PIN management

Set, rotate, verify, and remove the signing PIN.

The PIN gates signMessage, signTransactionHash, and deleteWallet when requirePin is true. It is stored only as a salted PBKDF2-HMAC-SHA256 digest (100 000 iterations) in platform secure storage — the raw PIN never touches disk.

The derivation runs in native code, so the 100 000 iterations never block the JavaScript thread.

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Set a PIN

Call setPin once after wallet provisioning. The PIN must be exactly BmoniEmbeddedSdk.pinLength characters (default 6).

await BmoniEmbeddedSdk.setPin('123456');

Throws pinAlreadySet if a PIN already exists. Check first:

if (!(await BmoniEmbeddedSdk.hasPin())) {
  await BmoniEmbeddedSdk.setPin('123456');
}

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Check whether a PIN is set

const hasPin = await BmoniEmbeddedSdk.hasPin();

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Verify a PIN without throwing

Use matchPin to check a PIN without raising an error. This is useful for validating a user’s entry before attempting a gated operation.

const matches = await BmoniEmbeddedSdk.matchPin('123456');
if (!matches) {
  // Show "Incorrect PIN" to the user.
}

matchPin returns false when no PIN is set, so use hasPin when you need to tell “no PIN” apart from “wrong PIN”.

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Change a PIN

Requires the current PIN. Both values must be pinLength characters.

await BmoniEmbeddedSdk.changePin({
  currentPin: '123456',
  newPin: '654321',
});

changePin takes an object rather than two positional strings, so you cannot accidentally swap the current and new PIN.

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Remove a PIN

Removes the stored digest entirely. After removal, hasPin() returns false and PIN-gated operations are unavailable until a new PIN is set.

await BmoniEmbeddedSdk.removePin('123456');

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PIN length enforcement

All PIN operations enforce the pinLength set in BmoniEmbeddedSdk.initialize. Passing a PIN of the wrong length throws BmoniSignerError with errorCode: pinInvalid.

Read the required length at runtime to drive your UI:

const requiredLength = BmoniEmbeddedSdk.pinLength; // 6 by default

<TextInput
  maxLength={requiredLength}
  keyboardType="number-pad"
  secureTextEntry
/>;

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Full example

// 1. One-time setup.
await BmoniEmbeddedSdk.setPin('123456');

// 2. Rotate the PIN.
await BmoniEmbeddedSdk.changePin({
  currentPin: '123456',
  newPin: '654321',
});

// 3. Verify without throwing — useful for a PIN confirmation step.
const ok = await BmoniEmbeddedSdk.matchPin('654321');
console.log('PIN matches:', ok); // true

// 4. Tear down (e.g. on logout).
await BmoniEmbeddedSdk.removePin('654321');