Problem solved.
The problem was that the signature contained a null terminating
character occasionally.
On 6 joulu, 21:22, Kivi <[EMAIL PROTECTED]> wrote:
> I have a following function for signing strings:
>
> void CCryptografia::RSASign(RSASS<PSSR, SHA>::Signer& signer, string&
> stream)
> {
> try
> {
> string signed_str; // Signed string is stored here
> unsigned int messageLen = stream.length();
> AutoSeededRandomPool rng;
>
> SecByteBlock signature(signer.MaxSignatureLength(messageLen));
> unsigned int signatureLen =
> signer.SignMessageWithRecovery( rng,
>
> (byte*)stream.c_str(),
>
> messageLen,
>
> NULL,
> 0,
>
> signature);
> // Store data to string
> signed_str.assign((char*)signature.data());
>
> if(signed_str.length() > signatureLen)
> { // In some cases the data contains extra characters.
> signed_str.erase(signatureLen);
> }
> else if(signed_str.length() < signatureLen)
> { // This is the error that occurs
> throw RSASignEx(ERR, "Signed string too short.");
> }
>
> // Replace original string with signed and encoded one
> Base64Encode(signed_str, stream);
> }
> catch (...)
> {
> // Exception handling...
> }
>
> }
>
> And if I call the previous function like this:
>
> string text = "Clear text to sign...";
> string private_key =
> "MIICdAIBADANBgkqhkiG9w0BAQEFAASCAl4wggJaAgEAAoGBALyem3b2erPfT8opXTkkQhg1
> tlHIfNXgVK6OSGEZihhna/E/uUmFF65kXRCKGueDL/abQhBSfwMrdbrH/yOPl
> +6wSdr89LMi bPxtnhT6OSagcqPLQbC3dKc/
> c2kLMamtfy17yuFl9iCXKEpf0PiVz1RJgs1INsdnDyNpL2Zw OlVdAgERAoGAWMMb
> +79IzR3LMfVZC9TTzyhVzCIcoOIJu45ALbGqZdZQ6f/euS+SrGt3FteU
> MLY0sEkQB65Z41++7nw71H/
> PBhm448VYL2X8w3jVzDGNZoNP8A2mI7gCB5o8E9VOF7Qml4YR kqulDc3rWfzA1KitcY
> +sKhEsZ6p+JHE9Wp9U39ECQQDHFHiIZzVZKsVnjgIgAafOeri0rUnL
> VLPqEemFpvKyPCQEop5RFrU9abIEDAsUG2N0lqoxoeba+e4jTgfpfw7rAkEA8ox
> +cTIZEIkX pUnA8OsE+u4M
> +ZNbBRujLaHVYETEnHEHekLraCCuBCp5Iqspm0Nfg55JshaEQckn1T799Cbq
> 1wJAUflezsEV94oVDIXEo8RyRfZMDik8gOakb3DJkWLcZ4Is8tmMe74OZJTu8puMF1aSXS76
> ySSMPAyPO7a39rvY9wJBAJzxfv3zPWUNaacvuRRb1gvHNZJuaBJdLVnDEZik97CFXzD
> +H9n3 By/fP1Kq/M3gTNyxtzb/
> gsEnznrshjSRpwMCQBHSovRne9TxkJBfUclkiPy8nNZpXsfBGda7 LHNU5ZxbS/
> yoMDqrx0ck7ITEwLz8kqtFSRt7awrN3g19JG3KyY4= ";
>
> int success = 0, failed = 0;
>
> CryptoPP::StringSource ss_priv(private_key, true, new
> CryptoPP::Base64Decoder);
> CryptoPP::RSASS<CryptoPP::PSSR, CryptoPP::SHA>::Signer
> signer(ss_priv);
>
> for(int i = 0; i < 100; i++) // Do a testing loop
> {
> try
> {
> // Sign the string
> Sec.RSASign(rng, signer, text);
> success++; // Signing OK
> }
> catch (...)
> { // Signing has failed.
> failed++;
> }
>
> text.assign("Clear text to sign...");
>
> }
>
> Allmost half of the function calls fails. All failures occur because
> the signed string is shorter
> then it should be. Line "signed_str.assign((char*)signature.data());"
> assigns the signed string from (SecByteBlock) signature to a
> stl::string and when I attached a debugger to application it really
> shows that the signature contains less data than it should be.
> Function SignMessageWithRecovery returns allways the correct size
> (128). (SecByteBlock) signature's m_size member is also allways 128
> but the data is shorter.
>
> I'm using VS2005 and Cryptopp 5.2.2. Does any one have any idea why
> signing fails?
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