一：MD5加密

+ (NSString *)md5:(NSString *)str
{
    const char *concat_str = [str UTF8String];
    unsigned char result[CC_MD5_DIGEST_LENGTH];
    CC_MD5(concat_str, (unsigned int)strlen(concat_str), result);
    NSMutableString *hash = [NSMutableString string];
    for (int i =0; i<16; i++){
        [hash appendFormat:@"X", result[i]];
    }
    return [hash uppercaseString];
}

二：base64加密

@interface NSData (Base64)
/**
 *  @brief  字符串base64后转data
 */
+ (NSData *)dataWithBase64EncodedString:(NSString *)string
{
    if (![string length]) return nil;
    NSData *decoded = nil;
#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0
    if (![NSData instancesRespondToSelector:@selector(initWithBase64EncodedString:options:)])
    {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
        decoded = [[self alloc] initWithBase64Encoding:[string stringByReplacingOccurrencesOfString:@"[^A-Za-z0-9+/=]" withString:@"" options:NSRegularExpressionSearch range:NSMakeRange(0, [string length])]];
#pragma clang diagnostic pop
    }
    else
#endif
    {
        decoded = [[self alloc] initWithBase64EncodedString:string options:NSDataBase64DecodingIgnoreUnknownCharacters];
    }
    return [decoded length]? decoded: nil;
}
/**
 *  @brief  NSData转string
 *  @param wrapWidth 换行长度  76  64
 */
- (NSString *)base64EncodedStringWithWrapWidth:(NSUInteger)wrapWidth
{
    if (![self length]) return nil;
    NSString *encoded = nil;
#if __MAC_OS_X_VERSION_MIN_REQUIRED < __MAC_10_9 || __IPHONE_OS_VERSION_MIN_REQUIRED < __IPHONE_7_0
    if (![NSData instancesRespondToSelector:@selector(base64EncodedStringWithOptions:)])
    {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
        encoded = [self base64Encoding];
#pragma clang diagnostic pop

    }
    else
#endif
    {
        switch (wrapWidth)
        {
            case 64:
            {
                return [self base64EncodedStringWithOptions:NSDataBase64Encoding64CharacterLineLength];
            }
            case 76:
            {
                return [self base64EncodedStringWithOptions:NSDataBase64Encoding76CharacterLineLength];
            }
            default:
            {
                encoded = [self base64EncodedStringWithOptions:(NSDataBase64EncodingOptions)0];
            }
        }
    }
    if (!wrapWidth || wrapWidth >= [encoded length])
    {
        return encoded;
    }
    wrapWidth = (wrapWidth / 4) * 4;
    NSMutableString *result = [NSMutableString string];
    for (NSUInteger i = 0; i < [encoded length]; i+= wrapWidth)
    {
        if (i + wrapWidth >= [encoded length])
        {
            [result appendString:[encoded substringFromIndex:i]];
            break;
        }
        [result appendString:[encoded substringWithRange:NSMakeRange(i, wrapWidth)]];
        [result appendString:@"\r\n"];
    }
    return result;
}
/**
 *  @brief  NSData转string 换行长度默认64
 */
- (NSString *)base64EncodedString
{
    return [self base64EncodedStringWithWrapWidth:0];
}

三：AES加密

#import
@interface NSData (AES)
/**
 *  利用AES加密数据
 */
- (NSData*)encryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128];

    CCCryptorStatus status = CCCrypt(kCCEncrypt,kCCAlgorithmAES128,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,encryptedData.mutableBytes, encryptedData.length,&dataMoved);

    if (status == kCCSuccess) {
        encryptedData.length = dataMoved;
        return encryptedData;
    }

    return nil;
}

/**
 *  @brief  利用AES解密据
 */
- (NSData*)decryptedWithAESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSizeAES128];

    CCCryptorStatus result = CCCrypt(kCCDecrypt,kCCAlgorithmAES128,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,decryptedData.mutableBytes, decryptedData.length,&dataMoved);

    if (result == kCCSuccess) {
        decryptedData.length = dataMoved;
        return decryptedData;
    }

    return nil;

}

四：3DES加密

#import
@interface NSData (3DES)
/**
 *  利用3DES加密数据
 */
- (NSData*)encryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *encryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES];

    CCCryptorStatus result = CCCrypt(kCCEncrypt,kCCAlgorithm3DES,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,encryptedData.mutableBytes,encryptedData.length,&dataMoved);

    if (result == kCCSuccess) {
        encryptedData.length = dataMoved;
        return encryptedData;
    }

    return nil;

}
/**
 *  @brief   利用3DES解密数据
 */
- (NSData*)decryptedWith3DESUsingKey:(NSString*)key andIV:(NSData*)iv {

    NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

    size_t dataMoved;
    NSMutableData *decryptedData = [NSMutableData dataWithLength:self.length + kCCBlockSize3DES];

    CCCryptorStatus result = CCCrypt(kCCDecrypt,kCCAlgorithm3DES,kCCOptionPKCS7Padding,keyData.bytes,keyData.length,iv.bytes,self.bytes,self.length,decryptedData.mutableBytes,decryptedData.length,&dataMoved);

    if (result == kCCSuccess) {
        decryptedData.length = dataMoved;
        return decryptedData;
    }

    return nil;

}