C#实现RSA签名及认证

C#实现RSA签名及认证

/// <summary>

/// 签名

/// </summary>

/// <param name="str">需签名的数据</param>

/// <returns>签名后的值</returns>

public string Sign(string str, string str_privateKey) {
//根据需要加签时的哈希算法转化成对应的hash字符节
byte[] bt = Encoding.GetEncoding("utf-8").GetBytes(str);
var sha256 = new SHA256CryptoServiceProvider();
byte[] rgbHash = sha256.ComputeHash(bt);
RSACryptoServiceProvider key = new RSACryptoServiceProvider();
key.FromXmlString(str_privateKey);
RSAPKCS1SignatureFormatter formatter = new RSAPKCS1SignatureFormatter(key);
formatter.SetHashAlgorithm("SHA256"); //此处是你需要加签的hash算法，需要和上边你计算的hash值的算法一致，不然会报错。
byte[] inArray = formatter.CreateSignature(rgbHash);
return Convert.ToBase64String(inArray);
}

/// <summary>
/// 签名验证
/// </summary>
/// <param name="str">待验证的字符串</param>
/// <param name="sign">加签之后的字符串</param>
/// <returns>签名是否符合</returns>
public bool SignCheck(string str, string sign, string str_publicKey){
try{
byte[] bt = Encoding.GetEncoding("utf-8").GetBytes(str);
var sha256 = new SHA256CryptoServiceProvider();
byte[] rgbHash = sha256.ComputeHash(bt);
RSACryptoServiceProvider key = new RSACryptoServiceProvider();
key.FromXmlString(str_publicKey);
RSAPKCS1SignatureDeformatter deformatter = new RSAPKCS1SignatureDeformatter(key);
deformatter.SetHashAlgorithm("SHA256");
byte[] rgbSignature = Convert.FromBase64String(sign);
if (deformatter.VerifySignature(rgbHash, rgbSignature)){
return true;
}
return false;
}
catch{
return false;
}
}