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Hello all,
I tried to adapt the sample code from test.cpp to read the
public key and the signed message from a stringSource rather than from a
fileSource, however I seem to be doing something wrong (result is always
an invalid signature), can someone tell me what?
Sourcecode:
#include "cryptlib.h"
#include "filters.h"
#include "base64.h"
#include "files.h"
#include "osrng.h"
#include "pubkey.h"
#include "rsa.h"
#include "sha.h"
#include <iostream>
#include <string>
using namespace std;
using namespace CryptoPP;
int main() {
~ string privkey_fn = "privuser1.key";
~ string message = "blah \n blubb \n blah";
~ string signature = "";
~ string pubkey = "";
~ //This happens somewhere earlier in my code
~ FileSource("pubuser1.key", true,
new StringSink(pubkey));
~ //Here I do the signature
~ FileSource privFile(privkey_fn.c_str(), true,
new Base64Decoder);
~ RSASSA_PKCS1v15_SHA_Signer priv(privFile);
~ AutoSeededRandomPool rng;
~ StringSource(message, true,
~ new SignerFilter(rng, priv,
new Base64Encoder(
new StringSink(signature))));
~ // Here comes the signature verification
~ //Get public key
~ StringSource pubString(pubkey.c_str(), true,
new Base64Decoder);
~ RSASSA_PKCS1v15_SHA_Verifier pub(pubString);
~ //Get signature
~ StringSource sigString(signature.c_str(), true,
new Base64Decoder);
~ if (sigString.MaxRetrievable() != pub.SignatureLength()) {
~ cerr << "Invalid signature length\n";
}
~ SecByteBlock sig(pub.SignatureLength());
~ sigString.Get(sig, sig.size());
~ //Get signed text
~ VerifierFilter *verifierFilter = new VerifierFilter(pub);
~ verifierFilter->Put(sig, pub.SignatureLength());
~ StringSource f(message, true, verifierFilter);
~ if (!(verifierFilter->GetLastResult())) {
~ cerr << "Invalid signature\n";
~ } else {
~ cerr << "none\n";
~ }
};
Thank you in advance,
Ludwig
- --
Ludwig Seitz,
PhD student, LIRIS INSA-Lyon, France.
For contact information see my homepage at http://liris.cnrs.fr/~lseitz
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