Apache HttpClient – Log version of TLS that’s negotiated in a request?

I’ve got lots of code that uses Apache’s HttpClient, and I’d like to log the version of TLS that’s being negotiated when a request is made.

Is this possible?

I’d prefer an approach that doesn’t requiring changing how the request is being built, if possible – something that inspects a response or views a log or something like that?

From my review, it appears this is only possible if we debug SSL at the VM level, or perhaps if a custom SSLContext is used?

Answer

If you turn on debug level logging for org.apache.http.conn.ssl category HttpClient will log quite a bit of details about the SSL session used including TLS/SSL protocol version.

[DEBUG] DefaultHttpClientConnectionOperator - Connecting to httpbin.org/54.225.150.40:443
[DEBUG] SSLConnectionSocketFactory - Connecting socket to httpbin.org/54.225.150.40:443 with timeout 0
[DEBUG] SSLConnectionSocketFactory - Enabled protocols: [TLSv1, TLSv1.1, TLSv1.2]
[DEBUG] SSLConnectionSocketFactory - Enabled cipher suites:[TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, TLS_RSA_WITH_AES_128_CBC_SHA256, TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256, TLS_DHE_RSA_WITH_AES_128_CBC_SHA256, TLS_DHE_DSS_WITH_AES_128_CBC_SHA256, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDH_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_DSS_WITH_AES_128_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, TLS_RSA_WITH_AES_128_GCM_SHA256, TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256, TLS_DHE_RSA_WITH_AES_128_GCM_SHA256, TLS_DHE_DSS_WITH_AES_128_GCM_SHA256, TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA, TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
[DEBUG] SSLConnectionSocketFactory - Starting handshake
[DEBUG] SSLConnectionSocketFactory - Secure session established
[DEBUG] SSLConnectionSocketFactory -  negotiated protocol: TLSv1.2
[DEBUG] SSLConnectionSocketFactory -  negotiated cipher suite: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
[DEBUG] SSLConnectionSocketFactory -  peer principal: CN=httpbin.org
[DEBUG] SSLConnectionSocketFactory -  peer alternative names: [httpbin.org, www.httpbin.org]
[DEBUG] SSLConnectionSocketFactory -  issuer principal: CN=Let's Encrypt Authority X3, O=Let's Encrypt, C=US
[DEBUG] DefaultHttpClientConnectionOperator - Connection established 192.168.43.64:57534<->54.225.150.40:443