# ECC openssl cms support
    # openssl cms -decrypt -in encrypted.txt -inkey client.key -recip client.pem
    # openssl cms -encrypt -aes256 -in message.txt -out encrypted.txt \
    #                      -recip client.pem -keyopt ecdh_kdf_md:sha256

    # RSA GnuPG S/MIME support
    # gpgsm --list-keys
    # gpgsm --list-secret-keys
    # gpgsm -r 0xD3C8F78A -e CNAME > cms.bin
    # gpgsm -u 0xD3C8F78A -d cms.bin
    # gpgsm --export-secret-key-p12 0xD3C8F78A > key.bin
    # openssl pkcs12 -in key.bin -nokeys -out public.pem
    # openssl pkcs12 -in key.bin -nocerts -nodes -out private.pem

    # KEK openssl cms support
    # openssl cms -encrypt -secretkeyid 07 -secretkey 0123456789ABCDEF0123456789ABCDEF \
    #             -aes256 -in message.txt -out encrypted2.txt
    # openssl cms -decrypt -secretkeyid 07 -secretkey 0123456789ABCDEF0123456789ABCDEF \
    #             -in encrypted2.txt