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HM_U333
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Aug 22, 2022

F5 LTM version 12.1.2 HTTPS monitor uses TLSv1 - No Client and server SSL profile

I need suggestion to fix the issue i'm facing.

Device details: Version 12.1.2, Build 1.0.271, Edition Hotfix HF1

1. No Client and Server SSL profile associated to 'Standard' Vs.

2. Pool member is on 443 port and associated HTTPS monitor.

3. Ciphers - DEFAULT:+SHA:+3DES:+kEDH and under 'Client Cert' and 'Client Key' i have tried using different SSL cert. Still same error and same issue in pcap.

4. Im seeing F5 using TLSv1 protocol for 'Client Hello' in PCAP and server is not responding with 'Server Hello', Server send RST message immediately.

Openssl and curl o/p is as below:

>>Used ab.c.d for my pool member IP.

Command 1 - # openssl s_client -connect a.b.c.d:443
CONNECTED(00000003)
write:errno=104
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 277 bytes
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
---
Command 2:  # curl -I https://a.b.c.d/ForwardSearchOrderSend.svc
curl: (35) Unknown SSL protocol error in connection to a.b.c.d:443


 Command 3:  # curl -Ivk https://a.b.c.d/ForwardSearchOrderSend.svc
* About to connect() to a.b.c.d port 443 (#0)
* Trying a.b.c.d... connected
* Connected to a.b.c.d (a.b.c.d) port 443 (#0)
* successfully set certificate verify locations:
* CAfile: /etc/pki/tls/certs/ca-bundle.crt
CApath: none
* SSLv3, TLS handshake, Client hello (1):
* Unknown SSL protocol error in connection to a.b.c.d:443
* Closing connection #0
curl: (35) Unknown SSL protocol error in connection to a.b.c.d:443

 

5.  I have checked below articles- Still no use.

https://community.f5.com/t5/technical-forum/f5-server-ssl-profile-using-tls-1-0-instead-of-tls-1-2/m-p/231208#M214902 

https://community.f5.com/t5/technical-forum/f5-health-monitor-suddenly-use-tlsv1/td-p/213711 

6.  To check with server team about server cert, They rasied question about F5 using 'TLS v1' for 'Client Hello'.

7. Server has Private Interface and Public Interface. Via Public Interface HTTP monitor is working for one application. We want to monitor different App using HTTPS via Private interface.

Can someone suggest whats casuing HTTPS to fail as its old version and no SSL profile, im bit confused.

  • Interesting problem. I have no suggestion but questions. 

    You say you do not use any client, nor server ssl profiles. In that case the device should not intercept any SSL at all.
    However, you also say you use an HTTPS monitor and this one would try to establish a TLS session when connecting to the pool member. A few questions:

    Where are the ciphers you mentioned configured? The HTTPS monitor?

    Can you run this command to check what Ciphers that equals?

    tmm --serverciphers 'DEFAULT:+SHA:+3DES:+kEDH'

     I am not sure if 12.1.2 supports TLS1.2 and if the member server is patched and hardened you might have an issue during the cipher negotiation. Try changing the monitor to TCP to rule it out?

    Kind regards,
    Patrik

    • HM_U333's avatar
      HM_U333
      Icon for Cirrus rankCirrus

      Hello Patrik, Thanks for inputs.

      Here are details about Ciphers. This confirms we have TLSv1.2 Ciphers too.

