Merge branch 'mkirk/overflow-rebased'

Scripts/precommit.py

@@ -313,7 +313,7 @@ def process(filepath):
     
     filename = os.path.basename(filepath)
     if filename.startswith('.'):
-        return
+        raise "shouldn't call process with dotfile"
     file_ext = os.path.splitext(filename)[1]
     if file_ext in ('.swift'):
         env_copy = os.environ.copy()
@@ -389,6 +389,32 @@ def process_if_appropriate(filepath):
     process(filepath)
 
 
+def check_diff_for_keywords():
+    keywords = ["OWSAssert\(", "OWSFail\(", "ows_add_overflow\(", "ows_sub_overflow\("]
+    matching_expression = "|".join(keywords) 
+    command_line = 'git diff --staged | grep --color=always -C 3 -E "%s"' % matching_expression
+    print(command_line)
+    try:
+        output = subprocess.check_output(command_line, shell=True)
+    except subprocess.CalledProcessError, e:
+        # > man grep
+        #  EXIT STATUS
+        #  The grep utility exits with one of the following values:
+        #  0     One or more lines were selected.
+        #  1     No lines were selected.
+        #  >1    An error occurred.
+        if e.returncode == 1:
+            # no keywords in diff output
+            return
+        else:
+            # some other error - bad grep expression?
+            raise e
+
+    if len(output) > 0:
+        print("⚠️  keywords detected in diff:")
+        print(output)
+
+
 if __name__ == "__main__":
     
     parser = argparse.ArgumentParser(description='Precommit script.')
@@ -426,3 +452,5 @@ if __name__ == "__main__":
 
     print 'git clang-format...'
     print commands.getoutput('git clang-format')
+
+    check_diff_for_keywords()

Signal/src/ViewControllers/DebugUI/DebugUIBackup.m

@@ -134,7 +134,8 @@ NS_ASSUME_NONNULL_BEGIN
                                                   NSData *_Nullable data =
                                                       [NSKeyedArchiver archivedDataWithRootObject:interaction];
                                                   OWSAssertDebug(data);
-                                                  interactionSizeTotal += data.length;
+                                                  ows_add_overflow(
+                                                      interactionSizeTotal, data.length, &interactionSizeTotal);
                                               }];
         [transaction enumerateKeysAndObjectsInCollection:[TSAttachment collection]
                                               usingBlock:^(NSString *key, id object, BOOL *stop) {
@@ -143,7 +144,8 @@ NS_ASSUME_NONNULL_BEGIN
                                                   NSData *_Nullable data =
                                                       [NSKeyedArchiver archivedDataWithRootObject:attachment];
                                                   OWSAssertDebug(data);
-                                                  attachmentSizeTotal += data.length;
+                                                  ows_add_overflow(
+                                                      attachmentSizeTotal, data.length, &attachmentSizeTotal);
                                               }];
     }];
 

Signal/src/util/FunctionalUtil.h

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
 //
 
 @interface NSArray (FunctionalUtil)
@@ -19,15 +19,6 @@
 /// Returns an array of all the results of passing items from this array through the given projection function.
 - (NSArray *)filter:(int (^)(id item))predicate;
 
-/// Returns the sum of the doubles in this array of doubles.
-- (double)sumDouble;
-
-/// Returns the sum of the unsigned integers in this array of unsigned integers.
-- (NSUInteger)sumNSUInteger;
-
-/// Returns the sum of the integers in this array of integers.
-- (NSInteger)sumNSInteger;
-
 - (NSDictionary *)keyedBy:(id (^)(id))keySelector;
 - (NSDictionary *)groupBy:(id (^)(id value))keySelector;
 

Signal/src/util/FunctionalUtil.m

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
 //
 
 #import "FunctionalUtil.h"
@@ -52,27 +52,7 @@
     }
     return r;
 }
-- (double)sumDouble {
+
-    double s = 0.0;
-    for (NSNumber *e in self) {
-        s += [e doubleValue];
-    }
-    return s;
-}
-- (NSUInteger)sumNSUInteger {
-    NSUInteger s = 0;
-    for (NSNumber *e in self) {
-        s += [e unsignedIntegerValue];
-    }
-    return s;
-}
-- (NSInteger)sumNSInteger {
-    NSInteger s = 0;
-    for (NSNumber *e in self) {
-        s += [e integerValue];
-    }
-    return s;
-}
 - (NSDictionary *)keyedBy:(id (^)(id value))keySelector {
     OWSAssertDebug(keySelector != nil);
 

