log: better sanitation

log/format.go

@@ -86,6 +86,7 @@ type TerminalStringer interface {
 // [DBUG] [May 16 20:58:45] remove route ns=haproxy addr=127.0.0.1:50002
 func TerminalFormat(usecolor bool) Format {
  return FormatFunc(func(r *Record) []byte {
+ msg := escapeMessage(r.Msg)
  var color = 0
  if usecolor {
  switch r.Lvl {
@@ -122,19 +123,19 @@ func TerminalFormat(usecolor bool) Format {
 
  // Assemble and print the log heading
  if color > 0 {
- fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m[%s|%s]%s %s ", color, lvl, r.Time.Format(termTimeFormat), location, padding, r.Msg)
+ fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m[%s|%s]%s %s ", color, lvl, r.Time.Format(termTimeFormat), location, padding, msg)
  } else {
- fmt.Fprintf(b, "%s[%s|%s]%s %s ", lvl, r.Time.Format(termTimeFormat), location, padding, r.Msg)
+ fmt.Fprintf(b, "%s[%s|%s]%s %s ", lvl, r.Time.Format(termTimeFormat), location, padding, msg)
  }
  } else {
  if color > 0 {
- fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m[%s] %s ", color, lvl, r.Time.Format(termTimeFormat), r.Msg)
+ fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m[%s] %s ", color, lvl, r.Time.Format(termTimeFormat), msg)
  } else {
- fmt.Fprintf(b, "%s[%s] %s ", lvl, r.Time.Format(termTimeFormat), r.Msg)
+ fmt.Fprintf(b, "%s[%s] %s ", lvl, r.Time.Format(termTimeFormat), msg)
  }
  }
  // try to justify the log output for short messages
- length := utf8.RuneCountInString(r.Msg)
+ length := utf8.RuneCountInString(msg)
  if len(r.Ctx) > 0 && length < termMsgJust {
  b.Write(bytes.Repeat([]byte{' '}, termMsgJust-length))
  }
@@ -167,6 +168,8 @@ func logfmt(buf *bytes.Buffer, ctx []interface{}, color int, term bool) {
  v := formatLogfmtValue(ctx[i+1], term)
  if !ok {
  k, v = errorKey, formatLogfmtValue(k, term)
+ } else {
+ k = escapeString(k)
  }
 
  // XXX: we should probably check that all of your key bytes aren't invalid
@@ -471,7 +474,7 @@ func formatLogfmtBigInt(n *big.Int) string {
 func escapeString(s string) string {
  needsQuoting := false
  for _, r := range s {
- // We quote everything below " (0x34) and above~ (0x7E), plus equal-sign
+ // We quote everything below " (0x22) and above~ (0x7E), plus equal-sign
  if r <= '"' || r > '~' || r == '=' {
  needsQuoting = true
  break
@@ -482,3 +485,26 @@ func escapeString(s string) string {
  }
  return strconv.Quote(s)
 }
+
+// escapeMessage checks if the provided string needs escaping/quoting, similarly
+// to escapeString. The difference is that this method is more lenient: it allows
+// for spaces and linebreaks to occur without needing quoting.
+func escapeMessage(s string) string {
+ needsQuoting := false
+ for _, r := range s {
+ // Carriage return and Line feed are ok
+ if r == 0xa || r == 0xd {
+ continue
+ }
+ // We quote everything below <space> (0x20) and above~ (0x7E),
+ // plus equal-sign
+ if r < ' ' || r > '~' || r == '=' {
+ needsQuoting = true
+ break
+ }
+ }
+ if !needsQuoting {
+ return s
+ }
+ return strconv.Quote(s)
+}

log/format_test.go

@@ -1,9 +1,11 @@
 package log
 
 import (
+ "fmt"
  "math"
  "math/big"
  "math/rand"
+ "strings"
  "testing"
 )
 
@@ -93,3 +95,47 @@ func BenchmarkPrettyUint64Logfmt(b *testing.B) {
  sink = FormatLogfmtUint64(rand.Uint64())
  }
 }
+
+func TestSanitation(t *testing.T) {
+ msg := "\u001b[1G\u001b[K\u001b[1A"
+ msg2 := "\u001b \u0000"
+ msg3 := "NiceMessage"
+ msg4 := "Space Message"
+ msg5 := "Enter\nMessage"
+
+ for i, tt := range []struct {
+ msg string
+ want string
+ }{
+ {
+ msg: msg,
+ want: fmt.Sprintf("] %q %q=%q\n", msg, msg, msg),
+ },
+ {
+ msg: msg2,
+ want: fmt.Sprintf("] %q %q=%q\n", msg2, msg2, msg2),
+ },
+ {
+ msg: msg3,
+ want: fmt.Sprintf("] %s %s=%s\n", msg3, msg3, msg3),
+ },
+ {
+ msg: msg4,
+ want: fmt.Sprintf("] %s %q=%q\n", msg4, msg4, msg4),
+ },
+ {
+ msg: msg5,
+ want: fmt.Sprintf("] %s %q=%q\n", msg5, msg5, msg5),
+ },
+ } {
+ var (
+ logger = New()
+ out = new(strings.Builder)
+ )
+ logger.SetHandler(LvlFilterHandler(LvlInfo, StreamHandler(out, TerminalFormat(false))))
+ logger.Info(tt.msg, tt.msg, tt.msg)
+ if have := out.String()[24:]; tt.want != have {
+ t.Fatalf("test %d: want / have: \n%v\n%v", i, tt.want, have)
+ }
+ }
+}