      Spoiler
      # tmm --serverciphers 'DEFAULT:+SHA:+3DES:+kEDH'
      ID SUITE BITS PROT METHOD CIPHER MAC KEYX
      0: 159 DHE-RSA-AES256-GCM-SHA384 256 TLS1.2 Native AES-GCM SHA384 EDH/RSA
      1: 158 DHE-RSA-AES128-GCM-SHA256 128 TLS1.2 Native AES-GCM SHA256 EDH/RSA
      2: 107 DHE-RSA-AES256-SHA256 256 TLS1.2 Native AES SHA256 EDH/RSA
      3: 103 DHE-RSA-AES128-SHA256 128 TLS1.2 Native AES SHA256 EDH/RSA
      4: 157 AES256-GCM-SHA384 256 TLS1.2 Native AES-GCM SHA384 RSA
      5: 156 AES128-GCM-SHA256 128 TLS1.2 Native AES-GCM SHA256 RSA
      6: 61 AES256-SHA256 256 TLS1.2 Native AES SHA256 RSA
      7: 60 AES128-SHA256 128 TLS1.2 Native AES SHA256 RSA
      8: 49200 ECDHE-RSA-AES256-GCM-SHA384 256 TLS1.2 Native AES-GCM SHA384 ECDHE_RSA
      9: 49199 ECDHE-RSA-AES128-GCM-SHA256 128 TLS1.2 Native AES-GCM SHA256 ECDHE_RSA
      10: 49192 ECDHE-RSA-AES256-SHA384 256 TLS1.2 Native AES SHA384 ECDHE_RSA
      11: 49191 ECDHE-RSA-AES128-SHA256 128 TLS1.2 Native AES SHA256 ECDHE_RSA
      12: 57 DHE-RSA-AES256-SHA 256 TLS1 Native AES SHA EDH/RSA
      13: 57 DHE-RSA-AES256-SHA 256 TLS1.1 Native AES SHA EDH/RSA
      14: 57 DHE-RSA-AES256-SHA 256 TLS1.2 Native AES SHA EDH/RSA
      15: 57 DHE-RSA-AES256-SHA 256 DTLS1 Native AES SHA EDH/RSA
      16: 51 DHE-RSA-AES128-SHA 128 TLS1 Native AES SHA EDH/RSA
      17: 51 DHE-RSA-AES128-SHA 128 TLS1.1 Native AES SHA EDH/RSA
      18: 51 DHE-RSA-AES128-SHA 128 TLS1.2 Native AES SHA EDH/RSA
      19: 51 DHE-RSA-AES128-SHA 128 DTLS1 Native AES SHA EDH/RSA
      20: 53 AES256-SHA 256 TLS1 Native AES SHA RSA
      21: 53 AES256-SHA 256 TLS1.1 Native AES SHA RSA
      22: 53 AES256-SHA 256 TLS1.2 Native AES SHA RSA
      23: 53 AES256-SHA 256 DTLS1 Native AES SHA RSA
      24: 47 AES128-SHA 128 TLS1 Native AES SHA RSA
      25: 47 AES128-SHA 128 TLS1.1 Native AES SHA RSA
      26: 47 AES128-SHA 128 TLS1.2 Native AES SHA RSA
      27: 47 AES128-SHA 128 DTLS1 Native AES SHA RSA
      28: 49172 ECDHE-RSA-AES256-CBC-SHA 256 TLS1 Native AES SHA ECDHE_RSA
      29: 49172 ECDHE-RSA-AES256-CBC-SHA 256 TLS1.1 Native AES SHA ECDHE_RSA
      30: 49172 ECDHE-RSA-AES256-CBC-SHA 256 TLS1.2 Native AES SHA ECDHE_RSA
      31: 49171 ECDHE-RSA-AES128-CBC-SHA 128 TLS1 Native AES SHA ECDHE_RSA
      32: 49171 ECDHE-RSA-AES128-CBC-SHA 128 TLS1.1 Native AES SHA ECDHE_RSA
      33: 49171 ECDHE-RSA-AES128-CBC-SHA 128 TLS1.2 Native AES SHA ECDHE_RSA
      34: 22 DHE-RSA-DES-CBC3-SHA 168 TLS1 Native DES SHA EDH/RSA
      35: 22 DHE-RSA-DES-CBC3-SHA 168 TLS1.1 Native DES SHA EDH/RSA
      36: 22 DHE-RSA-DES-CBC3-SHA 168 TLS1.2 Native DES SHA EDH/RSA
      37: 22 DHE-RSA-DES-CBC3-SHA 168 DTLS1 Native DES SHA EDH/RSA
      38: 10 DES-CBC3-SHA 168 TLS1 Native DES SHA RSA
      39: 10 DES-CBC3-SHA 168 TLS1.1 Native DES SHA RSA
      40: 10 DES-CBC3-SHA 168 TLS1.2 Native DES SHA RSA
      41: 10 DES-CBC3-SHA 168 DTLS1 Native DES SHA RSA
      42: 49170 ECDHE-RSA-DES-CBC3-SHA 168 TLS1 Native DES SHA ECDHE_RSA
      43: 49170 ECDHE-RSA-DES-CBC3-SHA 168 TLS1.1 Native DES SHA ECDHE_RSA
      44: 49170 ECDHE-RSA-DES-CBC3-SHA 168 TLS1.2 Native DES SHA ECDHE_RSA

      >> Where are the ciphers you mentioned configured? The HTTPS monitor?

      > In 12.1.2 HTTPS monitor intself has option to mention Cipher and cert. I have mentoned Ciphers there, No SSL cert mentioned. We have few other HTTPS monitors which is working for different servers/pool, i have compared the configurations, its same. Still this HTTPS monitor is not working.

      As per Article 12.x has this option and i see in my 12.1.2 F5.  https://support.f5.com/csp/article/K51131340 

       

      >> Server has Cert associated with Website. F5 sends 'Client Hello' but no server hello at all. Question is why F5 is sending via TLSv1. PCAP attached. After F5 sends Client Hello, 'SERVER' is sending RST as you see.

      Any suggestions? What could be causing this issue?

       

      • See, in the Client Hello packet includes the list of protocol and ciphers that the client supports. My suspicion from the things you wrote above would be that the device (F5 BigIP) does not support the ciphers that the server requires.

        Perhaps you can confirm this by checking the server config or run the tests from a functioning client and determine one of the supported ciphers from there. If you have no functioning client perhaps looking at the server SSL config would be in order.

        Kind regards,
        Patrik