OpenSSLKey

http://www.jensign.com/opensslkey/opensslkey.cs

//**********************************************************************************

//

//OpenSSLKey
// .NET 2.0 OpenSSL Public & Private Key Parser
//
/*
Copyright (c) 2000 JavaScience Consulting, Michel Gallant

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
//***********************************************************************************
//
// opensslkey.cs
//
// Reads and parses:
// (1) OpenSSL PEM or DER public keys
// (2) OpenSSL PEM or DER traditional SSLeay private keys (encrypted and unencrypted)
// (3) PKCS #8 PEM or DER encoded private keys (encrypted and unencrypted)
// Keys in PEM format must have headers/footers .
// Encrypted Private Key in SSLEay format not supported in DER
// Removes header/footer lines.
// For traditional SSLEAY PEM private keys, checks for encrypted format and
// uses PBE to extract 3DES key.
// For SSLEAY format, only supports encryption format: DES-EDE3-CBC
// For PKCS #8, only supports PKCS#5 v2.0 3des.
// Parses private and public key components and returns .NET RSA object.
// Creates dummy unsigned certificate linked to private keypair and
// optionally exports to pkcs #12
//
// See also:
// http://www.openssl.org/docs/crypto/pem.html#PEM_ENCRYPTION_FORMAT
//**************************************************************************************

using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Runtime.InteropServices;
using System.Security;
using System.Diagnostics;
using System.ComponentModel;

namespace JavaScience {

public class Win32 {

[DllImport("crypt32.dll", SetLastError=true)]
public static extern IntPtr CertCreateSelfSignCertificate(
IntPtr hProv,
ref CERT_NAME_BLOB pSubjectIssuerBlob,
uint dwFlagsm,
ref CRYPT_KEY_PROV_INFO pKeyProvInfo,
IntPtr pSignatureAlgorithm,
IntPtr pStartTime,
IntPtr pEndTime,
IntPtr other) ;

[DllImport("crypt32.dll", SetLastError=true)]
public static extern bool CertStrToName(
uint dwCertEncodingType,
String pszX500,
uint dwStrType,
IntPtr pvReserved,
[In, Out] byte[] pbEncoded,
ref uint pcbEncoded,
IntPtr other);

[DllImport("crypt32.dll", SetLastError=true)]
public static extern bool CertFreeCertificateContext(
IntPtr hCertStore) ;

}

[StructLayout(LayoutKind.Sequential)]
public struct CRYPT_KEY_PROV_INFO
{
[MarshalAs(UnmanagedType.LPWStr)] public String pwszContainerName;
[MarshalAs(UnmanagedType.LPWStr)] public String pwszProvName;
public uint dwProvType;
public uint dwFlags;
public uint cProvParam;
public IntPtr rgProvParam;
public uint dwKeySpec;
}

[StructLayout(LayoutKind.Sequential)]
public struct CERT_NAME_BLOB
{
public int cbData;
public IntPtr pbData;
}

public class opensslkey {

const String pemprivheader = "-----BEGIN RSA PRIVATE KEY-----" ;
const String pemprivfooter = "-----END RSA PRIVATE KEY-----" ;
const String pempubheader = "-----BEGIN PUBLIC KEY-----" ;
const String pempubfooter = "-----END PUBLIC KEY-----" ;
const String pemp8header = "-----BEGIN PRIVATE KEY-----" ;
const String pemp8footer = "-----END PRIVATE KEY-----" ;
const String pemp8encheader = "-----BEGIN ENCRYPTED PRIVATE KEY-----" ;
const String pemp8encfooter = "-----END ENCRYPTED PRIVATE KEY-----" ;

// static byte[] pempublickey;
// static byte[] pemprivatekey;
// static byte[] pkcs8privatekey;
// static byte[] pkcs8encprivatekey;

static bool verbose = false;

public static void Main(String[] args) {

if(args.Length == 1)
if(args[0].ToUpper() == "V")
verbose = true;

Console.ForegroundColor = ConsoleColor.Gray;
Console.Write(" RSA public, private or PKCS #8 key file to decode: ");
String filename = Console.ReadLine().Trim();
if (filename == "") //exit while(true) loop
return;
if (!File.Exists(filename)) {
Console.WriteLine("File "{0}" does not exist! ", filename);
return;
}

StreamReader sr = File.OpenText(filename);
String pemstr = sr.ReadToEnd().Trim();
sr.Close();
if(pemstr.StartsWith("-----BEGIN"))
DecodePEMKey(pemstr);
else
DecodeDERKey(filename);
}

