服务器问候完成后的 TLS 握手错误

Question

我有一个 python 应用程序正在连接到一个 java 应用程序，两者都使用相同的证书。 这个证书也被导入到双方的trusted-certs中。

整个 TLS 握手过程的功能已通过自签名证书进行了验证。

但是，当我想改用全局 CA 签名证书时，会遇到握手错误：

这是我通过在服务器端（java 应用程序）启用-Djavax.net.debug=ssl,handshake得到的 SSL 日志：

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***
update handshake state: certificate[11]
upcoming handshake states: server_key_exchange[12](optional)
upcoming handshake states: certificate_request[13](optional)
upcoming handshake states: server_hello_done[14]
upcoming handshake states: client certificate[11](optional)
upcoming handshake states: client_key_exchange[16]
upcoming handshake states: certificate_verify[15](optional)
upcoming handshake states: client change_cipher_spec[-1]
upcoming handshake states: client finished[20]
upcoming handshake states: server change_cipher_spec[-1]
upcoming handshake states: server finished[20]
*** ECDH ServerKeyExchange
Signature Algorithm SHA256withRSA
Server key: Sun EC public key, 256 bits
  public x coord: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
  public y coord: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
  parameters: secp256r1 [NIST P-256, X9.62 prime256v1] (1.2.840.10045.3.1.7)
update handshake state: server_key_exchange[12]
upcoming handshake states: certificate_request[13](optional)
upcoming handshake states: server_hello_done[14]
upcoming handshake states: client certificate[11](optional)
upcoming handshake states: client_key_exchange[16]
upcoming handshake states: certificate_verify[15](optional)
upcoming handshake states: client change_cipher_spec[-1]
upcoming handshake states: client finished[20]
upcoming handshake states: server change_cipher_spec[-1]
upcoming handshake states: server finished[20]
*** ServerHelloDone
update handshake state: server_hello_done[14]
upcoming handshake states: client certificate[11](optional)
upcoming handshake states: client_key_exchange[16]
upcoming handshake states: certificate_verify[15](optional)
upcoming handshake states: client change_cipher_spec[-1]
upcoming handshake states: client finished[20]
upcoming handshake states: server change_cipher_spec[-1]
upcoming handshake states: server finished[20]
Thread-54, WRITE: TLSv1.2 Handshake, length = 2075
Thread-54, READ: TLSv1.2 Alert, length = 2
Thread-54, RECV TLSv1.2 ALERT:  fatal, unknown_ca
%% Invalidated:  [Session-2, SSL_NULL_WITH_NULL_NULL]
%% Invalidated:  [Session-4, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384]
Thread-54, called closeSocket()
Thread-54, handling exception: javax.net.ssl.SSLHandshakeException: Received fatal alert: unknown_ca

最后几行，在ServerHelloDone之后，指示错误：

Thread-54, WRITE: TLSv1.2 Handshake, length = 2075
Thread-54, READ: TLSv1.2 Alert, length = 2
Thread-54, RECV TLSv1.2 ALERT:  fatal, unknown_ca
%% Invalidated:  [Session-2, SSL_NULL_WITH_NULL_NULL]
%% Invalidated:  [Session-4, TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384]
Thread-54, called closeSocket()
Thread-54, handling exception: javax.net.ssl.SSLHandshakeException: Received fatal alert: unknown_ca

下一步显然是client_key_exchange 。 它是否与客户的私钥有任何关系？

unknown_ca是什么意思？ 客户端的 trust_cert 或服务器的证书中是否缺少证书？

下图也是使用 Wireshark 捕获的流量，主要行使用自签名证书，最后 3 行是有问题的证书，如上所述：

Answer 1

unknown_ca 是什么意思？ 客户端的 trust_cert 或服务器的证书中是否缺少证书？

unknown_ca表示由于信任库中缺少 CA，证书不受信任。 由于警报是由客户端发送的，这意味着客户端不信任颁发服务器证书的 CA。 这可能是因为信任存储中缺少根 CA，但也可能是服务器没有发送必要的中间证书，以便客户端可以建立到本地根 CA 的信任链。