There are no common encryption algorithms. Why is this situation possible?

By constantly spending time on the Internet, a person increases the likelihood of infection of the equipment used by various malicious programs. It is not surprising that today there are many ways to protect yourself from such troubles.

The average user's computer is protected by specialized software built into the system itself, an antivirus program, as well as special security protocols used by the browsers themselves. Unfortunately, but sometimes it is the last option that can cause the ssl error no cypher overlap error to appear on the screen.

It is especially annoying when the ssl error no cypher overlap error code occurs when you try to visit a really good and safe resource.
Naturally, the question arises - how to live further and what to do?

Why is this situation possible?

Almost always, a similar nuisance is observed if the user uses the Firefox Internet browser to access the network.

The program updated to version 34+, for some reason, may stop accepting the SSLv3 protocol used on the sites, thereby denying access to it.

Also, a possible root cause is sometimes an antivirus program operated on a computer or a Trojan introduced through negligence.

How to fix ssl error no cypher overlap? Initially, it is advisable to use the following instruction:

Install effective software that copes well with Trojans. For example, you can try AdwCleaner or its equivalent.
Temporarily disable the active antivirus program to check the ability to grant access.
Switch to an alternative Internet browser and try to use it to carry out the previously interrupted operation. In this case, it is strongly recommended to completely demolish Firefox and be sure to restart your computer after that.
Go to your internet browser settings to delete your history, cookies and cache.

If the owner of the PC categorically refuses to switch to other versions of the browsers available today, and none of the above points brought the desired result, then there is another way to fix it - to make changes to the FireFox settings:

Activate the main page of this software.
Go to the program search bar, where you want to drive in "about: config".
Agree with further actions, taking responsibility for the changes made.
After a rather impressive list appears on the screen, once again use the built-in search capabilities by typing "security.tls.version" into it.
Of all the proposed options, focus on only two: "security.tls.version.min" and "security.tls.version.fallback-limit".
By alternately clicking on them with the right mouse button, go to the "Change" offer. Set numerical values \u200b\u200bto "0".
Restart the equipment. Check the result.
In the absence of a positive result from the above proposed instruction, it is recommended to repeat it completely, only to set one instead of zero.

When trying to connect to any site, the user may receive an ssl_error_no_cypher_overlap error message. In this article I will tell you what the error code is, explain the reasons for its occurrence, and also tell you how to fix the ssl_error_no_cypher_overlap error on your PC.

What is this SSL error

As you can see from the wording of the ssl_error_no_cypher_overlap error, this problem occurs when certain sites do not support some encryption protocols (no_cypher_overlap). Usually, we are talking about the use of the SSL version 3.0 protocol by the site (created back in 1996), the work with which in our time can have the most sad effect on the overall security of the connection and the safety of the transmitted data.

Despite the fact that the SSL protocol has undergone its further development, objectified in the TLS protocols, some sites still continue to require users to use outdated SSL. Therefore, the activation and application of SSL on your browser will be done by you at your own risk.

Reasons for the error in the browser

As already mentioned, the main reason for the SSL Error is the use of an outdated protocol by the site, and the activity of virus and anti-virus programs that block or modify the network Internet connection can also cause the problem.

At the same time, the error in question is most often fixed on the Mozilla Firefox browser (especially after update # 34), on other browsers it is extremely rare.

How to fix ssl_error_no_cypher_overlap error

I will give a list of methods for eliminating the error in question:

Reboot your computer. This cliché advice sometimes helps;
Check your computer for virus programs using a reliable antivirus;
Try to temporarily disable your antivirus and firewall, and then try to go to the problem site;
Please use a different browser. Since this error most often occurs on Firefox, changing the browser can fix the problem;
Change Firefox preferences. To do this, open a new window in your Mozilla, enter about: config in the address bar and press enter. Confirm that you accept the risk, and then enter security.tls.version in the search bar. After receiving the results from several values, change the value of the security.tls.version.fallback-limit and security.tls.version.min parameters to 0. After these innovations, try again to visit the problem site, it should load.
Disable https. Instruction.

