AES128在CBC模式下实现使用Crypto ++库 [英] AES128 in CBC mode implementation using Crypto++ library
问题描述
在输入文件中，我有：
在第一行一个以十六进制编码，长度为16字节的密钥;
在第二行加密消息（AES128在CBC模式下，随机添加一个加密消息）。
b
$ b
这是我如何解密：
＃include< iostream>
使用命名空间std;
#include< fstream>
#include< string.h>
#include< cryptopp / aes.h>
#include< cryptopp / modes.h>
#include< cryptopp / filters.h>
使用命名空间CryptoPP;
int main（void）{
ifstream in（input0.txt）;
ofstream out（output0.txt）;
string hex_key =，hex_ct =;
in>> hex_key>> hex_ct;
byte key [AES :: DEFAULT_KEYLENGTH]，iv [AES :: BLOCKSIZE];
string ciphertext =，restoredtext =; （int i = 0; i< hex_key.size（）; i + = 2）{
key [i / 2] =（char）strtol（（hex_key.substr i，2））。c_str（），0,16）;
}
//然后我将文本从
中分开（int i = 0; i< AES :: BLOCKSIZE * 2; i + = 2）{
iv [i / 2] =（char）strtol（（hex_ct.substr（i，2））。c_str（），0,16）; （int i = AES :: BLOCKSIZE * 2; i< hex_ct.size（）; i ++）{
ciphertext.push_back（hex_ct [i]）
}
;
}
//解密
CBC_Mode< AES> ::解密d
d.SetKeyWithIV（key，AES :: DEFAULT_KEYLENGTH，iv）;
StringSink sink（deletedtext）;
StreamTransformationFilter stf（
d，
& sink
）;
StringSource ss（
ciphertext，
true，
& stf
）;
out<< recoveredtext;
return 0;
}
我在维基。
我也尝试过，而且它有效，但是没有用我的替换密钥和密文。
嗯，使用上面的代码我有这个输出：
AES128CBC：/usr/local/include/cryptopp/misc.h:304：void CryptoPP :: memcpy_s（void *， size_t，const void *，size_t）：断言`dest！= __null'失败。
中止（核心转储）
使用此代码时：
//解密
AES ::解密aesDecryption（key，AES :: DEFAULT_KEYLENGTH）;
CBC_Mode_ExternalCipher ::解密cbcDecryption（aesDecryption，iv）;
StreamTransformationFilter stfDecryptor（
cbcDecryption，
new StringSink（deletedtext），
BlockPaddingSchemeDef :: NO_PADDING
）;
stfDecryptor.Put（reinterpret_cast< const unsigned char *>（ciphertext.c_str（）），ciphertext.size（））;
stfDecryptor.MessageEnd（）;
它的工作原理，但输出不是有效的字符序列。
我安装了lib：
sudo apt-get install libcrypto ++ -dev libcrypto ++ - doc libcrypto ++ - utils
我编译它：
g ++ -o AESCBC128 AESCBC128.cpp -lcryptopp
我找不到什么问题。
提前感谢帮助。
输入示例：
140b41b22a29beb4061bda66b6747e14
4ca00ff4c898d61e1edbf1800618fb2828a226d160dad07883d04e008a7897ee2e4b7465d5290d0c0e6c6822236e1daafb94ffe0c5da05d9476be028ad7c1d81
我不知道输出示例，因为这是一个练习，我的目标是发现秘密消息。
测试输入和转换为字节数组：
out<< KEY：\\\
<< hex_key<< ENDL; （int i = 0; i< AES :: DEFAULT_KEYLENGTH; i ++）
{
out< setfill（'0'）<< setw（2）< hex< （INT）键[I];
}
out<< endl< Received message：\\\
<< hex_ct<< ENDL;
out<< IV：\\\
; （int i = 0; i< AES :: BLOCKSIZE; i ++）
{
out< setfill（'0'）<< setw（2）< hex< （int）的四[I];
}
out<< endl< CT：\\\
<<密文<< ENDL;
结果：
code> KEY：
140b41b22a29beb4061bda66b6747e14
140b41b22a29beb4061bda66b6747e14
接收消息：
4ca00ff4c898d61e1edbf1800618fb2828a226d160dad07883d04e008a7897ee2e4b7465d5290d0c0e6c6822236e1daafb94ffe0c5da05d9476be028ad7c1d81
IV：
4ca00ff4c898d61e1edbf1800618fb28
CT：
28a226d160dad07883d04e008a7897ee2e4b7465d5290d0c0e6c6822236e1daafb94ffe0c5da05d9476be028ad7c1d81