// ------- Decode PEM pubic, private or pkcs8 key ----------------
public static void DecodePEMKey(String pemstr)
{
byte[] pempublickey;
byte[] pemprivatekey;
byte[] pkcs8privatekey;
byte[] pkcs8encprivatekey;

if(pemstr.StartsWith(pempubheader) && pemstr.EndsWith(pempubfooter))
{
Console.WriteLine("Trying to decode and parse a PEM public key ..");
pempublickey = DecodeOpenSSLPublicKey(pemstr);
if(pempublickey != null)
{
if(verbose)
showBytes(" RSA public key", pempublickey) ;
//PutFileBytes("rsapubkey.pem", pempublickey, pempublickey.Length) ;
RSACryptoServiceProvider rsa = DecodeX509PublicKey(pempublickey);
Console.WriteLine(" Created an RSACryptoServiceProvider instance ") ;
String xmlpublickey =rsa.ToXmlString(false) ;
Console.WriteLine(" XML RSA public key: {0} bits {1} ", rsa.KeySize, xmlpublickey) ;
}
}

else if(pemstr.StartsWith(pemprivheader) && pemstr.EndsWith(pemprivfooter))
{
Console.WriteLine("Trying to decrypt and parse a PEM private key ..");
pemprivatekey = DecodeOpenSSLPrivateKey(pemstr);
if(pemprivatekey != null)
{
if(verbose)
showBytes(" RSA private key", pemprivatekey) ;
//PutFileBytes("rsaprivkey.pem", pemprivatekey, pemprivatekey.Length) ;
RSACryptoServiceProvider rsa = DecodeRSAPrivateKey(pemprivatekey);
Console.WriteLine(" Created an RSACryptoServiceProvider instance ") ;
String xmlprivatekey =rsa.ToXmlString(true) ;
Console.WriteLine(" XML RSA private key: {0} bits {1} ", rsa.KeySize, xmlprivatekey) ;
ProcessRSA(rsa);
}
}

else if(pemstr.StartsWith(pemp8header) && pemstr.EndsWith(pemp8footer))
{
Console.WriteLine("Trying to decode and parse as PEM PKCS #8 PrivateKeyInfo ..");
pkcs8privatekey = DecodePkcs8PrivateKey(pemstr);
if(pkcs8privatekey != null)
{
if(verbose)
showBytes(" PKCS #8 PrivateKeyInfo", pkcs8privatekey) ;
//PutFileBytes("PrivateKeyInfo", pkcs8privatekey, pkcs8privatekey.Length) ;
RSACryptoServiceProvider rsa = DecodePrivateKeyInfo(pkcs8privatekey);
if(rsa !=null)
{
Console.WriteLine(" Created an RSACryptoServiceProvider instance ") ;
String xmlprivatekey =rsa.ToXmlString(true) ;
Console.WriteLine(" XML RSA private key: {0} bits {1} ", rsa.KeySize, xmlprivatekey) ;
ProcessRSA(rsa) ;
}
else
Console.WriteLine(" Failed to create an RSACryptoServiceProvider");
}
}

else if(pemstr.StartsWith(pemp8encheader) && pemstr.EndsWith(pemp8encfooter))
{
Console.WriteLine("Trying to decode and parse as PEM PKCS #8 EncryptedPrivateKeyInfo ..");
pkcs8encprivatekey = DecodePkcs8EncPrivateKey(pemstr);
if(pkcs8encprivatekey != null)
{
if(verbose)
showBytes(" PKCS #8 EncryptedPrivateKeyInfo", pkcs8encprivatekey) ;
//PutFileBytes("EncryptedPrivateKeyInfo", pkcs8encprivatekey, pkcs8encprivatekey.Length) ;
RSACryptoServiceProvider rsa = DecodeEncryptedPrivateKeyInfo(pkcs8encprivatekey);
if(rsa !=null)
{
Console.WriteLine(" Created an RSACryptoServiceProvider instance ") ;
String xmlprivatekey =rsa.ToXmlString(true) ;
Console.WriteLine(" XML RSA private key: {0} bits {1} ", rsa.KeySize, xmlprivatekey) ;
ProcessRSA(rsa) ;
}
else
Console.WriteLine(" Failed to create an RSACryptoServiceProvider");
}
}

else
{
Console.WriteLine("Not a PEM public, private key or a PKCS #8");
return;
}
}

// ------- Decode PEM pubic, private or pkcs8 key ----------------
public static void DecodeDERKey(String filename)
{
RSACryptoServiceProvider rsa = null ;
byte[] keyblob = GetFileBytes(filename);
if(keyblob == null)
return;

rsa = DecodeX509PublicKey(keyblob);
if(rsa !=null)
{
Console.WriteLine(" A valid SubjectPublicKeyInfo ") ;
Console.WriteLine(" Created an RSACryptoServiceProvider instance ") ;
String xmlpublickey =rsa.ToXmlString(false) ;
Console.WriteLine(" XML RSA public key: {0} bits {1} ", rsa.KeySize, xmlpublickey) ;
return;
}

rsa = DecodeRSAPrivateKey(keyblob);
if(rsa != null)
{
Console.WriteLine(" A valid RSAPrivateKey ") ;
Console.WriteLine(" Created an RSACryptoServiceProvider instance ") ;
String xmlprivatekey =rsa.ToXmlString(true) ;
Console.WriteLine(" XML RSA private key: {0} bits {1} ", rsa.KeySize, xmlprivatekey) ;
ProcessRSA(rsa) ;
return;
}

