Cargo Features

gm-sm2 = { version = "0.13.0", default-features = false, features = ["sec1"] }
default = sec1

The sec1 feature is set by default whenever gm-sm2 is added without default-features = false somewhere in the dependency tree.

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

sec1 default