OpenSSL - Encrypt plain text using RSAES_OAEP_SHA_256

Question

I want to encrypt local plain text file using openssl and RSAES_OAEP_SHA_256 algorithm. I tried to use the same approach with this blog entry but it did not work. https://europatech.co.uk/encryption-decryption-with-kms-and-openssl/

$ echo "hello" > plaintext.txt
$ openssl pkeyutl -encrypt -pkeyopt rsa_padding_mode:oaep -pkeyopt rsa_oaep_md:sha256 \
  -in plaintext.txt -pubin -inkey pubkey.pem -out plaintext.bin
-pkeyopt command before -inkey
Usage: pkeyutl [options]
-in file        input file
-out file       output file
-sigfile file signature file (verify operation only)
-inkey file     input key
-keyform arg    private key format - default PEM
-pubin          input is a public key
-certin         input is a certificate carrying a public key
-pkeyopt X:Y    public key options
-sign           sign with private key
-verify         verify with public key
-verifyrecover  verify with public key, recover original data
-encrypt        encrypt with public key
-decrypt        decrypt with private key
-derive         derive shared secret
-hexdump        hex dump output
-passin arg     pass phrase source

am I missing something?

Answer 1

I was looking for the same openssl command and this worked for me:

openssl pkeyutl -in data.txt -encrypt -pubin -inkey Oaep_Pub_Rsa.pem -pkeyopt rsa_padding_mode:oaep -pkeyopt rsa_oaep_md:sha256 -pkeyopt rsa_mgf1_md:sha256 -out enc.pem