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Browser still uses TLS_AES_128_GCM_SHA256 (0x1301) 128-bit SSL encryption cipher even when disabled in about:config

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  • Last reply by cor-el

user1555634
user1555634
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Even after disabling all the 128-bit cipher suites in about:config, the cipher TLS_AES_128_GCM_SHA256 (0x1301) is still being used.

I used Qualys SSL Labs Client Test (https://www.ssllabs.com/ssltest/viewMyClient.html), and saw that TLS_AES_128_GCM_SHA256 (0x1301) remains to be the most preferred cipher suite.

All TLS 1.3 connections, such as facebook.com and cloudflare.com, uses that particular AES-128 cipher suite.

Is this a feature or a bug?

Even after disabling all the 128-bit cipher suites in about:config, the cipher TLS_AES_128_GCM_SHA256 (0x1301) is still being used. I used Qualys SSL Labs Client Test (https://www.ssllabs.com/ssltest/viewMyClient.html), and saw that TLS_AES_128_GCM_SHA256 (0x1301) remains to be the most preferred cipher suite. All TLS 1.3 connections, such as facebook.com and cloudflare.com, uses that particular AES-128 cipher suite. Is this a feature or a bug?

Chosen solution

See:

  • Bug 1490902 - TLS 1.3 Adds & Prioritizes 3 Cipher Suites with inferior security to TLS 1.2 Suites

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)

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cor-el
cor-el
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Chosen Solution

See:

  • Bug 1490902 - TLS 1.3 Adds & Prioritizes 3 Cipher Suites with inferior security to TLS 1.2 Suites

(please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html)