add command to derive child key from master public key

[KonradStaniec]

• add comand to derive private key from master private public key

[Lazar955]

nice work! lgtm

[Lazar955]

Suggested change

	func ParsePath(path string) ([]uint32, error) {
	splitted := strings.Split(path, "/")
	if len(splitted) != ExpectedDerivationDepth {
	return nil, fmt.Errorf("invalid derivation path length")
	}
	h1, err := parseHardened(splitted[0])
	if err != nil {
	return nil, fmt.Errorf("invalid derivation path element at index 0: %w", err)
	}
	h2, err := parseHardened(splitted[1])
	if err != nil {
	return nil, fmt.Errorf("invalid derivation path element at index 1: %w", err)
	}
	h3, err := parseHardened(splitted[2])
	if err != nil {
	return nil, fmt.Errorf("invalid derivation path element at index 2: %w", err)
	}
	n4, err := parseNormal(splitted[3])
	if err != nil {
	return nil, fmt.Errorf("invalid derivation path element at index 3: %w", err)
	}
	n5, err := parseNormal(splitted[4])
	if err != nil {
	return nil, fmt.Errorf("invalid derivation path element at index 4: %w", err)
	}
	return []uint32{h1, h2, h3, n4, n5}, nil
	}
	func ParsePath(path string) ([]uint32, error) {
	const expectedDepth = 5
	parsers := []func(string) (uint32, error){
	parseHardened,
	parseHardened,
	parseHardened,
	parseNormal,
	parseNormal,
	}
	splitted := strings.Split(path, "/")
	if len(splitted) != expectedDepth {
	return nil, fmt.Errorf("invalid derivation path length")
	}
	result := make([]uint32, expectedDepth)
	for i, part := range splitted {
	parsed, err := parsers[i](part)
	if err != nil {
	return nil, fmt.Errorf("invalid derivation path element at index %d: %w", i, err)
	}
	result[i] = parsed
	}
	return result, nil
	}

[Lazar955]

suggestion, you don't have to accept it

[KonradStaniec]

oh tbh I find this flow a bit convoluted

Current is a bit verbose, but it is super simple. (though it may be one of those things that everybody sees a bit different)

I will leave it as it is.

[Lazar955]

Suggested change

	var keyResult *hdkeychain.ExtendedKey = parsedMasterKey
	keyResult := parsedMasterKey

[Lazar955]

a bit less verbose