Result TAG can fetched after encrypt final

IB-7877 Signed-off-by: Raul Metsma <raul@metsma.ee>
open-eid · Nov 9, 2023 · 3931a95 · 3931a95
1 parent 7e67739
commit 3931a95
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Showing 3 changed files with 17 additions and 7 deletions.
diff --git a/client/CDoc2.cpp b/client/CDoc2.cpp
@@ -692,12 +692,16 @@ bool CDoc2::save(const QString &path)
 		file.remove();
 		return false;
 	}
-	file.write(enc.resultTAG());
 	if(!enc.result())
 	{
 		file.remove();
 		return false;
 	}
+	QByteArray tag = enc.tag();
+#ifndef NDEBUG
+	qDebug() << "tag" << tag.toHex();
+#endif
+	file.write(tag);
 	return true;
 }
 

diff --git a/client/Crypto.cpp b/client/Crypto.cpp
@@ -77,12 +77,17 @@ bool Crypto::Cipher::result() const
 	return true;
 }
 
-QByteArray Crypto::Cipher::resultTAG() const
+QByteArray Crypto::Cipher::tag() const
 {
-	QByteArray result(EVP_CIPHER_CTX_block_size(ctx.get()), 0);
-	if(isError(EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_AEAD_GET_TAG, int(result.size()), result.data())))
-		result.clear();
-	return result;
+	if(QByteArray result(tagLen(), 0);
+		!isError(EVP_CIPHER_CTX_ctrl(ctx.get(), EVP_CTRL_AEAD_GET_TAG, int(result.size()), result.data())))
+		return result;
+	return {};
+}
+
+int Crypto::Cipher::tagLen()
+{
+	return 16;
 }
 
 QByteArray Crypto::aes_wrap(const QByteArray &key, const QByteArray &data, bool encrypt)

diff --git a/client/Crypto.h b/client/Crypto.h
@@ -45,7 +45,8 @@ class Crypto
 		QByteArray update(const QByteArray &data) const;
 		bool update(char *data, int size) const;
 		bool result() const;
-		QByteArray resultTAG() const;
+		QByteArray tag() const;
+		static int tagLen();
 	};
 
 	static QByteArray aes_wrap(const QByteArray &key, const QByteArray &data, bool encrypt);