Forum Discussion
NimbostratusHow do you select right chiper?
Hi
I need you to help me, I have a problem with a virtual Server that uses SSL, I have captured traffic and I see that the client gives a fatal error, I think that the root cause of the error is the chiper
Attach you will find the evidence of what I see when the request is made from the client side.
New TCP connection 1: 172.18.48.159(63731) <-> 172.22.156.172(443)
1 1 0.0359 (0.0359) C>S Handshake ClientHello Version 3.0 cipher suites SSL_RSA_WITH_3DES_EDE_CBC_SHA SSL_RSA_WITH_RC4_128_SHA SSL_RSA_WITH_RC4_128_MD5 SSL_RSA_WITH_DES_CBC_SHA SSL_RSA_EXPORT_WITH_RC4_40_MD5 SSL_RSA_EXPORT_WITH_DES40_CBC_SHA compression methods NULL
1 2 0.0359 (0.0000) S>C Handshake ServerHello Version 3.0 session_id[32]= 21 bd b8 db d4 bb b0 06 57 37 16 e1 4e af de 9a 13 51 16 09 15 11 0b 59 f9 b8 e1 a9 1d ee 4a d9 cipherSuite SSL_RSA_WITH_3DES_EDE_CBC_SHA compressionMethod NULL
1 3 0.0359 (0.0000) S>C Handshake Certificate
1 4 0.0359 (0.0000) S>C Handshake ServerHelloDone
1 5 0.0366 (0.0006) C>S Alert level fatal value close_notify
1 0.0368 (0.0002) C>S TCP FIN
1 0.0368 (0.0000) S>C TCP FIN
In this moment I have set up Chiper "EXPORT:DHE+AES-GCM:DHE+AES:DHE+3DES:AES-GCM+RSA:RSA+AES:RSA+3DES:ECDHE+AES-GCM:ECDHE+AES:ECDHE-RSA-DES-CBC3-SHA"
I try with different chipers but I don't solve this error. I added the imagen of certificate
Regards,
Cipher's aren't the problem - the capture shows you're negotiating the "DES-CBC3-SHA" cipher, which is the F5's default for SSLv3 clients. RC4-SHA and RC4-MD5 are also options for SSLv3 if the client doesn't support 3DES.
Instead, the issue here is actually with your certificate. It's SHA-2 signed, and SSLv3 only knows about SHA-1 and MD5. You'll need to have the CA re-issue the certificate in SHA-1 format. Note that it won't be possible to get SHA-1 certificates starting in about 2016, so you'll need to upgrade your application to support TLS before then.
5 Replies
t-royWhat version of code are you running?? When we upgraded to 11.4 we broke some stuff that was trying to do SSLv3 so we had to add this to the cipher list: !EXPORT:!DH:!MD5:RSA+AES:RSA+3DES:RSA+RC4:ECDHE+AES:ECDHE+3DES:ECDHE+RSA:@SPEED
Having said that, SSLv3 is vulnerable so I DO NOT recommend using this if you can avoid it.
JAIME_QUIROGA_1Hi
Thkns for your answer, The LTM's version 11.5.1 with hootfix 4.
Not it's possible, The client uses the SSLv3.
- JAIME_QUIROGA_1
Hi
I did try with your chiper but the app fault, You can view the follewing the capture of three Handshake SSL.
New TCP connection 1: 172.18.48.159(55735) <-> 172.22.156.172(443) 1 1 0.0431 (0.0431) C>S Handshake ClientHello Version 3.0 cipher suites SSL_RSA_WITH_3DES_EDE_CBC_SHA SSL_RSA_WITH_RC4_128_SHA SSL_RSA_WITH_RC4_128_MD5 SSL_RSA_WITH_DES_CBC_SHA SSL_RSA_EXPORT_WITH_RC4_40_MD5 SSL_RSA_EXPORT_WITH_DES40_CBC_SHA compression methods NULL 1 2 0.0432 (0.0000) S>C Handshake ServerHello Version 3.0 session_id[32]= 21 bd b8 db d4 bb f0 72 57 37 16 e1 4e af de 9a 13 52 d6 5b 15 12 cb 67 f9 b8 e1 a9 1d ed 5a f2 cipherSuite SSL_RSA_WITH_3DES_EDE_CBC_SHA compressionMethod NULL 1 3 0.0432 (0.0000) S>C Handshake Certificate 1 4 0.0432 (0.0000) S>C Handshake ServerHelloDone 1 5 0.0438 (0.0005) C>S Alert level fatal value close_notify 1 0.0439 (0.0001) C>S TCP FIN 1 0.0439 (0.0000) S>C TCP FIN
- nitass
Employee
if client and server (bigip) do not share cipher, i think bigip could send reset right away after getting client hello.
Troubleshooting TLS Problems With ssldump by George Watkins
https://devcentral.f5.com/articles/troubleshooting-tls-problems-with-ssldump - John_Heyer_1508
Cirrostratus
Cipher's aren't the problem - the capture shows you're negotiating the "DES-CBC3-SHA" cipher, which is the F5's default for SSLv3 clients. RC4-SHA and RC4-MD5 are also options for SSLv3 if the client doesn't support 3DES.
Instead, the issue here is actually with your certificate. It's SHA-2 signed, and SSLv3 only knows about SHA-1 and MD5. You'll need to have the CA re-issue the certificate in SHA-1 format. Note that it won't be possible to get SHA-1 certificates starting in about 2016, so you'll need to upgrade your application to support TLS before then.