Signal/src/util/OWSBackupExportJob.m

@@ -630,27 +630,30 @@ NS_ASSUME_NONNULL_BEGIN
     {
         unsigned long long databaseFileSize = 0;
         for (OWSBackupExportItem *item in self.unsavedDatabaseItems) {
-            databaseFileSize += [OWSFileSystem fileSizeOfPath:item.encryptedItem.filePath].unsignedLongLongValue;
+            unsigned long long fileSize =
+                [OWSFileSystem fileSizeOfPath:item.encryptedItem.filePath].unsignedLongLongValue;
+            ows_add_overflow(databaseFileSize, fileSize, &databaseFileSize);
         }
         OWSLogInfo(@"exporting %@: count: %zd, bytes: %llu.",
             @"database items",
             self.unsavedDatabaseItems.count,
             databaseFileSize);
-        totalFileSize += databaseFileSize;
+        ows_add_overflow(totalFileSize, databaseFileSize, &totalFileSize);
-        totalFileCount += self.unsavedDatabaseItems.count;
+        ows_add_overflow(totalFileCount, self.unsavedDatabaseItems.count, &totalFileCount);
     }
     {
         unsigned long long attachmentFileSize = 0;
         for (OWSAttachmentExport *attachmentExport in self.unsavedAttachmentExports) {
-            attachmentFileSize +=
+            unsigned long long fileSize =
                 [OWSFileSystem fileSizeOfPath:attachmentExport.attachmentFilePath].unsignedLongLongValue;
+            ows_add_overflow(attachmentFileSize, fileSize, &attachmentFileSize);
         }
         OWSLogInfo(@"exporting %@: count: %zd, bytes: %llu.",
             @"attachment items",
             self.unsavedAttachmentExports.count,
             attachmentFileSize);
-        totalFileSize += attachmentFileSize;
+        ows_add_overflow(totalFileSize, attachmentFileSize, &totalFileSize);
-        totalFileCount += self.unsavedAttachmentExports.count;
+        ows_add_overflow(totalFileCount, self.unsavedAttachmentExports.count, &totalFileSize);
     }
     OWSLogInfo(@"exporting %@: count: %zd, bytes: %llu.", @"all items", totalFileCount, totalFileSize);
 

SignalServiceKit/src/Util/Cryptography.h

@@ -46,7 +46,6 @@ extern const NSUInteger kAES256_KeyByteLength;
 @interface Cryptography : NSObject
 
 typedef NS_ENUM(NSInteger, TSMACType) {
-    TSHMACSHA1Truncated10Bytes   = 1,
     TSHMACSHA256Truncated10Bytes = 2,
     TSHMACSHA256AttachementType  = 3
 };

SignalServiceKit/src/Util/Cryptography.m

@@ -26,6 +26,9 @@ static const NSUInteger kAESGCM256_IVLength = 12;
 // length of authentication tag for AES256-GCM
 static const NSUInteger kAESGCM256_TagLength = 16;
 
+// length of key used for websocket envelope authentication
+static const NSUInteger kHMAC256_EnvelopeKeyLength = 20;
+
 const NSUInteger kAES256_KeyByteLength = 32;
 
 @implementation OWSAES256Key
@@ -230,42 +233,13 @@ const NSUInteger kAES256_KeyByteLength = 32;
     return [ourHmacData copy];
 }
 
