(Ruby) Export a Certificate's Private Key to Various Formats

Loads a digital certificate and private key from a PFX file (also known as PKCS#12) and exports the private key to various formats: (1) PKCS8 Encrypted, (2) PKCS8 Encrypted PEM, (3) PKCS8 unencrypted, (4) PKCS8 PEM unencrypted, (5) RSA DER unencrypted, (6) RSA PEM unencrypted, (7) XML.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

cert = Chilkat::CkCert.new()

# Load from the PFX file
pfxFilename = "/Users/chilkat/testData/pfx/chilkat_ssl_pwd_is_test.pfx"
pfxPassword = "test"

# A PFX typically contains certificates in the chain of authentication.
# The Chilkat cert object will choose the certificate w/
# private key farthest from the root authority cert.
# To access all the certificates in a PFX, use the 
# Chilkat certificate store object instead.
success = cert.LoadPfxFile(pfxFilename,pfxPassword)
if (success != true)
    print cert.lastErrorText() + "\n";
    exit
end

# Get the private key...

# privKey is a CkPrivateKey
privKey = cert.ExportPrivateKey()
if (cert.get_LastMethodSuccess() == false)
    print cert.lastErrorText() + "\n";
    exit
end

# Export to various formats:

password = "secret"

# PKCS8 Encrypted DER
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8_enc.der"
success = privKey.SavePkcs8EncryptedFile(password,path)
if (success != true)
    print privKey.lastErrorText() + "\n";

    exit
end

# PKCS8 Encrypted PEM
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8_enc.pem"
success = privKey.SavePkcs8EncryptedPemFile(password,path)
if (success != true)
    print privKey.lastErrorText() + "\n";

    exit
end

# PKCS8 Unencrypted DER
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8.der"
success = privKey.SavePkcs8File(path)
if (success != true)
    print privKey.lastErrorText() + "\n";

    exit
end

# PKCS8 Unencrypted PEM
path = "/Users/chilkat/testData/privkeys/chilkat_pkcs8.pem"
success = privKey.SavePkcs8PemFile(path)
if (success != true)
    print privKey.lastErrorText() + "\n";

    exit
end

#  RSA DER (unencrypted)
path = "/Users/chilkat/testData/privkeys/chilkat_rsa.der"
success = privKey.SavePkcs1File(path)
if (success != true)
    print privKey.lastErrorText() + "\n";

    exit
end

# RSA PEM (unencrypted)
path = "/Users/chilkat/testData/privkeys/chilkat_rsa.pem"
success = privKey.SavePemFile(path)
if (success != true)
    print privKey.lastErrorText() + "\n";

    exit
end

# XML (unencrypted)
path = "/Users/chilkat/testData/privkeys/chilkat.xml"
success = privKey.SaveXmlFile(path)
if (success != true)
    print privKey.lastErrorText() + "\n";

    exit
end

print "Private key exported to all formats." + "\n";