113 lines
2.3 KiB
Go
113 lines
2.3 KiB
Go
package pwgen
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import (
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"errors"
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)
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const (
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DefaultLength = 20
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DefaultSpecialsAlphabet = `!?~@#$%^&*()-+={}[]\/{}|<>`
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)
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var ErrLengthOverflow = errors.New("length overflow")
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type generationOptionFunc func(options *options)
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func (f generationOptionFunc) ApplyToOptions(options *options) {
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f(options)
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}
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func WithLength(length uint) GenerationOption {
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return generationOptionFunc(func(options *options) {
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options.Length = length
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})
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}
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func WithLetters(letters uint) GenerationOption {
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return generationOptionFunc(func(options *options) {
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options.Letters = letters
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})
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}
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func WithUppercase(uppercase uint) GenerationOption {
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return generationOptionFunc(func(options *options) {
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options.Uppercase = uppercase
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})
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}
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func WithLowercase(lowercase uint) GenerationOption {
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return generationOptionFunc(func(options *options) {
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options.Lowercase = lowercase
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})
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}
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func WithDigits(digits uint) GenerationOption {
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return generationOptionFunc(func(options *options) {
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options.Digits = digits
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})
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}
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func WithSpecials(specials uint) GenerationOption {
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return generationOptionFunc(func(options *options) {
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options.Specials = specials
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})
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}
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func WithSpecialsAlphabet(specialsAlphabet string) GenerationOption {
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return generationOptionFunc(func(options *options) {
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if specialsAlphabet == "" {
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specialsAlphabet = DefaultSpecialsAlphabet
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}
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options.SpecialsAlphabet = specialsAlphabet
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})
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}
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func defaultOptions(opts ...GenerationOption) *options {
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o := &options{
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Length: DefaultLength,
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Letters: 0,
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Digits: 3,
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Uppercase: 3,
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Lowercase: 3,
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Specials: 3,
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SpecialsAlphabet: DefaultSpecialsAlphabet,
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}
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for i := range opts {
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opts[i].ApplyToOptions(o)
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}
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return o
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}
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type options struct {
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Length uint
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Letters uint
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Digits uint
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Uppercase uint
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Lowercase uint
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Specials uint
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SpecialsAlphabet string
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}
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func (o options) effectiveLength() (uint, error) {
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var length uint
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for _, i := range []uint{o.Digits, o.Lowercase, o.Uppercase, o.Specials} {
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if length+i < length {
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return 0, ErrLengthOverflow
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}
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length += i
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}
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if upperAndLower := o.Lowercase + o.Uppercase; upperAndLower < o.Letters {
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length += o.Letters - upperAndLower
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}
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if length > o.Length {
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return length, nil
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}
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return o.Length, nil
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}
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