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WAF only 128bit SSL

Hi,

i have one ASG that only uses a RC4 encryption 128bit. I guess its a revision 4, Firmware 8.309.
All of my Rev. 5 and UTM9 are using Camellia 256bit encryption.

Does the encryption algorythm depend on the ASG revision or is it a bug in my machine?

Thanks for your help (hope my english was not to bad).

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0 BarryG over 11 years ago

Hi, all the CBC modes are frowned upon due to BEAST (at least until TLS gets upgraded everywhere), and apparently ECB is not very secure:
https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Electronic_codebook_.28ECB.29

Unfortunately, that seems to rule out all the AES modes for now.

BTW, upgrading servers to TLS 1.1 or 1.2 doesn't completely solve the problem as they will fallback to TLS 1.0 modes if the client doesn't have support for the newer protocols.

IMHO, we shouldn't care so much about BEAST as it's already been worked-around in most clients, but the PCI group and/or the assessors don't seem to care.

Barry
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0 BarryG over 11 years ago

https://en.wikipedia.org/wiki/Transport_Layer_Security#Dealing_with_RC4_and_BEAST

According to this, CBC ciphers are considered safer than RC4, but I don't know if the PCI group feels this way yet.

Barry
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0 adriand over 11 years ago

Beast is a client side attack, needed something extra to work (a Java flaw "opened" its way, without Java was just theory, old theory). In TLS 1.1/1.2 the CBC suites are OK.
It's not much you can do on server side.

The PCI group mostly comes with a report generated by an automatic scanner, report which is full of we know what [:)]
Normally such things are worked out with the PCI guy who deals with the report.

If I connect with Chrome to v9 admin UI, Chrome says TLS 1.2 and AES GCM. Which coresps to what Bob posted above regarding OpenSSL. Don't have the WAF enabled to test.
If I connect to v8, says RC4 and TLS 1.0.

Ivan Risti?: Updated SSL/TLS Deployment Best Practices deprecates RC4

Currently there is not a straight way to secure things. Probably the most practical way is to prioritize the cipher suites and put last likes as RC4/3DES. Disabling those will disable IE6 clients.

If you do a "openssl ciphers -V" you should see the available ciphers on the UTM.
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0 adriand over 11 years ago

Btw, AES-CBC and 3DEC-CBC are FIPS certified ciphers whereas RC4 was never such.
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0 BAlfson over 11 years ago

Thanks, Adrian - that list I posted above is less interesting than:

