When did basically all DH based cipher-suites go from WEAK to INSECURE? Is there any rationale behind this change?
The latter - and this already since 2010 actually if you followed NIST recommendations.
Lower than 1024 is just bad.
Using 1024 is as it now states 'weak'. You may have to if you need to support some older Java based products, but it is just not strong anymore. And since the world is phasing out 1024 bit RSA keys it is only fair to mark DH as weak as well, as computational power required to break them is in the same ballpark.
yes see Qualys SSL Labs - Projects / SSL Server Rating Guide
DH key <1024bit = unsave
DH key <2048bit = weak
Was there some kind of exploit or explanation as to why DH keys were downgraded? Were there any attacks on DH keys that warranted this, or did it just become theoretically feasible to brute-force these keys with existing methods and computing abilities?
How do you control the DH key size? It seems like the same cipher suite name TLS_DHE_RSA_WITH_AES_128_CBC_SHA is used for different DH key sizes.
Hi what server do you use ?
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