65 lines
1.6 KiB
Go
65 lines
1.6 KiB
Go
// password is a package for reading a password securely from a terminal.
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// The code in this package disables echo in the terminal so that the
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// password is not echoed back in plaintext to the user.
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package password
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import (
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"errors"
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"io"
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"os"
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"os/signal"
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)
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var ErrInterrupted = errors.New("interrupted")
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// Read reads the password from the given os.File. The password
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// will not be echoed back to the user. Ctrl-C will automatically return
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// from this function with a blank string and an ErrInterrupted.
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func Read(f *os.File) (string, error) {
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ch := make(chan os.Signal, 1)
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signal.Notify(ch, os.Interrupt)
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defer signal.Stop(ch)
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// Run the actual read in a go-routine so that we can still detect signals
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var result string
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var resultErr error
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doneCh := make(chan struct{})
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go func() {
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defer close(doneCh)
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result, resultErr = read(f)
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}()
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// Wait on either the read to finish or the signal to come through
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select {
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case <-ch:
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return "", ErrInterrupted
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case <-doneCh:
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return result, resultErr
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}
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}
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func readline(f *os.File) (string, error) {
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var buf [1]byte
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resultBuf := make([]byte, 0, 64)
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for {
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n, err := f.Read(buf[:])
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if err != nil && err != io.EOF {
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return "", err
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}
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if n == 0 || buf[0] == '\n' || buf[0] == '\r' {
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break
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}
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// ASCII code 3 is what is sent for a Ctrl-C while reading raw.
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// If we see that, then get the interrupt. We have to do this here
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// because terminals in raw mode won't catch it at the shell level.
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if buf[0] == 3 {
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return "", ErrInterrupted
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}
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resultBuf = append(resultBuf, buf[0])
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}
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return string(resultBuf), nil
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}
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