Cargo Features

bip32 = { version = "0.5.1", default-features = false, features = ["std", "alloc", "bip39", "mnemonic", "secp256k1", "secp256k1-ffi"] }
default = bip39, secp256k1, std

These default features are set whenever bip32 is added without default-features = false somewhere in the dependency tree.

std default bip39 = alloc
alloc mnemonic? std

Enables alloc of zeroize

bip39 default = mnemonic, pbkdf2, std
mnemonic bip39 = alloc, once_cell
secp256k1 default = k256

Affects private_key::XPrv, public_key::XPub

Features from optional dependencies

In crates that don't use the dep: syntax, optional dependencies automatically become Cargo features. These features may have been created by mistake, and this functionality may be removed in the future.

k256 secp256k1

Enables k256

optional dependencies

once_cell mnemonic?
pbkdf2 bip39
secp256k1-ffi implicit feature

Enables secp256k1 ^0.27