正如预期的那样。
可能的原因是填补错误不是填充，而是解密是错误的，参数的提供方式可能不正确。
我在提供的KEY，IV和CT上对解密进行了编码。结果具有0x08的8个字节的PKCS＃7填充。
（正确删除iv）
解密删除填充：
42617369 63204342 43206d6f 64652065 6e637279 7074696f 6e206e65 65647320 70616464 696e672e
或文字：
基本的CBC模式加密需要填充。
解密填充完整（注意填充的尾随8个字符）：
42617369 63204342 43206d6f 64652065 6e637279 7074696f 6e206e65 65647320 70616464 696e672e 08080808 08080808
输出大部分是ASCII，有一些例外，如第3个字节0xfc。
由于填充是正确的，我相信这是加密的真实数据。
对于过于好奇的是我的测试代码：
NSData * key = [Utilities dataFro mHexString：@ 140b41b22a29beb4061bda66b6747e14];
NSData * iv = [实用程序dataFromHexString：@4ca00ff4c898d61e1edbf1800618fb28];
NSData * dataIn = [实用程序dataFromHexString：@28a226d160dad07883d04e008a7897ee2e4b7465d5290d0c0e6c6822236e1daafb94ffe0c5da05d9476be028ad7c1d81];
size_t cryptBytes = 0;
NSMutableData * dataOut = [NSMutableData dataWithLength：dataIn.length + kCCBlockSizeAES128];
CCCrypt（kCCDecrypt，
kCCAlgorithmAES，
kCCOptionPKCS7Padding，
key.bytes，key.length，
iv.bytes，
dataIn。 bytes，dataIn.length，
dataOut.mutableBytes，dataOut.length，
& cryptBytes）;
dataOut.length = cryptBytes;
NSLog（@dataOut：％@，dataOut）;
NSLog（@dataOut：％@，[[NSString alloc] initWithData：dataOut encoding：NSUTF8StringEncoding]）;
In the input file I have:
on the first line a key which is encoded in hex and with length of 16 bytes;
on the second line encrypted message ( AES128 in CBC mode , with a random iv prepended to the encrypted message).
This is how I tried to decrypt:
#include<iostream>
using namespace std;
#include <fstream>
#include <string.h>
#include <cryptopp/aes.h>
#include <cryptopp/modes.h>
#include <cryptopp/filters.h>
using namespace CryptoPP;
int main(void) {
ifstream in("input0.txt");
ofstream out("output0.txt");
string hex_key = "", hex_ct = "";
in >> hex_key >> hex_ct;
byte key[ AES::DEFAULT_KEYLENGTH ], iv[ AES::BLOCKSIZE ];
string ciphertext = "", recoveredtext = "";
for(int i = 0; i < hex_key.size(); i+=2) {
key[i/2] = (char) strtol((hex_key.substr(i, 2)).c_str(), 0, 16);
}
//then I divide iv from the text
for(int i = 0; i < AES::BLOCKSIZE*2; i+=2) {
iv[i/2] = (char) strtol((hex_ct.substr(i, 2)).c_str(), 0, 16);
}
for(int i = AES::BLOCKSIZE*2; i < hex_ct.size(); i++) {
ciphertext.push_back(hex_ct[i]);
}
//decryption
CBC_Mode< AES >::Decryption d;
d.SetKeyWithIV(key, AES::DEFAULT_KEYLENGTH, iv);
StringSink sink( recoveredtext );
StreamTransformationFilter stf (
d,
&sink
);
StringSource ss (
ciphertext,
true,
&stf
);
out << recoveredtext;
return 0;
}
I used this implementation following the Wiki.
I also tried with this and it worked, but not replacing key and ciphertext with my.
Well, using the code above I have this output:
AES128CBC: /usr/local/include/cryptopp/misc.h:304: void CryptoPP::memcpy_s(void*, size_t, const void*, size_t): Assertion `dest != __null' failed.