Conclusion

The most common cause of the ssl_error_no_cypher_overlap problem is the outdated SSL cryptographic protocol that some sites use. If you use the "fox", then change the value of some browser settings as indicated above, in other cases, temporarily disabling the antivirus and firewall, as well as changing the browser, can help.

Modern browsers are distinguished by really effective antivirus capabilities. Even without various third-party programs, they will be able to protect your computer from the penetration of spyware Trojans. However, precisely because of such excessive measures, users receive blocking of reliable Internet pages without reason. “Ssl_error_no_cypher_overlap” becomes one of such blocking. Yesterday's good site (for example, zakupki.gov) suddenly stops loading. This is very common on Firefox and Internet Explorer.

Error reasons

From the error itself, you can understand that the SSLv3 protocol is no longer supported, and without this level of security, the browser cannot make a connection. That is, no one can vouch for your safety, so the best solution is to block the Internet connection.

Error code "ssl_error_no_cypher_overlap" in Mozilla Firefox

The reason is the update of the Firefox browser to the latest version, for some unknown reason, from version 34, it begins to be very indignant when connecting suspicious SSL. The browser finds on the visited resource some plugins, scripts and hacked security protocols that can collect information about the user, and blocks access to the website. Another possible problem is antivirus or a Trojan (browser hijacker) running on your system.

Correcting the connection error

I will note right away that we will remove the moment with the infected PC, the user must constantly scan the system with antiviruses and scanners for malware. It fights well against hijackers - AdwCleaner, for example.

So, for starters, here are some simple tips for a quick solution:

Using Firefox, clear all cookies and cache as well as history.
Disable for a while the protection of the OS and with it the antivirus screen.
Use another browser, after uninstalling Firefox and restarting your PC.
Replace the hosts file with the recommended one from Microsoft. You can find it on the official website of the corporation.

Changing Firefox settings

The more difficult option is to change the browser settings. You should go to its root menu and change several required items:

Let's open a new page in Firefox. We write in the search box: about: config

From several points, we select only two: security.tls.version.fallback-limit and security.tls.version.min

Keep in mind that by setting zero values, you made the browser vulnerable, so try to immediately return all values \u200b\u200bback. And it is desirable for the site administrator to point out the problem.

This in most cases it helps to fix the ssl_error_no_cypher_overlap error code in the browser. But there is a very important point to keep in mind, now you are less protected from malware. Therefore, it is better to think over and over again whether this site is worth the increased risks of infecting your computer with virus programs. It may be easier to change browser or find another source on the internet.

I "m developing a web app. Currently, I" m using a self-signed certificate (getting it properly signed comes later).

When I have the web server set so that it only accepts TLS1.1 and TLS1.2, I "m getting a SSL_ERROR_NO_CYPHER_OVERLAP error. And, of course, trying the" use outdated security "link doesn" t work, since the web server won "t allow those connections.

If I temporarily allow insecure connections on the web server, Firefox will then allow me to accept the cert. After the cert is accepted, Firefox can then connect over only TLS1.1 and TLS1.2. So, most of the time, Firefox can find a common cypher for TLS1.1 / 1.2 connections.

(The web server is on an Ubuntu kernel, with OpenSSL1.0.1f.)

I "m developing a web app. Currently, I" m using a self-signed certificate (getting it properly signed comes later). When I have the web server set so that it only accepts TLS1.1 and TLS1.2, I "m getting a SSL_ERROR_NO_CYPHER_OVERLAP error. And, of course, trying the" use outdated security "link doesn" t work, since the web server won "t allow those connections. If I temporarily allow insecure connections on the web server, Firefox will then allow me to accept the cert. After the cert is accepted, Firefox can then connect over only TLS1.1 and TLS1.2. So, most of the time, Firefox can find a common cypher for TLS1.1 / 1.2 connections. (The web server is on an Ubuntu kernel, with OpenSSL1.0.1f.)

