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New Member
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Server has a weak ephemeral Diffie-Hellman public key

wondering why this problem not largely exposed... do i set up my controller wrongly? Smiley Frustrated

after updating my Google Chrome to v45, suddenly i can't access my UniFi Controller, saying that server's DH key is too weak. *ERR_SSL_WEAK_SERVER_EPHEMERAL_DH_KEY* after testing with Qualys's SSL test, it is true that UniFi's web server use weak 768bit DH.

there is solution for UniFi-Video here but it doesn't work with mine. after some other googling, i found out that thus solution is for Apache Tomcat. there is conf folder in UniFi, but its empty, and i don't think UniFi Controller use Tomcat either.

 

so, does anyone know how to change SSL setting for UniFi's web server? ('-'a)


Accepted Solutions
New Member
Posts: 16
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Re: Server has a weak ephemeral Diffie-Hellman public key

[ Edited ]

solve this issue by ugrading my controller to the latest

looks like UniFi already mitigating this issue, by disabling DH Key Exchange altogther... hahaha Lol

and it only support two ciphers...

 

now i got C score from Qualys's SSL test because UniFi only supporting TLS1.0

whatever... i use this controller internally anyway

View solution in original post

screenshot-SSL Server Test (Powered by Qualys SSL Labs)-2015-09-06-20-45-23.png
SuperUser
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Re: Server has a weak ephemeral Diffie-Hellman public key

I've added, in my system.properties, these lines

 

unifi.https.ciphers=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
unifi.https.sslEnabledProtocols=TLSv1.2

 

Regards

View solution in original post


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SuperUser
Posts: 20,370
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Re: Server has a weak ephemeral Diffie-Hellman public key

you can, IIRC, use your own SSL certificate if you want.  Takes a bit of work though; this link should help.

 

https://community.ubnt.com/t5/UniFi-Wireless/Your-own-SSL-key-and-cert/m-p/285516#M16786

New Member
Posts: 16
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Re: Server has a weak ephemeral Diffie-Hellman public key

i already use my own certificate, a wild card one.

the problem is not with the certificate.

the problem is how UniFi's web server choose DH key.

New Member
Posts: 16
Registered: ‎10-19-2014
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Re: Server has a weak ephemeral Diffie-Hellman public key

[ Edited ]

solve this issue by ugrading my controller to the latest

looks like UniFi already mitigating this issue, by disabling DH Key Exchange altogther... hahaha Lol

and it only support two ciphers...

 

now i got C score from Qualys's SSL test because UniFi only supporting TLS1.0

whatever... i use this controller internally anyway

screenshot-SSL Server Test (Powered by Qualys SSL Labs)-2015-09-06-20-45-23.png
SuperUser
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Re: Server has a weak ephemeral Diffie-Hellman public key

I've added, in my system.properties, these lines

 

unifi.https.ciphers=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
unifi.https.sslEnabledProtocols=TLSv1.2

 

Regards

New Member
Posts: 16
Registered: ‎10-19-2014
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Solutions: 2

Re: Server has a weak ephemeral Diffie-Hellman public key

[ Edited ]

thanks @redfive for the hint... i can get A- now \(^-^)/

but somehow i can not get ECDHE working, so i comment out unifi.https.ciphers part.

 

after another try, i found out that this is the only ciphers supported on my linux. what does affect this?

i run an apache web server in this same server and can get all green status from chrome.

ECDHE+AESGCM are working with apache.

screenshot-SSL Server Test  helpdesk.indokoneksi.com (Powered by Qualys SSL Labs)-2015-09-06-22-04-26.png
SuperUser
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Re: Server has a weak ephemeral Diffie-Hellman public key

To be honest, my controller is on debian 8.1 and is the 4.7.3 version ....

Regards

SuperUser
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Re: Server has a weak ephemeral Diffie-Hellman public key

For make chrome happy, use in system.properties (4.7.3 sure, probably also 4.6.6)
unifi.https.ciphers=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
unifi.https.sslEnabledProtocols=TLSv1.2

Regards

New Member
Posts: 37
Registered: ‎03-21-2014
Kudos: 4

Re: Server has a weak ephemeral Diffie-Hellman public key

Can you expand on how to get to this step and execute it properly?

