OpenSSL Generated Keys?

[CaffeineLab]

We created a key as:

openssl ecparam -name prime256v1 -genkey -noout -out private-key.pem

But whenever trying to decrypt we get an error for wrong curve.

curve = sslcrypto.ecc.get_curve("prime256v1")
print(curve.decrypt(ciphertext, private_key, algo="aes-256-ofb") )

Not sure if I'm far off or close enough - but any direction will be appreciated.

[purplesyringa]

Perhaps the problem is in the ciphertext format. sslcrypto expects the ciphertext to start with 16 bits of AES IV, followed by the ephemeral public key, followed by the AES-encrypted data.

It'd be great if you specified which library you're using to encrypt the data and how you're using it.

[CaffeineLab]

The app sending me the encrypted message is JAVA - here's the encryption snippet:

        byte[] plainTextBytes = inputData.getBytes("UTF-8");
        cipher = Cipher.getInstance("ECIES", BouncyCastleProvider.PROVIDER_NAME);
        cipher.init(Cipher.ENCRYPT_MODE, keys.getPublic());
        byte[] encryptedData = cipher.doFinal(plainTextBytes);
        return Base64.getEncoder().encodeToString(encryptedData);

[purplesyringa]

It'd help if you sent me an example of a ciphertext (here or to imachug@gmail.com). I can only guess the format is probably PKCS #7, but I'd like to make sure.

[CaffeineLab]

Sent.