Add a method to Darwin SetupPayload to test whether a passcode is val…

…id. (#37193)
project-chip · Jan 24, 2025 · 281adfd · 281adfd
1 parent 8a916c1
commit 281adfd
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Showing 3 changed files with 53 additions and 1 deletion.
diff --git a/src/darwin/Framework/CHIP/MTRSetupPayload.h b/src/darwin/Framework/CHIP/MTRSetupPayload.h
@@ -175,7 +175,7 @@ MTR_AVAILABLE(ios(16.1), macos(13.0), watchos(9.1), tvos(16.1))
 /**
  * Generate a random Matter-valid setup PIN.
  */
-+ (NSUInteger)generateRandomPIN;
++ (NSUInteger)generateRandomPIN MTR_NEWLY_DEPRECATED("Please use generateRandomSetupPasscode");
 
 /**
  * Generate a random Matter-valid setup passcode.
@@ -214,6 +214,12 @@ MTR_AVAILABLE(ios(16.1), macos(13.0), watchos(9.1), tvos(16.1))
  */
 - (NSString * _Nullable)qrCodeString MTR_AVAILABLE(ios(17.6), macos(14.6), watchos(10.6), tvos(17.6));
 
+/**
+ * Check whether the provided setup passcode (represented as an unsigned
+ * integer) is a valid setup passcode.
+ */
++ (BOOL)isValidSetupPasscode:(NSNumber *)setupPasscode MTR_NEWLY_AVAILABLE;
+
 @end
 
 MTR_AVAILABLE(ios(17.6), macos(14.6), watchos(10.6), tvos(17.6))

diff --git a/src/darwin/Framework/CHIP/MTRSetupPayload.mm b/src/darwin/Framework/CHIP/MTRSetupPayload.mm
@@ -476,6 +476,17 @@ - (nullable NSString *)qrCodeString
     return [self qrCodeStringSkippingValidation:NO];
 }
 
++ (BOOL)isValidSetupPasscode:(NSNumber *)setupPasscode
+{
+    using namespace chip;
+
+    uint64_t passCode = setupPasscode.unsignedLongLongValue;
+    if (!CanCastTo<uint32_t>(passCode)) {
+        return NO;
+    }
+    return SetupPayload::IsValidSetupPIN(static_cast<uint32_t>(passCode));
+}
+
 - (nullable NSString *)qrCodeStringSkippingValidation:(BOOL)allowInvalid
 {
     chip::QRCodeSetupPayloadGenerator generator(_payload);

diff --git a/src/darwin/Framework/CHIPTests/MTRSetupPayloadTests.m b/src/darwin/Framework/CHIPTests/MTRSetupPayloadTests.m
@@ -439,4 +439,39 @@ - (void)testDescriptionShowsUnknownDiscoveryMethods
     XCTAssertNotEqualObjects(a.description, b.description);
 }
 
+- (uint32)generateRepeatedDigitPasscode:(uint8_t)digit
+{
+    // "digit" is expected to be a single digit.  Generates a number that has
+    // that digit repeated 8 times.
+    uint32_t passcode = 0;
+    for (int i = 0; i < 8; ++i) {
+        passcode = passcode * 10 + digit;
+    }
+    return passcode;
+}
+
+- (void)testValidSetupPasscode
+{
+    // First, check the repeated-digit cases.
+    for (uint8_t digit = 0; digit <= 9; ++digit) {
+        XCTAssertFalse([MTRSetupPayload isValidSetupPasscode:@([self generateRepeatedDigitPasscode:digit])]);
+    }
+
+    // Then the sequential special cases.
+    XCTAssertFalse([MTRSetupPayload isValidSetupPasscode:@(12345678)]);
+    XCTAssertFalse([MTRSetupPayload isValidSetupPasscode:@(87654321)]);
+
+    // Then the "too big" cases:
+    XCTAssertFalse([MTRSetupPayload isValidSetupPasscode:@(100000000)]);
+    XCTAssertFalse([MTRSetupPayload isValidSetupPasscode:@(1lu << 27)]);
+    XCTAssertFalse([MTRSetupPayload isValidSetupPasscode:@((1llu << 32) + 1)]);
+
+    // Now some tests for known-valid passcodes:
+    XCTAssertTrue([MTRSetupPayload isValidSetupPasscode:@(1)]);
+    XCTAssertTrue([MTRSetupPayload isValidSetupPasscode:@(78654321)]);
+
+    // And we should only generate valid ones.
+    XCTAssertTrue([MTRSetupPayload isValidSetupPasscode:[MTRSetupPayload generateRandomSetupPasscode]]);
+}
+
 @end