/SharpSSH/jsch/IdentityFile.cs

using System;

using System.IO;



using SharpSsh.Jsch;

using SharpSsh;



namespace SharpSsh.jsch

{

    /*

    Copyright (c) 2002,2003,2004 ymnk, JCraft,Inc. All rights reserved.



    Redistribution and use in source and binary forms, with or without

    modification, are permitted provided that the following conditions are met:



      1. Redistributions of source code must retain the above copyright notice,

         this list of conditions and the following disclaimer.



      2. Redistributions in binary form must reproduce the above copyright 

         notice, this list of conditions and the following disclaimer in 

         the documentation and/or other materials provided with the distribution.



      3. The names of the authors may not be used to endorse or promote products

         derived from this software without specific prior written permission.



    THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,

    INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

    FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JCRAFT,

    INC. OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,

    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,

    OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,

    EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    */



    internal class IdentityFile : IIdentity

    {

        string m_identity;

        byte[] m_key;

        byte[] m_iv;

        private JSch m_jsch;

        private HashAlgorithm m_hash;

        private byte[] m_encoded_data;



        private Cipher m_cipher;



        // DSA

        private byte[] m_P;

        private byte[] m_Q;

        private byte[] m_G_array;

        private byte[] m_pub;

        private byte[] m_prv;



        // RSA

        private byte[] m_n;   // modulus

        private byte[] m_e;   // public exponent

        private byte[] m_d;   // private exponent



        private byte[] m_p;

        private byte[] m_q;

        private byte[] m_dmp1;

        private byte[] m_dmq1;

        private byte[] m_iqmp;



        //  private string algname="ssh-dss";

        //private string algname="ssh-rsa";



        private const int ERROR = 0;

        private const int RSA = 1;

        private const int DSS = 2;

        internal const int UNKNOWN = 3;



        private const int OPENSSH = 0;

        private const int FSECURE = 1;

        private const int PUTTY = 2;



        private int m_type = ERROR;

        private int m_keytype = OPENSSH;



        private byte[] m_publickeyblob = null;



        private bool m_encrypted = true;



        internal IdentityFile(string identity, JSch jsch)

        {

            this.m_identity = identity;

            this.m_jsch = jsch;

            try

            {

                Type c = Type.GetType(jsch.GetConfig("3des-cbc"));

                m_cipher = (Cipher)Activator.CreateInstance(c);

                m_key = new byte[m_cipher.BlockSize];   // 24

                m_iv = new byte[m_cipher.IVSize];       // 8

                c = Type.GetType(jsch.GetConfig("md5"));

                m_hash = (HashAlgorithm)(Activator.CreateInstance(c));

                m_hash.Init();

                FileInfo file = new FileInfo(identity);

                FileStream fis = File.OpenRead(identity);

                byte[] buf = new byte[(int)(file.Length)];

                int len = fis.Read(buf, 0, buf.Length);

                fis.Close();



                int i = 0;

                while (i < len)

                {

                    if (buf[i] == 'B' && buf[i + 1] == 'E' && buf[i + 2] == 'G' && buf[i + 3] == 'I')

                    {

                        i += 6;

                        if (buf[i] == 'D' && buf[i + 1] == 'S' && buf[i + 2] == 'A') { m_type = DSS; }

                        else if (buf[i] == 'R' && buf[i + 1] == 'S' && buf[i + 2] == 'A') { m_type = RSA; }

                        else if (buf[i] == 'S' && buf[i + 1] == 'S' && buf[i + 2] == 'H')

                        { // FSecure

                            m_type = UNKNOWN;

                            m_keytype = FSECURE;

                        }

                        else

                        {

                            //System.out.println("invalid format: "+identity);

                            throw new JSchException("invaid privatekey: " + identity);

                        }

                        i += 3;

                        continue;

                    }

                    if (buf[i] == 'C' && buf[i + 1] == 'B' && buf[i + 2] == 'C' && buf[i + 3] == ',')

                    {

                        i += 4;

                        for (int ii = 0; ii < m_iv.Length; ii++)

                        {

                            m_iv[ii] = (byte)(((a2b(buf[i++]) << 4) & 0xf0) +

                                (a2b(buf[i++]) & 0xf));

                        }

                        continue;

                    }

                    if (buf[i] == 0x0d &&

                        i + 1 < buf.Length && buf[i + 1] == 0x0a)

