public static RSACryptoServiceProvider ParseRSAPublicKey(Asn1Sequence RSAPublicKey)
{
Byte[][] RSAPublicKeyData;
RSAParameters RSAParams = new RSAParameters();
if (RSAPublicKey.SequenceLength != 2)
{
throw new ArgumentException("ASN.1 Sequence has wrong number of elements for RSAPublicKey.");
}
RSAPublicKeyData = new Byte[RSAPublicKey.SequenceLength][];
for(int i=0; i<RSAPublicKey.SequenceLength; i++)
{
RSAPublicKeyData[i] = RSAPublicKey[i].ContentsToArray();
// Trim leading zeros if any
if ( (RSAPublicKeyData[i][0] == 0x00) && (RSAPublicKeyData[i].Length > 1) )
{
Byte[] temp = new Byte[RSAPublicKeyData[i].Length - 1];
Array.Copy(RSAPublicKeyData[i],1,temp,0,RSAPublicKeyData[i].Length - 1);
RSAPublicKeyData[i] = temp;
}
}
RSAParams.Modulus = RSAPublicKeyData[0];
RSAParams.Exponent = RSAPublicKeyData[1];
// Import the params into the RSA CSP
try
{
RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
RSA.ImportParameters(RSAParams);
return RSA;
}
catch
{
return null;
}
}
private static RSACryptoServiceProvider LoadPEMKey(String fileName)
{
StreamReader sr = File.OpenText(fileName);
String fileStr = sr.ReadToEnd().Trim();
sr.Close();
if( fileStr.StartsWith(PEMStartString+PEMPubString) && fileStr.EndsWith(PEMEndString+PEMPubString) )
{
// Unencrypted Private Key PEM file
byte[] keyBlob = null;
Console.WriteLine("Reading PEM public key from file {0}...", fileName);
fileStr = TrimPEMData(fileStr);
try
{
// Get binary data from Base64 string
keyBlob = Convert.FromBase64String (fileStr);
// Convert binary data to ASN.1 Sequence object and then parse the sequence
// into RSAPrivateKey Components, then use to create an RSA CSP object.
Asn1Sequence seq = new Asn1Sequence(keyBlob);
if (seq.SequenceLength == 2)
{
if ( (seq[0].ContentID.TagNumber == Asn1TagNumber.INTEGER) &&
(seq[1].ContentID.TagNumber == Asn1TagNumber.INTEGER) )
{
return ParseRSAPublicKey(seq);
}
else if ( (seq[0].ContentID.TagNumber == Asn1TagNumber.SEQUENCE) &&
(seq[1].ContentID.TagNumber == Asn1TagNumber.BITSTRING) )
{
Byte[] tempData = seq[1].ContentsToArray();
// Trim leading zeros in BitString
if ( (tempData[0] == 0x00) && (tempData.Length > 1) )
{
Byte[] tempData2 = new Byte[tempData.Length - 1];
Array.Copy(tempData,1,tempData2,0,tempData.Length - 1);
tempData = tempData2;
}
// Now see if we can interpret the BITSTRING data as an ASN.1 Sequence
seq = new Asn1Sequence(tempData);
if ( (seq.SequenceLength == 2) &&
(seq[0].ContentID.TagNumber == Asn1TagNumber.INTEGER) &&
(seq[1].ContentID.TagNumber == Asn1TagNumber.INTEGER) )
{
return ParseRSAPublicKey(seq);
}
else
{
return null;
}
}
else
{
return null;
}
}
else
{
return null;
}
}
catch(FormatException )
{
Console.WriteLine("Error in the PEM data!");
return null;
}
}
else if( fileStr.StartsWith(PEMStartString+PEMPrivString) && fileStr.EndsWith(PEMEndString+PEMPrivString) )
{
// Unencrypted Private Key PEM file
byte[] keyBlob = null;
Console.WriteLine("Reading PEM private key from file {0}...", fileName);
fileStr = TrimPEMData(fileStr);
try
{
// Get binary data from Base64 string
keyBlob = Convert.FromBase64String (fileStr);
// Convert binary data to ASN.1 Sequence object and then parse the sequence
// into RSAPrivateKey Components, then use to create an RSA CSP object.
