error on launching postgres in ssl mode

hello.....I've created the server.key and server.crt in this manner:

openssl req -new -nodes -keyout server.key -out server.csr

openssl req -key /home/data/server.key -in /home/data/server.csr -out
server.crt

then:

chmod 700 /home/data/server.key /home/data/server.crt

chown postgres:postgres /home/data/server.key /home/data/server.crt

and I put theese in my data home.

I launch postgres in this manner:

postmaster -il -p '$PGPORT' -D '$PGDATA_LOCAL' ${PGOPTS} &

when I launch it I have this error:

FATAL: could not load server certificate file "/home/data/server.crt": no
start line

why?