                    {

                        i++;

                        continue;

                    }

                    if (buf[i] == 0x0a && i + 1 < buf.Length)

                    {

                        if (buf[i + 1] == 0x0a) { i += 2; break; }

                        if (buf[i + 1] == 0x0d &&

                            i + 2 < buf.Length && buf[i + 2] == 0x0a)

                        {

                            i += 3; break;

                        }

                        bool inheader = false;

                        for (int j = i + 1; j < buf.Length; j++)

                        {

                            if (buf[j] == 0x0a) break;

                            //if(buf[j]==0x0d) break;

                            if (buf[j] == ':') { inheader = true; break; }

                        }

                        if (!inheader)

                        {

                            i++;

                            m_encrypted = false;    // no passphrase

                            break;

                        }

                    }

                    i++;

                }



                if (m_type == ERROR)

                {

                    throw new JSchException("invaid privatekey: " + identity);

                }



                int start = i;

                while (i < len)

                {

                    if (buf[i] == 0x0a)

                    {

                        bool xd = (buf[i - 1] == 0x0d);

                        Array.Copy(buf, i + 1,

                            buf,

                            i - (xd ? 1 : 0),

                            len - i - 1 - (xd ? 1 : 0)

                            );

                        if (xd) len--;

                        len--;

                        continue;

                    }

                    if (buf[i] == '-') { break; }

                    i++;

                }

                m_encoded_data = Util.FromBase64(buf, start, i - start);



                if (m_encoded_data.Length > 4 &&            // FSecure

                    m_encoded_data[0] == (byte)0x3f &&

                    m_encoded_data[1] == (byte)0x6f &&

                    m_encoded_data[2] == (byte)0xf9 &&

                    m_encoded_data[3] == (byte)0xeb)

                {



                    ByteBuffer _buf = new ByteBuffer(m_encoded_data);

                    _buf.GetInt();  // 0x3f6ff9be

                    _buf.GetInt();

                    byte[] _type = _buf.GetString();

                    //System.out.println("type: "+new string(_type)); 

                    byte[] _cipher = _buf.GetString();

                    string s_cipher = System.Text.Encoding.Default.GetString(_cipher);

                    //System.out.println("cipher: "+cipher); 

                    if (s_cipher.Equals("3des-cbc"))

                    {

                        _buf.GetInt();

                        byte[] foo = new byte[m_encoded_data.Length - _buf.Offset];

                        _buf.GetByte(foo);

                        m_encoded_data = foo;

                        m_encrypted = true;

                        throw new JSchException("unknown privatekey format: " + identity);

                    }

                    else if (s_cipher.Equals("none"))

                    {

                        _buf.GetInt();

                        //_buf.getInt();



                        m_encrypted = false;



                        byte[] foo = new byte[m_encoded_data.Length - _buf.Offset];

                        _buf.GetByte(foo);

                        m_encoded_data = foo;

                    }



                }



                try

                {

                    file = new FileInfo(identity + ".pub");

                    fis = File.OpenRead(identity + ".pub");

                    buf = new byte[(int)(file.Length)];

                    len = fis.Read(buf, 0, buf.Length);

                    fis.Close();

                }

                catch

                {

                    return;

                }



                if (buf.Length > 4 &&             // FSecure's public key

                    buf[0] == '-' && buf[1] == '-' && buf[2] == '-' && buf[3] == '-')

                {



                    i = 0;

                    do { i++; } while (buf.Length > i && buf[i] != 0x0a);

                    if (buf.Length <= i) return;



                    while (true)

                    {

                        if (buf[i] == 0x0a)

                        {

                            bool inheader = false;

                            for (int j = i + 1; j < buf.Length; j++)

                            {

                                if (buf[j] == 0x0a) break;

                                if (buf[j] == ':') { inheader = true; break; }

                            }

                            if (!inheader)

                            {

                                i++;

                                break;

                            }

                        }

                        i++;

                    }

                    if (buf.Length <= i) return;



                    start = i;

                    while (i < len)

                    {

                        if (buf[i] == 0x0a)

                        {

                            Array.Copy(buf, i + 1, buf, i, len - i - 1);

                            len--;

                            continue;

                        }

                        if (buf[i] == '-') { break; }

                        i++;

