Ok nevermind i figured it out. For anyone in the future having the same
problem, here is a stackoverflow post solving my
situation:
https://stackoverflow.com/questions/30633594/c-convert-hexadecimal-string-with-to-original-binary-string
.Thanks a lot for the answers, the format thing you said helped a lot.
On Tuesday, November 29, 2022 at 8:35:16 PM UTC+2 Nikos Karavidas wrote:
> Ok so i got this figured out with this:
>
> stringstream ss;
>
> for (int i = 0; i < ciphertext.size(); ++i)
> {
> ss << hex << (0xFF & static_cast<byte>(ciphertext[i])) << " ";
> }
>
> string mystr = ss.str();
>
> cout << "mystr: " << mystr << endl;
>
>
> and it works fine, all characters are printed in hex and i can write them
> in a txt file, no problem. BUT when i read them from the txt file, i dont
> know how to convert them back from hex, so i can do the decryption.
> On Tuesday, November 29, 2022 at 8:23:19 PM UTC+2 Nikos Karavidas wrote:
>
>> I 've got the following function:
>> void encrypt(string ivInString, string keyInString, const string
>> &filename_in, const string &filename_out)
>> {
>> SecByteBlock iv(reinterpret_cast<const byte*>(&ivInString[0]),
>> ivInString.size());
>> SecByteBlock key(reinterpret_cast<const byte*>(&keyInString[0]),
>> keyInString.size());
>>
>>
>> CFB_Mode<AES>::Encryption e;
>> e.SetKeyWithIV(key.data(), key.size(), iv.data());
>>
>> ifstream in{ filename_in, ios::binary };
>> ofstream out{ filename_out, ios::binary };
>>
>> FileSource f{ in, /*pumpAll=*/true, new StreamTransformationFilter{
>> e, new FileSink{out} } };
>> }
>>
>> and a similar for decrypting, and they work fine, but this is to encrypt
>> any sort of file, which is my only way of encrypting the txt, but its not
>> what i need. What i need is to encrypt a string. The 1st answer in this
>> link:
>> https://stackoverflow.com/questions/12306956/example-of-aes-using-crypto
>> , prints all the ciphered text in hex in the line that says "cout << "0x"
>> << hex << (0xFF & static_cast<byte>(ciphertext[i])) << " ";". But im not
>> sure how that hex part even works. Do you know how i can write that into a
>> txt file?
>>
>>
>>
>> On Tuesday, November 29, 2022 at 7:43:08 PM UTC+2 [email protected]
>> wrote:
>>
>>> Could you try to write a minimal working example in a separate project
>>> and share the code if you still have any issues? Try to write that
>>> encryption/decryption routines yourself line by line instead of copy&paste
>>> any examples.
>>>
>>> The idea is simple: you read data source, you put data through the
>>> filter (which does the encryption or decryption) and put the result to the
>>> sink. So you should setup a source: read file in buffer and use
>>> StringSource or VectorSource or use FileSource. Then you should prepare an
>>> encryption filter (StreamTransformationFilter) with appropriate options
>>> (you could learn it from example code). Then you put the data into the Sink.
>>> https://www.cryptopp.com/wiki/FileSource
>>>
>>> Remember to use same key & iv for decryption. Also binary/text mode is
>>> important when reading files. Also remember to use same mode (CBC, ECB,
>>> etc.) for both encryption/decryption algorithm. Use authenticated
>>> encryption to catch message checksum errors.
>>>
>>> Try to experiment with pipelining, e.g. calculating messag digest and
>>> printing it in hex. When you get the strong feeling what works and what
>>> isn't you could easily use any encryption/decryption algorithm in Cryptopp.
>>> Just take some time to read wiki and experiment with library primitives.
>>> And good luck with that!
>>> https://www.cryptopp.com/wiki/Pipelining
>>>
>>> вторник, 29 ноября 2022 г. в 23:01:33 UTC+7, [email protected]:
>>>
>>>> Not sure what you mean by format, i just use something like
>>>> "myFileStream << cipher", and then read it back again. Do you mean that
>>>> the
>>>> txt file should be utf-8 or something like that? What would be the right
>>>> way to write the ciphered string to the txt file and read it afterwards?
>>>> Thanks a lot for answering btw.
>>>>
>>>> On Tuesday, November 29, 2022 at 4:15:37 PM UTC+2 [email protected]
>>>> wrote:
>>>>
>>>>> I think I have an idea of what is happening to you, what happens
>>>>> that you must decrypt in the same format that you encrypted, since that
>>>>> happened to me at some point, you must also see the format in how you
>>>>> return the txt file, or the text of txt if it is the same format that is
>>>>> needed to decrypt it. Greetings.
>>>>>
>>>>> El lunes, 28 de noviembre de 2022 a las 14:30:04 UTC-5,
>>>>> [email protected] escribió:
>>>>>
>>>>>> Ok so based on the example from this link (
>>>>>> https://www.cryptopp.com/wiki/Advanced_Encryption_Standard), i
>>>>>> have tried encrypting a "plain" string into a "cipher" string and
>>>>>> writing
>>>>>> that "cipher" string to a .txt file in one program, and in another
>>>>>> program
>>>>>> afterwards reading that same .txt file into a string and decrypting it.
>>>>>> But
>>>>>> when i cout that "recovered" string, it is just random characters and
>>>>>> not
>>>>>> my original "plain" string. I think the problem starts when i attempt to
>>>>>> get the "cipher" string in the .txt file, but not sure. Any help is
>>>>>> greatly
>>>>>> appreciated. Thanks in advance.
>>>>>
>>>>>
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