MD5加密实现

通过NSString分类的方式实现

NSString+MD5.h

#import <Foundation/Foundation.h>

@interface NSString (MD5)

- (NSString *)MD5;

@end

NSString+MD5.m

#import "NSString+MD5.h"
#import <CommonCrypto/CommonDigest.h>

@implementation NSString (MD5)

- (NSString *)MD5 {
    
    const char * pointer = [self UTF8String];
    unsigned char md5Buffer[CC_MD5_DIGEST_LENGTH];
    
    CC_MD5(pointer, (CC_LONG)strlen(pointer), md5Buffer);
    
    NSMutableString *string = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH * 2];
    for (int i = 0; i < CC_MD5_DIGEST_LENGTH; i++)
        [string appendFormat:@"%02x",md5Buffer[i]];
    
    return string;
}

@end