IMPORTANT
- Windows Server needs to have a static IP - Else, we’d need to renew, request and install new certificates everytime.
- This doesn’t take into account Active Directory Certificate Services
- This method does not take into account the verification server (Revocation list) either.
- Test PoC Server: Windows (Windows Server 2016 Datacenter)
1. Cert Authority Generation
- CA Generation:
# Generate CA Priv Key: --PASSWORD PROTECTED--
openssl genrsa -aes256 -out ca-key.pem 4096
# Generate Public CA Key
openssl req -new -x509 -sha256 -days 365 -key ca-key.pem -out ca.pem
################################################################################################
# Inspect Pub Cert's content:
openssl x509 -in ca.pem -text
openssl x509 -in ca.pem -purpose -noout -text- Cert Generation:
openssl genrsa -out cert-key.pem 4096
# Cert signing request:
openssl req -new -sha256 -subj "/CN=yourcn" -key cert-key.pem -out cert.csr
# Extfile with the altname(s):
# Originally we'd create a cert with a DNS name:
echo "subjectAltName=DNS:your-dns.record,IP:257.10.10.1" >> extfile.cnf
# But this time we're only using an IP address:
echo "subjectAltName=IP:257.10.10.1" >> extfile.cnf
# Create CERTIFICATE:
openssl x509 -req -sha256 -days 365 -in cert.csr -CA ca.pem -CAkey ca-key.pem -out cert.pem -extfile extfile.cnf -CAcreateserial
# PFX conversion
openssl pkcs12 -export -out mysite.pfx -inkey cert-key.pem -in cert.pem
# Convert to B64:
base64 mysite.pfx > pfx-cert.base64
2. CA Installation on RDP Server
Using certutil.exe in Windows Server (.PFX)
# BASE64 -> PFX:
$base64Content = Get-Content C:\PATH\certpfxB64.txt
$decodedBytes = [System.Convert]::FromBase64String($base64Content)
Set-Content -Path C:\PATH\new.pfx -Value $decodedBytes -Encoding Byte
# Verify PFX is valid:
Get-PfxCertificate -FilePath .\new.pfx
# Install ce®tificate:
certutil.exe -p "<PASSWORD>" -importPFX C:\PATH\certificate.pfx noExport
# Export thumbprint of the certificate to a variable ($tp)
$tp = (ls Cert:\LocalMachine\my | WHERE {$_.Subject -match "<IP ADDRESS> ó Identificador a ser buscado" } | Select -First 1).Thumbprint
# Verify the variable is as expected:
echo $tp
# Using WMIC to add it and specify the SSL cert to be used by service (RDP or Terminal Services):
& wmic /namespace:\\root\CIMV2\TerminalServices PATH Win32_TSGeneralSetting Set SSLCertificateSHA1Hash="$tp"
# No reboot required3. Windows Client Certificate installation
# Install cert:
certutil -addstore root C:\PATH\ca.pem
# or:
import-certificate -filepath "C:\ca.pem" -certstorelocation Cert:\LocalMachine\RootTESTS
