My private key file is a X509 RSAPrivate key ASN representation :
SEQUENCE ::={
version INTEGER;
privateKeyAlgorithmIdentifier SEQUENCE
algorithm RSAEncryption OID
parameters
privateKey OCTET STRING
modulus;
publicExponent;
privateExponent ;
prime1;
prime2;
exponent1;
exponent2;
coefficient;
}
- Can crypto++ use this type of key directly ? If yes, how can I do so, do
you have some examples? with InvertibleRSAFunction?
- To sign a message with crypto++, should I first hash and next crypt it or
is there a method to do it directly?
thanks
Guillaume.
----- Original Message -----
From: "Shawn Masters" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, July 18, 2003 4:01 PM
Subject: Re: RSA private key file problems
> There are many ways to represent a PK type key in ASN.1 as most of them
> rely on a collection of numbers to form the key. There are well formed
> standards for specific ASN.1 layouts. Crypto++ offers some of the more
> common formats, and also provides ASN.1 parsing for handling most of the
> others. This is probably an X.509 public key which has it's own object.
> Give it a try, if that doesn't work it isn't very hard to just read
> the ASN.1 stream diectly into Integers and place them in the RSA object.
>
> 73,
> Shawn
>
> Guillaume JOLIVET wrote:
>
> > You're absolutly right.
> >
> > I have made my tests with a RSA public key generated by crypto++, and it
> > worked, but now I use a public key generated by CA and of course my
> > program fails because the key is now an ASN.1 BEREncode structure.
> > I've never looked at the key file because I thought that the problem was
> > due to my program.
> >
> > I have however some questions :
> > - Can crypto++ use ASN.1 structure key directly ? If yes, how can I do
so?
> > - If not, do you know the ASN.1 structure of a RSA public key ?
> > - To sign a message with crypto++, should I first hash and next crypt it
> > or is there a method to do it directly?
> >
> > Thanks.
> > Guillaume.
> >
> > ----- Original Message -----
> > *From:* Shawn Masters <mailto:[EMAIL PROTECTED]>
> > *To:* [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
> > *Sent:* Tuesday, July 15, 2003 3:13 PM
> > *Subject:* RE: RSA private key file problems
> >
> > Normally you will need to do more then just hex decode
> > the key, as the key is just not one value but a small collection.
> > Crypto++ only really accepts loading of RSA keys in one of three
> > ways, ASN.1(BERdecode), loading the individual numbers separately
> > with sets, or name value pairs (This is new and I have not tried
> > it). Of these ASN.1 is the most common, and only it and the name
> > values pairs can be easily marshaled to a file.
> >
> >
> >
> > Do you know what format the key is in? Until you know
> > and have the code working with it, everything past forming the RSA
> > object is not going to work. You probably should read up on ASN.1
> > and RSA before proceeding. You can find decent information at
RSALabs.
> >
> >
> >
> > 73,
> >
> > Shawn
> >
> >
> >
> > -----Original Message-----
> > *From:* Guillaume JOLIVET [mailto:[EMAIL PROTECTED]
> > *Sent:* Tuesday, July 15, 2003 8:50 AM
> > *To:* [EMAIL PROTECTED]
> > *Subject:* Re: RSA private key file problems
> >
> >
> >
> > Thank you for your help, but does someone have any example for
> > signing (RSA with MD5 or RSA with SHA1) a byte buffer using a
> > private key file.
> >
> >
> >
> >
> >
> > For the moment, I've got :
> >
> > AutoSeededRandomPool rng;
> >
> >
> > // Buffer I want to sign
> >
> > byte* bufferIWantToSign = new byte[16];
> >
> > memcpy(bufferIWantToSign, "0123456789ABCDEF", 16);
> >
> >
> > // Private key file
> > FileSource privFile(//<privateKeyFilePath>//, true, new
> > HexDecoder());
> >
> >
> >
> > RSASSA_PKCS1v15_MD5_Signer priv(privFile);
> >
> >
> > // Signature length
> > long lSignedTextLength = priv.SignatureLength();
> >
> >
> >
> > // Create signature buffer
> > byte* abySignedBuffer = new byte[lSignedTextLength];
> >
> >
> >
> > // Sign
> > priv.SignMessage(
> > rng,
> > bufferIWantToSign,
> > 16,
> > abySignedBuffer);
> >
> > Is this solution correct ? Does //abySignedBuffer// contain the
> > result of the signature of //bufferIWantToSign //? If no, how would
> > you do it.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > ----- Original Message -----
> >
> > From: "Shawn Masters" <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>>
> >
> > To: <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>>
> >
> > Sent: Tuesday, July 15, 2003 2:15 PM
> >
> > Subject: RE: RSA private key file problems
> >
> >
> >
> > I think the problem may be a little deeper then this.
> > RSASSA_PKCS1v15_MD5_Signer is not an encryptor, but a signer. This
> > means it
> > takes a private key and encrypts the MD5 of the data being signed.
The
> > PKCS1 defines how the resulting data is formed so it is secure (or
> > atleast
> > more so then some simpler methods of using RSA) and readable by the
> > verifier.
> > To encrypt with RSA you will use a public key, and some symmetric
> > cipher. Once you get to that point use debugging methods to look
> > into the
> > values to make sure that you have loaded all of the correct numbers
> > for the
> > algorithm chosen.
> >
> > 73,
> > Shawn
> >
> > -----Original Message-----
> > From: Guillaume JOLIVET [mailto:[EMAIL PROTECTED]
> > Sent: Tuesday, July 15, 2003 6:37 AM
> > To: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>
> > Subject: RSA private key file problems
> >
> > Hi all,
> >
> > I would like to crypt data with a RSA with MD5 algorithm but I've
> > got some
> > problems.
> > My private key file is a variable-size hexadecimal format file.
> >
> > Here are my code lines :
> >
> > FileSource privFile(<myKeyFilePath>, true, new HexDecoder());
> > RSASSA_PKCS1v15_MD5_Signer priv(privFile);
> >
> >
> > When I try to crypt, the program fails on the creation of the
> > RSASSA_PKCS1v15_MD5_Signer object.
> > I think that the FileSource object is not correct because of the key
> > file
> > format, but I don't know what kind of object to use instead the
> > HexDecoder
> > object.
> >
> >
> > Does somebody got any idea,
> >
> > Thanks,
> > Guillaume.
> >
>
>
