.NET使用OpenSSL生成的pem密钥文件

using System;
using System.Security.Cryptography;

/// <summary>
/// 作者：http://thinhunan.cnblogs.com
/// 名称：RsaUtility.cs
/// 时间：2014-11-04 16:48:42
/// 描述：将pem格式的1024位或2048位的公钥和私钥转换为RSAParameters
/// </summary>
public class PemConverter
{
/// <summary>
/// 将pem格式公钥(1024 or 2048)转换为RSAParameters
/// </summary>
/// <param name="pemFileConent">pem公钥内容</param>
/// <returns>转换得到的RSAParamenters</returns>
public static RSAParameters ConvertFromPemPublicKey(string pemFileConent)
{
if (string.IsNullOrEmpty(pemFileConent))
{
throw new ArgumentNullException("pemFileConent", "This arg cann't be empty.");
}
pemFileConent = pemFileConent.Replace("-----BEGIN PUBLIC KEY-----", "").Replace("-----END PUBLIC KEY-----", "").Replace("\n", "").Replace("\r", "");
byte[] keyData = Convert.FromBase64String(pemFileConent);
bool keySize1024 = (keyData.Length == 162);
bool keySize2048 = (keyData.Length == 294);
if (!(keySize1024 || keySize2048))
{
throw new ArgumentException("pem file content is incorrect, Only support the key size is 1024 or 2048");
}
byte[] pemModulus = (keySize1024 ? new byte[128] : new byte[256]);
var pemPublicExponent = new byte[3];
Array.Copy(keyData, (keySize1024 ? 29 : 33), pemModulus, 0, (keySize1024 ? 128 : 256));
Array.Copy(keyData, (keySize1024 ? 159 : 291), pemPublicExponent, 0, 3);
var para = new RSAParameters { Modulus = pemModulus, Exponent = pemPublicExponent };
return para;
}

/// <summary>
/// 将pem格式私钥(1024 or 2048)转换为RSAParameters
/// </summary>
/// <param name="pemFileConent">pem私钥内容</param>
/// <returns>转换得到的RSAParamenters</returns>
public static RSAParameters ConvertFromPemPrivateKey(string pemFileConent)
{
if (string.IsNullOrEmpty(pemFileConent))
{
throw new ArgumentNullException("pemFileConent", "This arg cann't be empty.");
}
//pemFileConent = pemFileConent.Replace("-----BEGIN RSA PRIVATE KEY-----", "").Replace("-----END RSA PRIVATE KEY-----", "").Replace("\n", "").Replace("\r", "");
pemFileConent = pemFileConent.Replace("-----BEGIN PRIVATE KEY-----", "").Replace("-----END PRIVATE KEY-----", "").Replace("\n", "").Replace("\r", "");
byte[] keyData = Convert.FromBase64String(pemFileConent);
//byte[] keyData = System.Text.Encoding.Default.GetBytes(pemFileConent);
bool keySize1024 = (keyData.Length == 609 || keyData.Length == 610);
bool keySize2048 = (keyData.Length == 1190 || keyData.Length == 1192);

if (!(keySize1024 || keySize2048))
{
throw new ArgumentException("pem file content is incorrect, Only support the key size is 1024 or 2048");
}

int index = (keySize1024 ? 11 : 12);
byte[] pemModulus = (keySize1024 ? new byte[128] : new byte[256]);
Array.Copy(keyData, index, pemModulus, 0, pemModulus.Length);

index += pemModulus.Length;
index += 2;
var pemPublicExponent = new byte[3];
Array.Copy(keyData, index, pemPublicExponent, 0, 3);

index += 3;
index += 4;
if (keyData[index] == 0)
{
index++;
}
byte[] pemPrivateExponent = (keySize1024 ? new byte[128] : new byte[256]);
Array.Copy(keyData, index, pemPrivateExponent, 0, pemPrivateExponent.Length);

index += pemPrivateExponent.Length;
index += (keySize1024 ? ((int)keyData[index + 1] == 64 ? 2 : 3) : ((int)keyData[index + 2] == 128 ? 3 : 4));
byte[] pemPrime1 = (keySize1024 ? new byte[64] : new byte[128]);
Array.Copy(keyData, index, pemPrime1, 0, pemPrime1.Length);

index += pemPrime1.Length;
index += (keySize1024 ? ((int)keyData[index + 1] == 64 ? 2 : 3) : ((int)keyData[index + 2] == 128 ? 3 : 4));
byte[] pemPrime2 = (keySize1024 ? new byte[64] : new byte[128]);
Array.Copy(keyData, index, pemPrime2, 0, pemPrime2.Length);

index += pemPrime2.Length;
index += (keySize1024 ? ((int)keyData[index + 1] == 64 ? 2 : 3) : ((int)keyData[index + 2] == 128 ? 3 : 4));
byte[] pemExponent1 = (keySize1024 ? new byte[64] : new byte[128]);
Array.Copy(keyData, index, pemExponent1, 0, pemExponent1.Length);

