iOS10中的CFRelease崩溃 [英] CFRelease crash in iOS10
问题描述
下面是我的代码，该代码在iOS 9之前都可以正常工作.
Below is my code, which used to work fine till iOS 9.
- (NSData *)encryptWithDataPublicKey:(NSString*)data keyTag:(NSString*)tag
{
SecKeyRef publicKey = NULL;
NSData *publicTag = [NSData dataWithBytes:[tag UTF8String] length:[tag length]];
NSMutableDictionary *queryPublicKey =
[[NSMutableDictionary alloc] init];
[queryPublicKey setObject:(__bridge id)kSecClassKey forKey:(__bridge id)kSecClass];
[queryPublicKey setObject:publicTag forKey:(__bridge id)kSecAttrApplicationTag];
[queryPublicKey setObject:(__bridge id)kSecAttrKeyTypeRSA forKey:(__bridge id)kSecAttrKeyType];
[queryPublicKey setObject:[NSNumber numberWithBool:YES] forKey:(__bridge id)kSecReturnRef];
OSStatus status = SecItemCopyMatching
((__bridge CFDictionaryRef)queryPublicKey, (CFTypeRef *)&publicKey);
NSData *encodedData = nil;
if (status == noErr && publicKey) {
NSData *dataToEncrypt = [data dataUsingEncoding:NSUTF8StringEncoding];
encodedData = [self encryptData:dataToEncrypt withKeyRef:publicKey];
CFRelease(publicKey);
}
return encodedData;
}
该方法以前在iOS 9.x之前都可以正常工作，但是今天，当我将XCode更新为8并在iOS 10设备上运行时.应用程序在
时崩溃了 CFRelease(publicKey) .
This method used to work fine till iOS 9.x, But today when I have updated my XCode to 8 and run on iOS 10 device. Application is getting crashed at
CFRelease(publicKey).
在崩溃之前，下面是来自控制台的日志.
Before crashing below is the log from console.
无法加载任何Objective-C类信息.这会大大降低了可用类型信息的质量
could not load any Objective-C class information. This will significantly reduce the quality of type information available
无法完全找到问题.
当我启用Zombie并重现崩溃时.下面是控制台的日志.
When I enabled Zombie, and reproduce the crash. Below is the log from console.
***-[非A类型发行版]:消息发送到已释放实例0x170225880
*** -[Not A Type release]: message sent to deallocated instance 0x170225880
谢谢.
我知道了.有一个内部方法encodeData = [self cryptoData:dataToEncrypt withKeyRef:publicKey];
I got the Issue. there is an inner method encodedData = [self encryptData:dataToEncrypt withKeyRef:publicKey];
释放SecKeyRef对象的位置.
where SecKeyRef object is getting released.
但是我不知道它在iOS9之前如何工作???????
But I wonder how this worked till iOS9???????
-(NSData *)encryptData:(NSData *)data withKeyRef:(SecKeyRef) keyRef{
const uint8_t *srcbuf = (const uint8_t *)[data bytes];
size_t srclen = (size_t)data.length;
size_t block_size = SecKeyGetBlockSize(keyRef) * sizeof(uint8_t);
void *outbuf = malloc(block_size);
size_t src_block_size = block_size - 11;
NSMutableData *ret = [[NSMutableData alloc] init];
for(int idx=0; idx<srclen; idx+=src_block_size){
size_t data_len = srclen - idx;
if(data_len > src_block_size){
data_len = src_block_size;
}
size_t outlen = block_size;
OSStatus status = noErr;
status = SecKeyEncrypt(keyRef,
kSecPaddingPKCS1,
srcbuf + idx,
data_len,
outbuf,
&outlen
);
if (status != 0) {
ret = nil;
break;
}else{
[ret appendBytes:outbuf length:outlen];
}
}
free(outbuf);
CFRelease(keyRef);
return ret;
}
推荐答案
在 encryptData:withKeyRef:中，方法结尾处的 CFRelease 不平衡.该方法中的任何内容都不会保留 keyRef ，但是您将其释放.删除该呼叫.
In encryptData:withKeyRef: you have an unbalanced CFRelease at the end of the method. Nothing in that method retained keyRef, but you release it. Remove that call.
为什么以前没有崩溃?因为以前可能在内部保留了其他内容，可能是缓存，也可能是其他内容.可可没有保证过度释放会立即(或曾经)导致崩溃.你陷入了不确定的行为.
Why didn't it crash before? Because something else was likely retaining it internally previously, possibly a cache, possibly something else. Cocoa makes no promises that an over-release will immediately (or ever) lead to a crash. You were into undefined behavior.
但是，非常令人沮丧的是，静态分析器没有检测到这一点.我将打开有关该错误的报告(bugreport.apple.com).您的内存管理违规情况非常明显，分析器应已发现它.
It's very distressing, though, that the static analyzer isn't detecting this. I would open a bug report about that (bugreport.apple.com). You have a very clear memory management violation and the analyzer should have caught it.
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