From d235e2c6a5788ec4a6cff15a16f56b38a3876a0d Mon Sep 17 00:00:00 2001 From: Determinant Date: Sun, 28 Jun 2020 14:47:41 -0400 Subject: ... --- accounts/hd.go | 152 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 152 insertions(+) create mode 100644 accounts/hd.go (limited to 'accounts/hd.go') diff --git a/accounts/hd.go b/accounts/hd.go new file mode 100644 index 0000000..75c4761 --- /dev/null +++ b/accounts/hd.go @@ -0,0 +1,152 @@ +// Copyright 2017 The go-ethereum Authors +// This file is part of the go-ethereum library. +// +// The go-ethereum library is free software: you can redistribute it and/or modify +// it under the terms of the GNU Lesser General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// The go-ethereum library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Lesser General Public License for more details. +// +// You should have received a copy of the GNU Lesser General Public License +// along with the go-ethereum library. If not, see . + +package accounts + +import ( + "encoding/json" + "errors" + "fmt" + "math" + "math/big" + "strings" +) + +// DefaultRootDerivationPath is the root path to which custom derivation endpoints +// are appended. As such, the first account will be at m/44'/60'/0'/0, the second +// at m/44'/60'/0'/1, etc. +var DefaultRootDerivationPath = DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0} + +// DefaultBaseDerivationPath is the base path from which custom derivation endpoints +// are incremented. As such, the first account will be at m/44'/60'/0'/0/0, the second +// at m/44'/60'/0'/0/1, etc. +var DefaultBaseDerivationPath = DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0, 0} + +// LegacyLedgerBaseDerivationPath is the legacy base path from which custom derivation +// endpoints are incremented. As such, the first account will be at m/44'/60'/0'/0, the +// second at m/44'/60'/0'/1, etc. +var LegacyLedgerBaseDerivationPath = DerivationPath{0x80000000 + 44, 0x80000000 + 60, 0x80000000 + 0, 0} + +// DerivationPath represents the computer friendly version of a hierarchical +// deterministic wallet account derivaion path. +// +// The BIP-32 spec https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki +// defines derivation paths to be of the form: +// +// m / purpose' / coin_type' / account' / change / address_index +// +// The BIP-44 spec https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki +// defines that the `purpose` be 44' (or 0x8000002C) for crypto currencies, and +// SLIP-44 https://github.com/satoshilabs/slips/blob/master/slip-0044.md assigns +// the `coin_type` 60' (or 0x8000003C) to Ethereum. +// +// The root path for Ethereum is m/44'/60'/0'/0 according to the specification +// from https://github.com/ethereum/EIPs/issues/84, albeit it's not set in stone +// yet whether accounts should increment the last component or the children of +// that. We will go with the simpler approach of incrementing the last component. +type DerivationPath []uint32 + +// ParseDerivationPath converts a user specified derivation path string to the +// internal binary representation. +// +// Full derivation paths need to start with the `m/` prefix, relative derivation +// paths (which will get appended to the default root path) must not have prefixes +// in front of the first element. Whitespace is ignored. +func ParseDerivationPath(path string) (DerivationPath, error) { + var result DerivationPath + + // Handle absolute or relative paths + components := strings.Split(path, "/") + switch { + case len(components) == 0: + return nil, errors.New("empty derivation path") + + case strings.TrimSpace(components[0]) == "": + return nil, errors.New("ambiguous path: use 'm/' prefix for absolute paths, or no leading '/' for relative ones") + + case strings.TrimSpace(components[0]) == "m": + components = components[1:] + + default: + result = append(result, DefaultRootDerivationPath...) + } + // All remaining components are relative, append one by one + if len(components) == 0 { + return nil, errors.New("empty derivation path") // Empty relative paths + } + for _, component := range components { + // Ignore any user added whitespace + component = strings.TrimSpace(component) + var value uint32 + + // Handle hardened paths + if strings.HasSuffix(component, "'") { + value = 0x80000000 + component = strings.TrimSpace(strings.TrimSuffix(component, "'")) + } + // Handle the non hardened component + bigval, ok := new(big.Int).SetString(component, 0) + if !ok { + return nil, fmt.Errorf("invalid component: %s", component) + } + max := math.MaxUint32 - value + if bigval.Sign() < 0 || bigval.Cmp(big.NewInt(int64(max))) > 0 { + if value == 0 { + return nil, fmt.Errorf("component %v out of allowed range [0, %d]", bigval, max) + } + return nil, fmt.Errorf("component %v out of allowed hardened range [0, %d]", bigval, max) + } + value += uint32(bigval.Uint64()) + + // Append and repeat + result = append(result, value) + } + return result, nil +} + +// String implements the stringer interface, converting a binary derivation path +// to its canonical representation. +func (path DerivationPath) String() string { + result := "m" + for _, component := range path { + var hardened bool + if component >= 0x80000000 { + component -= 0x80000000 + hardened = true + } + result = fmt.Sprintf("%s/%d", result, component) + if hardened { + result += "'" + } + } + return result +} + +// MarshalJSON turns a derivation path into its json-serialized string +func (path DerivationPath) MarshalJSON() ([]byte, error) { + return json.Marshal(path.String()) +} + +// UnmarshalJSON a json-serialized string back into a derivation path +func (path *DerivationPath) UnmarshalJSON(b []byte) error { + var dp string + var err error + if err = json.Unmarshal(b, &dp); err != nil { + return err + } + *path, err = ParseDerivationPath(dp) + return err +} -- cgit v1.2.3