                    }

                    m_publickeyblob = Util.FromBase64(buf, start, i - start);



                    if (m_type == UNKNOWN)

                    {

                        if (m_publickeyblob[8] == 'd')

                        {

                            m_type = DSS;

                        }

                        else if (m_publickeyblob[8] == 'r')

                        {

                            m_type = RSA;

                        }

                    }

                }

                else

                {

                    if (buf[0] != 's' || buf[1] != 's' || buf[2] != 'h' || buf[3] != '-') return;

                    i = 0;

                    while (i < len) { if (buf[i] == ' ')break; i++; } i++;

                    if (i >= len) return;

                    start = i;

                    while (i < len) { if (buf[i] == ' ')break; i++; }

                    m_publickeyblob = Util.FromBase64(buf, start, i - start);

                }



            }

            catch (Exception e)

            {

                Trace.TraceError("Error:\r\n{0}", e.ToString());

                if (e is JSchException)

                    throw (JSchException)e;

                throw new JSchException(e.ToString());

            }



        }



        public string AlgName

        {

            get

            {

                if (m_type == RSA) 

                    return "ssh-rsa";

                return "ssh-dss";

            }

        }



        public bool SetPassphrase(string _passphrase)

        {

            /*

            hash is MD5

            h(0) <- hash(passphrase, iv);

            h(n) <- hash(h(n-1), passphrase, iv);

            key <- (h(0),...,h(n))[0,..,key.Length];

            */

            try

            {

                if (m_encrypted)

                {

                    if (_passphrase == null) return false;

                    byte[] passphrase = System.Text.Encoding.Default.GetBytes(_passphrase);

                    int hsize = m_hash.BlockSize;

                    byte[] hn = new byte[m_key.Length / hsize * hsize +

                        (m_key.Length % hsize == 0 ? 0 : hsize)];

                    byte[] tmp = null;

                    if (m_keytype == OPENSSH)

                    {

                        for (int index = 0; index + hsize <= hn.Length; )

                        {

                            if (tmp != null) { m_hash.Update(tmp, 0, tmp.Length); }

                            m_hash.Update(passphrase, 0, passphrase.Length);

                            m_hash.Update(m_iv, 0, m_iv.Length);

                            tmp = m_hash.Digest();

                            Array.Copy(tmp, 0, hn, index, tmp.Length);

                            index += tmp.Length;

                        }

                        Array.Copy(hn, 0, m_key, 0, m_key.Length);

                    }

                    else if (m_keytype == FSECURE)

                    {

                        for (int index = 0; index + hsize <= hn.Length; )

                        {

                            if (tmp != null) { m_hash.Update(tmp, 0, tmp.Length); }

                            m_hash.Update(passphrase, 0, passphrase.Length);

                            tmp = m_hash.Digest();

                            Array.Copy(tmp, 0, hn, index, tmp.Length);

                            index += tmp.Length;

                        }

                        Array.Copy(hn, 0, m_key, 0, m_key.Length);

                    }

                }

                if (Decrypt())

                {

                    m_encrypted = false;

                    return true;

                }

                m_P = m_Q = m_G_array = m_pub = m_prv = null;

                return false;

            }

            catch (Exception e)

            {

                if (e is JSchException) throw (JSchException)e;

                throw new JSchException(e.ToString());

            }

        }



        public byte[] PublicKeyBlob

        {

            get

            {

                if (m_publickeyblob != null)

                    return m_publickeyblob;

                if (m_type == RSA)

                    return PublicKeyBlob_rsa();

                return PublicKeyBlob_dss();

            }

        }



        byte[] PublicKeyBlob_rsa()

        {

            if (m_e == null) return null;

            ByteBuffer buf = new ByteBuffer("ssh-rsa".Length + 4 +

                m_e.Length + 4 +

                m_n.Length + 4);

            buf.PutString(System.Text.Encoding.Default.GetBytes("ssh-rsa"));

            buf.PutString(m_e);

            buf.PutString(m_n);

            return buf.m_buffer;

        }



        byte[] PublicKeyBlob_dss()

        {

            if (m_P == null) return null;

