feat(api): log session/audit subject from UserAccessControl

Read identity from request context after handlers run so Basic, Bearer,
OIDC, mTLS, etc. are covered; use subject "anonymous" when unset.
Redact Authorization in SessionLogger without decoding credentials.
Add session_test.go for SessionLogger and SessionAuditLogger.

Signed-off-by: Andrei Aaron <andreifdaaron@gmail.com>

Author: andaaron

pkg/api/session.go

@@ -1,17 +1,16 @@
 package api
 
 import (
-	"encoding/base64"
 	"net/http"
 	"strconv"
-	"strings"
 	"time"
 
 	"github.com/didip/tollbooth/v7"
 	"github.com/gorilla/mux"
 
 	"zotregistry.dev/zot/v2/pkg/extensions/monitoring"
 	"zotregistry.dev/zot/v2/pkg/log"
+	reqCtx "zotregistry.dev/zot/v2/pkg/requestcontext"
 )
 
 type statusWriter struct {
@@ -94,24 +93,18 @@ func SessionLogger(ctlr *Controller) mux.MiddlewareFunc {
 
 			for key, value := range request.Header {
 				if key == "Authorization" { // anonymize from logs
-					s := strings.SplitN(value[0], " ", 2) //nolint:mnd
-					if len(s) == 2 && strings.EqualFold(s[0], "basic") {
-						b, err := base64.StdEncoding.DecodeString(s[1])
-						if err == nil {
-							pair := strings.SplitN(string(b), ":", 2) //nolint:mnd
-							//nolint:mnd
-							if len(pair) == 2 {
-								log = log.Str("username", pair[0])
-							}
-						}
-					}
-
 					value = []string{"******"}
 				}
 
 				headers[key] = value
 			}
 
+			if userAc, err := reqCtx.UserAcFromContext(request.Context()); err == nil {
+				if username := userAc.GetUsername(); username != "" {
+					log = log.Str("username", username)
+				}
+			}
+
 			statusCode := stwr.status
 			bodySize := stwr.length
 
@@ -153,20 +146,10 @@ func SessionAuditLogger(audit *log.Logger) mux.MiddlewareFunc {
 
 			clientIP := request.RemoteAddr
 			method := request.Method
-			username := ""
-
-			for key, value := range request.Header {
-				if key == "Authorization" { // anonymize from logs
-					s := strings.SplitN(value[0], " ", 2) //nolint:mnd
-					if len(s) == 2 && strings.EqualFold(s[0], "basic") {
-						b, err := base64.StdEncoding.DecodeString(s[1])
-						if err == nil {
-							pair := strings.SplitN(string(b), ":", 2) //nolint:mnd
-							if len(pair) == 2 {                       //nolint:mnd
-								username = pair[0]
-							}
-						}
-					}
+			subject := "anonymous"
+			if userAc, err := reqCtx.UserAcFromContext(request.Context()); err == nil {
+				if username := userAc.GetUsername(); username != "" {
+					subject = username
 				}
 			}
 
@@ -182,7 +165,7 @@ func SessionAuditLogger(audit *log.Logger) mux.MiddlewareFunc {
 				audit.Info().
 					Str("component", "session").
 					Str("clientIP", clientIP).
-					Str("subject", username).
+					Str("subject", subject).
 					Str("action", method).
 					Str("object", path).
 					Int("status", statusCode).