rsa = DecodePrivateKeyInfo(keyblob); //PKCS #8 unencrypted
if(rsa !=null)
{
Console.WriteLine(" A valid PKCS #8 PrivateKeyInfo ") ;
Console.WriteLine(" Created an RSACryptoServiceProvider instance ") ;
String xmlprivatekey =rsa.ToXmlString(true) ;
Console.WriteLine(" XML RSA private key: {0} bits {1} ", rsa.KeySize, xmlprivatekey) ;
ProcessRSA(rsa);
return;
}

rsa = DecodeEncryptedPrivateKeyInfo(keyblob); //PKCS #8 encrypted
if(rsa !=null) {
Console.WriteLine(" A valid PKCS #8 EncryptedPrivateKeyInfo ") ;
Console.WriteLine(" Created an RSACryptoServiceProvider instance ") ;
String xmlprivatekey =rsa.ToXmlString(true) ;
Console.WriteLine(" XML RSA private key: {0} bits {1} ", rsa.KeySize, xmlprivatekey) ;
ProcessRSA(rsa);
return;
}
Console.WriteLine("Not a binary DER public, private or PKCS #8 key");
return;
}

public static void ProcessRSA(RSACryptoServiceProvider rsa)
{
if(verbose)
showRSAProps(rsa);
Console.Write(" Export RSA private key to PKCS #12 file? (Y or N) ");
String resp = Console.ReadLine().ToUpper() ;
if(resp == "Y" || resp == "YES")
RSAtoPKCS12(rsa) ;
}

//-------- Generate pkcs #12 from an RSACryptoServiceProvider ---------
public static void RSAtoPKCS12(RSACryptoServiceProvider rsa)
{
CspKeyContainerInfo keyInfo = rsa.CspKeyContainerInfo;
String keycontainer = keyInfo.KeyContainerName;
uint keyspec = (uint) keyInfo.KeyNumber;
String provider = keyInfo.ProviderName;
uint cspflags = 0; //CryptoAPI Current User store; LM would be CRYPT_MACHINE_KEYSET = 0x00000020
String fname = keycontainer + ".p12" ;
//---- need to pass in rsa since underlying keycontainer is not persisted and might be deleted too quickly ---
byte[] pkcs12 = GetPkcs12(rsa, keycontainer, provider, keyspec , cspflags) ;
if ( (pkcs12 !=null) && verbose)
showBytes(" pkcs #12", pkcs12);
if(pkcs12 !=null){
PutFileBytes(fname, pkcs12, pkcs12.Length) ;
Console.WriteLine(" Wrote pkc #12 file '{0}' ", fname) ;
}
else
Console.WriteLine(" Problem getting pkcs#12") ;
}

//-------- Get the binary PKCS #8 PRIVATE key --------
public static byte[] DecodePkcs8PrivateKey(String instr)
{
const String pemp8header = "-----BEGIN PRIVATE KEY-----" ;
const String pemp8footer = "-----END PRIVATE KEY-----" ;
String pemstr = instr.Trim() ;
byte[] binkey;
if(!pemstr.StartsWith(pemp8header) || !pemstr.EndsWith(pemp8footer))
return null;
StringBuilder sb = new StringBuilder(pemstr) ;
sb.Replace(pemp8header, "") ; //remove headers/footers, if present
sb.Replace(pemp8footer, "") ;

String pubstr = sb.ToString().Trim(); //get string after removing leading/trailing whitespace

try{
binkey = Convert.FromBase64String(pubstr) ;
}
catch(System.FormatException) { //if can't b64 decode, data is not valid
return null;
}
return binkey;
}

//------- Parses binary asn.1 PKCS #8 PrivateKeyInfo; returns RSACryptoServiceProvider ---
public static RSACryptoServiceProvider DecodePrivateKeyInfo(byte[] pkcs8)
{
// encoded OID sequence for PKCS #1 rsaEncryption szOID_RSA_RSA = "1.2.840.113549.1.1.1"
// this byte[] includes the sequence byte and terminal encoded null
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 ------
MemoryStream mem = new MemoryStream(pkcs8) ;
int lenstream = (int) mem.Length;
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;

bt = binr.ReadByte();
if(bt != 0x02)
return null;

twobytes = binr.ReadUInt16();

if(twobytes != 0x0001)
return null;

seq = binr.ReadBytes(15); //read the Sequence OID
if(!CompareBytearrays(seq, SeqOID)) //make sure Sequence for OID is correct
return null;

bt = binr.ReadByte();
if(bt != 0x04) //expect an Octet string
return null;

bt = binr.ReadByte(); //read next byte, or next 2 bytes is 0x81 or 0x82; otherwise bt is the byte count
if(bt == 0x81)
binr.ReadByte();
else
if(bt == 0x82)
binr.ReadUInt16();
//------ at this stage, the remaining sequence should be the RSA private key

byte[] rsaprivkey = binr.ReadBytes((int)(lenstream -mem.Position)) ;
RSACryptoServiceProvider rsacsp = DecodeRSAPrivateKey(rsaprivkey);
return rsacsp;
}

catch(Exception){
return null;
}

finally { binr.Close(); }

}

//-------- Get the binary PKCS #8 Encrypted PRIVATE key --------
public static byte[] DecodePkcs8EncPrivateKey(String instr)
{
const String pemp8encheader = "-----BEGIN ENCRYPTED PRIVATE KEY-----" ;
const String pemp8encfooter = "-----END ENCRYPTED PRIVATE KEY-----" ;
String pemstr = instr.Trim() ;
byte[] binkey;
if(!pemstr.StartsWith(pemp8encheader) || !pemstr.EndsWith(pemp8encfooter))
return null;
StringBuilder sb = new StringBuilder(pemstr) ;
sb.Replace(pemp8encheader, "") ; //remove headers/footers, if present
sb.Replace(pemp8encfooter, "") ;

