[PM-42349] fix: use fixed-length password mask

[488315]

Tracking

Fixes #7290 (PM-42337)

Objective

Use a fixed eight-character mask for hidden login passwords and custom hidden fields so their displayed mask no longer reveals the underlying value length.

The shared password component keeps its existing length-based behavior by default. Only the affected login-password and custom-hidden-field call sites opt into the fixed-length mask, so existing behavior for card numbers, security codes, bank fields, identity fields, SSH keys, and other masked values is unchanged.

Regression coverage verifies:

• fixed-length masking for opted-in read-only password fields;
• the real value is shown after reveal;
• default read-only password masking still preserves value length for non-opted-in fields;
• non-interactable login password fields use the fixed mask.

Validation:

• ./gradlew.bat :ui:testDebugUnitTest
• ./gradlew.bat :ui:lintDebug
• ./gradlew.bat detekt -Pprecommit=true --rerun-tasks
• git diff --check

All completed checks passed with JDK 21.

Screenshots

N/A. There is no layout or styling change; affected hidden login/custom values consistently render eight mask characters.

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All committers have signed the CLA.

[bitwarden-bot]

Thank you for your contribution! We've added this to our internal tracking system for review.
ID: PM-42349
Link: https://bitwarden.atlassian.net/browse/PM-42349

Details on our contribution process can be found here: https://contributing.bitwarden.com/contributing/pull-requests/community-pr-process.

[andrebispo5]

Hi @488315
When the fixed mask is on, lastTextValue is still seeded from the raw value while the field renders displayedValue. The two disagree, so the first tap on the field makes the TextField's onValueChange fire with "********" instead of staying quiet.

It's harmless right now since all three opted-in call sites pass onValueChange = { }, but useFixedLengthMask is public on a shared :ui component. The next caller that wires a real callback would get the mask handed to it on first tap, and if that value ever gets saved the password becomes eight asterisks.

Repro (drop into BitwardenPasswordFieldTest, fails on this branch with expected:<[]> but was:<[********]>):

@Test
fun `tapping a masked read only field does not emit the mask`() {
    val emitted = mutableListOf<String>()

    setTestContent {
        BitwardenTheme {
            BitwardenPasswordField(
                label = "Password",
                value = "correct horse battery staple",
                showPassword = false,
                showPasswordChange = { },
                onValueChange = { emitted += it },
                readOnly = true,
                useFixedLengthMask = true,
                cardStyle = CardStyle.Full,
            )
        }
    }

    composeTestRule.onNodeWithText("Password").performClick()
    composeTestRule.waitForIdle()

    assertEquals(emptyList<String>(), emitted)
}

Keying the state off the displayed value fixes it, and the existing tests still pass:

var lastTextValue by remember(displayedValue) { mutableStateOf(value = displayedValue) }

Could you double check this one?

Thanks for the submission 👍

[codecov]

Codecov Report

❌ Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 43.82%. Comparing base (d817f6b) to head (839a7ad).

Files with missing lines	Patch %	Lines
...ult/feature/item/component/VaultItemCustomField.kt	0.00%	2 Missing ⚠️
...den/ui/vault/feature/item/VaultItemLoginContent.kt	0.00%	1 Missing ⚠️

❗ There is a different number of reports uploaded between BASE (d817f6b) and HEAD (839a7ad). Click for more details.

HEAD has 2 uploads less than BASE

Flag	BASE (d817f6b)	HEAD (839a7ad)
app-ui-auth-tools	1	0
app-ui-vault	1	0

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #7293       +/-   ##
===========================================
- Coverage   86.35%   43.82%   -42.53%     
===========================================
  Files         893      896        +3     
  Lines       65488    64454     -1034     
  Branches     9861     9790       -71     
===========================================
- Hits        56550    28247    -28303     
- Misses       5464    34224    +28760     
+ Partials     3474     1983     -1491     

Flag	Coverage Δ
app-data	17.89% <0.00%> (-0.01%)	⬇️
app-ui-auth-tools	?
app-ui-platform	16.37% <0.00%> (-0.01%)	⬇️
app-ui-vault	?
authenticator	6.07% <0.00%> (-0.03%)	⬇️
lib-core-network-bridge	4.10% <0.00%> (+0.01%)	⬆️
lib-data-ui	1.20% <0.00%> (+<0.01%)	⬆️

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[488315]

Thanks for catching that. I double checked it and you were right.

I reproduced it with the regression test you sent first, and it failed with the mask being emitted on the initial tap. I updated lastTextValue to key off displayedValue, added that regression test, and pushed the fix in 06742ac.

I also reran the focused BitwardenPasswordFieldTest suite (5/5), the full :ui:testDebugUnitTest suite, :ui:lintDebug, and staged Detekt precommit checks. All are passing on JDK 21.

Appreciate you pointing this one out.