iOS 5：數據加密AES-256 EncryptWithKey：未找到

Question

問題是關於iOS5應用程序。我有一個視圖控制器，我有一些UITextFields。 我想用AES-256加密數據。

事實上，我不知道我必須添加哪些先決條件包來進行加密和解密。我已經走過其他職位，但太多的解釋搞砸了。

請讓我知道，所有的包，頭文件我已經包括使用AES-256

錢德拉

Answer 1

是指一類之後對數據進行加密。

FAQ：什麼是類別？

總之，可可API添加方法。簡要擴充課程。

更多信息，

CustomizingExistingClasses

Category

文件 - 新建 - 可可觸摸 - Objective-C的

如果你想使用一個類別的類別，你的班級添加#import「NSData + Encryption.h」

//NSData+Encryption.h

@interface NSData (Encryption) 
- (NSData *)AES256EncryptWithKey:(NSString *)key; 
- (NSData *)AES256DecryptWithKey:(NSString *)key; 
@end 

---

//NSData+Encryption.m

#import "NSData+Encryption.h" 
#import <CommonCrypto/CommonCryptor.h> 

@implementation NSData (Encryption) 
- (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