DockerCLI/vendor/github.com/howeyc/gopass/pass.go

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package gopass
import (
"errors"
"fmt"
"io"
"os"
)
var defaultGetCh = func() (byte, error) {
buf := make([]byte, 1)
if n, err := os.Stdin.Read(buf); n == 0 || err != nil {
if err != nil {
return 0, err
}
return 0, io.EOF
}
return buf[0], nil
}
var (
maxLength = 512
ErrInterrupted = errors.New("interrupted")
ErrMaxLengthExceeded = fmt.Errorf("maximum byte limit (%v) exceeded", maxLength)
// Provide variable so that tests can provide a mock implementation.
getch = defaultGetCh
)
// getPasswd returns the input read from terminal.
// If masked is true, typing will be matched by asterisks on the screen.
// Otherwise, typing will echo nothing.
func getPasswd(masked bool) ([]byte, error) {
var err error
var pass, bs, mask []byte
if masked {
bs = []byte("\b \b")
mask = []byte("*")
}
if isTerminal(os.Stdin.Fd()) {
if oldState, err := makeRaw(os.Stdin.Fd()); err != nil {
return pass, err
} else {
defer restore(os.Stdin.Fd(), oldState)
}
}
// Track total bytes read, not just bytes in the password. This ensures any
// errors that might flood the console with nil or -1 bytes infinitely are
// capped.
var counter int
for counter = 0; counter <= maxLength; counter++ {
if v, e := getch(); e != nil {
err = e
break
} else if v == 127 || v == 8 {
if l := len(pass); l > 0 {
pass = pass[:l-1]
fmt.Print(string(bs))
}
} else if v == 13 || v == 10 {
break
} else if v == 3 {
err = ErrInterrupted
break
} else if v != 0 {
pass = append(pass, v)
fmt.Print(string(mask))
}
}
if counter > maxLength {
err = ErrMaxLengthExceeded
}
fmt.Println()
return pass, err
}
// GetPasswd returns the password read from the terminal without echoing input.
// The returned byte array does not include end-of-line characters.
func GetPasswd() ([]byte, error) {
return getPasswd(false)
}
// GetPasswdMasked returns the password read from the terminal, echoing asterisks.
// The returned byte array does not include end-of-line characters.
func GetPasswdMasked() ([]byte, error) {
return getPasswd(true)
}