Trait CryptoProvider 

pub trait CryptoProvider:
    Send
    + Sync
    + 'static {
    // Required method
    fn recover_signer_unchecked(
        &self,
        sig: &[u8; 65],
        msg: &[u8; 32],
    ) -> Result<Address, RecoveryError>;
}

Available on crate feature crypto-backend only.

Trait for cryptographic providers that can perform signature recovery.

This trait allows pluggable cryptographic backends for Ethereum signature recovery. By default, alloy uses compile-time selected implementations (secp256k1 or k256), but applications can install a custom provider to override this behavior.

Why is this needed?

The primary reason is performance - when targeting special execution environments that require custom cryptographic logic. For example, zkVMs (zero-knowledge virtual machines) may have special accelerators that would allow them to perform signature recovery faster.

Usage

1. Enable the crypto-backend feature in your Cargo.toml
2. Implement the CryptoProvider trait for your custom backend
3. Install it globally using install_default_provider
4. All subsequent signature recovery operations will use your provider

Note: This trait currently only provides signature recovery functionality, not signature creation. For signature creation, use the compile-time selected implementations in the secp256k1 module.

use alloy_consensus::crypto::backend::{CryptoProvider, install_default_provider};
use alloy_primitives::Address;
use alloc::sync::Arc;

struct MyCustomProvider;

impl CryptoProvider for MyCustomProvider {
    fn recover_signer_unchecked(
        &self,
        sig: &[u8; 65],
        msg: &[u8; 32],
    ) -> Result<Address, RecoveryError> {
        // Your custom implementation here
        todo!()
    }
}

// Install your provider globally
install_default_provider(Arc::new(MyCustomProvider)).unwrap();

Required Methods

fn recover_signer_unchecked( &self, sig: &[u8; 65], msg: &[u8; 32], ) -> Result<Address, RecoveryError>

Recover signer from signature and message hash, without ensuring low S values.

Implementors