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使用3des ios7加密nsstring

3des objective-c

1

user3437050 · 技术社区 · 11 年前

我是iOS7开发和目标c的新手,我需要开发一个应用程序,它将使用3DES向服务器发送加密数据。我在堆栈溢出和Net中进行了搜索,但仍然无法正常工作。最后我尝试了这段代码,但结果为空,

+ (NSString*)encrypt:(NSString*)plainText withKey:(NSString*)key{
    uint8_t keyByte[kSecrectKeyLength];

    NSMutableData *keyData = [[NSMutableData alloc] init];
    int i;
    for (i=0; i < [key length] / 2; i++) {
        NSString *tempNumber = [key substringWithRange: NSMakeRange(i * 2, 2)];
        NSScanner *scanner=[NSScanner scannerWithString:tempNumber];
        unsigned int temp;
        [scanner scanHexInt:&temp];
        Byte B = (Byte)(0xFF & temp);
        keyByte[i] = B;
    }

    NSData* data = [plainText dataUsingEncoding:NSUTF8StringEncoding];
    size_t plainTextBufferSize = [data length];
    const void *vplainText = (const void *)[data bytes];

    CCCryptorStatus ccStatus;
    uint8_t *bufferPtr = NULL;
    size_t bufferPtrSize = 0;
    size_t movedBytes = 0;

    bufferPtrSize = (plainTextBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);
    bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));
    memset((void *)bufferPtr, 0x0, bufferPtrSize);

    const void *vkey = (const void *) keyByte;
    const void *vinitVec = (const void *) [gIv UTF8String];

    ccStatus = CCCrypt(kCCEncrypt,
                       kCCAlgorithm3DES,
                       kCCOptionPKCS7Padding,
                       vkey,
                       kCCKeySize3DES,
                       vinitVec,
                       vplainText,
                       plainTextBufferSize,
                       (void *)bufferPtr,
                       bufferPtrSize,
                       &movedBytes);

    NSData *myData = [NSData dataWithBytes:(const void *)bufferPtr length:(NSUInteger)movedBytes];
    //NSString *result = [GTMBase64 stringByEncodingData:myData];
    NSString *result = [[NSString alloc] initWithData:myData encoding:NSUTF8StringEncoding];

    NSLog(@"result=%@",result);

    return result;
}

请你对解决方案有什么想法???

1 回复 | 直到 11 年前

1

5

Fonix 11 年前

lol前几天我自己也遇到了这个问题,现在我有了一个有效的解决方案,使用这个代码

+ (NSData *)tripleDesEncryptString:(NSString *)input
                               key:(NSString *)key
                             error:(NSError **)error
{
NSParameterAssert(input);
NSParameterAssert(key);

NSData *inputData = [input dataUsingEncoding:NSUTF8StringEncoding];
NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

size_t outLength;

NSAssert(keyData.length == kCCKeySize3DES, @"the keyData is an invalid size");

NSMutableData *outputData = [NSMutableData dataWithLength:(inputData.length  +  kCCBlockSize3DES)];

CCCryptorStatus
result = CCCrypt(kCCEncrypt, // operation
                 kCCAlgorithm3DES, // Algorithm
                 kCCOptionPKCS7Padding | kCCOptionECBMode, // options
                 keyData.bytes, // key
                 keyData.length, // keylength
                 nil,// iv
                 inputData.bytes, // dataIn
                 inputData.length, // dataInLength,
                 outputData.mutableBytes, // dataOut
                 outputData.length, // dataOutAvailable
                 &outLength); // dataOutMoved

if (result != kCCSuccess) {
    if (error != NULL) {
        *error = [NSError errorWithDomain:@"com.your_domain.your_project_name.your_class_name."
                                     code:result
                                 userInfo:nil];
    }
    return nil;
}
[outputData setLength:outLength];
return outputData;
}



+ (NSString *)tripleDesDecryptData:(NSData *)input
                               key:(NSString *)key
                             error:(NSError **)error
{
NSParameterAssert(input);
NSParameterAssert(key);

NSData *inputData = input;
NSData *keyData = [key dataUsingEncoding:NSUTF8StringEncoding];

size_t outLength;

NSAssert(keyData.length == kCCKeySize3DES, @"the keyData is an invalid size");

NSMutableData *outputData = [NSMutableData dataWithLength:(inputData.length  +  kCCBlockSize3DES)];

CCCryptorStatus
result = CCCrypt(kCCDecrypt, // operation
                 kCCAlgorithm3DES, // Algorithm
                 kCCOptionPKCS7Padding | kCCOptionECBMode, // options
                 keyData.bytes, // key
                 keyData.length, // keylength
                 nil,// iv
                 inputData.bytes, // dataIn
                 inputData.length, // dataInLength,
                 outputData.mutableBytes, // dataOut
                 outputData.length, // dataOutAvailable
                 &outLength); // dataOutMoved

if (result != kCCSuccess) {
    if (error != NULL) {
        *error = [NSError errorWithDomain:@"com.your_domain.your_project_name.your_class_name."
                                     code:result
                                 userInfo:nil];
    }
    return nil;
}
[outputData setLength:outLength];
return [[NSString alloc] initWithData:outputData encoding:NSUTF8StringEncoding];
}

您可能希望对加密方法产生的数据进行base64编码,然后对任何您想要解密的数据进行反base64编码。NSData现在有内置的方法来实现这一点,例如:

[data base64EncodedDataWithOptions:(NSDataBase64EncodingOptions)];

为了测试这些函数是否有效,我使用了这个测试函数

+ (void) testEncryptionAndDecryption {

    NSData *encrypted = [self tripleDesEncryptString:@"test" key:@"123456789123456789123456" error:nil];
    NSLog(@"encrypted data length: %lu", (unsigned long)encrypted.length);
    NSString *decrypted = [self tripleDesDecryptData:encrypted key:@"123456789123456789123456" error:nil];
    NSLog(@"decrypted text: %@", decrypted);
}

这给了我你所期望的正确输出