1.1 for example)

For testing purposes, you can:

1. Use a test EV certificate from providers like DigiCert or Sectigo
2. Configure browser flags to simulate EV behavior (Chrome's --ignore-certificate-errors-spki-list)
3. Implement a local proxy that modifies certificate validation

// Example: Node.js server with forced EV-like response
const https = require('https');
const fs = require('fs');

const options = {
  key: fs.readFileSync('server.key'),
  cert: fs.readFileSync('server.crt'),
  headers: {
    'Strict-Transport-Security': 'max-age=63072000'
  }
};

https.createServer(options, (req, res) => {
  res.writeHead(200);
  res.end('Simulated EV SSL Connection\n');
}).listen(443);