In TLS 1.2, do the TLS_ECDHE_ECDSA_WITH_AES_256_CCM and TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 ciphersuites support the SHA-384 or SHA-512 hash functions?
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This is specified in the informational RFC 7251 where is states in Appendix A
An implementation that includes either TLS_ECDHE_ECDSA_WITH_AES_256_CCM or TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 SHOULD support [...] the SHA-384 hash function, and MAY support [...] the SHA-512 hash function.
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$\begingroup$ Thanks Daniel, in this case how the server & client negotiates for which hash algorithm to be used (say both sha 384 and Sha 512) supported $\endgroup$ Commented Sep 2 at 11:24
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$\begingroup$ By using the
hashfield of aSignatureAndHashAlgorithmpart of asignature_algorithmsextension to aHello. See section 7.4.1.4.1 of RFC 5246 (TLS1.2) $\endgroup$– Daniel SCommented Sep 2 at 11:44