Aborted (core dumped)
While using this code:
//decryption
AES::Decryption aesDecryption(key, AES::DEFAULT_KEYLENGTH);
CBC_Mode_ExternalCipher::Decryption cbcDecryption( aesDecryption, iv );
StreamTransformationFilter stfDecryptor(
cbcDecryption,
new StringSink( recoveredtext ),
BlockPaddingSchemeDef::NO_PADDING
);
stfDecryptor.Put( reinterpret_cast<const unsigned char*>( ciphertext.c_str() ), ciphertext.size() );
stfDecryptor.MessageEnd();
It works but the output isn't a valid sequence of characters.
I installed the lib with:
sudo apt-get install libcrypto++-dev libcrypto++-doc libcrypto++-utils
and I compiled it with:
g++ -o AESCBC128 AESCBC128.cpp -lcryptopp
I can't find what's wrong.
Thanks in advance for the help.
Sample of input:
140b41b22a29beb4061bda66b6747e14
4ca00ff4c898d61e1edbf1800618fb2828a226d160dad07883d04e008a7897ee2e4b7465d5290d0c0e6c6822236e1daafb94ffe0c5da05d9476be028ad7c1d81
I don't know a sample of output because this is an exercise and my goal is to discover the secret message.
Test on the inputs and on conversion to byte arrays:
out << "KEY:\n" << hex_key << endl;
for(int i = 0; i < AES::DEFAULT_KEYLENGTH; i++) {
out << setfill('0') << setw(2) << hex << (int)key[i];
}
out << endl << "Received message:\n" << hex_ct << endl;
out << "IV:\n";
for(int i = 0; i < AES::BLOCKSIZE; i++) {
out << setfill('0') << setw(2) << hex << (int)iv[i];
}
out << endl << "CT:\n" << ciphertext << endl;
Result:
KEY:
140b41b22a29beb4061bda66b6747e14
140b41b22a29beb4061bda66b6747e14
Received message:
4ca00ff4c898d61e1edbf1800618fb2828a226d160dad07883d04e008a7897ee2e4b7465d5290d0c0e6c6822236e1daafb94ffe0c5da05d9476be028ad7c1d81
IV:
4ca00ff4c898d61e1edbf1800618fb28
CT:
28a226d160dad07883d04e008a7897ee2e4b7465d5290d0c0e6c6822236e1daafb94ffe0c5da05d9476be028ad7c1d81
They are as expected.
A probable reason you are getting a padding error is not the padding but that the decryption is wrong, the way the parameters are supplied is probably incorrect.
I coded up decryption on the supplied KEY, IV and CT. The result has PKCS#7 padding of 8 bytes of 0x08.
(correct to remove iv)
Decryption with padding removed:
42617369 63204342 43206d6f 64652065 6e637279 7074696f 6e206e65 65647320 70616464 696e672e
or in text:
Basic CBC mode encryption needs padding.
Decryption with padding intact (note the trailing 8 characters of padding):
42617369 63204342 43206d6f 64652065 6e637279 7074696f 6e206e65 65647320 70616464 696e672e 08080808 08080808
The output is mostly ASCII with a few exceptions such as the 3rd byte 0xfc.
Because the padding is correct I believe this is the true data that was encrypted.
For the overly curious here is my test code:
NSData *key = [Utilities dataFromHexString:@"140b41b22a29beb4061bda66b6747e14"];
NSData *iv = [Utilities dataFromHexString:@"4ca00ff4c898d61e1edbf1800618fb28"];
NSData *dataIn = [Utilities dataFromHexString:@"28a226d160dad07883d04e008a7897ee2e4b7465d5290d0c0e6c6822236e1daafb94ffe0c5da05d9476be028ad7c1d81"];
size_t cryptBytes = 0;
NSMutableData *dataOut = [NSMutableData dataWithLength:dataIn.length + kCCBlockSizeAES128];
CCCrypt(kCCDecrypt,
kCCAlgorithmAES,
kCCOptionPKCS7Padding,
key.bytes, key.length,
iv.bytes,
dataIn.bytes, dataIn.length,
dataOut.mutableBytes, dataOut.length,
&cryptBytes);
dataOut.length = cryptBytes;
NSLog(@"dataOut: %@", dataOut);
NSLog(@"dataOut: %@", [[NSString alloc] initWithData:dataOut encoding:NSUTF8StringEncoding]);
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