我尝试使用 AES 解密来解密字符串消息。
- (NSData *)AES256DecryptWithKey:(NSString *)key andIV:(NSString*)iv{
// '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,
//[iv cStringUsingEncoding:NSUTF8StringEncoding] /* initialization vector (optional) */,
NULL,
[self bytes], dataLength, /* input */
buffer, bufferSize, /* output */
&numBytesDecrypted );
if( cryptStatus == kCCSuccess )
{
NSLog(@"CRYPTSTATUS %d",cryptStatus);
//the returned NSData takes ownership of the buffer and will free it on deallocation
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}
NSLog(@"CRYPTSTATUS %d",cryptStatus);
free( buffer ); //free the buffer
return nil;
}
但是结果被截断了，有人有建议吗？填充似乎有问题，但我不知道。稍后将发送 AES 密钥（RSA 加密）。
如果你能给我建议就好了。
编辑：输入（base64 编码）
NSData *keydata = [[NSData alloc]initWithBase64EncodedString:@"QUFBQUE5MThEOTMyOEJCQkJCQkJCODhFMTM3MURFREQ="];
NSString *key = [[NSString alloc]initWithData:keydata encoding:NSUTF8StringEncoding];
NSData *msgnormal = [[NSData alloc]initWithBase64EncodedString:@"oE4LOCjOfjPeggXsDbLQ4ko+57kdb/5EBUcmlTBvaaI="];
NSData *decrypted = [msgnormal AES256DecryptWithKey:key andIV:@""];
NSLog(@"DECRYPTED: %@",[[NSString alloc]initWithData:decrypted encoding:NSUTF8StringEncoding]);