我正在编写一个.Net类，它从我们的中央身份验证服务器读取cookie。它包含UserId，一些时间戳和openssl_sign（）使用2048位RSA密钥和SHA1哈希创建的签名。
当前公钥在服务器上以 openssl PEM 格式提供，有时会更改。我无法单独使用 .Net 托管代码读取密钥（尚），并制定了以下过程以使其工作：
- 从公钥中提取指数和模数
- 校验键仍然是 2048 位
- 存储键长度，在 Source 中对模数进行指数化，编译和部署（从模中删除前导零以使其工作）
然后，该类创建一个new RSACryptoServiceProvider(2048)，并使用RSAParameters结构将公共组件馈送到 CSP 中。然后，签名验证成功。
我希望在每次密钥更改时无需创建、编译和部署新程序集即可使其正常工作。为了使事情变得有趣，我想只坚持使用托管代码（排除我找到的大多数示例）。听起来很完美的是创建AsnEncodedData(oid, data)实例时的内部 ASN.1 读取器，但我发现唯一可以匹配的 oid，RSA aka 1.2.840.113549.1.1.1，不起作用，仅产生原始字节。
新增：以前的公钥
-----开始公钥
-----
----- MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAMW90O6C17fapbS35auKolsy7kI0FOE1
C08y5HqgZ0rMXoocV4nHSHYBm2HVx2QSR5OLQtERgWDmxOu+vwU1GXUCAwEAAQ==
-----结束公钥
我发现 pempublic.cs 似乎使用来自 openSSL 的源代码（看起来）解决了这个问题。我将把这个问题留待解决，看看是否有任何其他解决方案。
要加载私钥，让我们使用以下代码：
private RSACryptoServiceProvider GetPrivateKey(string privateKey)
{
byte[] privkey = Convert.FromBase64String(privateKey);
byte[] MODULUS, E, D, P, Q, DP, DQ, IQ;
// --------- Set up stream to decode the asn.1 encoded RSA private key ------
MemoryStream mem = new MemoryStream(privkey);
BinaryReader binr = new BinaryReader(mem); //wrap Memory Stream with BinaryReader for easy reading
byte bt = 0;
ushort twobytes = 0;
int elems = 0;
try
{
twobytes = binr.ReadUInt16();
if (twobytes == 0x8130) //data read as little endian order (actual data order for Sequence is 30 81)
binr.ReadByte(); //advance 1 byte
else if (twobytes == 0x8230)
binr.ReadInt16(); //advance 2 bytes
else
return null;
twobytes = binr.ReadUInt16();
if (twobytes != 0x0102) //version number
return null;
bt = binr.ReadByte();
if (bt != 0x00)
return null;
//------ all private key components are Integer sequences ----
elems = GetIntegerSize(binr);
MODULUS = binr.ReadBytes(elems);
elems = GetIntegerSize(binr);
E = binr.ReadBytes(elems);
elems = GetIntegerSize(binr);
D = binr.ReadBytes(elems);
elems = GetIntegerSize(binr);
P = binr.ReadBytes(elems);
elems = GetIntegerSize(binr);
Q = binr.ReadBytes(elems);
elems = GetIntegerSize(binr);
DP = binr.ReadBytes(elems);
elems = GetIntegerSize(binr);
DQ = binr.ReadBytes(elems);
elems = GetIntegerSize(binr);
IQ = binr.ReadBytes(elems);
// ------- create RSACryptoServiceProvider instance and initialize with public key -----
CspParameters CspParameters = new CspParameters();
CspParameters.Flags = CspProviderFlags.UseMachineKeyStore;
RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(1024, CspParameters);
RSAParameters RSAparams = new RSAParameters();
RSAparams.Modulus = MODULUS;
RSAparams.Exponent = E;
RSAparams.D = D;
RSAparams.P = P;
RSAparams.Q = Q;
RSAparams.DP = DP;
RSAparams.DQ = DQ;
RSAparams.InverseQ = IQ;
RSA.ImportParameters(RSAparams);
return RSA;
}
catch (Exception ex)
{
return null;
}
finally
{
binr.Close();
}
}
要加载公钥，让我们使用以下代码：
private RSACryptoServiceProvider GetPublicKey(string publicKeyString)
{
// encoded OID sequence for PKCS #1 rsaEncryption szOID_RSA_RSA = "1.2.840.113549.1.1.1"
byte[] SeqOID = {0x30, 0x0D, 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x01, 0x01, 0x05, 0x00} ;
