Remove unused function.

We don't need CheckPassphrase() anymore.

GpgMEWorker.cpp

@@ -347,32 +347,6 @@ const Error GpgMEWorker::CreateSubKey(GpgME::Key& k,
     return e;
 }
 
-const Error GpgMEWorker::CheckPassphrase(const char* fpr,
-                                         const string& passphrase)
-{
-    Error e;
-    Context * ctx = Context::createForProtocol(Protocol::OpenPGP);
-    LoopbackPassphraseProvider * ppp = new LoopbackPassphraseProvider(passphrase);
-    ctx->setPinentryMode(Context::PinentryMode::PinentryLoopback);
-    ctx->setPassphraseProvider(ppp);
-
-    Key k = FindKey(fpr, e, true);
-    if (e.code() != 0)
-        return e;
-    e = ctx->addSigningKey(k);
-    if (e.code() != 0)
-        return e;
-    Data plain("dummy");
-    Data signature;
-    SigningResult result = ctx->sign(plain, signature, SignatureMode::Detached);
-    e = result.error();
-
-    delete ppp;
-    delete ctx;
-    
-    return e;
-}
-
 const Error GpgMEWorker::ExportPrivateKey(const char * pattern, string& buffer,
                                           const string& passphrase)
 {

GpgMEWorker.h

@@ -181,21 +181,6 @@ public:
                              const char * algo,
                              const string& passphrase,
                              ulong expires = 63072000);
-    /**
-     * Checks that passphrase can unlock secret key with fingerprint fpr.
-     * \n This is a workaround when exporting secret keys.
-     * \n To date, with GnuPG 2.2.23 and GpgME 1.1.15, a secret key can be
-     * exported when the right passphrase is provided. With a bad passphrase,
-     * application crashes.
-     * \n See https://dev.gnupg.org/T5151
-     * \n Application may validate a passphrase before invoking engine.
-     * \n Until it is hopefully fixed in upstream and available in mainstream.
-     * @param fpr
-     * @param passphrase
-     * @return 
-     */
-    const Error CheckPassphrase(const char * fpr,
-                                const string& passphrase);
     /**
      * Export a secret key.
      * @param pattern : a key fingerprint