Chosen solution

I finally figured out what is going on.

The fix is \u200b\u200breally in configuring OpenSSL; however, since Firefox is the browser that most readily displays the problem, I "m going to post the answer here.

Anyway, at issue is the separation in OpenSSL of the protocols supported vs. the cipher list.

In an app using OpenSSL, if you "re using anything older than OpenSSL 1.1.0, you" ll need to disable any protocol older than TLSv1. Do this with:

SSL_CTX_set_options (ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);

(Note that recent versions of OpenSSL before version 1.1.0 have SSLv2 turned off by default, but it doesn "t hurt to explicitly disable it with this call. Also note that if you disable TLSv1, you" ll break compatibility with some apps that make HTTPS calls; for example Firefox appears to use TLSv1 to do the certificate exchange, before going to stronger protocols for the session).

The key to understanding the SSL_NO_CYPHER_OVERLAP error is that TLSv1 only uses SSLv3 ciphers.

So, I was running into this issue because when I disabled SSLv3, I was also disabling the SSLv3 ciphers. To set the OpenSSL ciphers, use something like:

SSL_CTL_set_cipher_list (ctx, "TLSv1.2: TLSv1: SSLv3:! SSLv2: HIGH:! MEDIUM:! LOW");

If you use instead (as I was originally using):

SSL_CTL_set_cipher_list (ctx, "TLSv1.2: TLSv1:! SSLv3:! SSLv2: HIGH:! MEDIUM:! LOW");

You "ll effectively disable TLSv1, since there are no TLSv1-specific ciphers (at least in OpenSSL), and with the SSLv3 ciphers disabled, it isn" t possible to establish a TLSv1 connection.

With SSLv3 disabled, but the TLSv1 / SSLv3 ciphers enabled, Firefox is able to get the certificates. After this, I see that Firefox then establishes a TLSv1.2 connection.

Most of the above solution is not needed for OpenSSL 1.1.0, since that has no support for SSLv3 at all.

Read this answer in context 4

Question owner

Thanks for your reply.

Unfortunately, I "m developing behind a firewall, so said site isn" t able to scan it.

Is there a way to find out what ciphers Firefox attempted?

(It still seems strange that if I have Firefox accept the certificate, by temporarily reducing security, that Firefox is then able to agree on a high security cipher.)

Thanks for your reply. Unfortunately, I "m developing behind a firewall, so said site isn" t able to scan it. Is there a way to find out what ciphers Firefox attempted? (It still seems strange that if I have Firefox accept the certificate, by temporarily reducing security, that Firefox is then able to agree on a high security cipher.)

What connection settings does Firefox use if you allow lower security?

You can check that in the Security tab in the Network Monitor.

What connection settings does Firefox use if you allow lower security? You can check that in the Security tab in the Network Monitor. * https: //developer.mozilla.org/Tools/Network_Monitor

Question owner

Don "t know if I" m quite clicking on the correct place.

With Network Monitor open, if I click on the GET request, the security tab is only saying that the security certificate is invalid (which I expect, since it is invalid).

In experimenting with different security settings on the server, it appears that when I get "invalid certificate", it is using SSLv3, while if I set the server for TLS only, I get "no cypher overlap" (although I "m not seeing a SSLv3 warning in the security tab).

If I go to about: config, and search on security * ssl, I see a large number of enabled ciphers in the list. If I search on security * tls, I don "t see any ciphers listed.

I "ve attached screen shots. The one with" no cypher overlap "is what I get when I disable SSLv3 on my web server, and the one with" unknown issuer "is what I get when I enable SSLv3 on my web server.

(Both Chrome and IE just give me the "invalid certificate" error, but will otherwise connect.)

