Lib.rs

This is largely based on sp_core crate. Draft.

Key differences here:

• no-std compatible with arm
• sr25519 supports external Rng, for usability on baremetal
• ecdsa support based on pure Rust crate k256, to avoid no-std target compiling difficulties (original sp-core has ecdsa from secp256k1, a C wrapper crate, and as a result ecdsa parts from sp-core do not compile on certain no-std targets and create extremely large binary blob on others)
• ecdsa pair has zeroize on drop

Cryptographic code for Substrate chains in pure rust with better baremetal support.

This is largely based on sp_core crate.

Key differences here:

• no-std compatible with arm,
• sr25519 supports external Rng, for usability on baremetal
• ecdsa support based on pure Rust crate k256, to avoid compiling difficulties (original sp-core has ecdsa from secp256k1 C wrapper crate and it does not compile on certain no-std targets and creates extremely large binary blob on others)