-+ (nullable NSData *)computeSHA1HMAC:(NSData *)data withHMACKey:(NSData *)HMACKey
-{
-    if (data.length >= SIZE_MAX) {
-        OWSFailDebug(@"data is too long.");
-        return nil;
-    }
-    size_t dataLength = (size_t)data.length;
-    if (HMACKey.length >= SIZE_MAX) {
-        OWSFailDebug(@"HMAC key is too long.");
-        return nil;
-    }
-    size_t hmacKeyLength = (size_t)HMACKey.length;
-
-    NSMutableData *_Nullable ourHmacData = [[NSMutableData alloc] initWithLength:CC_SHA1_DIGEST_LENGTH];
-    if (!ourHmacData) {
-        OWSFailDebug(@"could not allocate buffer.");
-        return nil;
-    }
-    CCHmac(kCCHmacAlgSHA1, [HMACKey bytes], hmacKeyLength, [data bytes], dataLength, ourHmacData.mutableBytes);
-    return [ourHmacData copy];
-}
-
-+ (nullable NSData *)truncatedSHA1HMAC:(NSData *)dataToHMAC
-                           withHMACKey:(NSData *)HMACKey
-                            truncation:(NSUInteger)truncation
-{
-    OWSAssertDebug(truncation <= CC_SHA1_DIGEST_LENGTH);
-
-    return [[Cryptography computeSHA1HMAC:dataToHMAC withHMACKey:HMACKey] subdataWithRange:NSMakeRange(0, truncation)];
-}
-
 + (nullable NSData *)truncatedSHA256HMAC:(NSData *)dataToHMAC
                              withHMACKey:(NSData *)HMACKey
                               truncation:(NSUInteger)truncation
 {
-    OWSAssertDebug(truncation <= CC_SHA256_DIGEST_LENGTH);
+    OWSAssert(truncation <= CC_SHA256_DIGEST_LENGTH);
+    OWSAssert(dataToHMAC);
+    OWSAssert(HMACKey);
 
     return
         [[Cryptography computeSHA256HMAC:dataToHMAC withHMACKey:HMACKey] subdataWithRange:NSMakeRange(0, truncation)];
@@ -287,29 +261,60 @@ const NSUInteger kAES256_KeyByteLength = 32;
                        matchingHMAC:(NSData *)hmac
                              digest:(nullable NSData *)digest
 {
-    if (dataToDecrypt.length >= (SIZE_MAX - kCCBlockSizeAES128)) {
+    OWSAssert(dataToDecrypt);
-        OWSFailDebug(@"data is too long.");
+    OWSAssert(key);
+    if (key.length != kCCKeySizeAES256) {
+        OWSFailDebug(@"key had wrong size.");
+        return nil;
+    }
+    OWSAssert(iv);
+    if (iv.length != kCCBlockSizeAES128) {
+        OWSFailDebug(@"iv had wrong size.");
+        return nil;
+    }
+    OWSAssert(hmacKey);
+    OWSAssert(hmac);
+
+    size_t bufferSize;
+    BOOL didOverflow = __builtin_add_overflow(dataToDecrypt.length, kCCBlockSizeAES128, &bufferSize);
+    if (didOverflow) {
+        OWSFailDebug(@"bufferSize was too large.");
         return nil;
     }
 
     // Verify hmac of: version? || iv || encrypted data
+
+    NSUInteger dataToAuthLength = 0;
+    if (__builtin_add_overflow(dataToDecrypt.length, iv.length, &dataToAuthLength)) {
+        OWSFailDebug(@"dataToAuth was too large.");
+        return nil;
+    }
+    if (version != nil && __builtin_add_overflow(dataToAuthLength, version.length, &dataToAuthLength)) {
+        OWSFailDebug(@"dataToAuth was too large.");
+        return nil;
+    }
+
     NSMutableData *dataToAuth = [NSMutableData data];
     if (version != nil) {
         [dataToAuth appendData:version];
     }
-
     [dataToAuth appendData:iv];
     [dataToAuth appendData:dataToDecrypt];
 
     NSData *_Nullable ourHmacData;
 
-    if (hmacType == TSHMACSHA1Truncated10Bytes) {
+    if (hmacType == TSHMACSHA256Truncated10Bytes) {
-        ourHmacData = [Cryptography truncatedSHA1HMAC:dataToAuth withHMACKey:hmacKey truncation:10];
+        // used to authenticate envelope from websocket
-    } else if (hmacType == TSHMACSHA256Truncated10Bytes) {
+        OWSAssert(hmacKey.length == kHMAC256_EnvelopeKeyLength);
         ourHmacData = [Cryptography truncatedSHA256HMAC:dataToAuth withHMACKey:hmacKey truncation:10];
+        OWSAssert(ourHmacData.length == 10);
     } else if (hmacType == TSHMACSHA256AttachementType) {
+        OWSAssert(hmacKey.length == HMAC256_KEY_LENGTH);
         ourHmacData =
             [Cryptography truncatedSHA256HMAC:dataToAuth withHMACKey:hmacKey truncation:HMAC256_OUTPUT_LENGTH];
+        OWSAssert(ourHmacData.length == HMAC256_OUTPUT_LENGTH);
+    } else {
+        OWSFail(@"unknown HMAC scheme: %ld", (long)hmacType);
     }
 
     if (hmac == nil || ![ourHmacData ows_constantTimeIsEqualToData:hmac]) {
@@ -333,7 +338,6 @@ const NSUInteger kAES256_KeyByteLength = 32;
     }
 
