iOS 5：数据加密AES-256 EncryptWithKey：未找到

Question

问题是关于iOS5应用程序。我有一个视图控制器，我有一些UITextFields。 我想用AES-256加密数据。

事实上，我不知道我必须添加哪些先决条件包来进行加密和解密。我已经走过其他职位，但太多的解释搞砸了。

请让我知道，所有的包，头文件我已经包括使用AES-256

钱德拉

Answer 1

是指一类之后对数据进行加密。

FAQ：什么是类别？

总之，可可API添加方法。简要扩充课程。

更多信息，

CustomizingExistingClasses

Category

文件 - 新建 - 可可触摸 - Objective-C的

如果你想使用一个类别的类别，你的班级添加#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