log: better sanitation (#26556)

This commit is contained in:
Martin Holst Swende 2023-01-30 12:43:12 -05:00 committed by GitHub
parent 3ff3d07e2c
commit 17017b2516
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2 changed files with 78 additions and 6 deletions

View File

@ -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)
}

View File

@ -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)
}
}
}