Don "t know if I" m quite clicking on the correct place. With Network Monitor open, if I click on the GET request, the security tab is only saying that the security certificate is invalid (which I expect, since it is invalid). In experimenting with different security settings on the server, it appears that when I get "invalid certificate", it is using SSLv3, while if I set the server for TLS only, I get "no cypher overlap" (although I "m not seeing a SSLv3 warning in the security tab). If I go to about: config, and search on security * ssl, I see a large number of enabled ciphers in the list. If I search on security * tls, I don "t see any ciphers listed. I "ve attached screen shots. The one with" no cypher overlap "is what I get when I disable SSLv3 on my web server, and the one with" unknown issuer "is what I get when I enable SSLv3 on my web server. ( Both Chrome and IE just give me the "invalid certificate" error, but will otherwise connect.)

Modified May 18, 2016 at 9:55:13 AM PDT by gshonle

Question owner

I did a tcpdump trace; 10.1.233.67 is the system running Firefox; 10.1.85.41 is the Linux server. See attached image.

Here are the TLSv1.2 ciphers supported by the Linux OpenSSL:

ECDHE-RSA-AES256-GCM-SHA384 ECDHE-ECDSA-AES256-GCM-SHA384 ECDHE-RSA-AES256-SHA384 ECDHE-ECDSA-AES256-SHA384 DHE-DSS-AES256-GCM-SHA384-RSA-RSA-AES256-DHE-SHA384 DHE-RSA-AES256-SHA256 DHE-DSS-AES256-SHA256 ECDH-RSA-AES256-GCM-SHA384 ECDH-ECDSA-AES256-GCM-SHA384 ECDH-RSA-AES256-SHA384 ECDH-ECD256-A38ES SHA384 AES256-SHA256 ECDHE-RSA-AES128-GCM-SHA256 ECDHE-ECDSA-AES128-GCM-SHA256 ECDHE-RSA-AES128-SHA256 ECDHE-ECDSA-AES128-SHA256 DHE128-DSS-GCES-DHA256 DHE128-DSS-GC -GCM-SHA256 DHE-RSA-AES128-SHA256 DHE-DSS-AES128-SHA256 ECDH-RSA-AES128-GCM-SHA256 ECDH-ECDSA-AES128-GCM-SHA256 ECDH-RSA-AES128-SHA6256 ECDH-RSA-AES128-SHA258 ECDA AES128-GCM-SHA256 AES128-SHA256

So, it looks like they almost overlap ...

I did a tcpdump trace; 10.1.233.67 is the system running Firefox; 10.1.85.41 is the Linux server. See attached image. Here are the TLSv1.2 ciphers supported by the Linux OpenSSL: ECDHE-RSA-AES256-GCM-SHA384 ECDHE-ECDSA-AES256-GCM-SHA384 ECDHE-RSA-AES256-SHA384 ECDHE-ECDSA-DHES256-SHA384 -GCM-SHA384 DHE-RSA-AES256-GCM-SHA384 DHE-RSA-AES256-SHA256 DHE-DSS-AES256-SHA256 ECDH-RSA-AES256-GCM-SHA384 ECDH-ECDSA-AES256-ECDH-SHA384 -SHA384 ECDH-ECDSA-AES256-SHA384 AES256-GCM-SHA384 AES256-SHA256 ECDHE-RSA-AES128-GCM-SHA256 ECDHE-ECDSA-AES128-GCM-SHA256 ECDHE-RSHA-AES12 ECDHE-RSHA256 ECDHE-RSHA-AES12 -DSS-AES128-GCM-SHA256 DHE-RSA-AES128-GCM-SHA256 DHE-RSA-AES128-SHA256 DHE-DSS-AES128-SHA256 ECDH-RSA-AES128-GCM-SHA256 ECDH-ECDSA-AES128-SHA256 ECDH-ECDSA-AES128-SHA256 -RSA-AES128-SHA256 ECDH-ECDSA-AES128-SHA256 AES128-GCM-SHA256 AES128-SHA256 So, it looks like they almost overlap ...

