fix(beginLogin): custom challenge take effect

webauthn/login.go

@@ -90,7 +90,7 @@ func (webauthn *WebAuthn) beginLogin(userID []byte, allowedCredentials []protoco
 	}
 
 	session = &SessionData{
-		Challenge:            challenge.String(),
+		Challenge:            assertion.Response.Challenge.String(),
 		RelyingPartyID:       assertion.Response.RelyingPartyID,
 		UserID:               userID,
 		AllowedCredentialIDs: assertion.Response.GetAllowedCredentialIDs(),

webauthn/login_test.go

@@ -108,3 +108,70 @@ func TestWithLoginRelyingPartyID(t *testing.T) {
 		})
 	}
 }
+
+func TestCustomerChallenge(t *testing.T) {
+	customerChallenge := "hello world"
+	nonCustomerChallenge := make(protocol.URLEncodedBase64, 0)
+	testCases := []struct {
+		name              string
+		have              *Config
+		opts              []LoginOption
+		expectedChallenge func() protocol.URLEncodedBase64
+		err               string
+	}{
+		{
+			name: "NonCustomerChallenge",
+			have: &Config{
+				RPID:          "https://example.com",
+				RPDisplayName: "Test Non-Customer Challenge",
+				RPOrigins:     []string{"https://example.com"},
+			},
+			opts: []LoginOption{
+				func(opt *protocol.PublicKeyCredentialRequestOptions) {
+					nonCustomerChallenge = opt.Challenge
+				},
+			},
+			expectedChallenge: func() protocol.URLEncodedBase64 {
+				return nonCustomerChallenge
+			},
+		},
+		{
+			name: "CustomerChallenge",
+			have: &Config{
+				RPID:          "https://example.com",
+				RPDisplayName: "Test Customer Challenge",
+				RPOrigins:     []string{"https://example.com"},
+			},
+			opts: []LoginOption{
+				func(opt *protocol.PublicKeyCredentialRequestOptions) {
+					opt.Challenge = protocol.URLEncodedBase64(customerChallenge)
+				},
+			},
+			expectedChallenge: func() protocol.URLEncodedBase64 {
+				return []byte(customerChallenge)
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			w, err := New(tc.have)
+			assert.NoError(t, err)
+
+			user := &defaultUser{
+				credentials: []Credential{
+					{},
+				},
+			}
+
+			creation, _, err := w.BeginLogin(user, tc.opts...)
+			if tc.err != "" {
+				assert.EqualError(t, err, tc.err)
+			} else {
+				assert.NoError(t, err)
+				require.NotNil(t, creation)
+				assert.Equal(t, tc.expectedChallenge(), creation.Response.Challenge)
+			}
+		})
+	}
+}