我正在尝试使用 AES 128 位加密来加密字符串,但转换后的加密数据在转换为字符串时始终返回 null。
NSString *iv = @"fedcba9876543210";
NSString *key = @"0123456789abcdef";
- (NSData *)AES128EncryptWithKey
{
char keyPtr[kCCKeySizeAES128 + 1];
bzero( keyPtr, sizeof( keyPtr ) );
[key getCString:keyPtr maxLength:sizeof( keyPtr ) encoding:NSUTF8StringEncoding];
NSUInteger dataLength = [self length];
size_t bufferSize = dataLength + kCCBlockSizeAES128;
void *buffer = malloc( bufferSize );
size_t numBytesEncrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt( kCCEncrypt, kCCAlgorithmAES128, kCCOptionECBMode | kCCOptionPKCS7Padding,
keyPtr, kCCKeySizeAES128,
NULL ,
[self bytes], dataLength,
buffer, bufferSize,
&numBytesEncrypted );
if( cryptStatus == kCCSuccess )
{
return [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
}
}
这是我的加密函数。
NSData *data = [@"String to encrypt" dataUsingEncoding:NSUTF8StringEncoding];
NSData *encryptedData = [[NSData alloc] init];
encryptedData = [data AES128EncryptWithKey];
NSLog(@"Encrypted Data Length %d", [encryptedData length]);
if (encryptedData != nil)
{
NSString* myString;
myString = [[NSString alloc] initWithData:encryptedData encoding:NSUTF8StringEncoding];
NSString* newStr = [NSString stringWithUTF8String:[encryptedData bytes]];
}
加密后,加密数据长度报告为 16,但在将其转换为 NSString
后返回 null。如果我使用 stringWithUTF16String
来转换它,它会像“軽ﶁែ뼐끨骖퐇”一样返回。这里有什么问题?
最佳答案
try this code
#define kCryptingKey @"1234567890abcdef"
@implementation Tool
+ (NSString*) crypt:(NSString*)recource
{
NSData *data = [recource dataUsingEncoding:NSUTF8StringEncoding];
NSData *encrypt = [self AES128EncryptWithKey:kCryptingKey withData:data];
return [self stringWithHexBytes:encrypt];
}
+ (NSString*) decryptData:(NSData*)recource
{
NSData *decrypt = [self AES128DecryptWithKey:kCryptingKey withData:recource];
return [[NSString alloc] initWithData:decrypt encoding:NSUTF8StringEncoding];
}
+ (NSString*) decrypt:(NSString*)recource
{
NSData* data=[self decodeFromHexidecimal:recource];
NSData *decrypt = [self AES128DecryptWithKey:kCryptingKey withData:data];
return [[NSString alloc] initWithData:decrypt encoding:NSUTF8StringEncoding];
}
+ (NSData *) decodeFromHexidecimal:(NSString*)str
{
NSString *command = [NSString stringWithString:str];
command = [command stringByReplacingOccurrencesOfString:@" " withString:@""];
NSMutableData *commandToSend = [[NSMutableData data] init];
unsigned char whole_byte;
char byte_chars[3] = {'\0','\0','\0'};
int i;
for (i=0; i < [command length]/2; i++) {
byte_chars[0] = [command characterAtIndex:i*2];
byte_chars[1] = [command characterAtIndex:i*2+1];
whole_byte = strtol(byte_chars, NULL, 16);
[commandToSend appendBytes:&whole_byte length:1];
}
return commandToSend;
}
+ (NSData *)AES128EncryptWithKey:(NSString *)key withData:(NSData*)_data
{
// ‘key’ should be 16 bytes for AES128
char keyPtr[kCCKeySizeAES128 + 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 = [_data 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, kCCOptionECBMode | kCCOptionPKCS7Padding,
keyPtr, kCCKeySizeAES128,
NULL /* initialization vector (optional) */,
[_data 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 *)AES128DecryptWithKey:(NSString *)key withData:(NSData*)data
{
// 'key' should be 32 bytes for AES256, will be null-padded otherwise
char keyPtr[kCCKeySizeAES128+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 = [data 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, kCCOptionECBMode | kCCOptionPKCS7Padding,
keyPtr, kCCKeySizeAES128,
NULL /* initialization vector (optional) */,
[data 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;
}
+ (NSString*) stringWithHexBytes:(NSData*)_data {
NSMutableString *stringBuffer = [NSMutableString stringWithCapacity:([_data length] * 2)];
const unsigned char *dataBuffer = [_data bytes];
int i;
for (i = 0; i < [_data length]; ++i) {
[stringBuffer appendFormat:@"%02lX", (unsigned long)dataBuffer[i]];
}
return [[stringBuffer copy] autorelease];
}
@end
关于ios - 128 位 AES 加密在 Objective-C 中返回 null,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/18416645/