Wrapper around openssl to extract RSA private key

extract_rsa_privatekey.ps1

### Requires openssl (https://www.openssl.org/).
### Usage:
### .\extract_rsa_privatekey.ps1 .\YOUR_CERTIFICATE.pfx (ConvertTo-SecureString "YOUR_STRONG_PASSWORD" -AsPlainText -Force)

param(
  [Parameter(Mandatory=$true)][string] $certificatePfxPath,
  [SecureString] $password,
  [string] $pathToOpenSsl = '.'
)

try
{
  # Export the private key
  & "$pathToOpenSsl\openssl.exe" pkcs12 -in $certificatePfxPath -nocerts -out key.pem -nodes -password pass:$(ConvertFrom-SecureString $password -AsPlainText)
  
  # Export the certificate
  & "$pathToOpenSsl\openssl.exe" pkcs12 -in $certificatePfxPath -nokeys -out cert.pem -password pass:$(ConvertFrom-SecureString $password -AsPlainText)
  
  # RSA key without password in plaintext
  & "$pathToOpenSsl\openssl.exe" rsa -in key.pem -out rsa_private.key
}
finally 
{
  Remove-Item key.pem -Force -Confirm:$false | Out-Null
  Remove-Item cert.pem -Force -Confirm:$false | Out-Null
}