/// <summary>
/// 根据十六进制还是base64来进行RSA的初始化
/// </summary>
/// <param name="privateKey"></param>
/// <returns></returns>
public static RSA CreateRsaProviderFromPrivateKey(byte[] privateKeyByte)
{
using (var rsa = RSA.Create())
{
var rsaParameters = new RSAParameters();
using (BinaryReader binr = new BinaryReader(new MemoryStream(privateKeyByte)))
{
byte bt = 0;
ushort twobytes = 0;
twobytes = binr.ReadUInt16();
if (twobytes == 0x8130)
{
binr.ReadByte();
}
else if (twobytes == 0x8230)
{
binr.ReadInt16();
}
else
{
throw new Exception("Unexpected value read binr.ReadUInt16()");
}
twobytes = binr.ReadUInt16();
if (twobytes != 0x0102)
{
throw new Exception("Unexpected version");
}
bt = binr.ReadByte();
if (bt != 0x00)
{
throw new Exception("Unexpected value read binr.ReadByte()");
}
rsaParameters.Modulus = binr.ReadBytes(SecretAlg.GetIntegerSize(binr));
rsaParameters.Exponent = binr.ReadBytes(SecretAlg.GetIntegerSize(binr));
rsaParameters.D = binr.ReadBytes(SecretAlg.GetIntegerSize(binr));
rsaParameters.P = binr.ReadBytes(SecretAlg.GetIntegerSize(binr));
rsaParameters.Q = binr.ReadBytes(SecretAlg.GetIntegerSize(binr));
rsaParameters.DP = binr.ReadBytes(SecretAlg.GetIntegerSize(binr));
rsaParameters.DQ = binr.ReadBytes(SecretAlg.GetIntegerSize(binr));
rsaParameters.InverseQ = binr.ReadBytes(SecretAlg.GetIntegerSize(binr));
}
rsa.ImportParameters(rsaParameters);
return(rsa);
}
}
/// <summary>
/// 根据十六进制还是base64来进行RSA的初始化
/// </summary>
/// <param name="publicKeyString"></param>
/// <returns></returns>
public static RSA CreateRsaProviderFromPublicKey(byte[] publicKeyByte)
{
// 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[] seq = new byte[15];
// --------- Set up stream to read the asn.1 encoded SubjectPublicKeyInfo blob ------
using (MemoryStream mem = new MemoryStream(publicKeyByte))
{
using (BinaryReader binr = new BinaryReader(mem)) //wrap Memory Stream with BinaryReader for easy reading
{
byte bt = 0;
ushort twobytes = 0;
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 (!SecretAlg.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 -----
using (var rsa = RSA.Create())
{
RSAParameters rsaKeyInfo = new RSAParameters
{
Modulus = modulus,
Exponent = exponent
};
rsa.ImportParameters(rsaKeyInfo);
return(rsa);
}
}
}
}
