Revert "Add back in the verification of the certs by open SSL library"

This reverts commit 9d13f1b.

cr https://code.amazon.com/reviews/CR-2114105

Author: Katyal

lib/instance_agent/plugins/codedeploy/deployment_specification.rb

@@ -106,17 +106,8 @@ def self.parse(envelope)
           case envelope.format
           when "PKCS7/JSON"
             pkcs7 = OpenSSL::PKCS7.new(envelope.payload)
-
-            # The PKCS7_NOCHAIN flag tells OpenSSL to ignore any PKCS7 CA chain that might be attached
-            # to the message directly and use the certificates from provided one only for validating the.
-            # signer's certificate.
-            #
-            # However, it will allow use the PKCS7 signer certificate provided to validate the signature.
-            #
-            # http://www.openssl.org/docs/crypto/PKCS7_verify.html#VERIFY_PROCESS
-            #
-            # The ruby wrapper returns true if OpenSSL returns 1
-            raise "Validation of PKCS7 signed message failed" unless pkcs7.verify([], @cert_store, nil, OpenSSL::PKCS7::NOCHAIN)
+            pkcs7.verify([], @cert_store, nil, OpenSSL::PKCS7::NOVERIFY)
+            # NOTE: the pkcs7.data field is only populated AFTER pkcs7.verify() is called!
             parse_deployment_spec_data(pkcs7.data)
           when "TEXT/JSON"
             raise "Unsupported DeploymentSpecification format: #{envelope.format}" unless AWS::CodeDeploy::Local::Deployer.running_as_developer_utility?