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Ruby

Save a Private Key as a Traditional DER File

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Demonstrates the Chilkat PrivateKey.SavePkcs1File method, which saves the key using the traditional/preferred unencrypted DER representation. The only argument is the destination path.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: This writes the older, algorithm-specific DER structure — useful for compatibility with tools that predate or do not accept PKCS #8. For new work, PKCS #8 (SavePkcs8File) is more interoperable. The output is unencrypted, so protect the file accordingly.

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Ruby
require 'chilkat'

success = false

#  Load a private key to export.
privKey = Chilkat::CkPrivateKey.new()
success = privKey.LoadPemFile("qa_data/private.pem")
if (success == false)
    print privKey.lastErrorText() + "\n";
    exit
end

#  Save using the traditional/preferred unencrypted DER representation.
success = privKey.SavePkcs1File("qa_output/private_pkcs1.der")
if (success == false)
    print privKey.lastErrorText() + "\n";
    exit
end

print "Saved." + "\n";