String pubstr = sb.ToString().Trim(); //get string after removing leading/trailing whitespace

try{
binkey = Convert.FromBase64String(pubstr) ;
}
catch(System.FormatException) { //if can't b64 decode, data is not valid
return null;
}
return binkey;
}

//------- Parses binary asn.1 EncryptedPrivateKeyInfo; returns RSACryptoServiceProvider ---
public static RSACryptoServiceProvider DecodeEncryptedPrivateKeyInfo(byte[] encpkcs8)
{
// encoded OID sequence for PKCS #1 rsaEncryption szOID_RSA_RSA = "1.2.840.113549.1.1.1"
// this byte[] includes the sequence byte and terminal encoded null
byte[] OIDpkcs5PBES2 = {0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x05, 0x0D } ;
byte[] OIDpkcs5PBKDF2 = {0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x05, 0x0C } ;
byte[] OIDdesEDE3CBC = {0x06, 0x08, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x03, 0x07} ;
byte[] seqdes = new byte[10] ;
byte[] seq = new byte[11];
byte[] salt ;
byte[] IV;
byte[] encryptedpkcs8;
byte[] pkcs8;

int saltsize, ivsize, encblobsize;
int iterations;

// --------- Set up stream to read the asn.1 encoded SubjectPublicKeyInfo blob ------
MemoryStream mem = new MemoryStream(encpkcs8) ;
int lenstream = (int) mem.Length;
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;

twobytes = binr.ReadUInt16(); //inner sequence
if(twobytes == 0x8130)
binr.ReadByte();
else if(twobytes == 0x8230)
binr.ReadInt16();

seq = binr.ReadBytes(11); //read the Sequence OID
if(!CompareBytearrays(seq, OIDpkcs5PBES2)) //is it a OIDpkcs5PBES2 ?
return null;

twobytes = binr.ReadUInt16(); //inner sequence for pswd salt
if(twobytes == 0x8130)
binr.ReadByte();
else if(twobytes == 0x8230)
binr.ReadInt16();

twobytes = binr.ReadUInt16(); //inner sequence for pswd salt
if(twobytes == 0x8130)
binr.ReadByte();
else if(twobytes == 0x8230)
binr.ReadInt16();

seq = binr.ReadBytes(11); //read the Sequence OID
if(!CompareBytearrays(seq, OIDpkcs5PBKDF2)) //is it a OIDpkcs5PBKDF2 ?
return null;

twobytes = binr.ReadUInt16();
if(twobytes == 0x8130)
binr.ReadByte();
else if(twobytes == 0x8230)
binr.ReadInt16();

bt = binr.ReadByte();
if(bt != 0x04) //expect octet string for salt
return null;
saltsize = binr.ReadByte();
salt = binr.ReadBytes(saltsize);

if(verbose)
showBytes("Salt for pbkd", salt);
bt=binr.ReadByte();
if (bt != 0x02) //expect an integer for PBKF2 interation count
return null;

int itbytes = binr.ReadByte(); //PBKD2 iterations should fit in 2 bytes.
if(itbytes ==1)
iterations = binr.ReadByte();
else if(itbytes == 2)
iterations = 256*binr.ReadByte() + binr.ReadByte();
else
return null;
if(verbose)
Console.WriteLine("PBKD2 iterations {0}", iterations);

twobytes = binr.ReadUInt16();
if(twobytes == 0x8130)
binr.ReadByte();
else if(twobytes == 0x8230)
binr.ReadInt16();

seqdes = binr.ReadBytes(10); //read the Sequence OID
if(!CompareBytearrays(seqdes, OIDdesEDE3CBC)) //is it a OIDdes-EDE3-CBC ?
return null;

bt = binr.ReadByte();
if(bt != 0x04) //expect octet string for IV
return null;
ivsize = binr.ReadByte(); // IV byte size should fit in one byte (24 expected for 3DES)
IV= binr.ReadBytes(ivsize);
if(verbose)
showBytes("IV for des-EDE3-CBC", IV);

bt=binr.ReadByte();
if(bt != 0x04) // expect octet string for encrypted PKCS8 data
return null;

bt = binr.ReadByte();

if(bt == 0x81)
encblobsize = binr.ReadByte(); // data size in next byte
else if(bt == 0x82)
encblobsize = 256*binr.ReadByte() + binr.ReadByte() ;
else
encblobsize = bt; // we already have the data size

encryptedpkcs8 = binr.ReadBytes(encblobsize) ;
//if(verbose)
// showBytes("Encrypted PKCS8 blob", encryptedpkcs8) ;

