与lib钠安全密钥交换

我想做一个测试应用程序，它使用libsodium从客户端到服务器通信。

有许多语言的许多端口:c#,PHP,…

总有一个例子是"bob"answers"alice"。这很好，但是他们从来没有展示如何以安全的方式在网络上交换公钥。

那么，建议如何交换"alice/client"answers"bob/server"的公钥呢?

它们总是使用同一个文件或同一台机器来生成密钥对。

libsodium-php扩展名:

$alice_kp = crypto_box_keypair();
$alice_secretkey = crypto_box_secretkey($alice_kp);
$alice_publickey = crypto_box_publickey($alice_kp);
$bob_kp = crypto_box_keypair();
$bob_secretkey = crypto_box_secretkey($bob_kp);
$bob_publickey = crypto_box_publickey($bob_kp);
$alice_to_bob_kp = crypto_box_keypair_from_secretkey_and_publickey
  ($alice_secretkey, $bob_publickey);
$bob_to_alice_kp = crypto_box_keypair_from_secretkey_and_publickey
  ($bob_secretkey, $alice_publickey);
$alice_to_bob_message_nonce = randombytes_buf(CRYPTO_BOX_NONCEBYTES);
$alice_to_bob_ciphertext = crypto_box('Hi, this is Alice',
                                      $alice_to_bob_message_nonce,
                                      $alice_to_bob_kp);
$alice_message_decrypted_by_bob = crypto_box_open($alice_to_bob_ciphertext,
                                                  $alice_to_bob_message_nonce,
                                                  $bob_to_alice_kp);
$bob_to_alice_message_nonce = randombytes_buf(CRYPTO_BOX_NONCEBYTES);
$bob_to_alice_ciphertext = crypto_box('Hi Alice! This is Bob',
                                      $bob_to_alice_message_nonce,
                                      $bob_to_alice_kp);
$bob_message_decrypted_by_alice = crypto_box_open($bob_to_alice_ciphertext,
                                                  $bob_to_alice_message_nonce,
                                                  $alice_to_bob_kp);