Function EVP_PKEY_meth_set_signctx

pub unsafe extern "C" fn EVP_PKEY_meth_set_signctx(
    pmeth: *mut evp_pkey_method_st,
    signctx_init: Option<unsafe extern "C" fn(_: *mut evp_pkey_ctx_st, _: *mut evp_md_ctx_st) -> i32>,
    signctx: Option<unsafe extern "C" fn(_: *mut evp_pkey_ctx_st, _: *mut u8, _: *mut usize, _: *mut evp_md_ctx_st) -> i32>,
)