pkg/api/session_test.go

@@ -0,0 +1,229 @@
+package api_test
+
+import (
+	"bytes"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	zotapi "zotregistry.dev/zot/v2/pkg/api"
+	monitoring "zotregistry.dev/zot/v2/pkg/extensions/monitoring"
+	"zotregistry.dev/zot/v2/pkg/log"
+	reqCtx "zotregistry.dev/zot/v2/pkg/requestcontext"
+)
+
+func TestSessionAuditLogger(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name        string
+		method      string
+		status      int
+		setUsername string
+		wantAudit   bool
+		wantSubject string
+	}{
+		{
+			name:        "mutating POST 200 anonymous",
+			method:      http.MethodPost,
+			status:      http.StatusOK,
+			wantAudit:   true,
+			wantSubject: "anonymous",
+		},
+		{
+			name:        "mutating PUT 201 authenticated",
+			method:      http.MethodPut,
+			status:      http.StatusCreated,
+			setUsername: "alice",
+			wantAudit:   true,
+			wantSubject: "alice",
+		},
+		{
+			name:        "mutating PATCH 202 anonymous",
+			method:      http.MethodPatch,
+			status:      http.StatusAccepted,
+			wantAudit:   true,
+			wantSubject: "anonymous",
+		},
+		{
+			name:        "mutating DELETE 200 anonymous",
+			method:      http.MethodDelete,
+			status:      http.StatusOK,
+			wantAudit:   true,
+			wantSubject: "anonymous",
+		},
+		{
+			name:      "GET 200 skipped",
+			method:    http.MethodGet,
+			status:    http.StatusOK,
+			wantAudit: false,
+		},
+		{
+			name:        "POST 401 skipped",
+			method:      http.MethodPost,
+			status:      http.StatusUnauthorized,
+			wantAudit:   false,
+			wantSubject: "",
+		},
+		{
+			name:        "POST 403 skipped even with username",
+			method:      http.MethodPost,
+			status:      http.StatusForbidden,
+			setUsername: "bob",
+			wantAudit:   false,
+		},
+	}
+
+	for _, testCase := range tests {
+		t.Run(testCase.name, func(t *testing.T) {
+			t.Parallel()
+
+			auditPath := filepath.Join(t.TempDir(), "audit.log")
+			audit := log.NewAuditLogger("info", auditPath)
+
+			inner := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				if testCase.setUsername != "" {
+					uac := reqCtx.NewUserAccessControl()
+					uac.SetUsername(testCase.setUsername)
+					uac.SaveOnRequest(r)
+				}
+
+				w.WriteHeader(testCase.status)
+			})
+
+			wrapped := zotapi.SessionAuditLogger(audit)(inner)
+
+			req := httptest.NewRequest(testCase.method, "/v2/repo/test/uploads", http.NoBody)
+			req.RemoteAddr = "127.0.0.1:12345"
+
+			recorder := httptest.NewRecorder()
+			wrapped.ServeHTTP(recorder, req)
+
+			data, err := os.ReadFile(auditPath)
+			require.NoError(t, err)
+
+			if !testCase.wantAudit {
+				assert.Empty(t, strings.TrimSpace(string(data)))
+
+				return
+			}
+
+			lines := bytes.Split(bytes.TrimSpace(data), []byte("\n"))
+			require.Len(t, lines, 1)
+
+			var payload map[string]any
+			require.NoError(t, json.Unmarshal(lines[0], &payload))
+
+			statusVal, ok := payload["status"].(float64)
+			require.True(t, ok, "JSON status should decode as float64")
+
+			assert.Equal(t, "HTTP API Audit", payload["message"])
+			assert.Equal(t, testCase.wantSubject, payload["subject"])
+			assert.Equal(t, testCase.method, payload["action"])
+			assert.InDelta(t, float64(testCase.status), statusVal, 0)
+			assert.Equal(t, "session", payload["component"])
+			assert.Equal(t, "127.0.0.1:12345", payload["clientIP"])
+			assert.Equal(t, "/v2/repo/test/uploads", payload["object"])
+		})
+	}
+}
+
+func TestSessionAuditLogger_rawQueryAppendedToObject(t *testing.T) {
+	t.Parallel()
+
+	auditPath := filepath.Join(t.TempDir(), "audit.log")
+	audit := log.NewAuditLogger("info", auditPath)
+
+	inner := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusCreated)
+	})
+
+	wrapped := zotapi.SessionAuditLogger(audit)(inner)
+
+	req := httptest.NewRequest(http.MethodPost, "/v2/a/b", http.NoBody)
+	req.URL.RawQuery = "digest=sha256:abc"
+
+	recorder := httptest.NewRecorder()
+	wrapped.ServeHTTP(recorder, req)
+
+	data, err := os.ReadFile(auditPath)
+	require.NoError(t, err)
+
+	var payload map[string]any
+	require.NoError(t, json.Unmarshal(bytes.TrimSpace(data), &payload))
+
+	assert.Equal(t, "/v2/a/b?digest=sha256:abc", payload["object"])
+}
+
+func TestSessionLogger_redactsAuthorizationAndLogsUsernameFromContext(t *testing.T) {
+	t.Parallel()
+
+	var buf bytes.Buffer
+
+	ctlr := &zotapi.Controller{
+		Log:     log.NewLoggerWithWriter("info", &buf),
+		Metrics: monitoring.NewMetricsServer(false, log.NewTestLogger()),
+	}
+	t.Cleanup(ctlr.Metrics.Stop)
+
+	inner := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		uac := reqCtx.NewUserAccessControl()
+		uac.SetUsername("alice")
+		uac.SaveOnRequest(r)
+
+		w.WriteHeader(http.StatusOK)
+
+		_, _ = w.Write([]byte("ok"))
+	})
+
+	wrapped := zotapi.SessionLogger(ctlr)(inner)
+
+	req := httptest.NewRequest(http.MethodGet, "/v2/_catalog", http.NoBody)
+	req.Header.Set("Authorization", "Bearer super-secret-token")
+	req.RemoteAddr = "10.0.0.1:4444"
+
+	recorder := httptest.NewRecorder()
+	wrapped.ServeHTTP(recorder, req)
+
+	out := buf.String()
+
+	assert.Contains(t, out, `"message":"HTTP API"`)
+	assert.Contains(t, out, `"username":"alice"`)
+	assert.Contains(t, out, `"Authorization":["******"]`)
+	assert.NotContains(t, out, "super-secret-token")
+}
+
+func TestSessionLogger_omitsUsernameWhenAnonymous(t *testing.T) {
+	t.Parallel()
+
+	var buf bytes.Buffer
+
+	ctlr := &zotapi.Controller{
+		Log:     log.NewLoggerWithWriter("info", &buf),
+		Metrics: monitoring.NewMetricsServer(false, log.NewTestLogger()),
+	}
+	t.Cleanup(ctlr.Metrics.Stop)
+
+	inner := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusNoContent)
+	})
+
+	wrapped := zotapi.SessionLogger(ctlr)(inner)
+
+	req := httptest.NewRequest(http.MethodGet, "/v2/_catalog", http.NoBody)
+
+	recorder := httptest.NewRecorder()
+	wrapped.ServeHTTP(recorder, req)
+
+	out := buf.String()
+
+	assert.Contains(t, out, `"message":"HTTP API"`)
+	assert.NotContains(t, out, `"username"`)
+}