From: Peter Williams (home_pwmsn.com)
Date: Sat Mar 12 2005 - 10:34:33 CST

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A long time ago, I believe I altered muscleTool's void doCrypt() method.
You can do the same to invoke encrypt/decrypt cipher modes across the
interface. See below.

In my modifications, I altered the sign feature, to invoke the applet's use
of PKCS#1 padding, rather than use "block encryption using the private key
transform." I don't recall if the removal of the hex2bin formatter on the
in/out stream was me, or was there in the CVS source. The formatter
hows - in any case - where you can apply additional processing, before and
after the RSA decryption (using private key) operation.

If you use the existing "sign" function in its original muscle form (with
RSA_RAW), and you first format your plaintext in an OAEP wrapper, you have
block encipherment exploiting randomness properties of the wrapping oracle.
Remember to keep the public key a secret, in such a mechanism.

This is the converse of the process specified in the documented cited
below. Using RSA decryption as an enciphering function over an RSA_RAW
block (using the private-key transform) may subject you to professional
censure, note; so, be warned! But you get the idea. Go alter the code - to
suit project requirements.

citation:
ftp://ftp.rsasecurity.com/pub/rsalabs/rsa_algorithm/rsa-oaep_spec.pdf

" if(strcmp(arg3, "sign") ==0 )
   cipherDir = (MSCUChar8)1;
  else if(strcmp(arg3, "verify") ==0 )
   cipherDir = (MSCUChar8)2;
  else {
    printf("ERR: Invalid Use: crypt [keynum] [sign/verify]\n");
    return;
  }
  //inDataSize = hexToBin(hexString, inCryptData);

  rv = MSCGetKeyAttributes( pConnection, (MSCUChar8)keyNum, &keyInfo );
  CHECK_ERR(rv != MSC_SUCCESS, "GetKeyAttributes Failed !");

  keySize = keyInfo.keySize / 8;

  cryptInit.keyNum = (MSCUChar8)keyNum;
#if 0
  cryptInit.cipherMode = MSC_MODE_RSA_NOPAD;
#else
  cryptInit.cipherMode = MSC_MODE_RSA_PAD_PKCS1
;
#endif
  cryptInit.cipherDirection = cipherDir;
  cryptInit.optParams = 0;
  cryptInit.optParamsSize = 0;

  //padData(inCryptData, inDataSize, keySize);
  //inDataSize = outDataSize = keySize;

  //binToHex(inCryptData, inDataSize, outCryptData);

  rv = MSCComputeCrypt( pConnection, &cryptInit,
   inCryptData, inDataSize,
   outCryptData, &outDataSize);

----- Original Message -----
From: "vsingh" <vsinghidrbt.ac.in>
To: <musclelists.musclecard.com>
Sent: Saturday, March 12, 2005 12:39 AM
Subject: [Muscle] Encryption /Signature in muscle tool

> Hi All!
> can any one please help me with this problem:
> i am using muscle tool provided with muscleframework 1.1.3.
> there is an option of performimg a "Crypt" function in muscle tool.can
> anyone tell me is that a function for "Encryption" or "Signature" using
> Private key.
> one more thing:Which "mode" and "padding" is being used by RSA in this
> case for performing this Crypt function.
> please help me if anyone is aware of it.
> thanks
> vigya
>
> _______________________________________________
> Muscle mailing list
> Musclelists.musclecard.com
> http://lists.drizzle.com/mailman/listinfo/muscle
>
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