fix: Crash deserializing empty envelope length>0 (#4281)

* fixes crash deserializing empty envelope length>0 * changelog
getsentry · Aug 14, 2024 · 464117d · 464117d
1 parent 02671d8
commit 464117d
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -10,6 +10,8 @@
 ### Fixes
 
 - Session replay not redacting buttons and other non UILabel texts (#4277)
+- Crash deserializing empty envelope length>0 (#4281]
+
 
 ## 8.33.0
 

diff --git a/Sources/Sentry/SentrySerialization.m b/Sources/Sentry/SentrySerialization.m
@@ -162,9 +162,6 @@ + (SentryEnvelope *_Nullable)envelopeWithData:(NSData *)data
  NSUInteger endOfEnvelope = data.length - 1;
  for (NSInteger i = itemHeaderStart; i <= endOfEnvelope; ++i) {
  if (bytes[i] == '\n' || i == endOfEnvelope) {
- if (endOfEnvelope == i) {
- i++; // 0 byte attachment
- }
 
  NSData *itemHeaderData =
  [data subdataWithRange:NSMakeRange(itemHeaderStart, i - itemHeaderStart)];
@@ -222,6 +219,9 @@ + (SentryEnvelope *_Nullable)envelopeWithData:(NSData *)data
  itemHeader = [[SentryEnvelopeItemHeader alloc] initWithType:type length:bodyLength];
  }
 
+ if (endOfEnvelope == i) {
+ i++; // 0 byte attachment
+ }
  NSData *itemBody = [data subdataWithRange:NSMakeRange(i + 1, bodyLength)];
 #ifdef DEBUG
  if ([SentryEnvelopeItemTypeEvent isEqual:type] ||

diff --git a/Tests/SentryTests/PrivateSentrySDKOnlyTests.swift b/Tests/SentryTests/PrivateSentrySDKOnlyTests.swift
@@ -114,6 +114,11 @@ class PrivateSentrySDKOnlyTests: XCTestCase {
  let itemData = "{}\n{\"length\":0,\"type\":\"attachment\"}\n".data(using: .utf8)!
  XCTAssertNotNil(PrivateSentrySDKOnly.envelope(with: itemData))
  }
+
+ func testEnvelopeWithDataLengthGtZero() throws {
+ let itemData = "{}\n{\"length\":1,\"type\":\"attachment\"}\n".data(using: .utf8)!
+ XCTAssertNil(PrivateSentrySDKOnly.envelope(with: itemData))
+ }
 
  func testGetDebugImages() {
  let images = PrivateSentrySDKOnly.getDebugImages()