cipher | Easy aes-256-cbc encryption | Encryption library

Here I'm wondering about the line [in s_client]
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES256-GCM-SHA384

You're apparently using OpenSSL 1.0.2, where that's a basically useless relic. Back in the days when OpenSSL supported SSLv2 (mostly until 2010, although almost no one used it much after 2000), the ciphersuite values used for SSLv3 and up (including all TLS, but before 2014 OpenSSL didn't implement higher than TLS1.0) were structured differently than those used for SSLv2, so it was important to qualify the ciphersuite by the 'universe' it existed in. It has almost nothing to do with the protocol version actually used, which appears later in the session-param decode:

The way you're encrypting data makes no sense. Asymmetric encryption can only encrypt a small, fixed amount of data. Never use asymmetric encryption such as RSA-OAEP for anything other than a symmetric key, and use that symmetric key to encrypt the actual data. For the symmetric encryption, use a proper AEAD mode such as AES-GCM or ChaCha20-Poly1305. This is called hybrid encryption.

Other things that are wrong with your code:

• A 1024-bit RSA key is not enough for security: 2048-bit is a minimum, and you should prepare to move away from RSA because its key sizes don't scale well. (Feel free to use 1024-bit keys for testing and learning, just don't use anything less than 2048-bit for RSA in production.)
• The encryption is a binary format, but you join up lines as if they were text. Text or binary: pick one. Preferably use a well-known format such as ASN.1 (complex but well-supported) for binary data or JSON for text. If you need to encode binary data in a text format, use Base64.

If this is for real-world use, scrap this and use NaCl or libsodium. In Python, use a Python wrapper such as libnacl, PyNaCl, pysodium or csodium. Use a public-key box. The Python APIs are slightly different for each Python wrapper, but all include a way to export the keys.

If this is a learning exercise, read up on hybrid encryption. Look inside libsodium to see how to do it correctly. Key import and export is done with the methods import_key and export_key. Symmetric encryption starts with Crypto.Cipher.AES.new(key, Crypto.Cipher.AES.MODE_GCM) or Crypto.Cipher.ChaCha20_Poly1305.new(key) (Crypto.Cipher.AES.new(key, Crypto.Cipher.AES.MODE_GCM, nonce=nonce) or Crypto.Cipher.ChaCha20_Poly1305.new(key, nonce=nonce) for decryption).

GCM is a stream cipher mode and therefore does not require padding. During encryption, an authentication tag is implicitly generated, which is used for authentication during decryption. Also, an IV/nonce of 12 bytes is recommended for GCM.

The posted Python code unnecessarily pads and doesn't take the authentication tag into account, unlike the JavaScript code, which may be the main reason for the different ciphertexts. Whether this is the only reason and whether the JavaScript code implements GCM correctly, is difficult to say, since the getMessageEncoding() method was not posted, so testing this was not possible.

Also, both codes apply a 16 bytes IV/nonce instead of the recommended 12 bytes IV/nonce.

Cryptography offers two possible implementations for GCM. One implementation uses the architecture of the non-authenticating modes like CBC. The posted Python code applies this design, but does not take authentication into account and therefore implements GCM incompletely. A correct example for this design can be found here.
Cryptography generally recommends the other approach for GCM (s. the Danger note), namely the AESGCM class, which performs implicit authentication so that this cannot be accidentally forgotten or incorrectly implemented.

The following implementation uses the AESGCM class (and also takes into account the optional additional authenticated data):

The referenced Python code uses P-384 (aka secp384r1) as elliptic curve. This is compatible with the WebCrypto API, which supports three curves P-256 (aka secp256r1), P-384 and P-521 (aka secp521r1), see EcKeyImportParams.

The following WebCrypto code generates a shared secret using ECDH and derives an AES key from the shared secret using HKDF. In detail the following happens:

• To allow comparison of the derived key with that of the referenced Python code, predefined EC keys are applied. The private key is imported as PKCS#8, the public key as X.509/SPKI. Note that due to a Firefox bug concerning the import of EC keys, the script below cannot be run in the Firefox browser.
• After the import the shared secret is created with ECDH using deriveBits() (and not deriveKey()).
• The shared secret is imported with importKey() and then the AES key is derived using HKDF, again with deriveBits().

I notice that you're connecting to https://mydomain.dev, but passing a host header for a different domain. My guess would be that curl is sending an SNI request for a mydomain.dev cert; since networking-ns-cert will acquire wildcard certs for *..my domain.dev, it's possible that the server doesn't have a cert matching the SNI request, and closes the TCP connection.

Try using the -kvv options to curl (instead of -v) to print more verbose debugging information and bypass some SSL errors. Since you have DNS and certs set up, I'd try:

curl -kvv https://helloworld-go.default.mydomain.dev

I think the issue is you are creating a new connection for each request, just do

Your issue is here enable.auto.commit = false. If you are not manually committing offset after consuming messages, You should configure this to true

If this is set to false, after consuming messages from Kafka, there is no feedback to Kafka whether you read or not. Then after you restart your consumer it will send messages from the start. If you enable this, your consumer make sure it will automatically send your last read offset to Kafka. Then Kafka saved that offset in __consumer_offsets topic with your consumer group_id, topic you consumed and partition.

Then after you restart the consumer, Kafka read your last position from __consumer_offsets topic and send from there.

see below (the code collects the tables data into a dict)

AES in CBC mode doesn't care about what you encypt: it simply encrypts the bytes that you supply (after padding it to the right size in most implementations).

Does data[key] contain the right characters? If so then you need to explicitly encode to e.g. UTF-8 before calling update. Otherwise you need to make sure that data[key] gets assigned the right value of course.

Note that using let message = data[key] followed by encrypted = cipher.update(message) would show you the contents of a message in the debugger; don't be hasty!