astaro:/root # openssl ciphers -V
0xC0,0x30 - ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AESGCM(256) Mac=AEAD
0xC0,0x2C - ECDHE-ECDSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AESGCM(256) Mac=AEAD
0xC0,0x28 - ECDHE-RSA-AES256-SHA384 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AES(256)  Mac=SHA384
0xC0,0x24 - ECDHE-ECDSA-AES256-SHA384 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AES(256)  Mac=SHA384
0xC0,0x14 - ECDHE-RSA-AES256-SHA    SSLv3 Kx=ECDH     Au=RSA  Enc=AES(256)  Mac=SHA1
0xC0,0x0A - ECDHE-ECDSA-AES256-SHA  SSLv3 Kx=ECDH     Au=ECDSA Enc=AES(256)  Mac=SHA1
0xC0,0x22 - SRP-DSS-AES-256-CBC-SHA SSLv3 Kx=SRP      Au=DSS  Enc=AES(256)  Mac=SHA1
0xC0,0x21 - SRP-RSA-AES-256-CBC-SHA SSLv3 Kx=SRP      Au=RSA  Enc=AES(256)  Mac=SHA1
0x00,0xA3 - DHE-DSS-AES256-GCM-SHA384 TLSv1.2 Kx=DH       Au=DSS  Enc=AESGCM(256) Mac=AEAD
0x00,0x9F - DHE-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(256) Mac=AEAD
0x00,0x6B - DHE-RSA-AES256-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA256
0x00,0x6A - DHE-DSS-AES256-SHA256   TLSv1.2 Kx=DH       Au=DSS  Enc=AES(256)  Mac=SHA256
0x00,0x39 - DHE-RSA-AES256-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(256)  Mac=SHA1
0x00,0x38 - DHE-DSS-AES256-SHA      SSLv3 Kx=DH       Au=DSS  Enc=AES(256)  Mac=SHA1
0x00,0x88 - DHE-RSA-CAMELLIA256-SHA SSLv3 Kx=DH       Au=RSA  Enc=Camellia(256) Mac=SHA1
0x00,0x87 - DHE-DSS-CAMELLIA256-SHA SSLv3 Kx=DH       Au=DSS  Enc=Camellia(256) Mac=SHA1
0xC0,0x32 - ECDH-RSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH/RSA Au=ECDH Enc=AESGCM(256) Mac=AEAD
0xC0,0x2E - ECDH-ECDSA-AES256-GCM-SHA384 TLSv1.2 Kx=ECDH/ECDSA Au=ECDH Enc=AESGCM(256) Mac=AEAD
0xC0,0x2A - ECDH-RSA-AES256-SHA384  TLSv1.2 Kx=ECDH/RSA Au=ECDH Enc=AES(256)  Mac=SHA384
0xC0,0x26 - ECDH-ECDSA-AES256-SHA384 TLSv1.2 Kx=ECDH/ECDSA Au=ECDH Enc=AES(256)  Mac=SHA384
0xC0,0x0F - ECDH-RSA-AES256-SHA     SSLv3 Kx=ECDH/RSA Au=ECDH Enc=AES(256)  Mac=SHA1
0xC0,0x05 - ECDH-ECDSA-AES256-SHA   SSLv3 Kx=ECDH/ECDSA Au=ECDH Enc=AES(256)  Mac=SHA1
0x00,0x9D - AES256-GCM-SHA384       TLSv1.2 Kx=RSA      Au=RSA  Enc=AESGCM(256) Mac=AEAD
0x00,0x3D - AES256-SHA256           TLSv1.2 Kx=RSA      Au=RSA  Enc=AES(256)  Mac=SHA256
0x00,0x35 - AES256-SHA              SSLv3 Kx=RSA      Au=RSA  Enc=AES(256)  Mac=SHA1
0x00,0x84 - CAMELLIA256-SHA         SSLv3 Kx=RSA      Au=RSA  Enc=Camellia(256) Mac=SHA1
0x00,0x8D - PSK-AES256-CBC-SHA      SSLv3 Kx=PSK      Au=PSK  Enc=AES(256)  Mac=SHA1
0xC0,0x12 - ECDHE-RSA-DES-CBC3-SHA  SSLv3 Kx=ECDH     Au=RSA  Enc=3DES(168) Mac=SHA1
0xC0,0x08 - ECDHE-ECDSA-DES-CBC3-SHA SSLv3 Kx=ECDH     Au=ECDSA Enc=3DES(168) Mac=SHA1
0xC0,0x1C - SRP-DSS-3DES-EDE-CBC-SHA SSLv3 Kx=SRP      Au=DSS  Enc=3DES(168) Mac=SHA1
0xC0,0x1B - SRP-RSA-3DES-EDE-CBC-SHA SSLv3 Kx=SRP      Au=RSA  Enc=3DES(168) Mac=SHA1
0x00,0x16 - EDH-RSA-DES-CBC3-SHA    SSLv3 Kx=DH       Au=RSA  Enc=3DES(168) Mac=SHA1
0x00,0x13 - EDH-DSS-DES-CBC3-SHA    SSLv3 Kx=DH       Au=DSS  Enc=3DES(168) Mac=SHA1
0xC0,0x0D - ECDH-RSA-DES-CBC3-SHA   SSLv3 Kx=ECDH/RSA Au=ECDH Enc=3DES(168) Mac=SHA1
0xC0,0x03 - ECDH-ECDSA-DES-CBC3-SHA SSLv3 Kx=ECDH/ECDSA Au=ECDH Enc=3DES(168) Mac=SHA1
0x00,0x0A - DES-CBC3-SHA            SSLv3 Kx=RSA      Au=RSA  Enc=3DES(168) Mac=SHA1
0x00,0x8B - PSK-3DES-EDE-CBC-SHA    SSLv3 Kx=PSK      Au=PSK  Enc=3DES(168) Mac=SHA1
0xC0,0x2F - ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AESGCM(128) Mac=AEAD
0xC0,0x2B - ECDHE-ECDSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AESGCM(128) Mac=AEAD
0xC0,0x27 - ECDHE-RSA-AES128-SHA256 TLSv1.2 Kx=ECDH     Au=RSA  Enc=AES(128)  Mac=SHA256
0xC0,0x23 - ECDHE-ECDSA-AES128-SHA256 TLSv1.2 Kx=ECDH     Au=ECDSA Enc=AES(128)  Mac=SHA256
