Esempio n. 1
0
 /// <summary>
 /// Checks if the file signature is valid.
 /// </summary>
 /// <param name="data">Original, decrypted file in raw format.</param>
 /// <param name="userId">Id of the user decrypting the file.</param>
 /// <param name="ownerPublicKey">Public RSA key of the file owner used to verify file signature.</param>
 /// <returns>true if the signature is valid, otherwise false.</returns>
 private bool CheckFileSignature(byte[] data, int userId, RSAParameters ownerPublicKey)
 {
     try
     {
         var hashAlgo = AlgorithmUtility.GetHashAlgoFromNameSignature(((SecurityDescriptor)Headers[1]).HashAlgorithmName);
         return(CheckFileSignatureHelper(data, userId, ownerPublicKey, hashAlgo));
     }
     catch (CryptographicException)
     {
         var hashAlgo = AlgorithmUtility.GetHashSignerFromNameSignature(((SecurityDescriptor)Headers[1]).HashAlgorithmName);
         return(CheckFileSignatureHelper(data, userId, ownerPublicKey, hashAlgo));
     }
 }
Esempio n. 2
0
 /// <summary>
 /// Creates a file signature using the unencripted data and user private RSA key.
 /// </summary>
 /// <param name="data">Original, unencrypted file in raw format.</param>
 /// <param name="userPrivateKey">Private RSA key of the user encrypting the file.</param>
 private void SignFile(byte[] data, ref RSAParameters userPrivateKey)
 {
     try
     {
         // Exception will be thrown if the hashing algoritm is MD2, MD4, RIPEMD or SHA224.
         var hashAlgo = AlgorithmUtility.GetHashAlgoFromNameSignature(((SecurityDescriptor)Headers[1]).HashAlgorithmName);
         ((SecurityDescriptor)Headers[1]).Signature = new RsaAlgorithm(userPrivateKey).CreateSignature(data, hashAlgo);
     }
     catch (CryptographicException)
     {
         var hashAlgo = AlgorithmUtility.GetHashSignerFromNameSignature(((SecurityDescriptor)Headers[1]).HashAlgorithmName);
         ((SecurityDescriptor)Headers[1]).Signature = new RsaAlgorithm(userPrivateKey).CreateSignature(data, hashAlgo);
     }
 }