44 lines
1.3 KiB
Go
44 lines
1.3 KiB
Go
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package readpassword
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import (
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"bytes"
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"os"
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"github.com/rfjakob/gocryptfs/internal/exitcodes"
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"github.com/rfjakob/gocryptfs/internal/tlog"
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)
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func readPassFile(passfile string) []byte {
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tlog.Info.Printf("passfile: reading from file %q", passfile)
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f, err := os.Open(passfile)
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if err != nil {
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tlog.Fatal.Printf("fatal: passfile: could not open %q: %v", passfile, err)
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os.Exit(exitcodes.ReadPassword)
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}
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defer f.Close()
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// +1 for an optional trailing newline,
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// +2 so we can detect if maxPasswordLen is exceeded.
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buf := make([]byte, maxPasswordLen+2)
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n, err := f.Read(buf)
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if err != nil {
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tlog.Fatal.Printf("fatal: passfile: could not read from %q: %v", passfile, err)
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os.Exit(exitcodes.ReadPassword)
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}
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buf = buf[:n]
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// Split into first line and "trailing garbage"
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lines := bytes.SplitN(buf, []byte("\n"), 2)
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if len(lines[0]) == 0 {
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tlog.Fatal.Printf("fatal: passfile: empty first line in %q", passfile)
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os.Exit(exitcodes.ReadPassword)
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}
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if len(lines[0]) > maxPasswordLen {
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tlog.Fatal.Printf("fatal: passfile: max password length (%d bytes) exceeded", maxPasswordLen)
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os.Exit(exitcodes.ReadPassword)
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}
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if len(lines) > 1 && len(lines[1]) > 0 {
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tlog.Warn.Printf("passfile: ignoring trailing garbage (%d bytes) after first line",
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len(lines[1]))
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}
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return lines[0]
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}
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