UEWA
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Re: Server has a weak ephemeral Diffie-Hellman public key

yeah, x2 @redfive. Enabling tls 1.2 (on ubuntu 14.04) using those ciphers listed produces this:

 

ssl_error_no_cypher_overlap

 

Setting it to tls 1.1 and removing the custom ciphers makes the port work again, but without tls 1.2 SSL certs will always be stuck at a C grade, at least for Qualsys.

SuperUser
Posts: 7,521
Registered: ‎01-05-2012
Kudos: 1982
Solutions: 985

Re: Server has a weak ephemeral Diffie-Hellman public key

@wispr Do you are on physical or VM  ?

Regards

Established Member
Posts: 1,258
Registered: ‎08-17-2010
Kudos: 238
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Re: Server has a weak ephemeral Diffie-Hellman public key

VM at Azure. Running our own (valid) certificate.

Ubiquiti Employee
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Registered: ‎12-14-2010
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Re: Server has a weak ephemeral Diffie-Hellman public key

[ Edited ]

Available cipher suites/SSL protocols depends on JVM.

The default value we used should work on all JVM. It's recommended updating these settings based on your JVM version to improve controller security.

 

The SSLInfo program here is handy.

 

Spoiler

yhlee@yhlee-mbpr:~/src/oss$ java -version

java version "1.6.0_65"

Java(TM) SE Runtime Environment (build 1.6.0_65-b14-462-11M4609)

Java HotSpot(TM) 64-Bit Server VM (build 20.65-b04-462, mixed mode)

yhlee@yhlee-mbpr:~/src/oss$ java SSLInfo

Default Cipher

* SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA

* SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA

* SSL_DHE_DSS_WITH_DES_CBC_SHA

* SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA

* SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA

* SSL_DHE_RSA_WITH_DES_CBC_SHA

  SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA

  SSL_DH_anon_EXPORT_WITH_RC4_40_MD5

  SSL_DH_anon_WITH_3DES_EDE_CBC_SHA

  SSL_DH_anon_WITH_DES_CBC_SHA

  SSL_DH_anon_WITH_RC4_128_MD5

* SSL_RSA_EXPORT_WITH_DES40_CBC_SHA

* SSL_RSA_EXPORT_WITH_RC4_40_MD5

* SSL_RSA_WITH_3DES_EDE_CBC_SHA

* SSL_RSA_WITH_DES_CBC_SHA

  SSL_RSA_WITH_NULL_MD5

  SSL_RSA_WITH_NULL_SHA

* SSL_RSA_WITH_RC4_128_MD5

* SSL_RSA_WITH_RC4_128_SHA

* TLS_DHE_DSS_WITH_AES_128_CBC_SHA

* TLS_DHE_DSS_WITH_AES_256_CBC_SHA

* TLS_DHE_RSA_WITH_AES_128_CBC_SHA

* TLS_DHE_RSA_WITH_AES_256_CBC_SHA

  TLS_DH_anon_WITH_AES_128_CBC_SHA

  TLS_DH_anon_WITH_AES_256_CBC_SHA

* TLS_EMPTY_RENEGOTIATION_INFO_SCSV

  TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5

  TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA

  TLS_KRB5_EXPORT_WITH_RC4_40_MD5

  TLS_KRB5_EXPORT_WITH_RC4_40_SHA

  TLS_KRB5_WITH_3DES_EDE_CBC_MD5

  TLS_KRB5_WITH_3DES_EDE_CBC_SHA

  TLS_KRB5_WITH_DES_CBC_MD5

  TLS_KRB5_WITH_DES_CBC_SHA

  TLS_KRB5_WITH_RC4_128_MD5

  TLS_KRB5_WITH_RC4_128_SHA

* TLS_RSA_WITH_AES_128_CBC_SHA

* TLS_RSA_WITH_AES_256_CBC_SHA

yhlee@yhlee-mbpr:~/src/oss$ JAVA_HOME=~/java/jre7u75 ~/java/jre7u75/bin/java -version

java version "1.7.0_75"

