MD5加密, 32位 小写

#pragma mark - 32位 小写

```

+(NSString *)MD5ForLower32Bate:(NSString *)tel {

    //要进行UTF8的转码

    const char* input = [tel 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;

}

```