NSData+MD5.h文件

#import <Foundation/Foundation.h>
@interface NSData (MD5)
– (NSString *)getMD5Data;
@end

NSData+MD5.m文件(实现加密过程)

import “NSData+MD5.h”
#import <CommonCrypto/CommonCrypto.h>
@implementation NSData (MD5)
– (NSString *)getMD5Data{
  //1: 创建一个MD5对象
  CC_MD5_CTX md5;
  //2: 初始化MD5
  CC_MD5_Init(&md5);
  //3: 准备MD5加密
  CC_MD5_Update(&md5, self.bytes, (CC_LONG)self.length);
  //4: 准备一个字符串数组, 存储MD5加密之后的数据
  unsigned char result[CC_MD5_DIGEST_LENGTH];
  //5: 结束MD5加密
  CC_MD5_Final(result, &md5);
  NSMutableString *resultString = [NSMutableString string];
  //6:从result数组中获取最终结果
  for (int i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
      [resultString appendFormat:@”%02X”, result[i]];
  }
  return resultString;
}
@end