            ByteBuffer buf = new ByteBuffer("ssh-dss".Length + 4 +

                m_P.Length + 4 +

                m_Q.Length + 4 +

                m_G_array.Length + 4 +

                m_pub.Length + 4);

            buf.PutString(System.Text.Encoding.Default.GetBytes("ssh-dss"));

            buf.PutString(m_P);

            buf.PutString(m_Q);

            buf.PutString(m_G_array);

            buf.PutString(m_pub);

            return buf.m_buffer;

        }



        public byte[] GetSignature(Session session, byte[] data)

        {

            if (m_type == RSA) return GetSignature_rsa(session, data);

            return GetSignature_dss(session, data);

        }



        byte[] GetSignature_rsa(Session session, byte[] data)

        {

            try

            {

                Type t = Type.GetType(m_jsch.GetConfig("signature.rsa"));

                ISignatureRSA rsa = (ISignatureRSA)Activator.CreateInstance(t);



                rsa.Init();

                rsa.SetPrvKey(m_e, m_n, m_d, m_p, m_q, m_dmp1, m_dmq1, m_iqmp);



                /*

                byte[] goo=new byte[4];

                goo[0]=(byte)(session.getSessionId().Length>>>24);

                goo[1]=(byte)(session.getSessionId().Length>>>16);

                goo[2]=(byte)(session.getSessionId().Length>>>8);

                goo[3]=(byte)(session.getSessionId().Length);

                rsa.update(goo);

                rsa.update(session.getSessionId());

                */

                rsa.Update(data);

                byte[] sig = rsa.Sign();

                ByteBuffer buf = new ByteBuffer("ssh-rsa".Length + 4 +

                    sig.Length + 4);

                buf.PutString(System.Text.Encoding.Default.GetBytes("ssh-rsa"));

                buf.PutString(sig);

                return buf.m_buffer;

            }

            catch (Exception e)

            {

                Trace.TraceError("Error:\r\n{0}", e.ToString());

            }

            return null;

        }



        byte[] GetSignature_dss(Session session, byte[] data)

        {

            /*

                byte[] foo;

                int i;

                System.out.print("P ");

                foo=P_array;

                for(i=0;  i<foo.Length; i++){

                System.out.print(Integer.toHexString(foo[i]&0xff)+":");

                }

                System.out.println("");

                System.out.print("Q ");

                foo=Q_array;

                for(i=0;  i<foo.Length; i++){

                System.out.print(Integer.toHexString(foo[i]&0xff)+":");

                }

                System.out.println("");

                System.out.print("G ");

                foo=G_array;

                for(i=0;  i<foo.Length; i++){

                System.out.print(Integer.toHexString(foo[i]&0xff)+":");

                }

                System.out.println("");

            */



            try

            {

                Type t = Type.GetType(m_jsch.GetConfig("signature.dss"));

                ISignatureDSA dsa = (ISignatureDSA)(Activator.CreateInstance(t));

                dsa.Init();

                dsa.SetPrvKey(m_prv, m_P, m_Q, m_G_array);



                /*

                byte[] goo=new byte[4];

                goo[0]=(byte)(session.getSessionId().Length>>>24);

                goo[1]=(byte)(session.getSessionId().Length>>>16);

                goo[2]=(byte)(session.getSessionId().Length>>>8);

                goo[3]=(byte)(session.getSessionId().Length);

                dsa.update(goo);

                dsa.update(session.getSessionId());

                */

                dsa.Update(data);

                byte[] sig = dsa.Sign();

                ByteBuffer buf = new ByteBuffer("ssh-dss".Length + 4 +

                    sig.Length + 4);

                buf.PutString(System.Text.Encoding.Default.GetBytes("ssh-dss"));

                buf.PutString(sig);

                return buf.m_buffer;

            }

            catch (Exception e)

            {

                Trace.TraceError("Error:\r\n{0}", e.ToString());

            }

            return null;

        }



        public bool Decrypt()

        {

            if (m_type == RSA) return Decrypt_rsa();

            return Decrypt_dss();

        }



        bool Decrypt_rsa()

        {

            //			byte[] p_array;

            //			byte[] q_array;

            //			byte[] dmp1_array;

            //			byte[] dmq1_array;

            //			byte[] iqmp_array;



            try

            {

                byte[] plain;

                if (m_encrypted)

                {

                    if (m_keytype == OPENSSH)

                    {

                        m_cipher.Init(Cipher.DECRYPT_MODE, m_key, m_iv);

                        plain = new byte[m_encoded_data.Length];

