我需要一些有关此 3DES 解密的帮助。我已经创建了一些用于解密的代码,但我无法让它正常工作。这是我第一次玩加密,我不知道我在这里到底做错了什么。
我正在从服务器接收解密密钥(这是密钥的示例值:0F7BC98767FF9A01F2B2AD1CD644AD33 - 它是随机生成字节的十六进制表示)。
这是我用来解密消息的方法:
-(NSString*)doCipher:(NSString*)message key:(NSString*)key operation:(CCOperation)encryptOrDecrypt {
const void *messageData;
size_t messageBufferSize;
if (encryptOrDecrypt == kCCDecrypt){
NSData *messageEncryptData= [NSData dataWithBase64EncodedString:message];
messageBufferSize= [messageEncryptData length];
messageData= [messageEncryptData bytes];
}
else{
messageBufferSize= message.length;
messageData = [[[message dataUsingEncoding: NSUTF8StringEncoding]mutableCopy] bytes];
}
CCCryptorStatus ccStatus;
uint8_t *bufferPtr = NULL;
size_t bufferPtrSize = 0;
size_t movedBytes = 0;
bufferPtrSize = (messageBufferSize + kCCBlockSize3DES) & ~(kCCBlockSize3DES - 1);
bufferPtr = malloc( bufferPtrSize * sizeof(uint8_t));
memset((void *)bufferPtr, 0x0, bufferPtrSize);
uint8_t iv[kCCBlockSize3DES];
memset((void *) iv, 0x0, (size_t) sizeof(iv));
NSData *keyData = [[key dataUsingEncoding:NSUTF8StringEncoding]mutableCopy];
ccStatus = CCCrypt(encryptOrDecrypt,
kCCAlgorithm3DES,
kCCOptionPKCS7Padding & kCCModeCBC,
(const void *)[keyData bytes],
kCCKeySize3DES,
iv,
messageData,
messageBufferSize,
(void *)bufferPtr,
bufferPtrSize,
&movedBytes);
if (ccStatus == kCCParamError) return @"PARAM ERROR";
else if (ccStatus == kCCBufferTooSmall) return @"BUFFER TOO SMALL";
else if (ccStatus == kCCMemoryFailure) return @"MEMORY FAILURE";
else if (ccStatus == kCCAlignmentError) return @"ALIGNMENT";
else if (ccStatus == kCCDecodeError) return @"DECODE ERROR";
else if (ccStatus == kCCUnimplemented) return @"UNIMPLEMENTED";
NSLog(@"bufferPtr: %s", bufferPtr);
NSString *s = [[NSString alloc] initWithFormat:@"%s", bufferPtr];
return s;
}
-- 编辑 --- 这是我从该方法收到的输出:
bufferPtr: ÕÏÁU
--- 编辑 2 ----- 我将密钥长度固定为 24 字节长,但现在最终结果是空字符串