     // decrypt
-    size_t bufferSize = [dataToDecrypt length] + kCCBlockSizeAES128;
     NSMutableData *_Nullable bufferData = [NSMutableData dataWithLength:bufferSize];
     if (!bufferData) {
         OWSLogError(@"Failed to allocate buffer.");
@@ -372,7 +376,9 @@ const NSUInteger kAES256_KeyByteLength = 32;
     size_t ivLength = 16;
     size_t macLength = 10;
     size_t nonCiphertextLength = versionLength + ivLength + macLength;
-    size_t ciphertextLength = payload.length - nonCiphertextLength;
+
+    size_t ciphertextLength;
+    ows_sub_overflow(payload.length, nonCiphertextLength, &ciphertextLength);
 
     if (payload.length < nonCiphertextLength) {
         OWSFailDebug(@"Invalid payload");
@@ -389,12 +395,12 @@ const NSUInteger kAES256_KeyByteLength = 32;
     NSData *ivData = [payload subdataWithRange:NSMakeRange(cursor, ivLength)];
     cursor += ivLength;
     NSData *ciphertextData = [payload subdataWithRange:NSMakeRange(cursor, ciphertextLength)];
-    cursor += ciphertextLength;
+    ows_add_overflow(cursor, ciphertextLength, &cursor);
     NSData *macData = [payload subdataWithRange:NSMakeRange(cursor, macLength)];
 
     NSData *signalingKey                = [NSData dataFromBase64String:signalingKeyString];
     NSData *signalingKeyAESKeyMaterial  = [signalingKey subdataWithRange:NSMakeRange(0, 32)];
-    NSData *signalingKeyHMACKeyMaterial = [signalingKey subdataWithRange:NSMakeRange(32, 20)];
+    NSData *signalingKeyHMACKeyMaterial = [signalingKey subdataWithRange:NSMakeRange(32, kHMAC256_EnvelopeKeyLength)];
     return [Cryptography decryptCBCMode:ciphertextData
                                     key:signalingKeyAESKeyMaterial
                                      IV:ivData
@@ -434,11 +440,14 @@ const NSUInteger kAES256_KeyByteLength = 32;
 
     // dataToDecrypt: IV || Ciphertext || truncated MAC(IV||Ciphertext)
     NSData *iv                  = [dataToDecrypt subdataWithRange:NSMakeRange(0, AES_CBC_IV_LENGTH)];
-    NSData *encryptedAttachment = [dataToDecrypt
+
-        subdataWithRange:NSMakeRange(AES_CBC_IV_LENGTH,
+    NSUInteger cipherTextLength;
-                                     [dataToDecrypt length] - AES_CBC_IV_LENGTH - HMAC256_OUTPUT_LENGTH)];
+    ows_sub_overflow(dataToDecrypt.length, (AES_CBC_IV_LENGTH + HMAC256_OUTPUT_LENGTH), &cipherTextLength);
-    NSData *hmac = [dataToDecrypt
+    NSData *encryptedAttachment = [dataToDecrypt subdataWithRange:NSMakeRange(AES_CBC_IV_LENGTH, cipherTextLength)];
-        subdataWithRange:NSMakeRange([dataToDecrypt length] - HMAC256_OUTPUT_LENGTH, HMAC256_OUTPUT_LENGTH)];
+
+    NSUInteger hmacOffset;
+    ows_sub_overflow(dataToDecrypt.length, HMAC256_OUTPUT_LENGTH, &hmacOffset);
+    NSData *hmac = [dataToDecrypt subdataWithRange:NSMakeRange(hmacOffset, HMAC256_OUTPUT_LENGTH)];
 