Java(TM) SE Runtime Environment (build 1.7.0_75-b13)

Java HotSpot(TM) 64-Bit Server VM (build 24.75-b04, mixed mode)

yhlee@yhlee-mbpr:~/src/oss$ JAVA_HOME=~/java/jre7u75 ~/java/jre7u75/bin/java SSLInfo

Default Cipher

  SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA

* SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA

  SSL_DHE_DSS_WITH_DES_CBC_SHA

  SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA

* SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA

  SSL_DHE_RSA_WITH_DES_CBC_SHA

  SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA

  SSL_DH_anon_EXPORT_WITH_RC4_40_MD5

  SSL_DH_anon_WITH_3DES_EDE_CBC_SHA

  SSL_DH_anon_WITH_DES_CBC_SHA

  SSL_DH_anon_WITH_RC4_128_MD5

  SSL_RSA_EXPORT_WITH_DES40_CBC_SHA

  SSL_RSA_EXPORT_WITH_RC4_40_MD5

* SSL_RSA_WITH_3DES_EDE_CBC_SHA

  SSL_RSA_WITH_DES_CBC_SHA

  SSL_RSA_WITH_NULL_MD5

  SSL_RSA_WITH_NULL_SHA

* SSL_RSA_WITH_RC4_128_MD5

* SSL_RSA_WITH_RC4_128_SHA

* TLS_DHE_DSS_WITH_AES_128_CBC_SHA

* TLS_DHE_DSS_WITH_AES_128_CBC_SHA256

* TLS_DHE_RSA_WITH_AES_128_CBC_SHA

* TLS_DHE_RSA_WITH_AES_128_CBC_SHA256

  TLS_DH_anon_WITH_AES_128_CBC_SHA

  TLS_DH_anon_WITH_AES_128_CBC_SHA256

* TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA

* TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA

* TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256

  TLS_ECDHE_ECDSA_WITH_NULL_SHA

* TLS_ECDHE_ECDSA_WITH_RC4_128_SHA

* TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA

* TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA

* TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256

  TLS_ECDHE_RSA_WITH_NULL_SHA

* TLS_ECDHE_RSA_WITH_RC4_128_SHA

* TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA

* TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA

* TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256

  TLS_ECDH_ECDSA_WITH_NULL_SHA

* TLS_ECDH_ECDSA_WITH_RC4_128_SHA

* TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA

* TLS_ECDH_RSA_WITH_AES_128_CBC_SHA

* TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256

  TLS_ECDH_RSA_WITH_NULL_SHA

* TLS_ECDH_RSA_WITH_RC4_128_SHA

  TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA

  TLS_ECDH_anon_WITH_AES_128_CBC_SHA

  TLS_ECDH_anon_WITH_NULL_SHA

  TLS_ECDH_anon_WITH_RC4_128_SHA

* TLS_EMPTY_RENEGOTIATION_INFO_SCSV

  TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5

  TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA

  TLS_KRB5_EXPORT_WITH_RC4_40_MD5

  TLS_KRB5_EXPORT_WITH_RC4_40_SHA

  TLS_KRB5_WITH_3DES_EDE_CBC_MD5

  TLS_KRB5_WITH_3DES_EDE_CBC_SHA

  TLS_KRB5_WITH_DES_CBC_MD5

  TLS_KRB5_WITH_DES_CBC_SHA

  TLS_KRB5_WITH_RC4_128_MD5

  TLS_KRB5_WITH_RC4_128_SHA

* TLS_RSA_WITH_AES_128_CBC_SHA

* TLS_RSA_WITH_AES_128_CBC_SHA256

  TLS_RSA_WITH_NULL_SHA256

yhlee@yhlee-mbpr:~/src/oss$ JAVA_HOME=~/java/jre8u60b27 ~/java/jre8u60b27/bin/java -version

java version "1.8.0_60"