index += pemExponent1.Length;
index += (keySize1024 ? ((int)keyData[index + 1] == 64 ? 2 : 3) : ((int)keyData[index + 2] == 128 ? 3 : 4));
byte[] pemExponent2 = (keySize1024 ? new byte[64] : new byte[128]);
Array.Copy(keyData, index, pemExponent2, 0, pemExponent2.Length);

index += pemExponent2.Length;
index += (keySize1024 ? ((int)keyData[index + 1] == 64 ? 2 : 3) : ((int)keyData[index + 2] == 128 ? 3 : 4));
byte[] pemCoefficient = (keySize1024 ? new byte[64] : new byte[128]);
Array.Copy(keyData, index, pemCoefficient, 0, pemCoefficient.Length);

var para = new RSAParameters
{
Modulus = pemModulus,
Exponent = pemPublicExponent,
D = pemPrivateExponent,
P = pemPrime1,
Q = pemPrime2,
DP = pemExponent1,
DQ = pemExponent2,
InverseQ = pemCoefficient
};
return para;
}

/// <summary>
/// 将pem格式公钥转换为RSAParameters
/// </summary>
/// <param name="pemFileConent">pem公钥内容</param>
/// <returns>转换得到的RSAParamenters</returns>
public static RSAParameters ConvertFromPemNormalPublicKey(string pemFileConent)
{
if (string.IsNullOrEmpty(pemFileConent))
{
throw new ArgumentNullException("pemFileConent", "This arg cann't be empty.");
}
pemFileConent = pemFileConent.Replace("-----BEGIN PUBLIC KEY-----", "").Replace("-----END PUBLIC KEY-----", "").Replace("\n", "").Replace("\r", "");
byte[] keyData = Convert.FromBase64String(pemFileConent);
if (keyData.Length < 162)
{
throw new ArgumentException("pem file content is incorrect.");
}
byte[] pemModulus = new byte[128];
byte[] pemPublicExponent = new byte[3];
Array.Copy(keyData, 29, pemModulus, 0, 128);
Array.Copy(keyData, 159, pemPublicExponent, 0, 3);
RSAParameters para = new RSAParameters();
para.Modulus = pemModulus;
para.Exponent = pemPublicExponent;
return para;
}

/// <summary>
/// 将pem格式私钥转换为RSAParameters
/// </summary>
/// <param name="pemFileConent">pem私钥内容</param>
/// <returns>转换得到的RSAParamenters</returns>
public static RSAParameters ConvertFromPemNormalPrivateKey(string pemFileConent)
{
if (string.IsNullOrEmpty(pemFileConent))
{
throw new ArgumentNullException("pemFileConent", "This arg cann't be empty.");
}
//pemFileConent = pemFileConent.Replace("-----BEGIN RSA PRIVATE KEY-----", "").Replace("-----END RSA PRIVATE KEY-----", "").Replace("\n", "").Replace("\r", "");
pemFileConent = pemFileConent.Replace("-----BEGIN PRIVATE KEY-----", "").Replace("-----END PRIVATE KEY-----", "").Replace("\n", "").Replace("\r", "");
byte[] keyData = Convert.FromBase64String(pemFileConent);
if (keyData.Length < 609)
{
throw new ArgumentException("pem file content is incorrect.");
}

int index = 11;
byte[] pemModulus = new byte[128];
Array.Copy(keyData, index, pemModulus, 0, 128);

index += 128;
index += 2;//141
byte[] pemPublicExponent = new byte[3];
Array.Copy(keyData, index, pemPublicExponent, 0, 3);

index += 3;
index += 4;//148
byte[] pemPrivateExponent = new byte[128];
Array.Copy(keyData, index, pemPrivateExponent, 0, 128);

index += 128;
index += ((int)keyData[index + 1] == 64 ? 2 : 3);//279
byte[] pemPrime1 = new byte[64];
Array.Copy(keyData, index, pemPrime1, 0, 64);

index += 64;
index += ((int)keyData[index + 1] == 64 ? 2 : 3);//346
byte[] pemPrime2 = new byte[64];
Array.Copy(keyData, index, pemPrime2, 0, 64);

index += 64;
index += ((int)keyData[index + 1] == 64 ? 2 : 3);//412/413
byte[] pemExponent1 = new byte[64];
Array.Copy(keyData, index, pemExponent1, 0, 64);

index += 64;
index += ((int)keyData[index + 1] == 64 ? 2 : 3);//479/480
byte[] pemExponent2 = new byte[64];
Array.Copy(keyData, index, pemExponent2, 0, 64);

index += 64;
index += ((int)keyData[index + 1] == 64 ? 2 : 3);//545/546
byte[] pemCoefficient = new byte[64];
Array.Copy(keyData, index, pemCoefficient, 0, 64);

RSAParameters para = new RSAParameters();
para.Modulus = pemModulus;
para.Exponent = pemPublicExponent;
para.D = pemPrivateExponent;
para.P = pemPrime1;
para.Q = pemPrime2;
para.DP = pemExponent1;
para.DQ = pemExponent2;
para.InverseQ = pemCoefficient;
return para;
}
}