redact sensitive headers in HTTP debug logs (#5873)

internal/protocols/httpp/handler_logger.go

@@ -14,6 +14,28 @@ const (
 	maxDumpedRequestBodySize = 10 * 1024
 )
 
+var requestHeadersToRedact = map[string]struct{}{
+	"Authorization":       {},
+	"Cookie":              {},
+	"Proxy-Authorization": {},
+	"Set-Cookie":          {},
+	"X-Api-Key":           {},
+	"X-Auth-Token":        {},
+}
+
+func cloneRequestForLogging(r *http.Request) *http.Request {
+	clone := r.Clone(r.Context())
+	clone.Header = r.Header.Clone()
+
+	for header := range requestHeadersToRedact {
+		if clone.Header.Get(header) != "" {
+			clone.Header.Set(header, "<redacted>")
+		}
+	}
+
+	return clone
+}
+
 func dumpRequestLimited(r *http.Request) ([]byte, error) {
 	peek, err := io.ReadAll(io.LimitReader(r.Body, maxDumpedRequestBodySize+1))
 	if err != nil {
@@ -28,8 +50,9 @@ func dumpRequestLimited(r *http.Request) ([]byte, error) {
 
 	original := r.Body
 	r.Body = io.NopCloser(bytes.NewReader(capped))
+	clone := cloneRequestForLogging(r)
 
-	dump, dumpErr := httputil.DumpRequest(r, true)
+	dump, dumpErr := httputil.DumpRequest(clone, true)
 
 	r.Body = io.NopCloser(io.MultiReader(bytes.NewReader(peek), original))
 

internal/protocols/httpp/handler_logger_test.go

@@ -0,0 +1,43 @@
+package httpp
+
+import (
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestDumpRequestLimitedRedactsSensitiveHeaders(t *testing.T) {
+	req, err := http.NewRequest(http.MethodPost, "http://localhost/test", strings.NewReader("request body"))
+	require.NoError(t, err)
+
+	req.Header.Set("Authorization", "Bearer secret-token")
+	req.Header.Set("Cookie", "session=secret-cookie")
+	req.Header.Set("Proxy-Authorization", "Bearer proxy-secret")
+	req.Header.Set("X-Api-Key", "secret-api-key")
+	req.Header.Set("X-Auth-Token", "secret-auth-token")
+
+	dump, err := dumpRequestLimited(req)
+	require.NoError(t, err)
+
+	dumpStr := string(dump)
+	require.Contains(t, dumpStr, "Authorization: <redacted>")
+	require.Contains(t, dumpStr, "Cookie: <redacted>")
+	require.Contains(t, dumpStr, "Proxy-Authorization: <redacted>")
+	require.Contains(t, dumpStr, "X-Api-Key: <redacted>")
+	require.Contains(t, dumpStr, "X-Auth-Token: <redacted>")
+	require.NotContains(t, dumpStr, "secret-token")
+	require.NotContains(t, dumpStr, "secret-cookie")
+	require.NotContains(t, dumpStr, "proxy-secret")
+	require.NotContains(t, dumpStr, "secret-api-key")
+	require.NotContains(t, dumpStr, "secret-auth-token")
+	require.Contains(t, dumpStr, "request body")
+
+	require.Equal(t, "Bearer secret-token", req.Header.Get("Authorization"))
+
+	body, err := io.ReadAll(req.Body)
+	require.NoError(t, err)
+	require.Equal(t, "request body", string(body))
+}