Getting error while trying to create the push certificate...

I am getting the following error while trying to create a push certificate for the mdm from the apple site.

Certificate Signature Verification failed because the signature is invalid.

I am mdm vendor as well as the customer. I did the following steps.

openssl x509 -inform der -in mdm_identity.cer -out mdm.pem

openssl x509 -inform der -in AppleWWDRCA.cer -out intermediate.pem

openssl x509 -inform der -in AppleIncRootCertificate.cer -out root.pem

openssl req -inform pem -outform der -in customer.csr -out customer.der

created the plist_encoded file using a java program which uses the "SHA1WthRSA"

When i tried to upload the plist_encoded file to the apple site (https://identity.apple.com/pushcert/), it creates a file with the following error

{"ErrorCode":-80018,"ErrorMessage":"Certificate Signature Verification failed","ErrorDescription":"Certificate Signature Verification failed because the <a href=\"http://www.apple.com/business/mdm\" target=\"_blank\">signature<\/a> is invalid."}

Any help would be greatly appreciated....