message too long for this public key. Was: system.security.cryptography.rsa.toxmlstring

[Mathieu Malaterre]

Thanks Jeffrey,

	Actually what I am trying to do is quite simple. It's just that I 
cannot find the information on internet(*). Here is what I have so far:

void Base64ToInteger(const char *base64String, Integer &xmlint)
{
  StringSource mod_s( base64String, true, new Base64Decoder);
  unsigned long mrs = mod_s.MaxRetrievable();
  char* mod_sstr = new char[mrs];
  mod_s.Get( (unsigned char*)mod_sstr, mrs );
  xmlint = Integer(mod_sstr);
  delete[] mod_sstr;
}

RSA::PublicKey CreatePublicKey()
{
  const char modulus[] = 
"wehzXu32ipNZZkhWqYMVrKoWs4o5AfPKZbdTLVVt8jPfC09yKzC/ajJTeGm87moeU+yZ6Lz8PXsKOmxxNFBE3vQpbMEq++fCjhI0QdC4q/h0H6FePN7MC3WZmR0hpI3yp5sGNfBSBMPNRsnpEGI00ByxQp1N8R9hj9pc0OvwswE=";
  const char exponent[] = "AQAB";
  Integer mod, exp;
  Base64ToInteger(modulus, mod);
  Base64ToInteger(exponent, exp);

  RSA::PublicKey key;
  key.Initialize(mod, exp);
  return key;
}

int main()
{
  RSA::PublicKey pubKey = CreatePublicKey();
  const char message[] = "hello";
  RSAES_OAEP_SHA_Encryptor pub(pubKey);
  AutoSeededRandomPool randPool;
  std::string result;
  StringSource(message, true, new PK_EncryptorFilter(randPool, pub,
      new Base64Encoder(new StringSink(result))));
}

All I get is:

terminate called after throwing an instance of 'CryptoPP::InvalidArgument'
  what():  RSA/OAEP-MGF1(SHA-1): message too long for this public key


	All I am trying is do the RSA encryption by setting parameter one by 
one, reading each XML elements(**).

Any suggestion ? Thanks
Mathieu

(*)
So I found this post by accident.
http://www.mail-archive.com/cryptopp-list@eskimo.com/msg01619.html
Indeed if you try to find this post by using keyword like 'SetModulus' 
or 'SetPublicExponent', I cannot find it either by using the internal 
search engine or via google:
http://www.google.com/search?hl=en&q=SetPublicExponent+site%3Awww.mail-archive.com

(**)
http://www.w3.org/TR/xmldsig-core/#sec-RSAKeyValue

Jeffrey Walton wrote:
Hi Mathieu,

I would assume you would provide a Cryptographic Sservice Package
(CSP). But I've never looked into in.

I am looking to replace the .NET Framework
crypto class by the CryptoPP one.
You probably cannot replace the .NET cryptography package per se. You
would provide the CSP, and then set it as the machine default CSP.
Again, I'm shooting from the hip.

Jeff

On 9/11/06, Mathieu Malaterre <[EMAIL PROTECTED]> wrote:
Hello,

       I am looking to replace the .NET Framework crypto class by the 
CryptoPP
one. Has anyone try doing so ? Could they share there experience ? I am
having a hard time understanding how to setup manually all the
parameters (Modulus, Exponent, InverseQ...) are there any examples
somewhere that I can look at ?
       Finally the only post I was able to find mentionned a problem of
endianness:

http://www.eggheadcafe.com/forumarchives/win32programmerdirectxvideo/dec2005/post24849638.asp 


       Is this something that has been solved since ?

Thanks for your time,
Mathieu