Introduces `CryptoBytes` type defined as:
```rust
pub struct CryptoBytes<const N: usize, Tag = ()>(pub [u8; N], PhantomData<fn() -> Tag>);
```
The type implements a bunch of methods and traits which are typically
expected from a byte array newtype
(NOTE: some of the methods and trait implementations IMO are a bit
redundant, but I decided to maintain them all to not change too much
stuff in this PR)
It also introduces two (generic) typical consumers of `CryptoBytes`:
`PublicBytes` and `SignatureBytes`.
```rust
pub struct PublicTag;
pub PublicBytes<const N: usize, CryptoTag> = CryptoBytes<N, (PublicTag, CryptoTag)>;
pub struct SignatureTag;
pub SignatureBytes<const N: usize, CryptoTag> = CryptoBytes<N, (SignatureTag, CryptoTag)>;
```
Both of them use a tag to differentiate the two types at a higher level.
Downstream specializations will further specialize using a dedicated
crypto tag. For example in ECDSA:
```rust
pub struct EcdsaTag;
pub type Public = PublicBytes<PUBLIC_KEY_SERIALIZED_SIZE, EcdsaTag>;
pub type Signature = PublicBytes<PUBLIC_KEY_SERIALIZED_SIZE, EcdsaTag>;
```
Overall we have a cleaner and most importantly **consistent** code for
all the types involved
All these details are opaque to the end user which can use `Public` and
`Signature` for the cryptos as before
This PR removes sp-std crate from substrate/primitives sub-directories.
For now crates that have `pub use` of sp-std or export macros that would
necessitate users of the macros to `extern crate alloc` have been
excluded from this PR.
There should be no breaking changes in this PR.
---------
Co-authored-by: Koute <koute@users.noreply.github.com>
Step towards https://github.com/paritytech/polkadot-sdk/issues/1975
As reported
https://github.com/paritytech/polkadot-sdk/issues/1975#issuecomment-1774534225
I'd like to encapsulate crypto related stuff in a dedicated folder.
Currently all cryptographic primitive wrappers are all sparsed in
`substrate/core` which contains "misc core" stuff.
To simplify the process, as the first step with this PR I propose to
move the cryptographic hashing there.
The `substrate/crypto` folder was already created to contains `ec-utils`
crate.
Notes:
- rename `sp-core-hashing` to `sp-crypto-hashing`
- rename `sp-core-hashing-proc-macro` to `sp-crypto-hashing-proc-macro`
- As the crates name is changed I took the freedom to restart fresh from
version 0.1.0 for both crates
---------
Co-authored-by: Robert Hambrock <roberthambrock@gmail.com>
Davide Galassi