Arbitrary labels for extended keys (u32, H256 built-in) #4438
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NikVolf
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A0-pleasereview 🤓
ethkey/src/extended.rs
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| @@ -21,6 +21,46 @@ use Public; | |||
| use bigint::hash::{H256, FixedHash}; | |||
| pub use self::derivation::Error as DerivationError; | |||
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| pub trait Label { | |||
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particularly the implied invariant on store that target.len() must be > T::len(), and that breaking this invariant will lead to panic.
ethkey/src/extended.rs
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| @@ -228,24 +266,24 @@ mod derivation { | |||
| // curve point (compressed public key) -- index | |||
| // 0.33 -- 33..37 | |||
| data[0..33].copy_from_slice(&public_serialized); | |||
| BigEndian::write_u32(&mut data[33..37], index); | |||
| index.store(&mut data[33..37]); | |||
rphmeier
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A5-grumble 🔥
NikVolf
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A0-pleasereview 🤓
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looks like this only supports hard derivation for > 31 bit indexes, no? it's important to support soft derivation for 256-bit indexes... |
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@gavofyork Nope, both soft and hard derivation can be made for any It's just the original bitcoin spec that splits 0..2^32 field to two fields of |
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cool |
ethkey/src/extended.rs
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| fn len() -> usize { 32 } | ||
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| fn store(&self, target: &mut [u8]) { | ||
| self.copy_to(&mut target[0..4]); |
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what's happening here? only copying the first 4 bytes?
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yeah right
i added it more like an example here, didn't payed much attention, thanx
gavofyork
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A8-looksgood 🦄
Can be basically any byte sequence (but caller must be sure what is he doing since key is compacted into a 512-bit hash after all, no matter of original data length). This slightly increase complexity of the signatures, but probably worth it.