Show warning for control/whitespace chars in passwords

app/src/main/java/eu/faircode/email/FragmentAccount.java

@@ -30,7 +30,9 @@ import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
+import android.text.Editable;
 import android.text.TextUtils;
+import android.text.TextWatcher;
 import android.text.method.LinkMovementMethod;
 import android.view.LayoutInflater;
 import android.view.Menu;
@@ -88,6 +90,7 @@ public class FragmentAccount extends FragmentBase {
     private EditText etPort;
     private EditText etUser;
     private TextInputLayout tilPassword;
+    private TextView tvCharacters;
     private Button btnOAuth;
     private TextView tvOAuthSupport;
     private EditText etRealm;
@@ -195,6 +198,7 @@ public class FragmentAccount extends FragmentBase {
         cbInsecure = view.findViewById(R.id.cbInsecure);
         etUser = view.findViewById(R.id.etUser);
         tilPassword = view.findViewById(R.id.tilPassword);
+        tvCharacters = view.findViewById(R.id.tvCharacters);
         btnOAuth = view.findViewById(R.id.btnOAuth);
         tvOAuthSupport = view.findViewById(R.id.tvOAuthSupport);
         etRealm = view.findViewById(R.id.etRealm);
@@ -310,6 +314,28 @@ public class FragmentAccount extends FragmentBase {
             }
         });
 
+        tilPassword.getEditText().addTextChangedListener(new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+                // Do nothing
+            }
+
+            @Override
+            public void onTextChanged(CharSequence s, int start, int before, int count) {
+                // Do nothing
+            }
+
+            @Override
+            public void afterTextChanged(Editable s) {
+                String password = s.toString();
+                boolean warning = (Helper.containsWhiteSpace(password) ||
+                        Helper.containsControlChars(password));
+                tvCharacters.setVisibility(warning &&
+                        tilPassword.getVisibility() == View.VISIBLE
+                        ? View.VISIBLE : View.GONE);
+            }
+        });
+
         btnOAuth.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
@@ -436,6 +462,7 @@ public class FragmentAccount extends FragmentBase {
 
         rgEncryption.setVisibility(View.GONE);
         cbInsecure.setVisibility(View.GONE);
+        tvCharacters.setVisibility(View.GONE);
 
         btnAdvanced.setVisibility(View.GONE);
 

app/src/main/java/eu/faircode/email/FragmentIdentity.java

@@ -99,6 +99,7 @@ public class FragmentIdentity extends FragmentBase {
     private EditText etPort;
     private EditText etUser;
     private TextInputLayout tilPassword;
+    private TextView tvCharacters;
     private Button btnOAuth;
     private EditText etRealm;
     private CheckBox cbUseIp;
@@ -183,6 +184,7 @@ public class FragmentIdentity extends FragmentBase {
         etPort = view.findViewById(R.id.etPort);
         etUser = view.findViewById(R.id.etUser);
         tilPassword = view.findViewById(R.id.tilPassword);
+        tvCharacters = view.findViewById(R.id.tvCharacters);
         btnOAuth = view.findViewById(R.id.btnOAuth);
         etRealm = view.findViewById(R.id.etRealm);
         cbUseIp = view.findViewById(R.id.cbUseIp);
@@ -292,6 +294,23 @@ public class FragmentIdentity extends FragmentBase {
             }
         });
 
+        tilPassword.getEditText().addTextChangedListener(new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+                // Do nothing
+            }
+
+            @Override
+            public void onTextChanged(CharSequence s, int start, int before, int count) {
+                // Do nothing
+            }
+
+            @Override
+            public void afterTextChanged(Editable s) {
+                checkPassword(s.toString());
+            }
+        });
+
         btnColor.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
@@ -347,6 +366,7 @@ public class FragmentIdentity extends FragmentBase {
             public void onClick(View v) {
                 int visibility = (grpAdvanced.getVisibility() == View.VISIBLE ? View.GONE : View.VISIBLE);
                 grpAdvanced.setVisibility(visibility);
+                checkPassword(tilPassword.getEditText().getText().toString());
                 if (visibility == View.VISIBLE)
                     new Handler().post(new Runnable() {
                         @Override
@@ -452,6 +472,7 @@ public class FragmentIdentity extends FragmentBase {
         btnAutoConfig.setEnabled(false);
         pbAutoConfig.setVisibility(View.GONE);
         cbInsecure.setVisibility(View.GONE);
+        tvCharacters.setVisibility(View.GONE);
 
         btnAdvanced.setVisibility(View.GONE);
 
@@ -515,6 +536,15 @@ public class FragmentIdentity extends FragmentBase {
         }.execute(this, args, "identity:config");
     }
 