return ParseRSAPrivateKey(new Asn1Sequence(keyBlob));
}
catch(FormatException )
{
Console.WriteLine("Error in the PEM data!");
return null;
}
}
else if( fileStr.StartsWith(PEMStartString+PEMPKCS8PrivString) && fileStr.EndsWith(PEMEndString+PEMPKCS8PrivString) )
{
// Unencrypted PKCS#8 Private Key PEM file
Console.WriteLine("Reading PKCS#8 PEM private key from file {0}...", fileName);
return null;
}
else if( fileStr.StartsWith(PEMStartString+PEMPKCS8EncPrivString) && fileStr.EndsWith(PEMEndString+PEMPKCS8EncPrivString) )
{
// Encrypted PKCS#8 Private Key PEM file
Console.WriteLine("Reading Encrypted PKCS#8 PEM private key from file {0}...", fileName);
return null;
}
else
return null;
}
/* ASN.1 definitions from PKCS#1 v2.1
RSAPublicKey ::= SEQUENCE {
modulus INTEGER, -- n
publicExponent INTEGER -- e
}
--
-- Representation of RSA private key with information for the CRT algorithm.
--
RSAPrivateKey ::= SEQUENCE {
version Version,
modulus INTEGER, -- n
publicExponent INTEGER, -- e
privateExponent INTEGER, -- d
prime1 INTEGER, -- p
prime2 INTEGER, -- q
exponent1 INTEGER, -- d mod (p-1)
exponent2 INTEGER, -- d mod (q-1)
coefficient INTEGER, -- (inverse of q) mod p
otherPrimeInfos OtherPrimeInfos OPTIONAL
}
Version ::= INTEGER { two-prime(0), multi(1) }
(CONSTRAINED BY {-- version must be multi if otherPrimeInfos present --})
OtherPrimeInfos ::= SEQUENCE SIZE(1..MAX) OF OtherPrimeInfo
OtherPrimeInfo ::= SEQUENCE {
prime INTEGER, -- ri
exponent INTEGER, -- di
coefficient INTEGER -- ti
}
*/
public static RSACryptoServiceProvider ParseRSAPrivateKey(Asn1Sequence RSAPrivateKey)
{
Byte[][] RSAPrivateKeyData;
RSAParameters RSAParams = new RSAParameters();
if ( (RSAPrivateKey.SequenceLength != 9) && (RSAPrivateKey.SequenceLength != 10) )
throw new ArgumentException("ASN.1 Sequence has wrong number of elements for RSAPrivateKey.");
RSAPrivateKeyData = new Byte[RSAPrivateKey.SequenceLength][];
for(int i=0; i<RSAPrivateKey.SequenceLength; i++)
{
RSAPrivateKeyData[i] = RSAPrivateKey[i].ContentsToArray();
// Trim leading zeros if any
if ( (RSAPrivateKeyData[i][0] == 0x00) && (RSAPrivateKeyData[i].Length > 1) )
{
Byte[] temp = new Byte[RSAPrivateKeyData[i].Length - 1];
Array.Copy(RSAPrivateKeyData[i],1,temp,0,RSAPrivateKeyData[i].Length - 1);
RSAPrivateKeyData[i] = temp;
}
}
// Verify version is v2.1
//Console.WriteLine(RSAPrivateKeyData[0][0]);
//Console.WriteLine(RSAPrivateKeyData[0][1]);
//if( (RSAPrivateKeyData[0][0] != 0x02) || (RSAPrivateKeyData[0][1] != 0x01) )
// throw new ArgumentException("ASN.1 RSAPrivateKey Sequence has wrong version number.");
// rsaData[0] is version field
RSAParams.Modulus = RSAPrivateKeyData[1];
RSAParams.Exponent = RSAPrivateKeyData[2];
RSAParams.D = RSAPrivateKeyData[3];
RSAParams.P = RSAPrivateKeyData[4];
RSAParams.Q = RSAPrivateKeyData[5];
RSAParams.DP = RSAPrivateKeyData[6];
RSAParams.DQ = RSAPrivateKeyData[7];
RSAParams.InverseQ = RSAPrivateKeyData[8];
// Import the params into the RSA CSP
try
{
RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
RSA.ImportParameters(RSAParams);
return RSA;
}
catch
{
return null;
}
}