SecureString secpswd = GetSecPswd("Enter password for Encrypted PKCS #8 ==>") ;
pkcs8 = DecryptPBDK2(encryptedpkcs8, salt, IV, secpswd, iterations) ;
if(pkcs8 == null) // probably a bad pswd entered.
return null;

//if(verbose)
// showBytes("Decrypted PKCS #8", pkcs8) ;
//----- With a decrypted pkcs #8 PrivateKeyInfo blob, decode it to an RSA ---
RSACryptoServiceProvider rsa = DecodePrivateKeyInfo(pkcs8) ;
return rsa;
}

catch(Exception){
return null;
}

finally { binr.Close(); }

}

// ------ Uses PBKD2 to derive a 3DES key and decrypts data --------
public static byte[] DecryptPBDK2(byte[] edata, byte[] salt, byte[]IV, SecureString secpswd, int iterations)
{
CryptoStream decrypt = null;

IntPtr unmanagedPswd = IntPtr.Zero;
byte[] psbytes = new byte[secpswd.Length] ;
unmanagedPswd = Marshal.SecureStringToGlobalAllocAnsi(secpswd);
Marshal.Copy(unmanagedPswd, psbytes, 0, psbytes.Length) ;
Marshal.ZeroFreeGlobalAllocAnsi(unmanagedPswd);

try
{
Rfc2898DeriveBytes kd = new Rfc2898DeriveBytes(psbytes, salt, iterations);
TripleDES decAlg = TripleDES.Create();
decAlg.Key = kd.GetBytes(24);
decAlg.IV = IV;
MemoryStream memstr = new MemoryStream();
decrypt = new CryptoStream(memstr,decAlg.CreateDecryptor(), CryptoStreamMode.Write);
decrypt.Write(edata, 0, edata.Length);
decrypt.Flush();
decrypt.Close() ; // this is REQUIRED.
byte[] cleartext = memstr.ToArray();
return cleartext;
}
catch (Exception e)
{
Console.WriteLine("Problem decrypting: {0}", e.Message) ;
return null;
}
}

//-------- Get the binary RSA PUBLIC key --------
public static byte[] DecodeOpenSSLPublicKey(String instr)
{
const String pempubheader = "-----BEGIN PUBLIC KEY-----" ;
const String pempubfooter = "-----END PUBLIC KEY-----" ;
String pemstr = instr.Trim() ;
byte[] binkey;
if(!pemstr.StartsWith(pempubheader) || !pemstr.EndsWith(pempubfooter))
return null;
StringBuilder sb = new StringBuilder(pemstr) ;
sb.Replace(pempubheader, "") ; //remove headers/footers, if present
sb.Replace(pempubfooter, "") ;

String pubstr = sb.ToString().Trim(); //get string after removing leading/trailing whitespace

try{
binkey = Convert.FromBase64String(pubstr) ;
}
catch(System.FormatException) { //if can't b64 decode, data is not valid
return null;
}
return binkey;
}

//------- Parses binary asn.1 X509 SubjectPublicKeyInfo; returns RSACryptoServiceProvider ---
public static RSACryptoServiceProvider DecodeX509PublicKey(byte[] x509key)
{
// 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 ------
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) ;

byte firstbyte = binr.ReadByte();
binr.BaseStream.Seek(-1, SeekOrigin.Current);

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);

showBytes(" Exponent", exponent);
showBytes(" Modulus", modulus) ;

// ------- 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;
}
catch(Exception){
return null;
}

finally { binr.Close(); }

}

//------- Parses binary ans.1 RSA private key; returns RSACryptoServiceProvider ---
public static RSACryptoServiceProvider DecodeRSAPrivateKey(byte[] privkey)
{
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) ;

Console.WriteLine("showing components ..");
if(verbose) {
showBytes(" Modulus", MODULUS) ;
showBytes(" Exponent", E);
showBytes(" D", D);
showBytes(" P", P);
showBytes(" Q", Q);
showBytes(" DP", DP);
showBytes(" DQ", DQ);
showBytes(" IQ", IQ);
}

// ------- create RSACryptoServiceProvider instance and initialize with public key -----
RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
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){
return null;
}
finally { binr.Close(); }
}

private static int GetIntegerSize(BinaryReader binr) {
byte bt = 0;
byte lowbyte = 0x00;
byte highbyte = 0x00;
int count = 0;
bt = binr.ReadByte();
if(bt != 0x02) //expect integer
return 0;
bt = binr.ReadByte();

if(bt == 0x81)
count = binr.ReadByte(); // data size in next byte
else
if(bt == 0x82) {
highbyte = binr.ReadByte(); // data size in next 2 bytes
lowbyte = binr.ReadByte();
byte[] modint = {lowbyte, highbyte, 0x00, 0x00} ;
count = BitConverter.ToInt32(modint, 0) ;
}
else {
count = bt; // we already have the data size
}

while(binr.ReadByte() == 0x00) { //remove high order zeros in data
count -=1;
}
binr.BaseStream.Seek(-1, SeekOrigin.Current); //last ReadByte wasn't a removed zero, so back up a byte
return count;
}