SSL handshaking is over my head, but two things:

(1) Under no circumstances will recent versions of Firefox use SSLv3 as a protocol... The lowest supported protocol is TLS 1.0.

(2) In about: config, the preference names for the ciphers contain ssl3, but this is an historical artifact and has no bearing on the protocol that is used. These ciphers need to be enabled in order to be available for TLS connections.

There are two ciphers I recommend setting to false, since they are associated with the Logjam issue:

security.ssl3.dhe_rsa_aes_128_sha security.ssl3.dhe_rsa_aes_256_sha

Some users may prefer to set the two RC4 ciphers to false as well, but this may create problems with older Microsoft IIS servers.

You should be able to connect securely using these ciphers (your list \u003d\u003e Firefox preference name):

ECDHE-RSA-AES128-GCM-SHA256 \u003d\u003e security.ssl3.ecdhe_rsa_aes_128_gcm_sha256

ECDHE-ECDSA-AES128-GCM-SHA256 \u003d\u003e

SSL handshaking is over my head, but two things: (1) Under no circumstances will recent versions of Firefox use SSLv3 as a "" protocol "". The lowest supported protocol is TLS 1.0. (2) In about: config, the preference names for the "" ciphers "" contain ssl3, but this is an historical artifact and has no bearing on the "" protocol "" that is used. These ciphers need to be enabled in order to be available for TLS connections. There are two ciphers I recommend setting to false, since they are associated with the Logjam issue: security.ssl3.dhe_rsa_aes_128_sha security.ssl3.dhe_rsa_aes_256_sha Some users may prefer to set the two RC4 ciphers to false as well, but this may create problems with older Microsoft IIS servers. You should be able to connect securely using these ciphers (your list \u003d\u003e Firefox preference name): ECDHE-RSA-AES128-GCM-SHA256 \u003d\u003e security.ssl3.ecdhe_rsa_aes_128_gcm_sha256 ECDHE-ECDSA-AES128-GCM-SHA256 \u003d\u003e .ecdhe_ecdsa_aes_128_gcm_sha256

Question owner

Both security.ssl3.ecdhe_rsa_aes_128_gcm_sha256 and security.ssl3.ecdhe_ecdsa_aes_128_gcm_sha256 are enabled in Firefox (I "m using the default settings for everything).

So ... Still puzzled about what "s going on ...

Both security.ssl3.ecdhe_rsa_aes_128_gcm_sha256 and security.ssl3.ecdhe_ecdsa_aes_128_gcm_sha256 are enabled in Firefox (I "m using the default settings for everything). So ... Still puzzled about what" s going on ...

See next post

"" See next post "" Looking at your last screen shot ("Client Hello"), I "m a little baffled. Is that the client machine" s cipher list? It doesn "t match Firefox" s list - in particular, to my knowledge, Firefox does not support any CBC ciphers, which comprise nearly all of what "s listed. Do you have a proxy in front of Firefox on the client?

Modified May 18, 2016 at 11:47:47 AM PDT by jscher2000

Oops, I "m wrong based on this site: https://www.ssllabs.com/ssltest/viewMyClient.html - CBC appears in several of the cipher names there even if they do not appear in about: config.

Cipher Suites (in order of preference) TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (0xc02b) Forward Secrecy 128 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (0xc02f) Forward Secrecy 128 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (0xc00a) Forward Secrecy 256 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (0xc009) Forward Secrecy 128 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (0xc013) Forward Secrecy 128 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (0xc014) Forward Secrecy 256 TLS_RSA_WITH_AES_128_CBC_SHA (0x2f) 128 TLS_RSA_WITH_AES_256_CBC_SHA (0x35) 256 TLS_RSA_WITH_3DES_EDE_CBC_SHA (0xa) 112

These two do not appear on my normal list, as I have disabled them as mentioned earlier:

TLS_DHE_RSA_WITH_AES_128_CBC_SHA (0x33) Forward Secrecy 128 TLS_DHE_RSA_WITH_AES_256_CBC_SHA (0x39) Forward Secrecy 256

With those, there are 11 as you saw in Client Hello.

