objective-c - 在 Objective-C 中生成 SHA256 哈希

Question

所以我需要在 Objective-C 中生成一个 Sha256 密码，但我一辈子都不知道该怎么做!有什么简单的东西我只是想念吗？

我已经尝试实现以下方法(它是为 iPhone 编写的，但我认为它可能会像某些 Objective-C 代码那样跨平台工作)

-(NSString*)sha256HashFor:(NSString*)input
{
    const char* str = [input UTF8String];
    unsigned char result[CC_SHA256_DIGEST_LENGTH];
    CC_SHA256(str, strlen(str), result);

    NSMutableString *ret = [NSMutableString stringWithCapacity:CC_SHA256_DIGEST_LENGTH*2];
    for(int i = 0; i<CC_SHA256_DIGEST_LENGTH; i++)
    {
        [ret appendFormat:@"%02x",result[i]];
    }
    return ret;
}

但这只是吐出有关 CC_SHA256_DIGEST_LENGTH 是未声明的标识符的错误。

Answer 1

您需要包含适当的头文件:

#include <CommonCrypto/CommonDigest.h>

根据Cryptographic Services documentation这应该在 iOS 和 OS X 上都可用。

In OS X v10.5 and later and iOS 5.0 and later, Common Crypto provides low-level C support for encryption and decryption. Common Crypto is not as straightforward as Security Transforms, but provides a wider range of features, including additional hashing schemes, cipher modes, and so on.