//----- Get the binary RSA PRIVATE key, decrypting if necessary ----
public static byte[] DecodeOpenSSLPrivateKey(String instr)
{
const String pemprivheader = "-----BEGIN RSA PRIVATE KEY-----" ;
const String pemprivfooter = "-----END RSA PRIVATE KEY-----" ;
String pemstr = instr.Trim() ;
byte[] binkey;
if(!pemstr.StartsWith(pemprivheader) || !pemstr.EndsWith(pemprivfooter))
return null;

StringBuilder sb = new StringBuilder(pemstr) ;
sb.Replace(pemprivheader, "") ; //remove headers/footers, if present
sb.Replace(pemprivfooter, "") ;

String pvkstr = sb.ToString().Trim(); //get string after removing leading/trailing whitespace

try{ // if there are no PEM encryption info lines, this is an UNencrypted PEM private key
binkey = Convert.FromBase64String(pvkstr) ;
return binkey;
}
catch(System.FormatException) { //if can't b64 decode, it must be an encrypted private key
//Console.WriteLine("Not an unencrypted OpenSSL PEM private key");
}

StringReader str = new StringReader(pvkstr);

//-------- read PEM encryption info. lines and extract salt -----
if(!str.ReadLine().StartsWith("Proc-Type: 4,ENCRYPTED"))
return null;
String saltline = str.ReadLine();
if(!saltline.StartsWith("DEK-Info: DES-EDE3-CBC,") )
return null;
String saltstr = saltline.Substring(saltline.IndexOf(",") + 1).Trim() ;
byte[] salt = new byte[saltstr.Length/2];
for (int i=0; i <salt.Length; i++)
salt[i] = Convert.ToByte(saltstr.Substring (i*2, 2), 16);
if(! (str.ReadLine() == ""))
return null;

//------ remaining b64 data is encrypted RSA key ----
String encryptedstr = str.ReadToEnd() ;

try{ //should have b64 encrypted RSA key now
binkey = Convert.FromBase64String(encryptedstr) ;
}
catch(System.FormatException) { // bad b64 data.
return null;
}

//------ Get the 3DES 24 byte key using PDK used by OpenSSL ----

SecureString despswd = GetSecPswd("Enter password to derive 3DES key==>") ;
//Console.Write(" Enter password to derive 3DES key: ");
//String pswd = Console.ReadLine();
byte[] deskey = GetOpenSSL3deskey(salt, despswd, 1, 2); // count=1 (for OpenSSL implementation); 2 iterations to get at least 24 bytes
if(deskey == null)
return null;
//showBytes("3DES key", deskey) ;

//------ Decrypt the encrypted 3des-encrypted RSA private key ------
byte[] rsakey = DecryptKey(binkey, deskey, salt); //OpenSSL uses salt value in PEM header also as 3DES IV
if(rsakey !=null)
return rsakey; //we have a decrypted RSA private key
else {
Console.WriteLine("Failed to decrypt RSA private key; probably wrong password.");
return null;
}
}

// ----- Decrypt the 3DES encrypted RSA private key ----------

public static byte[] DecryptKey(byte[] cipherData, byte[] desKey, byte[] IV)
{
MemoryStream memst = new MemoryStream();
TripleDES alg = TripleDES.Create();
alg.Key = desKey;
alg.IV = IV;
try{
CryptoStream cs = new CryptoStream(memst, alg.CreateDecryptor(), CryptoStreamMode.Write);
cs.Write(cipherData, 0, cipherData.Length);
cs.Close();
}
catch(Exception exc){
Console.WriteLine(exc.Message);
return null ;}
byte[] decryptedData = memst.ToArray();
return decryptedData;
}

//----- OpenSSL PBKD uses only one hash cycle (count); miter is number of iterations required to build sufficient bytes ---
private static byte[] GetOpenSSL3deskey(byte[] salt, SecureString secpswd, int count, int miter ) {
IntPtr unmanagedPswd = IntPtr.Zero;
int HASHLENGTH = 16; //MD5 bytes
byte[] keymaterial = new byte[HASHLENGTH*miter] ; //to store contatenated Mi hashed results

byte[] psbytes = new byte[secpswd.Length] ;
unmanagedPswd = Marshal.SecureStringToGlobalAllocAnsi(secpswd);
Marshal.Copy(unmanagedPswd, psbytes, 0, psbytes.Length) ;
Marshal.ZeroFreeGlobalAllocAnsi(unmanagedPswd);

//UTF8Encoding utf8 = new UTF8Encoding();
//byte[] psbytes = utf8.GetBytes(pswd);

// --- contatenate salt and pswd bytes into fixed data array ---
byte[] data00 = new byte[psbytes.Length + salt.Length] ;
Array.Copy(psbytes, data00, psbytes.Length); //copy the pswd bytes
Array.Copy(salt, 0, data00, psbytes.Length, salt.Length) ; //concatenate the salt bytes