+    private void checkPassword(String password) {
+        boolean warning = (Helper.containsWhiteSpace(password) ||
+                Helper.containsControlChars(password));
+        tvCharacters.setVisibility(warning &&
+                grpAdvanced.getVisibility() == View.VISIBLE
+                ? View.VISIBLE : View.GONE);
+
+    }
+
     private void onSave(boolean should) {
         EntityAccount account = (EntityAccount) spAccount.getSelectedItem();
 

app/src/main/java/eu/faircode/email/FragmentPop.java

@@ -26,7 +26,9 @@ import android.graphics.Color;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.Handler;
+import android.text.Editable;
 import android.text.TextUtils;
+import android.text.TextWatcher;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
@@ -64,6 +66,7 @@ public class FragmentPop extends FragmentBase {
     private EditText etPort;
     private EditText etUser;
     private TextInputLayout tilPassword;
+    private TextView tvCharacters;
 
     private EditText etName;
     private ViewButtonColor btnColor;
@@ -113,6 +116,7 @@ public class FragmentPop extends FragmentBase {
         cbInsecure = view.findViewById(R.id.cbInsecure);
         etUser = view.findViewById(R.id.etUser);
         tilPassword = view.findViewById(R.id.tilPassword);
+        tvCharacters = view.findViewById(R.id.tvCharacters);
 
         etName = view.findViewById(R.id.etName);
         btnColor = view.findViewById(R.id.btnColor);
@@ -132,6 +136,28 @@ public class FragmentPop extends FragmentBase {
 
         pbWait = view.findViewById(R.id.pbWait);
 
+        tilPassword.getEditText().addTextChangedListener(new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+                // Do nothing
+            }
+
+            @Override
+            public void onTextChanged(CharSequence s, int start, int before, int count) {
+                // Do nothing
+            }
+
+            @Override
+            public void afterTextChanged(Editable s) {
+                String password = s.toString();
+                boolean warning = (Helper.containsWhiteSpace(password) ||
+                        Helper.containsControlChars(password));
+                tvCharacters.setVisibility(warning &&
+                        tilPassword.getVisibility() == View.VISIBLE
+                        ? View.VISIBLE : View.GONE);
+            }
+        });
+
         btnColor.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
@@ -169,6 +195,7 @@ public class FragmentPop extends FragmentBase {
         // Initialize
         Helper.setViewsEnabled(view, false);
 
+        tvCharacters.setVisibility(View.GONE);
         pbSave.setVisibility(View.GONE);
         grpError.setVisibility(View.GONE);
 

app/src/main/java/eu/faircode/email/FragmentQuickSetup.java

@@ -24,7 +24,9 @@ import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.Handler;
+import android.text.Editable;
 import android.text.TextUtils;
+import android.text.TextWatcher;
 import android.text.method.LinkMovementMethod;
 import android.util.Patterns;
 import android.view.KeyEvent;
@@ -59,6 +61,7 @@ public class FragmentQuickSetup extends FragmentBase {
     private EditText etName;
     private EditText etEmail;
     private TextInputLayout tilPassword;
+    private TextView tvCharacters;
     private Button btnCheck;
     private ContentLoadingProgressBar pbCheck;
 
@@ -88,6 +91,7 @@ public class FragmentQuickSetup extends FragmentBase {
         etName = view.findViewById(R.id.etName);
         etEmail = view.findViewById(R.id.etEmail);
         tilPassword = view.findViewById(R.id.tilPassword);
+        tvCharacters = view.findViewById(R.id.tvCharacters);
         btnCheck = view.findViewById(R.id.btnCheck);
         pbCheck = view.findViewById(R.id.pbCheck);
 
@@ -119,6 +123,28 @@ public class FragmentQuickSetup extends FragmentBase {
             }
         });
 
+        tilPassword.getEditText().addTextChangedListener(new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+                // Do nothing
+            }
+
+            @Override
+            public void onTextChanged(CharSequence s, int start, int before, int count) {
+                // Do nothing
+            }
+
+            @Override
+            public void afterTextChanged(Editable s) {
+                String password = s.toString();
+                boolean warning = (Helper.containsWhiteSpace(password) ||
+                        Helper.containsControlChars(password));
+                tvCharacters.setVisibility(warning &&
+                        tilPassword.getVisibility() == View.VISIBLE
+                        ? View.VISIBLE : View.GONE);
+            }
+        });
+
         btnCheck.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
@@ -149,6 +175,7 @@ public class FragmentQuickSetup extends FragmentBase {
         });
 
         // Initialize
+        tvCharacters.setVisibility(View.GONE);
         pbCheck.setVisibility(View.GONE);
         pbSave.setVisibility(View.GONE);
         btnHelp.setVisibility(View.GONE);

app/src/main/java/eu/faircode/email/Helper.java

@@ -584,6 +584,26 @@ public class Helper {
         return result.toArray(new String[0]);
     }
 