Oops, I "m wrong based on this site: https://www.ssllabs.com/ssltest/viewMyClient.html - CBC appears in several of the cipher names there even if they do not appear in about: config. Cipher Suites (in order of preference) TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 (0xc02b) Forward Secrecy 128 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (0xc02f) Forward Secrecy 128 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA (0xc00a) Forward Secrecy 256 TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA (0xc009) Forward Secrecy 128 TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (0xc013) Forward Secrecy 128 TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (0xc014) Forward Secrecy 256 TLS_RSA_WITH_AES_128_CBC_SHA ( 0x2f) 128 TLS_RSA_WITH_AES_256_CBC_SHA (0x35) 256 TLS_RSA_WITH_3DES_EDE_CBC_SHA (0xa) 112 These two do not appear on my normal list, as I have disabled them as mentioned earlier: TLS_DHE_RSA_WITH_AES_128_CBC_SHA (0x33) Forward Secrecy 128 TLS_DHE_RSA_WITH_AES_256_CBC_SHA (0x39) Forward Secrecy 256 With those, there are 11 as you saw in Client Hello.

Question owner

The Hello Client packet is what was sent by the system running Firefox; it was sent when Firefox attempted the connection.

I double-checked, and I don "t have a proxy in front of Firefox.

To quote Alice: Curiouser and curiouser ...

The Hello Client packet is what was sent by the system running Firefox; it was sent when Firefox attempted the connection. I double-checked, and I don "t have a proxy in front of Firefox. To quote Alice: Curiouser and curiouser ...

Question owner

Yes, OpenSSL 1.0.1f is from January of 2014, and I "d prefer if we went to a newer version. Unfortunately, the current plan is to not move to a newer OpenSSL right now (not my choice).

Any ideas on a next step?

Yes, OpenSSL 1.0.1f is from January of 2014, and I "d prefer if we went to a newer version. Unfortunately, the current plan is to not move to a newer OpenSSL right now (not my choice). Any ideas on a next step?

What happens if you click the "(Not secure) Try loading" link?

If you also need to override the bad certificate, accept a temporary exception.

Then assuming you get a secure connection, check the protocol and cipher listed on the Page Info dialog, security panel, toward the bottom, which you can view using either:

right-click (on Mac Ctrl + click) a blank area of \u200b\u200bthe page and choose View Page Info\u003e Security
(menu bar) Tools\u003e Page Info\u003e Security
click the padlock or "i" icon in the address bar, then the "\u003e" button, then More Information

What shows as in use there?

What happens if you click the "(Not secure) Try loading" link? If you also need to override the bad certificate, accept a temporary exception. Then assuming you get a secure connection, check the protocol and cipher listed on the Page Info dialog, security panel, toward the bottom, which you can view using either: * right-click (on Mac Ctrl + click) a blank area of \u200b\u200bthe page and choose View Page Info\u003e Security * (menu bar) Tools\u003e Page Info\u003e Security * click the padlock or "i" icon in the address bar, then the "\u003e" button, then More Information What shows as in use there?

Question owner

See attached for what happens if I click on the (Not secure) link. Since my server is set to not use SSLv3, Firefox can "t connect.

If I temporarily enable SSLv3 on my server, I can accept the invalid certificate. Then, the connection uses TLS 1.2 (Cipher is TLS_RSA_WITH_AES_128_CBC_SHA, 128 bit keys). (If I permanently accept the certificate, I can always connect immediately, even with SSLv3 disabled on my server.)

See attached for what happens if I click on the (Not secure) link. Since my server is set to not use SSLv3, Firefox can "t connect. If I temporarily enable SSLv3 on my server, I can accept the invalid certificate. Then, the connection uses TLS 1.2 (Cipher is TLS_RSA_WITH_AES_128_CBC_SHA, 128 bit keys). ( If I permanently accept the certificate, I can always connect immediately, even with SSLv3 disabled on my server.)