byte[] x509key;
byte[] seq = new byte[15];
int x509size;
x509key = Convert.FromBase64String(publicKeyString);
x509size = x509key.Length;
// --------- Set up stream to read the asn.1 encoded SubjectPublicKeyInfo blob ------
MemoryStream mem = new MemoryStream(x509key);
BinaryReader binr = new BinaryReader(mem); //wrap Memory Stream with BinaryReader for easy reading
byte bt = 0;
ushort twobytes = 0;
try
{
twobytes = binr.ReadUInt16();
if (twobytes == 0x8130) //data read as little endian order (actual data order for Sequence is 30 81)
binr.ReadByte(); //advance 1 byte
else if (twobytes == 0x8230)
binr.ReadInt16(); //advance 2 bytes
else
return null;
seq = binr.ReadBytes(15); //read the Sequence OID
if (!CompareBytearrays(seq, SeqOID)) //make sure Sequence for OID is correct
return null;
twobytes = binr.ReadUInt16();
if (twobytes == 0x8103) //data read as little endian order (actual data order for Bit String is 03 81)
binr.ReadByte(); //advance 1 byte
else if (twobytes == 0x8203)
binr.ReadInt16(); //advance 2 bytes
else
return null;
bt = binr.ReadByte();
if (bt != 0x00) //expect null byte next
return null;
twobytes = binr.ReadUInt16();
if (twobytes == 0x8130) //data read as little endian order (actual data order for Sequence is 30 81)
binr.ReadByte(); //advance 1 byte
else if (twobytes == 0x8230)
binr.ReadInt16(); //advance 2 bytes
else
return null;
twobytes = binr.ReadUInt16();
byte lowbyte = 0x00;
byte highbyte = 0x00;
if (twobytes == 0x8102) //data read as little endian order (actual data order for Integer is 02 81)
lowbyte = binr.ReadByte(); // read next bytes which is bytes in modulus
else if (twobytes == 0x8202)
{
highbyte = binr.ReadByte(); //advance 2 bytes
lowbyte = binr.ReadByte();
}
else
return null;
byte[] modint = { lowbyte, highbyte, 0x00, 0x00 }; //reverse byte order since asn.1 key uses big endian order
int modsize = BitConverter.ToInt32(modint, 0);
int firstbyte = binr.PeekChar();
if (firstbyte == 0x00)
{ //if first byte (highest order) of modulus is zero, don't include it
binr.ReadByte(); //skip this null byte
modsize -= 1; //reduce modulus buffer size by 1
}
byte[] modulus = binr.ReadBytes(modsize); //read the modulus bytes
if (binr.ReadByte() != 0x02) //expect an Integer for the exponent data
return null;
int expbytes = (int)binr.ReadByte(); // should only need one byte for actual exponent data (for all useful values)
byte[] exponent = binr.ReadBytes(expbytes);
// ------- create RSACryptoServiceProvider instance and initialize with public key -----
RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
RSAParameters RSAKeyInfo = new RSAParameters();
RSAKeyInfo.Modulus = modulus;
RSAKeyInfo.Exponent = exponent;
RSA.ImportParameters(RSAKeyInfo);
return RSA;
}
finally
{
binr.Close();
}
}
您可以在此处阅读原始帖子以获取更多详细信息
您有私钥，因此从密钥生成自签名证书可能更容易。您可以使用System.Security.Cryptography.X509Certificates.X509Certificate（我认为您应该拥有 DER/ASN.1 格式而不是 PEM 格式的证书）来加载证书并X509Certificate.GetPublicKey()获取公钥。