如何在cocoa/iOS中使用SHA哈希

Question

给定消息和salt我如何编码它返回哈希字符串？

我需要重现php功能:

hash_hmac('sha256','message','salt');

谢谢

Answer 1

找到答案:

#import <CommonCrypto/CommonHMAC.h>

-(NSString *) hashString :(NSString *) data withSalt: (NSString *) salt {


   const char *cKey  = [salt cStringUsingEncoding:NSUTF8StringEncoding];
   const char *cData = [data cStringUsingEncoding:NSUTF8StringEncoding];
   unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];
   CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);

   NSString *hash;

   NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA256_DIGEST_LENGTH * 2];

   for(int i = 0; i < CC_SHA256_DIGEST_LENGTH; i++)
       [output appendFormat:@"%02x", cHMAC[i]];
   hash = output;
   return hash;

}