fix: refactor mfa models and add observability to loadFactor (#1669)

## What kind of change does this PR introduce?

Makes two changes:
- Ensures we track DB calls to loadFactor
- Changes the interface for creating a challenge in attempt to make
clear that Challenge should always have a Factor

internal/api/admin.go

@@ -70,21 +70,23 @@ func (a *API) loadUser(w http.ResponseWriter, r *http.Request) (context.Context,
 }
 
 func (a *API) loadFactor(w http.ResponseWriter, r *http.Request) (context.Context, error) {
+	ctx := r.Context()
+	db := a.db.WithContext(ctx)
 	factorID, err := uuid.FromString(chi.URLParam(r, "factor_id"))
 	if err != nil {
 		return nil, notFoundError(ErrorCodeValidationFailed, "factor_id must be an UUID")
 	}
 
 	observability.LogEntrySetField(r, "factor_id", factorID)
 
-	f, err := models.FindFactorByFactorID(a.db, factorID)
+	f, err := models.FindFactorByFactorID(db, factorID)
 	if err != nil {
 		if models.IsNotFoundError(err) {
 			return nil, notFoundError(ErrorCodeMFAFactorNotFound, "Factor not found")
 		}
 		return nil, internalServerError("Database error loading factor").WithInternalError(err)
 	}
-	return withFactor(r.Context(), f), nil
+	return withFactor(ctx, f), nil
 }
 
 func (a *API) getAdminParams(r *http.Request) (*AdminUserParams, error) {

internal/api/mfa.go

@@ -182,7 +182,7 @@ func (a *API) ChallengeFactor(w http.ResponseWriter, r *http.Request) error {
 	user := getUser(ctx)
 	factor := getFactor(ctx)
 	ipAddress := utilities.GetIPAddress(r)
-	challenge := models.NewChallenge(factor, ipAddress)
+	challenge := factor.CreateChallenge(ipAddress)
 
 	if err := db.Transaction(func(tx *storage.Connection) error {
 		if terr := tx.Create(challenge); terr != nil {

internal/api/mfa_test.go

@@ -265,7 +265,7 @@ func (ts *MFATestSuite) TestMFAVerifyFactor() {
 			req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
 
 			testIPAddress := utilities.GetIPAddress(req)
-			c := models.NewChallenge(f, testIPAddress)
+			c := f.CreateChallenge(testIPAddress)
 			require.NoError(ts.T(), ts.API.db.Create(c), "Error saving new test challenge")
 			if !v.validChallenge {
 				// Set challenge creation so that it has expired in present time.

internal/models/challenge.go

@@ -22,17 +22,6 @@ func (Challenge) TableName() string {
 	return tableName
 }
 
-func NewChallenge(factor *Factor, ipAddress string) *Challenge {
-	id := uuid.Must(uuid.NewV4())
-
-	challenge := &Challenge{
-		ID:        id,
-		FactorID:  factor.ID,
-		IPAddress: ipAddress,
-	}
-	return challenge
-}
-
 func FindChallengeByID(conn *storage.Connection, challengeID uuid.UUID) (*Challenge, error) {
 	var challenge Challenge
 	err := conn.Find(&challenge, challengeID)

internal/models/factor.go

@@ -187,6 +187,16 @@ func DeleteUnverifiedFactors(tx *storage.Connection, user *User) error {
 	return nil
 }
 
+func (f *Factor) CreateChallenge(ipAddress string) *Challenge {
+	id := uuid.Must(uuid.NewV4())
+	challenge := &Challenge{
+		ID:        id,
+		FactorID:  f.ID,
+		IPAddress: ipAddress,
+	}
+	return challenge
+}
+
 // UpdateFriendlyName changes the friendly name
 func (f *Factor) UpdateFriendlyName(tx *storage.Connection, friendlyName string) error {
 	f.FriendlyName = friendlyName