The error you got was SSL_ERROR_INAPPROPRIATE_FALLBACK_ALERT which indicated the server tried to downgrade from TLS1.2 to a lower protocol. That doesn "t really make sense from what you" re describing, but might be seen with RC4 ciphers.

Anyway, no point troubleshooting this old version of OpenSSL any further.

I don "t think this has anything to do with SSLv3, since Firefox 46 does not support SSLv3 at all under any circumstances. When you enable SSLv3 on the server, I think that must change something else at the same time. The error you got was SSL_ERROR_INAPPROPRIATE_FALLBACK_ALERT which indicated the server tried to downgrade from TLS1.2 to a lower protocol. That doesn "t really make sense from what you" re describing, but might be seen with RC4 ciphers. Anyway, no point troubleshooting this old version of OpenSSL any further.

Question owner

The product I "m working on has an embedded Linux system, with a web server as part of the total product. Because it is not running on standard hardware, we" re limited on which Linux distros we can use. The latest OpenSSL deb package for that distro is 1.0.1f. For reasons beyond the scope of this discussion, we are only using updates that have deb packages.

So, unfortunately, it looks like we "ll have to document that only Chrome and IE are supported, and to not use Firefox.

Modified May 24, 2016 at 1:07:42 PM PDT by gshonle

Helpful Reply

You might bring it to your supplier "s attention, since they ultimately will be blamed for your product" s inability to make a secure connection with Firefox.

I "m not sure if it" s applicable to your product, but for some websites, you can enable fallback by adding a host name to this preference:

(1) In a new tab, type or paste about: config in the address bar and press Enter / Return. Click the button promising to be careful.

(2) In the search box above the list, type or paste TLS and pause while the list is filtered

(3) Double-click the security.tls.insecure_fallback_hosts preference and, either:

(A) If it "s empty, type or paste the host name and click OK

(B) If one or more other host names is already listed, press the End key to go to the end, type a comma, then type or paste the additonal host name and click OK

You might bring it to your supplier "s attention, since they ultimately will be blamed for your product" s inability to make a secure connection with Firefox. I "m not sure if it" s applicable to your product, but for some websites, you can enable fallback by adding a host name to this preference: (1) In a new tab, type or paste "" "about: config" "" in the address bar and press Enter / Return. Click the button promising to be careful. (2) In the search box above the list, type or paste "" "TLS" "" and pause while the list is filtered (3) Double-click the "" "security.tls.insecure_fallback_hosts" "" preference and, either : (A) If it "s empty, type or paste the host name and click OK (B) If one or more other host names is already listed, press the End key to go to the end, type a comma, then type or paste the additonal host name and click OK

Question owner

If I add the host to the insecure_fallback_hosts, I now get: "The server rejected the handshake because the client downgraded to a lower TLS version than the server supports. Error code: SSL_ERROR_INAPPROPRIATE_FALLBACK_ALERT"

The server is currently configured for TLSv1.2, TLSv1.1 and TLSv1.

Forum volunteer can replicate fallback error connecting to server that supports TLS1.1 and TLS1.0 but not TLS1.2

Firewall configuration problem causing fallback error message

Server prefers RC4 ciphers (problem in Firefox 36+):

Unclear whether it was solved

BitDefender possible culprit

BitDefender was the culprit

Well, TLS 1.0 is the lowest TLS on both sides, so this error makes no sense. I really don "t know what is going on there. It" s not behaving like other servers users have reported (not that I can read everything posted here) ..] - forum volunteer can replicate fallback error connecting to server that supports TLS1. 1 and TLS1.0 but not TLS1..0.2] - firewall configuration problem causing fallback error message Server prefers RC4 ciphers (problem in Firefox 36+): - unclear whether it was solved - BitDefender possible culprit - BitDefender was the culprit

You can try to increase security.tls.version.min temporarily to 2 (or 3) to see what effect this has.