// ---- do multi-hashing and contatenate results D1, D2 ... into keymaterial bytes ----
MD5 md5 = new MD5CryptoServiceProvider();
byte[] result = null;
byte[] hashtarget = new byte[HASHLENGTH + data00.Length]; //fixed length initial hashtarget

for(int j=0; j<miter; j++)
{
// ---- Now hash consecutively for count times ------
if(j == 0)
result = data00; //initialize
else {
Array.Copy(result, hashtarget, result.Length);
Array.Copy(data00, 0, hashtarget, result.Length, data00.Length) ;
result = hashtarget;
//Console.WriteLine("Updated new initial hash target:") ;
//showBytes(result) ;
}

for(int i=0; i<count; i++)
result = md5.ComputeHash(result);
Array.Copy(result, 0, keymaterial, j*HASHLENGTH, result.Length); //contatenate to keymaterial
}
//showBytes("Final key material", keymaterial);
byte[] deskey = new byte[24];
Array.Copy(keymaterial, deskey, deskey.Length) ;

Array.Clear(psbytes, 0, psbytes.Length);
Array.Clear(data00, 0, data00.Length) ;
Array.Clear(result, 0, result.Length) ;
Array.Clear(hashtarget, 0, hashtarget.Length) ;
Array.Clear(keymaterial, 0, keymaterial.Length) ;

return deskey;
}

//------ Since we are using an RSA with nonpersisted keycontainer, must pass it in to ensure it isn't colledted -----
private static byte[] GetPkcs12(RSA rsa, String keycontainer, String cspprovider, uint KEYSPEC, uint cspflags)
{
byte[] pfxblob = null;
IntPtr hCertCntxt = IntPtr.Zero;

String DN = "CN=Opensslkey Unsigned Certificate";

hCertCntxt = CreateUnsignedCertCntxt(keycontainer, cspprovider, KEYSPEC, cspflags, DN) ;
if(hCertCntxt == IntPtr.Zero){
Console.WriteLine("Couldn't create an unsigned-cert ") ;
return null;
}
try{
X509Certificate cert = new X509Certificate(hCertCntxt) ; //create certificate object from cert context.
X509Certificate2UI.DisplayCertificate(new X509Certificate2(cert)) ; // display it, showing linked private key
SecureString pswd = GetSecPswd("Set PFX Password ==>") ;
pfxblob = cert.Export(X509ContentType.Pkcs12, pswd);
}

catch(Exception exc)
{
Console.WriteLine( "BAD RESULT" + exc.Message);
pfxblob = null;
}

rsa.Clear() ;
if(hCertCntxt != IntPtr.Zero)
Win32.CertFreeCertificateContext(hCertCntxt) ;
return pfxblob;
}

private static IntPtr CreateUnsignedCertCntxt(String keycontainer, String provider, uint KEYSPEC, uint cspflags, String DN) {
const uint AT_KEYEXCHANGE = 0x00000001;
const uint AT_SIGNATURE = 0x00000002;
const uint CRYPT_MACHINE_KEYSET = 0x00000020;
const uint PROV_RSA_FULL = 0x00000001;
const String MS_DEF_PROV = "Microsoft Base Cryptographic Provider v1.0";
const String MS_STRONG_PROV = "Microsoft Strong Cryptographic Provider";
const String MS_ENHANCED_PROV = "Microsoft Enhanced Cryptographic Provider v1.0";
const uint CERT_CREATE_SELFSIGN_NO_SIGN = 1 ;
const uint X509_ASN_ENCODING = 0x00000001;
const uint CERT_X500_NAME_STR = 3;
IntPtr hCertCntxt = IntPtr.Zero;
byte[] encodedName = null;
uint cbName = 0;

if( provider != MS_DEF_PROV && provider != MS_STRONG_PROV && provider != MS_ENHANCED_PROV)
return IntPtr.Zero;
if(keycontainer == "")
return IntPtr.Zero;
if( KEYSPEC != AT_SIGNATURE && KEYSPEC != AT_KEYEXCHANGE)
return IntPtr.Zero;
if(cspflags != 0 && cspflags != CRYPT_MACHINE_KEYSET) //only 0 (Current User) keyset is currently used.
return IntPtr.Zero;
if (DN == "")
return IntPtr.Zero;

if(Win32.CertStrToName(X509_ASN_ENCODING, DN, CERT_X500_NAME_STR, IntPtr.Zero, null, ref cbName, IntPtr.Zero))
{
encodedName = new byte[cbName] ;
Win32.CertStrToName(X509_ASN_ENCODING, DN, CERT_X500_NAME_STR, IntPtr.Zero, encodedName, ref cbName, IntPtr.Zero);
}

CERT_NAME_BLOB subjectblob = new CERT_NAME_BLOB();
subjectblob.pbData = Marshal.AllocHGlobal(encodedName.Length);
Marshal.Copy(encodedName, 0, subjectblob.pbData, encodedName.Length);
subjectblob.cbData = encodedName.Length;

