cocoa - 将 SecIdentityRef 存储到 NSUserDefaults 中

Question

我找到了将 APNS 与 cocoa 结合使用的绝佳解释。 APNS Pusher现在我不想每次都选择我的 SecIdentityRef (因为我很懒)我尝试将 SecIdentityRef 放入 NSData 并将其保存为默认值。下次应用程序启动时，我会再次加载它，它总是会收到 exc_bad_access 。这是我添加的代码:

// For saving
NSData *secRefData = [NSData dataWithBytes:[SFChooseIdentityPanel sharedChooseIdentityPanel].identity length:sizeof([SFChooseIdentityPanel sharedChooseIdentityPanel].identity)];
[[NSUserDefaults standardUserDefaults] setValue:secRefData forKey:@"identity"];

//For loading
NSData *secRefData = [[NSUserDefaults standardUserDefaults] valueForKey:@"identity"];
if([secRefData length] != 0) {
     [[APNS sharedAPNS] setIdentity:(SecIdentityRef)CFRetain([secRefData bytes])];
}

我怎样才能让它发挥作用？我还有其他方式存储身份吗？

编辑

因此，我通过保存身份的名称找到了一种解决方案，在启动应用程序时，它会查找哪些可用身份具有此名称并使用具有正确名称的身份。代码如下:

//For loading
    NSString *lastIdentityName = [[NSUserDefaults standardUserDefaults] valueForKey:@"identityName"];
    if([lastIdentityName length] != 0) {
        NSArray *allIdentities = [self identities];
        for (id object in allIdentities) {
            NSString *theName = [[[X509Certificate extractCertDictFromIdentity:(SecIdentityRef)object] valueForKey:@"Subject"] objectForKey:@"CommonName"];
            if([theName isEqualToString:lastIdentityName]) {
                [[APNS sharedAPNS] setIdentity:(SecIdentityRef)CFRetain((__bridge_retained SecIdentityRef)object)];
                [[NSUserDefaults standardUserDefaults] setValue:[self identityName] forKey:@"identityName"];
                // KVO trigger
                [self willChangeValueForKey:@"identityName"];
                [self didChangeValueForKey:@"identityName"];
            }
        }
    }

//For saving
    [[NSUserDefaults standardUserDefaults] setValue:[self identityName] forKey:@"identityName"];

Answer 1

使用SecKeychainItemCreatePersistentReference()和SecKeychainItemCopyFromPercientReference()——它们可以在进程之间传递或持久化。不过，有一些注意事项:

1. 您无法保留身份，只能保留证书，因此您必须经过额外的跃点才能在两者之间进行转换。
2. 您将获得带有长且不透明数据 block 的NSData，因此您必须将其存储为这样，而不是例如作为字符串；并且忘记能够手动编辑此设置。

这就是我在 PDF 签名应用程序中的做法，到目前为止它工作完美。以下是代码的相关部分:

- (NSData*) identityToPersistent:(SecIdentityRef)ident
{
    OSStatus status;
    SecCertificateRef cert;
    CFDataRef data = nil;

    status = SecIdentityCopyCertificate(ident, &cert);
    if (status != noErr)
        return nil;
    status = SecKeychainItemCreatePersistentReference((SecKeychainItemRef)cert, &data);
    CFRelease(cert);
    if (status != noErr)
        return nil;

    return CFBridgingRelease(data);
}

- (SecIdentityRef) identityFromPersistent:(NSData*)data
{
    OSStatus status;
    SecKeychainItemRef cert;
    SecIdentityRef ident = nil;

    status = SecKeychainItemCopyFromPersistentReference((__bridge CFDataRef)data, &cert);
    if (status != noErr)
        return nil;
    status = SecIdentityCreateWithCertificate(NULL, (SecCertificateRef)cert, &ident);
    CFRelease(cert);

    return ident;
}


- (SecIdentityRef) getPreferredIdentity
{
    NSData *data = [[NSUserDefaults standardUserDefaults] dataForKey:@"SigningIdentity"];
    if (!data)
        return nil;
    return [self identityFromPersistent:data];
}

- (void) setPreferredIdentity:(SecIdentityRef)ident
{
    NSData *data = [self identityToPersistent:ident];
    [[NSUserDefaults standardUserDefaults] setObject:data forKey:@"SigningIdentity"];
}