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openssl genpkey -out device1.key -algorithm RSA -pkeyopt rsa_keygen_bits:2048
openssl req -new -key device1.key -out device1.csr
openssl req -text -in device1.csr -noout
openssl x509 -req -days 7 -in device1.csr -signkey device1.key -out device1.crt
openssl genpkey -out device2.key -algorithm RSA -pkeyopt rsa_keygen_bits:2048
openssl req -new -key device2.key -out device2.csr
openssl x509 -req -days 14 -in device2.csr -signkey device2.key -out device2.crt