0xC0,0x13 - ECDHE-RSA-AES128-SHA    SSLv3 Kx=ECDH     Au=RSA  Enc=AES(128)  Mac=SHA1
0xC0,0x09 - ECDHE-ECDSA-AES128-SHA  SSLv3 Kx=ECDH     Au=ECDSA Enc=AES(128)  Mac=SHA1
0xC0,0x1F - SRP-DSS-AES-128-CBC-SHA SSLv3 Kx=SRP      Au=DSS  Enc=AES(128)  Mac=SHA1
0xC0,0x1E - SRP-RSA-AES-128-CBC-SHA SSLv3 Kx=SRP      Au=RSA  Enc=AES(128)  Mac=SHA1
0x00,0xA2 - DHE-DSS-AES128-GCM-SHA256 TLSv1.2 Kx=DH       Au=DSS  Enc=AESGCM(128) Mac=AEAD
0x00,0x9E - DHE-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=DH       Au=RSA  Enc=AESGCM(128) Mac=AEAD
0x00,0x67 - DHE-RSA-AES128-SHA256   TLSv1.2 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA256
0x00,0x40 - DHE-DSS-AES128-SHA256   TLSv1.2 Kx=DH       Au=DSS  Enc=AES(128)  Mac=SHA256
0x00,0x33 - DHE-RSA-AES128-SHA      SSLv3 Kx=DH       Au=RSA  Enc=AES(128)  Mac=SHA1
0x00,0x32 - DHE-DSS-AES128-SHA      SSLv3 Kx=DH       Au=DSS  Enc=AES(128)  Mac=SHA1
0x00,0x9A - DHE-RSA-SEED-SHA        SSLv3 Kx=DH       Au=RSA  Enc=SEED(128) Mac=SHA1
0x00,0x99 - DHE-DSS-SEED-SHA        SSLv3 Kx=DH       Au=DSS  Enc=SEED(128) Mac=SHA1
0x00,0x45 - DHE-RSA-CAMELLIA128-SHA SSLv3 Kx=DH       Au=RSA  Enc=Camellia(128) Mac=SHA1
0x00,0x44 - DHE-DSS-CAMELLIA128-SHA SSLv3 Kx=DH       Au=DSS  Enc=Camellia(128) Mac=SHA1
0xC0,0x31 - ECDH-RSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH/RSA Au=ECDH Enc=AESGCM(128) Mac=AEAD
0xC0,0x2D - ECDH-ECDSA-AES128-GCM-SHA256 TLSv1.2 Kx=ECDH/ECDSA Au=ECDH Enc=AESGCM(128) Mac=AEAD
0xC0,0x29 - ECDH-RSA-AES128-SHA256  TLSv1.2 Kx=ECDH/RSA Au=ECDH Enc=AES(128)  Mac=SHA256
0xC0,0x25 - ECDH-ECDSA-AES128-SHA256 TLSv1.2 Kx=ECDH/ECDSA Au=ECDH Enc=AES(128)  Mac=SHA256
0xC0,0x0E - ECDH-RSA-AES128-SHA     SSLv3 Kx=ECDH/RSA Au=ECDH Enc=AES(128)  Mac=SHA1
0xC0,0x04 - ECDH-ECDSA-AES128-SHA   SSLv3 Kx=ECDH/ECDSA Au=ECDH Enc=AES(128)  Mac=SHA1
0x00,0x9C - AES128-GCM-SHA256       TLSv1.2 Kx=RSA      Au=RSA  Enc=AESGCM(128) Mac=AEAD
0x00,0x3C - AES128-SHA256           TLSv1.2 Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA256
0x00,0x2F - AES128-SHA              SSLv3 Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA1
0x00,0x96 - SEED-SHA                SSLv3 Kx=RSA      Au=RSA  Enc=SEED(128) Mac=SHA1
0x00,0x41 - CAMELLIA128-SHA         SSLv3 Kx=RSA      Au=RSA  Enc=Camellia(128) Mac=SHA1
0x00,0x8C - PSK-AES128-CBC-SHA      SSLv3 Kx=PSK      Au=PSK  Enc=AES(128)  Mac=SHA1
0xC0,0x11 - ECDHE-RSA-RC4-SHA       SSLv3 Kx=ECDH     Au=RSA  Enc=RC4(128)  Mac=SHA1
0xC0,0x07 - ECDHE-ECDSA-RC4-SHA     SSLv3 Kx=ECDH     Au=ECDSA Enc=RC4(128)  Mac=SHA1
0xC0,0x0C - ECDH-RSA-RC4-SHA        SSLv3 Kx=ECDH/RSA Au=ECDH Enc=RC4(128)  Mac=SHA1
0xC0,0x02 - ECDH-ECDSA-RC4-SHA      SSLv3 Kx=ECDH/ECDSA Au=ECDH Enc=RC4(128)  Mac=SHA1
0x00,0x05 - RC4-SHA                 SSLv3 Kx=RSA      Au=RSA  Enc=RC4(128)  Mac=SHA1
0x00,0x04 - RC4-MD5                 SSLv3 Kx=RSA      Au=RSA  Enc=RC4(128)  Mac=MD5
0x00,0x8A - PSK-RC4-SHA             SSLv3 Kx=PSK      Au=PSK  Enc=RC4(128)  Mac=SHA1
0x00,0x15 - EDH-RSA-DES-CBC-SHA     SSLv3 Kx=DH       Au=RSA  Enc=DES(56)   Mac=SHA1
0x00,0x12 - EDH-DSS-DES-CBC-SHA     SSLv3 Kx=DH       Au=DSS  Enc=DES(56)   Mac=SHA1
0x00,0x09 - DES-CBC-SHA             SSLv3 Kx=RSA      Au=RSA  Enc=DES(56)   Mac=SHA1
0x00,0x14 - EXP-EDH-RSA-DES-CBC-SHA SSLv3 Kx=DH(512)  Au=RSA  Enc=DES(40)   Mac=SHA1 export
0x00,0x11 - EXP-EDH-DSS-DES-CBC-SHA SSLv3 Kx=DH(512)  Au=DSS  Enc=DES(40)   Mac=SHA1 export
0x00,0x08 - EXP-DES-CBC-SHA         SSLv3 Kx=RSA(512) Au=RSA  Enc=DES(40)   Mac=SHA1 export
0x00,0x06 - EXP-RC2-CBC-MD5         SSLv3 Kx=RSA(512) Au=RSA  Enc=RC2(40)   Mac=MD5  export
0x00,0x03 - EXP-RC4-MD5             SSLv3 Kx=RSA(512) Au=RSA  Enc=RC4(40)   Mac=MD5  export

