limiting java ssl debug logging

Using JVM flag

-Djavax.net.debug=ssl

is producing a tremendous ammount of logging, the details for every SSL event on the server. Is there anyway to only have it log errors? or possibly there is some better subset of these flags that produce tidier output

all            turn on all debugging
ssl            turn on ssl debugging

The following can be used with ssl:

    record       enable per-record tracing
    handshake    print each handshake message
    keygen       print key generation data
    session      print session activity
    defaultctx   print default SSL initialization
    sslctx       print SSLContext tracing
    sessioncache print session cache tracing
    keymanager   print key manager tracing
    trustmanager print trust manager tracing
    pluggability print pluggability tracing

    handshake debugging can be widened with:
    data         hex dump of each handshake message
    verbose      verbose handshake message printing

    record debugging can be widened with:
    plaintext    hex dump of record plaintext
    packet       print raw SSL/TLS packets

Further reading

• JavaSE 8: Java Secure Socket Extension (JSSE) Reference Guide: https://docs.oracle.com/javase/8/docs/technotes/guides/security/jsse/JSSERefGuide.html
• JavaSE 8: Debugging SSL/TLS Connections: https://docs.oracle.com/javase/8/docs/technotes/guides/security/jsse/ReadDebug.html
• JavaSE 11: Java Secure Socket Extension (JSSE) Reference Guide: https://docs.oracle.com/en/java/javase/11/security/java-secure-socket-extension-jsse-reference-guide.html

The format for using the additional ssl flags is ssl:[flag] for example:

-Djavax.net.debug=ssl:record or -Djavax.net.debug=ssl:handshake.

I also find that using -Djavax.net.debug=ssl (or even its filters) to be too cumbersome for debugging HTTPS issues.

It's a little bit involved, but what I prefer to do is setup mitmproxy on a cheap server somewhere and then configure my Java clients to proxy through it. This way I can comfortably inspect and replay HTTPS request/response flows on the proxy without having to comb through a bunch of logs.

If you are you interested, I've written a guide on how to get this going: Debugging SSL in Java using mitmproxy