Java(TM) SE Runtime Environment (build 1.8.0_60-b27)

Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed mode)

yhlee@yhlee-mbpr:~/src/oss$ JAVA_HOME=~/java/jre8u60b27 ~/java/jre8u60b27/bin/java SSLInfo

Default Cipher

  SSL_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA

* SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA

  SSL_DHE_DSS_WITH_DES_CBC_SHA

  SSL_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA

* SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA

  SSL_DHE_RSA_WITH_DES_CBC_SHA

  SSL_DH_anon_EXPORT_WITH_DES40_CBC_SHA

  SSL_DH_anon_WITH_3DES_EDE_CBC_SHA

  SSL_DH_anon_WITH_DES_CBC_SHA

  SSL_RSA_EXPORT_WITH_DES40_CBC_SHA

* SSL_RSA_WITH_3DES_EDE_CBC_SHA

  SSL_RSA_WITH_DES_CBC_SHA

  SSL_RSA_WITH_NULL_MD5

  SSL_RSA_WITH_NULL_SHA

* TLS_DHE_DSS_WITH_AES_128_CBC_SHA

* TLS_DHE_DSS_WITH_AES_128_CBC_SHA256

* TLS_DHE_DSS_WITH_AES_128_GCM_SHA256

* TLS_DHE_RSA_WITH_AES_128_CBC_SHA

* TLS_DHE_RSA_WITH_AES_128_CBC_SHA256

* TLS_DHE_RSA_WITH_AES_128_GCM_SHA256

  TLS_DH_anon_WITH_AES_128_CBC_SHA

  TLS_DH_anon_WITH_AES_128_CBC_SHA256

  TLS_DH_anon_WITH_AES_128_GCM_SHA256

* TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA

* TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA

* TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256

* TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256

  TLS_ECDHE_ECDSA_WITH_NULL_SHA

* TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA

* TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA

* TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256

* TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256

  TLS_ECDHE_RSA_WITH_NULL_SHA

* TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA

* TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA

* TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256

* TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256

  TLS_ECDH_ECDSA_WITH_NULL_SHA

* TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA

* TLS_ECDH_RSA_WITH_AES_128_CBC_SHA

* TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256

* TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256

  TLS_ECDH_RSA_WITH_NULL_SHA

  TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA

  TLS_ECDH_anon_WITH_AES_128_CBC_SHA

  TLS_ECDH_anon_WITH_NULL_SHA

* TLS_EMPTY_RENEGOTIATION_INFO_SCSV

  TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5

  TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA

  TLS_KRB5_WITH_3DES_EDE_CBC_MD5

  TLS_KRB5_WITH_3DES_EDE_CBC_SHA

  TLS_KRB5_WITH_DES_CBC_MD5

  TLS_KRB5_WITH_DES_CBC_SHA

* TLS_RSA_WITH_AES_128_CBC_SHA

* TLS_RSA_WITH_AES_128_CBC_SHA256

* TLS_RSA_WITH_AES_128_GCM_SHA256

  TLS_RSA_WITH_NULL_SHA256

yhlee@yhlee-mbpr:~/src/oss$

 

 

New Member
Posts: 16
Registered: ‎10-19-2014
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Solutions: 2

Re: Server has a weak ephemeral Diffie-Hellman public key

[ Edited ]

updating my version 1.7.0 java to the latest, turn out it doesn't support GCM yet.

try updating to 1.8.0, it is support GCM, but no ECDHE...

darnn you CentOS Icon Cry

 

for any of you wanting to keep using DH, edit your init script and add -Djdk.tls.ephemeralDHKeySize=2048 as an argument, eg: java -Djdk.tls.ephemeralDHKeySize=2048 -jar /opt/UniFi/lib/ace.jar start &

 

@UBNT-yhlee: is there any documentation about system.properties? is it possible to put this setting in system.properties? i read from the web that java application can set this properti programmatically. i was though that system.properties will be equal to System.properties java's system variable. but, trying to set jdk.tls.ephemeralDHKeySize=2048 in this file doesn't work.

