4 ms·

Is this really a "best practice" to disable dhe in firefox/chrome? Won't that just make the server/browser negotiate an even weaker scheme if they cannot find

by ck2 11y ago

Is this really a "best practice" to disable dhe in firefox/chrome? Won't that just make the server/browser negotiate an even weaker scheme if they cannot find a matching higher set? My firefox goes from: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA TLS_DHE_RSA_WITH_AES_128_CBC_SHA TLS_DHE_RSA_WITH_AES_256_CBC_SHA TLS_RSA_WITH_AES_128_CBC_SHA TLS_RSA_WITH_AES_256_CBC_SHA TLS_RSA_WITH_3DES_EDE_CBC_SHA to: TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA TLS_RSA_WITH_AES_128_CBC_SHA TLS_RSA_WITH_AES_256_CBC_SHA TLS_RSA_WITH_3DES_EDE_CBC_SHA Do you really want TLS_RSA? How about 3DES?

snuxoll 11y ago
RSA key exchange is still secure, but you lose PFS when downgrading to it since very few servers will generate ephemeral RSA keys like they will when using DHE. 3DES is secure, but slow. Ideally, you would want to just disable all ciphersuites that don't use ECDHE to do the key exchange, but that would probably hurt compatibility.