sha2_ctx_t
ctx_len = sizeof (sha2_ctx_t);
ctx->cc_provider_private = kmem_alloc(sizeof (sha2_ctx_t),
kmem_free(ctx->cc_provider_private, sizeof (sha2_ctx_t));
#define PROV_SHA2_CTX(ctx) ((sha2_ctx_t *)(ctx)->cc_provider_private)
kmem_free(ctx->cc_provider_private, sizeof (sha2_ctx_t));
kmem_free(ctx->cc_provider_private, sizeof (sha2_ctx_t));