_ec_sign_init
ATTRIBUTE_WARN_UNUSED_RET int _ec_sign_init(struct ec_sign_context *ctx,
return _ec_sign_init(ctx, key_pair, NULL, sig_type, hash_type,
ret = _ec_sign_init(&ctx, key_pair, rand, sig_type,
ret = _ec_sign_init(&ctx, key_pair, rand, sig_type, hash_type, adata, adata_len);