Save PublicKey to string and load from it

[Наталья]

Hi all!

I have an ordinary, but easy, problem. Need to save public key into string and load from this string.

Saving and loading are successed in the test code, but when I try to create decryptor from mey new public key (which are loaded wrom string) - i had an exception "Missing required parameter Primel1".

Wich parameter i need to add? What is the problem with this code?

In debug I see correct value inside all strings...

1. //for generate IV and Key
2. #include "D:/Crypto++/cryptopp820/osrng.h"
3. using CryptoPP::AutoSeededRandomPool;
4.  
5. #include <string>
6. using std::string;
7.  
8. //for exceptions
9. #include "D:/Crypto++/cryptopp820/cryptlib.h"
10. using CryptoPP::Exception;
11.  
12. //for hex viewing
13. #include "D:/Crypto++/cryptopp820/hex.h"
14. using CryptoPP::HexDecoder;
15. using CryptoPP::HexEncoder;
16.  
17. //converter input into cipher
18. #include "D:/Crypto++/cryptopp820/filters.h"
19. using CryptoPP::StringSink;
20. using CryptoPP::StreamTransformation;
21. using CryptoPP::StreamTransformationFilter;
22.  
23. //add AES
24. #include "D:/Crypto++/cryptopp820/aes.h"
25. using CryptoPP::AES;
26.  
27. #include "D:/Crypto++/cryptopp820/modes.h"
28. using CryptoPP::CBC_Mode;
29.  
30. #include "D:/Crypto++/cryptopp820/md5.h"
31. using CryptoPP::MD5;
32.  
33. #include "D:/Crypto++/cryptopp820/blowfish.h"
34. #include "D:/Crypto++/cryptopp820/rsa.h"
35. #include "D:/Crypto++/cryptopp820/eccrypto.h"
36. #include "D:/Crypto++/cryptopp820/base64.h"
37. using CryptoPP::Blowfish;
38. #include <iostream>
39. using namespace std;
40. using namespace CryptoPP;
41.  
42.  
43. int main()
44. {
45.     //create public+private keys
46.     //encrypt some text
47.     //pack public key into the string or vector char
48.     //unpack public key and decrypt text
49.  
50.  
51.     std::string testText = "Text text";
52.     std::string encryptText, decryptText, for_save_key, packedKey, unpackedKey;
53.  
54.     AutoSeededRandomPool rng(true);
55.     InvertibleRSAFunction params;
56.     params.GenerateRandomWithKeySize(rng, 3072);
57.  
58.     RSA::PrivateKey privateKey(params);
59.     RSA::PublicKey publicKey(params);
60.  
61.     RSAES_OAEP_SHA_Encryptor encryptor(publicKey);
62.     StringSource(testText, true, new PK_EncryptorFilter(rng, encryptor, new StringSink(encryptText)));
63.  
64.     //try to pack public key
65.     RSA::PublicKey newPublicKey;
66.     try
67.     {
68.         StringSink tmp_key(for_save_key);
69.         publicKey.Save(tmp_key);
70.         newPublicKey.Load(CryptoPP::StringStore((const byte*)for_save_key.data(), for_save_key.size()).Ref());
71.     }
72.     catch (const BERDecodeErr& ex)
73.     {
74.         cerr << ex.what() << endl;
75.     }
76.  
77.     try
78.     {
79.         RSAES_OAEP_SHA_Decryptor decryptor(newPublicKey);
80.         StringSource(encryptText, true, new PK_DecryptorFilter(rng, decryptor, new StringSink(decryptText)));
81.     }
82.     catch (InvalidArgument& ex)
83.     {
84.         cerr << ex.what() << endl;
85.     }  
86.  
87.     std::cout << "Decrypt text: " << decryptText << endl;
88.  
89.     system("pause");
90.     return 0;
91. }

[Jeffrey Walton]

The decryptor should use the private key, not the public key. This is incorrect:

RSAES_OAEP_SHA_Decryptor decryptor(newPublicKey);

Jeff

[Jeffrey Walton]

On Sun, Jun 2, 2019 at 5:53 AM Наталья <lire...@gmail.com> wrote:
>

> I have an ordinary, but easy, problem. Need to save public key into string and load from this string.
> Saving and loading are successed in the test code, but when I try to create decryptor from mey new public key (which are loaded wrom string) - i had an exception "Missing required parameter Primel1".
> Wich parameter i need to add? What is the problem with this code?

You might also be interested in
https://cryptopp.com/wiki/RSA_Cryptography and
https://www.cryptopp.com/wiki/Keys_and_Formats on the wiki.

Jeff

[Nataliia]

U are my hero!

How I could be so inattentive?!

All works properly.

Thanks a lot!

воскресенье, 2 июня 2019 г., 13:11:29 UTC+3 пользователь Jeffrey Walton написал: