xcode ios HMAC SHA 256散列
问题描述：
所以我想知道如何在ios上做一个hmacshad256哈希，因为这是我为wcf服务api做的哈希。我一直在试图寻找一些信息，但通常只是最终得到一个SHA-256哈希。
So I'm trying to figure out how to do a hmacshad256 hash on ios as that's the hash I did for the wcf service api I made. I've been trying to look for some info about it but would usually just end up getting a SHA-256 hash.
这是我唯一的参考资料：
This is the only reference I have:
我不知道这是唯一的方法（导入一个java hmac类）
And I'm not sure if that's the only way to do it (importing a java hmac class)
任何帮助赞赏。
谢谢！
答
NSString * parameters = @"string to hash"
NSString *salt = @"saltStringHere";
NSData *saltData = [salt dataUsingEncoding:NSUTF8StringEncoding];
NSData *paramData = [parameters dataUsingEncoding:NSUTF8StringEncoding];
NSMutableData* hash = [NSMutableData dataWithLength:CC_SHA256_DIGEST_LENGTH ];
CCHmac(kCCHmacAlgSHA256, saltData.bytes, saltData.length, paramData.bytes, paramData.length, hash.mutableBytes);
NSString *base64Hash = [hash base64Encoding];
以及
#import <CommonCrypto/CommonHMAC.h>
由于 base64Encoding 在iOS 7.0中已弃用，最后一行应为：
Since base64Encoding is deprecated from iOS 7.0, the last line should be:
NSString *base64Hash = [hash base64EncodedStringWithOptions:0];