     NSData *_Nullable paddedPlainText = [Cryptography decryptCBCMode:encryptedAttachment
                                                                  key:encryptionKey
@@ -469,7 +478,9 @@ const NSUInteger kAES256_KeyByteLength = 32;
             OWSLogInfo(@"decrypted unpadded attachment.");
             return [paddedPlainText copy];
         } else {
-            unsigned long paddingSize = paddedPlainText.length - unpaddedSize;
+            unsigned long paddingSize;
+            ows_sub_overflow(paddedPlainText.length, unpaddedSize, &paddingSize);
+
             OWSLogInfo(@"decrypted padded attachment with unpaddedSize: %lu, paddingSize: %lu",
                 (unsigned long)unpaddedSize,
                 paddingSize);
@@ -517,7 +528,8 @@ const NSUInteger kAES256_KeyByteLength = 32;
     paddedAttachmentData.length = desiredSize;
 
     // Encrypt
-    size_t bufferSize = [paddedAttachmentData length] + kCCBlockSizeAES128;
+    size_t bufferSize;
+    ows_add_overflow(paddedAttachmentData.length, kCCBlockSizeAES128, &bufferSize);
     NSMutableData *_Nullable bufferData = [NSMutableData dataWithLength:bufferSize];
     if (!bufferData) {
         OWSLogError(@"Failed to allocate buffer.");
@@ -790,14 +802,22 @@ const NSUInteger kAES256_KeyByteLength = 32;
 
 + (nullable NSData *)decryptAESGCMWithProfileData:(NSData *)encryptedData key:(OWSAES256Key *)key
 {
-    OWSAssertDebug(encryptedData.length > kAESGCM256_IVLength + kAESGCM256_TagLength);
+    NSUInteger cipherTextLength;
-    NSUInteger cipherTextLength = encryptedData.length - kAESGCM256_IVLength - kAESGCM256_TagLength;
+    BOOL didOverflow
+        = __builtin_sub_overflow(encryptedData.length, (kAESGCM256_IVLength + kAESGCM256_TagLength), &cipherTextLength);
+    if (didOverflow) {
+        OWSFailDebug(@"unexpectedly short encryptedData.length: %lu", (unsigned long)encryptedData.length);
+        return nil;
+    }
 
     // encryptedData layout: initializationVector || ciphertext || authTag
     NSData *initializationVector = [encryptedData subdataWithRange:NSMakeRange(0, kAESGCM256_IVLength)];
     NSData *ciphertext = [encryptedData subdataWithRange:NSMakeRange(kAESGCM256_IVLength, cipherTextLength)];
-    NSData *authTag =
+
-        [encryptedData subdataWithRange:NSMakeRange(kAESGCM256_IVLength + cipherTextLength, kAESGCM256_TagLength)];
+    NSUInteger tagOffset;
+    ows_add_overflow(kAESGCM256_IVLength, cipherTextLength, &tagOffset);
+
+    NSData *authTag = [encryptedData subdataWithRange:NSMakeRange(tagOffset, kAESGCM256_TagLength)];
 
     return [self decryptAESGCMWithInitializationVector:initializationVector
                                             ciphertext:ciphertext

SignalServiceKit/src/Util/FunctionalUtil.h

@@ -1,5 +1,5 @@
 //
-//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
+//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
 //
 
 @interface NSArray (FunctionalUtil)
@@ -19,15 +19,6 @@
 /// Returns an array of all the results of passing items from this array through the given projection function.
 - (NSArray *)filter:(int (^)(id item))predicate;
 
-/// Returns the sum of the doubles in this array of doubles.
-- (double)sumDouble;
-
-/// Returns the sum of the unsigned integers in this array of unsigned integers.
-- (NSUInteger)sumNSUInteger;
-
-/// Returns the sum of the integers in this array of integers.
-- (NSInteger)sumNSInteger;
-
 - (NSDictionary *)keyedBy:(id (^)(id))keySelector;
 - (NSDictionary *)groupBy:(id (^)(id value))keySelector;
 

SignalServiceKit/src/Util/FunctionalUtil.m

@@ -75,27 +75,7 @@
     }
     return r;
 }
-- (double)sumDouble {
+
-    double s = 0.0;
-    for (NSNumber *e in self) {
-        s += [e doubleValue];
-    }
-    return s;
-}
-- (NSUInteger)sumNSUInteger {
-    NSUInteger s = 0;
-    for (NSNumber *e in self) {
-        s += [e unsignedIntegerValue];
-    }
-    return s;
-}
-- (NSInteger)sumNSInteger {
-    NSInteger s = 0;
-    for (NSNumber *e in self) {
-        s += [e integerValue];
-    }
-    return s;
-}
 - (NSDictionary *)keyedBy:(id (^)(id value))keySelector {
     tskit_require(keySelector != nil);