How to create a certificate to send APNS notifications, manually using OpenSSL

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Create your key.

openssl genrsa -out truc.example.org.key 2048

Create the certificate request:

openssl req -new -key truc.example.org.key -out truc.example.org.csr

Upload the CSR to Apple, and get the resultant certificate.

Optionally convert the certificate to PEM format.

openssl x509 -inform der -in truc.example.org.cer -out truc.example.org.crt.pem

Check if you can connect to APNS with your credentials:

openssl s_client -connect gateway.sandbox.push.apple.com:2195 -cert truc.example.org.crt.pem -key truc.example.org.key

Use the key and certificate files for profit.

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