 

the one provided here doesn't even contain what redfive mentioned.

 

@redfive: where did you found thus unifi.https.* option? is there any equivalent for apache httpd's SSLHonorCipherOrder setting in UniFi?

SuperUser
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Registered: ‎01-05-2012
Kudos: 1982
Solutions: 985

Re: Server has a weak ephemeral Diffie-Hellman public key

Stop the controller, install java 8, then
update-java-alternatives -s java-8-oracle
apt-get install oracle-java8-set-default
Then, edit /etc/init.d/unifi file, at the beginning
support_java_ver='7 8'
and
JAVA_HOME=/usr/lib/jvm/java-8-oracle
Edit the system.properties file as described above, restart the controller.
Regards

New Member
Posts: 37
Registered: ‎03-21-2014
Kudos: 4

Re: Server has a weak ephemeral Diffie-Hellman public key

How do I go about installing Java 8?

UEWA
New Member
Posts: 16
Registered: ‎10-19-2014
Kudos: 2
Solutions: 2

Re: Server has a weak ephemeral Diffie-Hellman public key

[ Edited ]

for my CentOS, i didn't install it.

i download binary server JRE package from oracle, extract it to /opt,

then change my UniFi init script to use thus.

 

once again, thanks @redfive for the hint... i got A now Ihih

whats lack is Downgrade attack prevention, which java doesn't support yet,

and Secure Client-Initiated Renegotiation, which i don't know how to disable them.

i already add sun.security.ssl.allowUnsafeRenegotiation=false

and sun.security.ssl.allowLegacyHelloMessages=false

but they doesn't work.

 

New Member
Posts: 16
Registered: ‎10-19-2014
Kudos: 2
Solutions: 2

Re: Server has a weak ephemeral Diffie-Hellman public key


wispr wrote:

yeah, x2 @redfive. Enabling tls 1.2 (on ubuntu 14.04) using those ciphers listed produces this:

 

ssl_error_no_cypher_overlap

 

Setting it to tls 1.1 and removing the custom ciphers makes the port work again, but without tls 1.2 SSL certs will always be stuck at a C grade, at least for Qualsys.


hey @wispr, has you worked out this problem? try enable all TLS protocol, like this unifi.https.sslEnabledProtocols=TLSv1.2,TLSv1.1,TLSv1 then consult SSLInfo provided by @UBNT-yhlee to see what ciphers offered by your JVM to use in unifi.https.ciphers.

 

for Oracle's Java 8, i use this:

Spoiler
unifi.https.ciphers=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256,TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,TLS_DHE_RSA_WITH_AES_128_CBC_SHA,SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA,TLS_EMPTY_RENEGOTIATION_INFO_SCSV
New Member
Posts: 37
Registered: ‎03-21-2014
Kudos: 4

Re: Server has a weak ephemeral Diffie-Hellman public key

Quicker workaround for the lamens around here:

 

Download Firefox, do the following:

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.
(2) In the search box above the list, type or paste dhe and pause while the list is filtered
(3) Double-click the security.ssl3.dhe_rsa_aes_128_sha preference to switch it from true to false (disable Firefox from using this cipher)
(4) Double-click the security.ssl3.dhe_rsa_aes_256_sha preference to switch it from true to false (disable Firefox from using this cipher)

 

Navigate to your NVR, update Firmware to 3.1.2, update firmware on cameras, and now you can access via Chrome.

UEWA
Established Member
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Registered: ‎12-14-2009
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Solutions: 36

Re: Server has a weak ephemeral Diffie-Hellman public key

[ Edited ]

Banghead

 

V4.8.5 Controller (as used in the new CloudKey) still uses the obsolete cipher key in the Guest Portal which means those using Chrome can not use the credit card gateway.

 

Willy Nilly

Rob Clark
Freenet Warehouse
Certified airMAX Instructor
Certified UniFi Instructor
Certified Routing and Switching Instructor
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