Is it possible to transfer over OpenSSL encrypt/decrype network?

Question

PHP

There are two computers, physically in different places.
Computer A encodes the password string (1234) and sends the encrypted string to computer B.
Computer B will be able to decrypt the string given this password: 1234?
The openssl encrypt/decrypt function raises doubts - they encode/decode only on the basis of a salt or some other data specific to the hardware, for example? :)

Answer 1

Is it possible to transfer over OpenSSL encrypt/decrype network?

Sure you can. The main thing is that the password and IV match.
Block ciphers usually use AES-256-CBC.
If you plan to always use different passwords, you can think over a scheme for exchanging client-server keys using the Diffie-Hellman algorithm and, based on them, create a password and IV according to a certain algorithm.
For example, Telegram uses the following algorithm to generate a key and a vector:

// псевдокод
x = 0 for messages from client to server 
// or
x = 8 for those from server to client.

data = данные для шифрования или расшифрования
auth_key = ключ аутенификации 256 байт (зашить в клиент и сервер или получать при обмене ключами при помощи DH)
msg_key = substr(SHA1(data), 0, 16)

sha1_a = SHA1 (msg_key + substr (auth_key, x, 32));
sha1_b = SHA1 (substr (auth_key, 32+x, 16) + msg_key + substr (auth_key, 48+x, 16));
sha1_с = SHA1 (substr (auth_key, 64+x, 32) + msg_key);
sha1_d = SHA1 (msg_key + substr (auth_key, 96+x, 32));
aes_key = substr (sha1_a, 0, 8) + substr (sha1_b, 8, 12) + substr (sha1_c, 4, 12);
aes_iv = substr (sha1_a, 8, 12) + substr (sha1_b, 0, 8) + substr (sha1_c, 16, 4) + substr (sha1_d, 0, 8);

To protect against MITM, in the case of a key exchange, you can sew your own certificate into the client and server and reject requests not signed by it.
No, everything is clear. It's not random.