EVP_KDF_CTX_dup
EVP_KDF_CTX *EVP_KDF_CTX_dup(const EVP_KDF_CTX *src);
dstctx->kdfctx = EVP_KDF_CTX_dup(srcctx->kdfctx);
&& (ctx = EVP_KDF_CTX_dup(expected->ctx)) != NULL) {