+    static boolean containsWhiteSpace(String text) {
+        return text.matches(".*\\s+.*");
+    }
+
+    static boolean containsControlChars(String text) {
+        for (int offset = 0; offset < text.length(); ) {
+            int codePoint = text.codePointAt(offset);
+            offset += Character.charCount(codePoint);
+            switch (Character.getType(codePoint)) {
+                case Character.CONTROL:     // \p{Cc}
+                case Character.FORMAT:      // \p{Cf}
+                case Character.PRIVATE_USE: // \p{Co}
+                case Character.SURROGATE:   // \p{Cs}
+                case Character.UNASSIGNED:  // \p{Cn}
+                    return true;
+            }
+        }
+        return false;
+    }
+
     // Files
 
     static String sanitizeFilename(String name) {

app/src/main/res/layout/fragment_account.xml

@@ -243,6 +243,18 @@
                 android:textAppearance="@style/TextAppearance.AppCompat.Medium" />
         </com.google.android.material.textfield.TextInputLayout>
 
+        <TextView
+            android:id="@+id/tvCharacters"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:autoLink="web"
+            android:text="@string/title_setup_password_chars"
+            android:textAppearance="@style/TextAppearance.AppCompat.Small"
+            android:textColor="?attr/colorWarning"
+            android:textIsSelectable="true"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/tilPassword" />
+
         <Button
             android:id="@+id/btnOAuth"
             style="@style/buttonStyleSmall"
@@ -254,7 +266,7 @@
             android:tag="disable"
             android:text="@string/title_setup_authentication"
             app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/tilPassword" />
+            app:layout_constraintTop_toBottomOf="@id/tvCharacters" />
 
         <TextView
             android:id="@+id/tvOAuthSupport"

app/src/main/res/layout/fragment_identity.xml

@@ -430,6 +430,18 @@
                 android:textAppearance="@style/TextAppearance.AppCompat.Medium" />
         </com.google.android.material.textfield.TextInputLayout>
 
+        <TextView
+            android:id="@+id/tvCharacters"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:autoLink="web"
+            android:text="@string/title_setup_password_chars"
+            android:textAppearance="@style/TextAppearance.AppCompat.Small"
+            android:textColor="?attr/colorWarning"
+            android:textIsSelectable="true"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/tilPassword" />
+
         <Button
             android:id="@+id/btnOAuth"
             style="@style/buttonStyleSmall"
@@ -441,7 +453,7 @@
             android:tag="disable"
             android:text="@string/title_setup_authentication"
             app:layout_constraintEnd_toEndOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/tilPassword" />
+            app:layout_constraintTop_toBottomOf="@id/tvCharacters" />
 
         <TextView
             android:id="@+id/tvRealm"

app/src/main/res/layout/fragment_pop.xml

@@ -163,6 +163,18 @@
                 android:textAppearance="@style/TextAppearance.AppCompat.Medium" />
         </com.google.android.material.textfield.TextInputLayout>
 
+        <TextView
+            android:id="@+id/tvCharacters"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:autoLink="web"
+            android:text="@string/title_setup_password_chars"
+            android:textAppearance="@style/TextAppearance.AppCompat.Small"
+            android:textColor="?attr/colorWarning"
+            android:textIsSelectable="true"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/tilPassword" />
+
         <!-- name -->
 
         <TextView
@@ -173,7 +185,7 @@
             android:text="@string/title_account_name"
             android:textAppearance="@style/TextAppearance.AppCompat.Small"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/tilPassword" />
+            app:layout_constraintTop_toBottomOf="@id/tvCharacters" />
 
         <TextView
             android:id="@+id/tvNameRemark"

app/src/main/res/layout/fragment_quick_setup.xml

@@ -61,6 +61,18 @@
                 android:textAppearance="@style/TextAppearance.AppCompat.Medium" />
         </com.google.android.material.textfield.TextInputLayout>
 
+        <TextView
+            android:id="@+id/tvCharacters"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:autoLink="web"
+            android:text="@string/title_setup_password_chars"
+            android:textAppearance="@style/TextAppearance.AppCompat.Small"
+            android:textColor="?attr/colorWarning"
+            android:textIsSelectable="true"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/tilPassword" />
+
         <TextView
             android:id="@+id/tvHint"
             android:layout_width="wrap_content"
@@ -70,7 +82,7 @@
             android:textAppearance="@style/TextAppearance.AppCompat.Small"
             android:textStyle="italic"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/tilPassword" />
+            app:layout_constraintTop_toBottomOf="@id/tvCharacters" />
 
         <Button
             android:id="@+id/btnCheck"

app/src/main/res/values/strings.xml

@@ -182,6 +182,7 @@
     <string name="title_setup_import">Import settings</string>
     <string name="title_setup_import_do">Imported accounts will be added without overwriting any existing ones</string>
     <string name="title_setup_password">Password</string>
+    <string name="title_setup_password_chars">Password contains control or whitespace characters</string>
     <string name="title_setup_password_repeat">Repeat password</string>
     <string name="title_setup_password_missing">Password missing</string>
     <string name="title_setup_password_different">Passwords don\'t match</string>