iOS中MD5加密算法的介绍和使用

#import@interface MD5Encrypt : NSObject
// MD5加密
/*
*由于MD5加密是不可逆的,多用来进行验证
*/
// 32位小写
+(NSString *)MD5ForLower32Bate:(NSString *)str;
// 32位大写
+(NSString *)MD5ForUpper32Bate:(NSString *)str;
// 16为大写
+(NSString *)MD5ForUpper16Bate:(NSString *)str;
// 16位小写
+(NSString *)MD5ForLower16Bate:(NSString *)str;
@end

#import "MD5Encrypt.h"
#import <CommonCrypto/CommonDigest.h>

@implementation MD5Encrypt

#pragma mark - 32位 小写
+(NSString *)MD5ForLower32Bate:(NSString *)str{

  //要进行UTF8的转码
  const char* input = [str UTF8String];
  unsigned char result[CC_MD5_DIGEST_LENGTH];
  CC_MD5(input, (CC_LONG)strlen(input), result);

  NSMutableString *digest = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
  for (NSInteger i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
    [digest appendFormat:@"%02x", result[i]];
  }

  return digest;
}

#pragma mark - 32位 大写
+(NSString *)MD5ForUpper32Bate:(NSString *)str{

  //要进行UTF8的转码
  const char* input = [str UTF8String];
  unsigned char result[CC_MD5_DIGEST_LENGTH];
  CC_MD5(input, (CC_LONG)strlen(input), result);

  NSMutableString *digest = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
  for (NSInteger i = 0; i < CC_MD5_DIGEST_LENGTH; i++) {
    [digest appendFormat:@"%02X", result[i]];
  }

  return digest;
}

#pragma mark - 16位 大写
+(NSString *)MD5ForUpper16Bate:(NSString *)str{

  NSString *md5Str = [self MD5ForUpper32Bate:str];

  NSString *string;
  for (int i=0; i<24; i++) {
    string=[md5Str substringWithRange:NSMakeRange(8, 16)];
  }
  return string;
}


#pragma mark - 16位 小写
+(NSString *)MD5ForLower16Bate:(NSString *)str{

  NSString *md5Str = [self MD5ForLower32Bate:str];

  NSString *string;
  for (int i=0; i<24; i++) {
    string=[md5Str substringWithRange:NSMakeRange(8, 16)];
  }
  return string;
}

@end