ssh/terminal: fix line endings handling in ReadPassword
Fixes golang/go#16552
Change-Id: I18a9c9b42fe042c4871b3efb3f51bef7cca335d0
Reviewed-on: https://go-review.googlesource.com/25355
Reviewed-by: Adam Langley <alangley@gmail.com>
Reviewed-by: Adam Langley <agl@golang.org>
diff --git a/terminal.go b/terminal.go
index 0c5bd56..d35e8b1 100644
--- a/terminal.go
+++ b/terminal.go
@@ -920,3 +920,31 @@
}
return s.entries[index], true
}
+
+// readPasswordLine reads from reader until it finds \n or io.EOF.
+// The slice returned does not include the \n.
+// readPasswordLine also ignores any \r it finds.
+func readPasswordLine(reader io.Reader) ([]byte, error) {
+ var buf [1]byte
+ var ret []byte
+
+ for {
+ n, err := reader.Read(buf[:])
+ if err != nil {
+ if err == io.EOF && len(ret) > 0 {
+ return ret, nil
+ }
+ return ret, err
+ }
+ if n > 0 {
+ switch buf[0] {
+ case '\n':
+ return ret, nil
+ case '\r':
+ // remove \r from passwords on Windows
+ default:
+ ret = append(ret, buf[0])
+ }
+ }
+ }
+}
diff --git a/terminal_test.go b/terminal_test.go
index 1d54c4f..901c72a 100644
--- a/terminal_test.go
+++ b/terminal_test.go
@@ -270,6 +270,50 @@
}
}
+func TestReadPasswordLineEnd(t *testing.T) {
+ var tests = []struct {
+ input string
+ want string
+ }{
+ {"\n", ""},
+ {"\r\n", ""},
+ {"test\r\n", "test"},
+ {"testtesttesttes\n", "testtesttesttes"},
+ {"testtesttesttes\r\n", "testtesttesttes"},
+ {"testtesttesttesttest\n", "testtesttesttesttest"},
+ {"testtesttesttesttest\r\n", "testtesttesttesttest"},
+ }
+ for _, test := range tests {
+ buf := new(bytes.Buffer)
+ if _, err := buf.WriteString(test.input); err != nil {
+ t.Fatal(err)
+ }
+
+ have, err := readPasswordLine(buf)
+ if err != nil {
+ t.Errorf("readPasswordLine(%q) failed: %v", test.input, err)
+ continue
+ }
+ if string(have) != test.want {
+ t.Errorf("readPasswordLine(%q) returns %q, but %q is expected", test.input, string(have), test.want)
+ continue
+ }
+
+ if _, err = buf.WriteString(test.input); err != nil {
+ t.Fatal(err)
+ }
+ have, err = readPasswordLine(buf)
+ if err != nil {
+ t.Errorf("readPasswordLine(%q) failed: %v", test.input, err)
+ continue
+ }
+ if string(have) != test.want {
+ t.Errorf("readPasswordLine(%q) returns %q, but %q is expected", test.input, string(have), test.want)
+ continue
+ }
+ }
+}
+
func TestMakeRawState(t *testing.T) {
fd := int(os.Stdout.Fd())
if !IsTerminal(fd) {
diff --git a/util.go b/util.go
index 747f1b8..d019196 100644
--- a/util.go
+++ b/util.go
@@ -17,7 +17,6 @@
package terminal // import "golang.org/x/crypto/ssh/terminal"
import (
- "io"
"syscall"
"unsafe"
)
@@ -88,6 +87,13 @@
return int(dimensions[1]), int(dimensions[0]), nil
}
+// passwordReader is an io.Reader that reads from a specific file descriptor.
+type passwordReader int
+
+func (r passwordReader) Read(buf []byte) (int, error) {
+ return syscall.Read(int(r), buf)
+}
+
// ReadPassword reads a line of input from a terminal without local echo. This
// is commonly used for inputting passwords and other sensitive data. The slice
// returned does not include the \n.
@@ -109,27 +115,5 @@
syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlWriteTermios, uintptr(unsafe.Pointer(&oldState)), 0, 0, 0)
}()
- var buf [16]byte
- var ret []byte
- for {
- n, err := syscall.Read(fd, buf[:])
- if err != nil {
- return nil, err
- }
- if n == 0 {
- if len(ret) == 0 {
- return nil, io.EOF
- }
- break
- }
- if buf[n-1] == '\n' {
- n--
- }
- ret = append(ret, buf[:n]...)
- if n < len(buf) {
- break
- }
- }
-
- return ret, nil
+ return readPasswordLine(passwordReader(fd))
}
diff --git a/util_windows.go b/util_windows.go
index ae9fa9e..e0a1f36 100644
--- a/util_windows.go
+++ b/util_windows.go
@@ -17,7 +17,6 @@
package terminal
import (
- "io"
"syscall"
"unsafe"
)
@@ -123,6 +122,13 @@
return int(info.size.x), int(info.size.y), nil
}
+// passwordReader is an io.Reader that reads from a specific Windows HANDLE.
+type passwordReader int
+
+func (r passwordReader) Read(buf []byte) (int, error) {
+ return syscall.Read(syscall.Handle(r), buf)
+}
+
// ReadPassword reads a line of input from a terminal without local echo. This
// is commonly used for inputting passwords and other sensitive data. The slice
// returned does not include the \n.
@@ -145,30 +151,5 @@
syscall.Syscall(procSetConsoleMode.Addr(), 2, uintptr(fd), uintptr(old), 0)
}()
- var buf [16]byte
- var ret []byte
- for {
- n, err := syscall.Read(syscall.Handle(fd), buf[:])
- if err != nil {
- return nil, err
- }
- if n == 0 {
- if len(ret) == 0 {
- return nil, io.EOF
- }
- break
- }
- if buf[n-1] == '\n' {
- n--
- }
- if n > 0 && buf[n-1] == '\r' {
- n--
- }
- ret = append(ret, buf[:n]...)
- if n < len(buf) {
- break
- }
- }
-
- return ret, nil
+ return readPasswordLine(passwordReader(fd))
}