CRYPT_KEY_PROV_INFO pInfo = new CRYPT_KEY_PROV_INFO();
pInfo.pwszContainerName = keycontainer;
pInfo.pwszProvName = provider;
pInfo.dwProvType = PROV_RSA_FULL;
pInfo.dwFlags = cspflags;
pInfo.cProvParam = 0;
pInfo.rgProvParam = IntPtr.Zero;
pInfo.dwKeySpec = KEYSPEC;

hCertCntxt = Win32.CertCreateSelfSignCertificate(IntPtr.Zero, ref subjectblob, CERT_CREATE_SELFSIGN_NO_SIGN, ref pInfo, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero);
if(hCertCntxt == IntPtr.Zero)
showWin32Error(Marshal.GetLastWin32Error());
Marshal.FreeHGlobal(subjectblob.pbData);
return hCertCntxt ;
}

private static SecureString GetSecPswd(String prompt)
{
SecureString password = new SecureString();

Console.ForegroundColor = ConsoleColor.Gray;
Console.Write(prompt);
Console.ForegroundColor = ConsoleColor.Magenta;

while (true)
{
ConsoleKeyInfo cki = Console.ReadKey(true);
if (cki.Key == ConsoleKey.Enter)
{
Console.ForegroundColor = ConsoleColor.Gray;
Console.WriteLine();
return password;
}
else if (cki.Key == ConsoleKey.Backspace)
{
// remove the last asterisk from the screen...
if (password.Length > 0)
{
Console.SetCursorPosition(Console.CursorLeft - 1, Console.CursorTop);
Console.Write(" ");
Console.SetCursorPosition(Console.CursorLeft - 1, Console.CursorTop);
password.RemoveAt(password.Length - 1);
}
}
else if (cki.Key == ConsoleKey.Escape)
{
Console.ForegroundColor = ConsoleColor.Gray;
Console.WriteLine();
return password;
}
else if (Char.IsLetterOrDigit(cki.KeyChar) || Char.IsSymbol(cki.KeyChar))
{
if (password.Length < 20)
{
password.AppendChar(cki.KeyChar);
Console.Write("*");
}
else
{
Console.Beep();
}
}
else
{
Console.Beep();
}
}
}

private static bool CompareBytearrays(byte [] a, byte[] b)
{
if(a.Length != b.Length)
return false;
int i =0;
foreach(byte c in a)
{
if(c != b[i] )
return false;
i++;
}
return true;
}

private static void showRSAProps(RSACryptoServiceProvider rsa) {
Console.WriteLine("RSA CSP key information:");
CspKeyContainerInfo keyInfo = rsa.CspKeyContainerInfo;
Console.WriteLine("Accessible property: " + keyInfo.Accessible);
Console.WriteLine("Exportable property: " + keyInfo.Exportable);
Console.WriteLine("HardwareDevice property: " + keyInfo.HardwareDevice);
Console.WriteLine("KeyContainerName property: " + keyInfo.KeyContainerName);
Console.WriteLine("KeyNumber property: " + keyInfo.KeyNumber.ToString());
Console.WriteLine("MachineKeyStore property: " + keyInfo.MachineKeyStore);
Console.WriteLine("Protected property: " + keyInfo.Protected);
Console.WriteLine("ProviderName property: " + keyInfo.ProviderName);
Console.WriteLine("ProviderType property: " + keyInfo.ProviderType);
Console.WriteLine("RandomlyGenerated property: " + keyInfo.RandomlyGenerated);
Console.WriteLine("Removable property: " + keyInfo.Removable);
Console.WriteLine("UniqueKeyContainerName property: " + keyInfo.UniqueKeyContainerName);
}

private static void showBytes(String info, byte[] data){
Console.WriteLine("{0} [{1} bytes]", info, data.Length);
for(int i=1; i<=data.Length; i++){
Console.Write("{0:X2} ", data[i-1]) ;
if(i%16 == 0)
Console.WriteLine();
}
Console.WriteLine(" ");
}

private static byte[] GetFileBytes(String filename){
if(!File.Exists(filename))
return null;
Stream stream=new FileStream(filename,FileMode.Open);
int datalen = (int)stream.Length;
byte[] filebytes =new byte[datalen];
stream.Seek(0,SeekOrigin.Begin);
stream.Read(filebytes,0,datalen);
stream.Close();
return filebytes;
}

private static void PutFileBytes(String outfile, byte[] data, int bytes) {
FileStream fs = null;
if(bytes > data.Length) {
Console.WriteLine("Too many bytes");
return;
}
try{
fs = new FileStream(outfile, FileMode.Create);
fs.Write(data, 0, bytes);
}
catch(Exception e) {
Console.WriteLine(e.Message) ;
}
finally {
fs.Close();
}
}

private static void showWin32Error(int errorcode)
{
Win32Exception myEx=new Win32Exception(errorcode);
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("Error code: 0x{0:X}", myEx.ErrorCode);
Console.WriteLine("Error message: {0} ", myEx.Message);
Console.ForegroundColor = ConsoleColor.Gray;
}

}
}