crypto++高手请进，能否给我解释下都是什么意思？我想要返回值该怎么改写？

[jcjunjin]

bool RSAVerifyFile(const char *pubFilename, const char *messageFilename, const char *signatureFilename)
{
FileSource pubFile(pubFilename, true, new HexDecoder);
RSASS<PKCS1v15, SHA>::Verifier pub(pubFile);

FileSource signatureFile(signatureFilename, true, new HexDecoder);
if (signatureFile.MaxRetrievable() != pub.SignatureLength())
return false;
SecByteBlock signature(pub.SignatureLength());
signatureFile.Get(signature, signature.size());

VerifierFilter *verifierFilter = new VerifierFilter(pub);
verifierFilter->Put(signature, pub.SignatureLength());
FileSource f(messageFilename, true, verifierFilter);

return verifierFilter->GetLastResult();
}

[踏岸寻柳]

又是RSA，又是PKCS的，肯定是PKI相关的内容。