BouncyCastle-ECDSA与SHA256,C#的数字签名验证

Question

下面是我的场景--我从条形码中读取数据，并将其转换为纯文本。本文是条码数据+数字签名的结合。数字签名附加在末尾，使我能够分离出实际数据和数字签名数据。数字签名数据使用sha256哈希-用户将公钥作为windows证书文件(.cer extension)发送给我。

所需实现：-需要从证书中提取公钥，并根据提供的条形码数据和数字签名验证公钥。

//Note : 
//1.  certPath : is the path where my certificate is located 
//2. GetStreamdata  get the stream of data from the certificate. 

//Get the certificate data here 
                Org.BouncyCastle.X509.X509Certificate cert1 = new X509CertificateParser().ReadCertificate(GetStreamData(cerPath)); 
//get the public key 
                ECPublicKeyParameters ecPublic = (ECPublicKeyParameters)cert1.GetPublicKey(); 
//create a signerutility with type SHA-256withECDSA 
                ISigner signer = SignerUtilities.GetSigner("SHA-256withECDSA"); 
//initial signer with the public key 
                signer.Init(false, ecPublic); 
//get signature in bytes : digitalsignature parameter contains signature that should be used. 
                byte[] dBytes = encoding.GetBytes(digitalsignature); 
//block/finalise update to signer : data : is the actual data. 
                signer.BlockUpdate(data, 0, data.Length); 
                    try 
                    { 
//verify signature 
                         verified =  signer.VerifySignature(dBytes); 
                    } 
                catch(Exception ex) 
                    { 
                        _log.LogException(ex); 
                    } 

问题：

Exception thrown on signer.verifysignature
  Message=Unable to cast object of type 'Org.BouncyCastle.Asn1.DerApplicationSpecific' to type 'Org.BouncyCastle.Asn1.Asn1Sequence'. 
  Source=BouncyCastle.Crypto 

Answer 1

问题是我必须在ISO-8859-1中编码digitalsignature值。我以前是用ASCII编码的。这就解决了问题，并且我能够验证签名。