Cheers - Bob

Sophos UTM Community Moderator
Sophos Certified Architect - UTM
Sophos Certified Engineer - XG
Gold Solution Partner since 2005

MediaSoft, Inc. USA

0 BarryG over 11 years ago in reply to BarryG

https://en.wikipedia.org/wiki/Transport_Layer_Security#Dealing_with_RC4_and_BEAST

According to this, CBC ciphers are considered safer than RC4, but I don't know if the PCI group feels this way yet.

Barry

We're using TrustWave for PCI scans, etc... they are now reporting the following on some of our servers as "Informational"; i.e. not a warning yet:

SSL RC4-based Ciphers
Supported
This server may be able to be configured to mitigate a vulnerability
present in some web browsers. An attack is possible when using
RC4-based ciphers that takes advantage of single-byte biases within
the RC4 algorithm, that could make it easier for remote attackers to
conduct plaintext-recovery attacks via statistical analysis of cipher
text in a larger number of sessions (i.e. millions of sessions) that use
the same plain text. The vulnerability is present on the browser, but
steps may be taken on web servers to mitigate it. As the attack exploits
RC4-based ciphers, SSL may be configured on web servers to disable
RC4 ciphers or to prefer ciphers over RC4-based ones. Alternatively,
the web server may be configured to allow only TLS versions 1.1 and
1.2, which are not vulnerable; however, support for these newer TLS
versions is not as widespread, and disabling previous versions may
prevent some users from connecting to the server.

Barry
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0 BarryG over 11 years ago

At the same time, they say:

re BEAST...
As the attack exploits block-based ciphers, SSL may be
configured on web servers to disable block ciphers or to prefer stream-based
ciphers (such as RC4) over block-based ones.

So, they can't make up their minds.

Barry
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WAF only 128bit SSL

Submitted a Tech Support Case lately from the Support Portal?