Source: aegis/aegis-keys/src/derivation.rs. SHA-256: bf2ba0570408be6fdb11d6e4d93fdfc51255b5970f1a9c2911e6203cbe2bd2de.

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derivation::derive_lineage_key

Derive a lineage key from a parent private key using HKDF-SHA256.

This implements the OAS lineage key derivation scheme where child keys are deterministically derived from parent keys, enabling cryptographic proof of the lineage chain.

Algorithm

HKDF-SHA256(
    IKM  = parent_private_key (32 bytes),
    Salt = child_did_utf8,
    Info = "oas-lineage-v1" || generation_be32,
    L    = 32
)

Arguments

• parent_private - The parent entity's 32-byte Ed25519 private key material.
• child_did - The child entity's DID string, used as salt.
• generation - The lineage generation number (distance from human root).

Returns

32 bytes of derived key material suitable for constructing a child Ed25519 signing key.

Errors

Returns KeyError::DerivationFailed if HKDF expansion fails.

pub fn derive_lineage_key(
    parent_private: &[u8; 32],
    child_did: &str,
    generation: u32,
) -> Result<[u8; 32], KeyError>;

Source line: 43.

derivation::derivation_path

Build a BIP-44 derivation path for a given blockchain chain.

Returns the standard m/44'/coin_type'/account'/0/index path used for HD key derivation across different blockchains.

Arguments

• chain - The target blockchain (determines the coin type).
• account - The account index.
• index - The address index within the account.

Returns

A BIP-44 derivation path string like m/44'/60'/0'/0/0 for Ethereum.

pub fn derivation_path(chain: Chain, account: u32, index: u32) -> String;

Source line: 82.