iPhone中的Sqlite數據庫保護

Question

我devloping一個應用程序，它將大量的數據存儲在sqlite數據庫中。但我想保持數據安全，以便沒有人侵入我的數據庫並查看數據庫中的數據。

現在我該如何加密和解密我的sqlite數據庫？

請幫我。

謝謝。

Answer 1

我的開發，需要一個應用程序，我已經使用

首先，我發起集體這樣

，把它稱爲 ConstantMethods.h+m

ConstantMethods.h

#import <Foundation/Foundation.h> 
#import <CommonCrypto/CommonCryptor.h> 

static NSString *keyEncryption = @"YourPrivateKey"; 
@interface ConstantMethods : NSObject { 

} 
+ (NSData*) encryptString:(NSString*)plaintext withKey:(NSString*)key; 
+ (NSString*) decryptData:(NSData*)ciphertext withKey:(NSString*)key; 

@end 

ConstantMethods.m

#import "ConstantMethods.h" 

@implementation NSData (AES256) 

- (NSData *)AES256EncryptWithKey:(NSString *)key { 
    // 'key' should be 32 bytes for AES256, will be null-padded otherwise 
    char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused) 
    bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding) 

    // fetch key data 
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; 

    NSUInteger dataLength = [self length]; 

    //See the doc: For block ciphers, the output size will always be less than or 
    //equal to the input size plus the size of one block. 
    //That's why we need to add the size of one block here 
    size_t bufferSize = dataLength + kCCBlockSizeAES128; 
    void *buffer = malloc(bufferSize); 

    size_t numBytesEncrypted = 0; 
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding, 
             keyPtr, kCCKeySizeAES256, 
             NULL /* initialization vector (optional) */, 
             [self bytes], dataLength, /* input */ 
             buffer, bufferSize, /* output */ 
             &numBytesEncrypted); 
    if (cryptStatus == kCCSuccess) { 
     //the returned NSData takes ownership of the buffer and will free it on deallocation 
     return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted]; 
    } 

    free(buffer); //free the buffer; 
    return nil; 
} 

- (NSData *)AES256DecryptWithKey:(NSString *)key { 
    // 'key' should be 32 bytes for AES256, will be null-padded otherwise 
    char keyPtr[kCCKeySizeAES256+1]; // room for terminator (unused) 
    bzero(keyPtr, sizeof(keyPtr)); // fill with zeroes (for padding) 

    // fetch key data 
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding]; 

    NSUInteger dataLength = [self length]; 

    //See the doc: For block ciphers, the output size will always be less than or 
    //equal to the input size plus the size of one block. 
    //That's why we need to add the size of one block here 
    size_t bufferSize = dataLength + kCCBlockSizeAES128; 
    void *buffer = malloc(bufferSize); 

    size_t numBytesDecrypted = 0; 
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding, 
             keyPtr, kCCKeySizeAES256, 
             NULL /* initialization vector (optional) */, 
             [self bytes], dataLength, /* input */ 
             buffer, bufferSize, /* output */ 
             &numBytesDecrypted); 

    if (cryptStatus == kCCSuccess) { 
     //the returned NSData takes ownership of the buffer and will free it on deallocation 
     return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted]; 
    } 

    free(buffer); //free the buffer; 
    return nil; 
} 

@end 

@implementation ConstantMethods 

+ (NSData*) encryptString:(NSString*)plaintext withKey:(NSString*)key { 
    return [[plaintext dataUsingEncoding:NSUTF8StringEncoding] AES256EncryptWithKey:key]; 
} 

+ (NSString*) decryptData:(NSData*)ciphertext withKey:(NSString*)key { 
    return [[[NSString alloc] initWithData:[ciphertext AES256DecryptWithKey:key] 
           encoding:NSUTF8StringEncoding] autorelease]; 
} 

@end 

然後，在您的課堂上，導入ConstantMethods.h和使用類，如下：

[ConstantMethods encryptString:@"yourString"]; 

，當你要解密，使用以下命令：

[ConstantMethods decryptData:@"yourString" withKey:keyEncryption]; 

加密後，加密的數據插入到數據庫中，並檢索時來自數據庫的數據，解密它。

我希望這可以幫助你。