[cryptopp-users] Re: How to encrypt string and write to txt
The thing is operator<< is used for formatted text output, not binary.
https://en.cppreference.com/w/cpp/io/basic_ostream/operator_ltlt
https://en.cppreference.com/w/cpp/named_req/FormattedOutputFunction
There are read/write functions to deal with binary files.
https://en.cppreference.com/w/cpp/io/basic_ostream/write
Since you get binary data after encryption, you must open file in binary
mode and use write() to put binary data to file.
FileSink with binary=true does exactly what you need.
If you still want to play with text, look at HexEncoder & HexDecoder filters
https://cryptopp.com/wiki/HexDecoder
среда, 30 ноября 2022 г. в 03:19:24 UTC+7, boomer1...@gmail.com:
> 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(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(&ivInString[0]),
>>> ivInString.size());
>>> SecByteBlock key(reinterpret_cast(&keyInString[0]),
>>> keyInString.size());
>>>
>>>
>>> CFB_Mode::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(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 schmid...@gmail.com
>>> 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, boomer1...@gmail.com:
> 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 creyesc...@gmail.com
> wrote:
>>>
[cryptopp-users] Re: How to encrypt string and write to txt
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, boomer1...@gmail.com: > 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 creyesc...@gmail.com > 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, >> boomer1...@gmail.com 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. >> >> -- You received this message because you are subscribed to the Google Groups "Crypto++ Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to cryptopp-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cryptopp-users/9137d9f2-9dc2-4504-80e1-a824f5e1b0e3n%40googlegroups.com.
[cryptopp-users] Re: How to decrypt a file in memory?
Just load file data into memory buffer (std::vector) and
use filter pipeline with VectorSource and VectorSink.
https://cryptopp.com/docs/ref/class_vector_source.html
https://cryptopp.com/docs/ref/class_vector_sink.html
четверг, 22 сентября 2022 г. в 00:59:54 UTC+7, kakaa...@gmail.com:
> I'm encrypting a file this way:
>
>
> #include
> #include
> #include
> #include
> #include
> #include
> #include
> #include
>
>
> void FileEncrypt(byte key[], byte iv[]
>, const std::string& file, const std::string& dest)
> {
> CTR_Mode< AES >::Encryption cipher;
> cipher.SetKeyWithIV(key, strlen((char*)key), iv,
> strlen((char*)iv));
>
> std::ifstream in{file, std::ios::binary};
> std::ofstream out{dest, std::ios::binary};
>
> CryptoPP::FileSource{in, true,
> new CryptoPP::StreamTransformationFilter{
> cipher, new CryptoPP::FileSink{out}}};
> }
>
> INT main(INT argc, PCHAR* argv)
> {
> std::string file = "...";
> std::string dest = "...";
>
> unsigned char* key[] = "p3s6v9y$B&E)H@Mc";
> unsigned char* iv[] = "VkXp2s5v8y/B?E(H";
>
> FileEncrypt(key, iv, file, dest);
> FileDecrypt(key, iv, file, dest);
> }
>
>
> Then when needed i'm downloading the encrypted file from my repo.
>
> I've been able to decrypt it with:
>
> ```c++
> void FileDecrypt(byte key[], byte iv[]
>, const std::string& file, const std::string& dest)
> {
> CTR_Mode< AES >::Decryption cipher;
> cipher.SetKeyWithIV(key, strlen((char*)key), iv,
> strlen((char*)iv));
>
> std::ifstream in{file, std::ios::binary};
> std::ofstream out{dest, std::ios::binary};
>
> CryptoPP::FileSource{in, true,
> new CryptoPP::StreamTransformationFilter{
> cipher, new CryptoPP::FileSink{out}}};
> }
> ```
> But this way the decrypted file is saved to disk, how could i decrypt it
> on memory without saving to disk?
>
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[cryptopp-users] Return (move) CBC_Mode::Encryption object from a function
I wanted to write a factory method to initialize CBC_Mode::Encryption
object like that
> CBC_Mode::Encryption GetEncryption(const SecByteBlock &key) {
> CBC_Mode::Encryption encryption;
> auto iv = GetIV(); // this is constant IV for entire application
> encryption.SetKeyWithIV(key.data(), key.size(), iv.data(), iv.size());
> return encryption;
> }
But when I use returned object in StreamTransformationFilter I get an
address access violation in CryptoPP code
> CryptoPP::BlockOrientedCipherModeBase::IsForwardTransformation()
modes.h:259
Is it a CryptoPP bug (move-ctors are not implemented correctly) or
Encryption objects cannot be moved for some security reasons? Or that is
kind of impossible to implement move-ctor for a template class?
Seems that I should rather implement
> template
> vector Encrypt(const T& text, const SecByteBlock& key) { ... }
but still curious about that 'move' issue.
CryptoPP library version 8.7.0
Test code is here
https://wandbox.org/permlink/OeWKeOs9ERWYZKpr
This is a stack trace when address access violation happened
> CryptoPP::BlockOrientedCipherModeBase::IsForwardTransformation()
modes.h:259
>
CryptoPP::StreamTransformationFilter::LastBlockSize(CryptoPP::StreamTransformation
&, BlockPaddingScheme) filters.cpp:630
>
CryptoPP::StreamTransformationFilter::InitializeDerivedAndReturnNewSizes(const
CryptoPP::NameValuePairs &, unsigned int &, unsigned int &, unsigned int &)
filters.cpp:658
> CryptoPP::FilterWithBufferedInput::IsolatedInitialize(const
CryptoPP::NameValuePairs &) filters.cpp:332
>
CryptoPP::StreamTransformationFilter::StreamTransformationFilter(CryptoPP::StreamTransformation
&, CryptoPP::BufferedTransformation *, BlockPaddingScheme) filters.cpp:598
> Test2() main.cpp:67
> main() main.cpp:81
> invoke_main() 0x007b3873
> __scrt_common_main_seh() 0x007b36f7
> __scrt_common_main() 0x007b358d
> mainCRTStartup(void *) 0x007b38f8
> 0x774cfa29
> 0x77817a9e
> 0x77817a6e
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