c# - 使用 itextsharp 进行数字签名

Question

有人可以解释以下代码..

该return语句将做什么。

 public byte[] sign(string text)
 {
    string password = "1234";
    X509Certificate2 cert = new X509Certificate2("c:\\certificate.pfx", password);
    RSACryptoServiceProvider crypt = (RSACryptoServiceProvider)cert.PrivateKey;
    SHA1Managed sha1 = new SHA1Managed();
    UnicodeEncoding encoding = new UnicodeEncoding();
    byte[] data = encoding.GetBytes(text);
    byte[] hash = sha1.ComputeHash(data);
    return crypt.SignHash(hash, CryptoConfig.MapNameToOID("SHA1"));
}

Answer 1

    public byte[] sign(string text)
         {
//Password for the PFX certificate
            string password = "1234";
//Importing the PFX certificate that contains the private key which will be used for creating the digital signature
            X509Certificate2 cert = new X509Certificate2("c:\\certificate.pfx", password);
//declaring RSA cryptographic service provider
            RSACryptoServiceProvider crypt = (RSACryptoServiceProvider)cert.PrivateKey;
//cryptographic hash of type SHA1
            SHA1Managed sha1 = new SHA1Managed();
//encoding the data to be signed
            UnicodeEncoding encoding = new UnicodeEncoding();
            byte[] data = encoding.GetBytes(text);
//generate Hash
            byte[] hash = sha1.ComputeHash(data);
//sign Hash
            return crypt.SignHash(hash, CryptoConfig.MapNameToOID("SHA1"));
        }

Answer 2

SignHash(byte[], string) 方法将根据从证书中读取的私钥计算作为第一个参数传递的哈希值的签名。看这里：

RSACryptoServiceProvider.SignHash 方法

其结果（随后返回）将是一个包含签名的字节 []，您可以将其与您的数据一起发送，以便其他人可以使用您的公钥验证该签名。