> I went through the capture between the app (local end) and the proxy. It 
appears that the sequence is:
    > 
    > ClientHello -> (from app to proxy, with a ton of cipher suites, including 
0xc02f)
    >       <-  ServerHello (with TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 – 
present in ClientHello)
    >       <- CertificateServer Key Exchange, Server Hello Done (includes 
proxy’s cert rather than the remote end’s cert)
    > 
    > Alert (Level: Fatal, Description: Certificate Unknown) ->
    > 
    > So it appears that the app expects the remote end’s cert, and is not 
happy getting the proxy’s cert instead?
    
    Please report tshark output, not an approximate rendition.  In what 
direction
    is the alert sent?

I’m using WireShark. The IP addresses on the Alert packet show local host as 
the source, and the proxy as the destination. Is there another way to tell the 
direction? Or how to present it in a way that I can sanitize the output and 
post here?

In response to this Alert packet I see two packets from the proxy to the local 
host: 
- [ACK]
- [PSH, ACK]

And then from the local host to the proxy:
- [FIN, ACK]
- [RST]
- [RST]


    
    It is indeed possible that the application is not configured for and 
correctly
    rejects the forged certificate of the MiTM proxy.  It would need the Root CA
    of the proxy as a trusted issuer, but that may not be configurable.  In 
which
    case you'd need to let the app connect directly to the remote server without
    an MiTM-proxy.

Understood, thanks! 

Attachment: smime.p7s
Description: S/MIME cryptographic signature

-- 
openssl-users mailing list
To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users

Reply via email to