How to obtain an acceptable APK file for Google Play ?

Question

There is the steps of my trying in my Google Play console :
1) With OpenSSL I've made a PEM file :
openssl pkcs12 -in certificatCreeSurFBuilder.p12 -out certificatCreeSurFBuilder.pem -nodes
With Notepad I've update the content of the PEM file : I've add the key provided between the markups of the "RSA Public Key", the public key from Google which I've divided the text to 64 caracters per row (for 64-base encoded).
So with OpenSSL I've made a PKCS12 file :
openssl pkcs12 -export -in certificatCreeSurFBuilder.pem -inkey certificatCreeSurFBuilder.pem -out certificatPourGooglePlay.p12
2) Finally I've uploaded the PKCS12 file using my console at https://play.google.com/apps/publish, but I've got this error message wich doesn't light me : "Import error. Try to import an other file" !
Moreover, I'd like to know if I would have a best result if I'd buy a certificate provided by a reputed organism, e.g. Verisign or Thatwe ?
NB : I have indicated my personnal datas in "bag attributes" labels named CN and C (CN=myName and C=myCountry), at the first step of primary certificate creation, in the FlashBuilder wizard tool. So is it usefull or is it bad in this case to indicate these datas ?
Thanks for help.

Answer 1

I write about my new tests,  I've found this good Google documentation URL : http://developer.android.com/tools/publishing/app-signing.html ;-).
I don't know if this method is more valid or even with my first method, but I downloaded the tools and I followed the method to create a keystore, with no success :
I've created a keystore/ pair of keys, it's Ok :
  keytool -genkey -v -keystore certificatAutoSigne-2013.keystore -alias certificatAutoSigne-2013 -keyalg RSA -keysize 2048 -validity 10000
But I don't understand where can I add the Google public key to sign my APK file, because the keystore isn't a text file !
Secondly I've error message with this command line :
  jarsigner -verbose -sigalg SHA1withRSA -digestalg SHA1 -keystore certificatAutoSigne-2013.keystore MyAPKFile
Obviously an APK file already signed can't be re-signed. I don't know how to creat APK file no signed with ADT, do you know ?