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Diffstat (limited to 'internal/readpassword/read.go')
-rw-r--r--internal/readpassword/read.go32
1 files changed, 32 insertions, 0 deletions
diff --git a/internal/readpassword/read.go b/internal/readpassword/read.go
index 49cf8ef..fe9be45 100644
--- a/internal/readpassword/read.go
+++ b/internal/readpassword/read.go
@@ -7,6 +7,8 @@ import (
"os"
"os/exec"
"strings"
+ "sync"
+ "time"
"golang.org/x/crypto/ssh/terminal"
@@ -141,3 +143,33 @@ func readLineUnbuffered(r io.Reader) (l string) {
l = l + string(b)
}
}
+
+// CheckTrailingGarbage tries to read one byte from stdin and exits with a
+// fatal error if the read returns any data.
+// This is meant to be called after reading the password, when there is no more
+// data expected. This helps to catch problems with third-party tools that
+// interface with gocryptfs.
+//
+// This is tested via TestInitTrailingGarbage() in tests/cli/cli_test.go.
+func CheckTrailingGarbage() {
+ if terminal.IsTerminal(int(os.Stdin.Fd())) {
+ // Be lenient when interacting with a human.
+ return
+ }
+ var wg sync.WaitGroup
+ wg.Add(1)
+ go func() {
+ b := make([]byte, 1)
+ wg.Done()
+ n, _ := os.Stdin.Read(b)
+ if n > 0 {
+ tlog.Fatal.Printf("Received trailing garbage after the password")
+ os.Exit(exitCode)
+ }
+ }()
+ // Wait for the goroutine to start up plus one millisecond for the read to
+ // return. If there is data available, this SHOULD be plenty of time to
+ // read one byte. However, I don't see a way to be sure.
+ wg.Wait()
+ time.Sleep(1 * time.Millisecond)
+}