CFINSPEC-84: Add be_valid matcher for x509_private_key

Signed-off-by: Sonu Saha <sonu.saha@progress.com>

lib/inspec/resources/x509_private_key.rb

@@ -0,0 +1,86 @@
+require "openssl" unless defined?(OpenSSL)
+require "inspec/utils/file_reader"
+
+module Inspec::Resources
+  class X509PrivateKey < Inspec.resource(1)
+    # Resource internal name.
+    name "x509_private_key"
+
+    # Restrict to only run on the below platforms (if none were given,
+    # all OS's and cloud API's supported)
+    supports platform: "unix"
+    supports platform: "windows"
+
+    desc "Use the ipnat InSpec audit resource to test the x509 private key"
+
+    example <<~EXAMPLE
+      describe "x509_private_key" do
+        its("shoe_size") { should cmp 10 }
+      end
+      describe "x509_private_key" do
+        it { should be_purple }
+      end
+    EXAMPLE
+
+    # Resource initialization.
+    attr_reader :secret_key_path, :passphrase, :openssl_utility
+    def initialize(secret_key_path, passphrase = nil)
+      @openssl_utility = check_openssl_or_error
+      @secret_key_path = secret_key_path
+      @passphrase = passphrase
+    end
+
+    # Define a resource ID. This is used in reporting engines to uniquely identify the individual resource.
+    # This might be a file path, or a process ID, or a cloud instance ID. Only meaningful to the implementation.
+    # Must be a string. Defaults to the empty string if not implemented.
+    def resource_id
+      # replace value specific unique to this individual resource instance
+      "something special"
+    end
+
+    # Define how you want your resource to appear in test reports. Commonly, this is just the resource name and the resource ID.
+    def to_s
+      "x509_private_key #{resource_id}"
+    end
+
+    def has_bells?
+      # positive or negative expectations specific to this resource instance
+      true # Jingle all the way
+    end
+
+    def valid?
+      # - With passphrase
+      # `openssl rsa -in alice_private.pem -check -noout -passin pass:alice123`
+      # - Without passphrase - 1
+      # `openssl rsa -in chloe_private.pem -check -noout -passin pass:stdin`
+      # - Without passphrase - 2
+      # `openssl rsa -in chloe_private.pem -check -noout`
+      openssl_valid_cmd = "#{openssl_utility} rsa -in #{secret_key_path} -check -noout"
+      openssl_valid_cmd.concat(" -passin pass:#{passphrase}") if passphrase
+      exec_openssl_valid_cmd = inspec.command(openssl_valid_cmd)
+      # require "byebug"; byebug
+      exec_openssl_valid_cmd.exit_status.to_i == 0
+
+    end
+
+    def encrypted?
+    end
+
+    
+
+    private
+
+    # This resource requires openssl to be available on the system
+    def check_openssl_or_error
+      %w{/usr/sbin/openssl /usr/bin/openssl /sbin/openssl /bin/openssl openssl}.each do |cmd|
+        return cmd if inspec.command(cmd).exist?
+      end
+
+      raise Inspec::Exceptions::ResourceFailed, "Could not find `openssl` on your system."
+    end
+
+    # def openssl_cmd
+    #   "#{openssl_utility} rsa -in #{secret_key_path} -check -noout"
+    # end
+  end
+end