feat(zeroize): added zeorizing to Felt
#100
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This is feature-gated behind the `zeroing` flag
| @@ -44,6 +46,7 @@ serde = ["alloc", "dep:serde"] | |||
| prime-bigint = ["dep:lazy_static"] | |||
| num-traits = [] | |||
| papyrus-serialization = ["std"] | |||
| zeroing = ["zeroize"] | |||
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zeroing = ["dep:zeroize"]
in ordr to disable the implicit feature.
https://doc.rust-lang.org/cargo/reference/features.html#optional-dependencies
Currently you have two features available
zeroing the one you defined
and
zeroize from the default behaviour of optional = true
| @@ -44,6 +46,7 @@ serde = ["alloc", "dep:serde"] | |||
| prime-bigint = ["dep:lazy_static"] | |||
| num-traits = [] | |||
| papyrus-serialization = ["std"] | |||
| zeroing = ["zeroize"] | |||
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for this types of feature that just depend on one single crate, I tend to name the feature by the crate name. Here zeroize rather than zeroing. Wdyt?
| @@ -1062,6 +1062,18 @@ mod errors { | |||
| } | |||
| } | |||
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| mod zeroing { | |||
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you don't really need to create a new module here. Or if you do, it should be behind the feature flag. Here it will happen in the path, even if it is empty, when the feature is not enabled
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I would recommend to make it a file. zeroize.rs. And put mod import behind the feature flag in felt/mod.rs
| use super::*; | ||
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| #[cfg(feature = "zeroing")] | ||
| impl zeroize::Zeroize for Felt { |
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Can't you just use leverage https://docs.rs/zeroize/latest/zeroize/trait.DefaultIsZeroes.html?
| #[cfg(feature = "zeroing")] | ||
| #[test] | ||
| fn zeroing_felt() { | ||
| use zeroize::Zeroize; | ||
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| let mut felt = Felt::from_hex_unchecked("0x01"); | ||
| felt.zeroize(); | ||
| assert_eq!(felt, Felt::ZERO); | ||
| } |
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move this tests to the new file too
This is feature-gated behind the
zeroingflagPull Request type
What is the current behavior?
Feltprovides no option to zeroize its memory, which can be an issue when dealing with sensitive cryptographic information such as private keys.Resolves: #99
What is the new behavior?
Feltthrough thezeroizecrate. Whilezeroizeis not used directly, Felt implements manually theZeroizetrait in the hopes of making this behavior more 'standard'. This has been gated behind thezeroingfeature.Note
Contrarily to
zeroize, this is done using safe rust by leveragingcore::mem::taketo replace the in-memory representation of a felt with its default value ofFelt::ZERO.Does this introduce a breaking change?
No. While the
zeroingfeature has been added todefault, zeroing has not been implemented on drop, both because this would interfere with theCopytrait ofFeltbut also because it seems like it should be up to the end user to determine when they are dealing with sensitive information.