zeroize_derive.rs

//! Integration tests for `zeroize_derive` proc macros

#[cfg(feature = "zeroize_derive")]
mod custom_derive_tests {
    use zeroize::{Zeroize, ZeroizeOnDrop};

    #[test]
    fn derive_tuple_struct_test() {
        #[derive(Zeroize, ZeroizeOnDrop)]
        struct Z([u8; 3]);

        let mut value = Z([1, 2, 3]);
        value.zeroize();
        assert_eq!(&value.0, &[0, 0, 0])
    }

    #[test]
    fn derive_struct_test() {
        #[derive(Zeroize, ZeroizeOnDrop)]
        struct Z {
            string: String,
            vec: Vec<u8>,
            bytearray: [u8; 3],
            number: usize,
            boolean: bool,
        }

        let mut value = Z {
            string: String::from("Hello, world!"),
            vec: vec![1, 2, 3],
            bytearray: [4, 5, 6],
            number: 42,
            boolean: true,
        };

        value.zeroize();

        assert!(value.string.is_empty());
        assert!(value.vec.is_empty());
        assert_eq!(&value.bytearray, &[0, 0, 0]);
        assert_eq!(value.number, 0);
        assert!(!value.boolean);
    }

    #[test]
    fn derive_enum_test() {
        #[derive(Zeroize, ZeroizeOnDrop)]
        enum Z {
            #[allow(dead_code)]
            Variant1,
            Variant2(usize),
        }

        let mut value = Z::Variant2(26);

        value.zeroize();

        assert!(matches!(value, Z::Variant2(0)));
    }

    /// Test that the custom macro actually derived `Drop` for `Z`
    #[test]
    fn derive_struct_drop() {
        #[derive(Zeroize, ZeroizeOnDrop)]
        struct Z([u8; 3]);

        assert!(std::mem::needs_drop::<Z>());
    }

    /// Test that the custom macro actually derived `Drop` for `Z`
    #[test]
    fn derive_enum_drop() {
        #[allow(dead_code)]
        #[derive(Zeroize, ZeroizeOnDrop)]
        enum Z {
            Variant1,
            Variant2(usize),
        }

        assert!(std::mem::needs_drop::<Z>());
    }

    /// Test that the custom macro actually derived `Drop` for `Z`
    #[test]
    fn derive_struct_only_drop() {
        #[derive(ZeroizeOnDrop)]
        struct Z([u8; 3]);

        assert!(std::mem::needs_drop::<Z>());
    }

    /// Test that the custom macro actually derived `Drop` for `Z`
    #[test]
    fn derive_enum_only_drop() {
        #[allow(dead_code)]
        #[derive(ZeroizeOnDrop)]
        enum Z {
            Variant1,
            Variant2(usize),
        }

        assert!(std::mem::needs_drop::<Z>());
    }

    /// Test that `Drop` is not derived in the following case by defining a
    /// `Drop` impl which should conflict if the custom derive defined one too
    #[allow(dead_code)]
    #[derive(Zeroize)]
    struct ZeroizeNoDropStruct([u8; 3]);

    impl Drop for ZeroizeNoDropStruct {
        fn drop(&mut self) {}
    }

    #[allow(dead_code)]
    #[derive(Zeroize)]
    enum ZeroizeNoDropEnum {
        Variant([u8; 3]),
    }

    impl Drop for ZeroizeNoDropEnum {
        fn drop(&mut self) {}
    }

    #[test]
    fn derive_struct_skip() {
        #[derive(Zeroize, ZeroizeOnDrop)]
        struct Z {
            string: String,
            vec: Vec<u8>,
            #[zeroize(skip)]
            bytearray: [u8; 3],
            number: usize,
            boolean: bool,
        }

        let mut value = Z {
            string: String::from("Hello, world!"),
            vec: vec![1, 2, 3],
            bytearray: [4, 5, 6],
            number: 42,
            boolean: true,
        };

        value.zeroize();

        assert!(value.string.is_empty());
        assert!(value.vec.is_empty());
        assert_eq!(&value.bytearray, &[4, 5, 6]);
        assert_eq!(value.number, 0);
        assert!(!value.boolean);
    }

    #[test]
    fn derive_enum_skip() {
        #[derive(Zeroize, ZeroizeOnDrop)]
        enum Z {
            #[allow(dead_code)]
            Variant1,
            #[zeroize(skip)]
            Variant2([u8; 3]),
            #[zeroize(skip)]
            Variant3 {
                string: String,
                vec: Vec<u8>,
                bytearray: [u8; 3],
                number: usize,
                boolean: bool,
            },
            Variant4 {
                string: String,
                vec: Vec<u8>,
                #[zeroize(skip)]
                bytearray: [u8; 3],
                number: usize,
                boolean: bool,
            },
        }

        let mut value = Z::Variant2([4, 5, 6]);

        value.zeroize();

        assert!(matches!(&value, Z::Variant2([4, 5, 6])));

        let mut value = Z::Variant3 {
            string: String::from("Hello, world!"),
            vec: vec![1, 2, 3],
            bytearray: [4, 5, 6],
            number: 42,
            boolean: true,
        };

        value.zeroize();

        assert!(matches!(
            &value,
            Z::Variant3 { string, vec, bytearray, number, boolean }
            if string == "Hello, world!" &&
                vec == &[1, 2, 3] &&
                bytearray == &[4, 5, 6] &&
                *number == 42 &&
                *boolean
        ));

        let mut value = Z::Variant4 {
            string: String::from("Hello, world!"),
            vec: vec![1, 2, 3],
            bytearray: [4, 5, 6],
            number: 42,
            boolean: true,
        };

        value.zeroize();

        assert!(matches!(
            &value,
            Z::Variant4 { string, vec, bytearray, number, boolean }
            if string.is_empty() &&
                vec.is_empty() &&
                bytearray == &[4, 5, 6] &&
                *number == 0 &&
                !boolean
        ));
    }

    #[test]
    fn derive_bound() {
        trait T: Zeroize {}

        impl T for u8 {}

        #[derive(Zeroize)]
        #[zeroize(bound = "X: T")]
        struct Z<X>(X);

        let mut value = Z(5_u8);

        value.zeroize();

        assert_eq!(value.0, 0);
    }

    #[test]
    fn derive_only_zeroize_on_drop() {
        #[derive(ZeroizeOnDrop)]
        struct X([u8; 3]);

        #[derive(ZeroizeOnDrop)]
        struct Z(X);

        let mut value = Z(X([1, 2, 3]));
        unsafe {
            std::ptr::drop_in_place(&mut value);
        }
        assert_eq!(&value.0 .0, &[0, 0, 0])
    }
}