                        m_cipher.Update(m_encoded_data, 0, m_encoded_data.Length, plain, 0);

                    }

                    else if (m_keytype == FSECURE)

                    {

                        for (int i = 0; i < m_iv.Length; i++) m_iv[i] = 0;

                        m_cipher.Init(Cipher.DECRYPT_MODE, m_key, m_iv);

                        plain = new byte[m_encoded_data.Length];

                        m_cipher.Update(m_encoded_data, 0, m_encoded_data.Length, plain, 0);

                    }

                    else

                    {

                        return false;

                    }

                }

                else

                {

                    if (m_n != null) return true;

                    plain = m_encoded_data;

                }



                if (m_keytype == FSECURE)

                {              // FSecure   

                    ByteBuffer buf = new ByteBuffer(plain);

                    int foo = buf.GetInt();

                    if (plain.Length != foo + 4)

                    {

                        return false;

                    }

                    m_e = buf.GetMPIntBits();

                    m_d = buf.GetMPIntBits();

                    m_n = buf.GetMPIntBits();

                    byte[] u_array = buf.GetMPIntBits();

                    m_p = buf.GetMPIntBits();

                    m_q = buf.GetMPIntBits();

                    return true;

                }



                int index = 0;

                int Length = 0;



                if (plain[index] != 0x30) return false;

                index++; // SEQUENCE

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }



                if (plain[index] != 0x02) return false;

                index++; // INTEGER

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                index += Length;



                //System.out.println("int: len="+Length);

                //System.out.print(Integer.toHexString(plain[index-1]&0xff)+":");

                //System.out.println("");



                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_n = new byte[Length];

                Array.Copy(plain, index, m_n, 0, Length);

                index += Length;

                /*

                System.out.println("int: N len="+Length);

                for(int i=0; i<n_array.Length; i++){

                System.out.print(Integer.toHexString(n_array[i]&0xff)+":");

                }

                System.out.println("");

                */

                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_e = new byte[Length];

                Array.Copy(plain, index, m_e, 0, Length);

                index += Length;

                /*

                System.out.println("int: E len="+Length);

                for(int i=0; i<e_array.Length; i++){

                System.out.print(Integer.toHexString(e_array[i]&0xff)+":");

                }

                System.out.println("");

                */

                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_d = new byte[Length];

                Array.Copy(plain, index, m_d, 0, Length);

                index += Length;

                /*

                System.out.println("int: D len="+Length);

                for(int i=0; i<d_array.Length; i++){

                System.out.print(Integer.toHexString(d_array[i]&0xff)+":");

                }

                System.out.println("");

                */



                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_p = new byte[Length];

                Array.Copy(plain, index, m_p, 0, Length);

                index += Length;

                /*

                System.out.println("int: P len="+Length);

                for(int i=0; i<p_array.Length; i++){

                System.out.print(Integer.toHexString(p_array[i]&0xff)+":");

                }

                System.out.println("");

                */

                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_q = new byte[Length];

                Array.Copy(plain, index, m_q, 0, Length);

                index += Length;

                /*

                System.out.println("int: q len="+Length);

                for(int i=0; i<q_array.Length; i++){

                System.out.print(Integer.toHexString(q_array[i]&0xff)+":");

                }

                System.out.println("");

                */

                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_dmp1 = new byte[Length];

                Array.Copy(plain, index, m_dmp1, 0, Length);

                index += Length;

                /*

                System.out.println("int: dmp1 len="+Length);

                for(int i=0; i<dmp1_array.Length; i++){

                System.out.print(Integer.toHexString(dmp1_array[i]&0xff)+":");

                }

                System.out.println("");

                */

                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_dmq1 = new byte[Length];

                Array.Copy(plain, index, m_dmq1, 0, Length);

                index += Length;

                /*

                System.out.println("int: dmq1 len="+Length);

                for(int i=0; i<dmq1_array.Length; i++){

                System.out.print(Integer.toHexString(dmq1_array[i]&0xff)+":");

                }

                System.out.println("");

                */

                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_iqmp = new byte[Length];

                Array.Copy(plain, index, m_iqmp, 0, Length);

                index += Length;

                /*

                System.out.println("int: iqmp len="+Length);

                for(int i=0; i<iqmp_array.Length; i++){

                System.out.print(Integer.toHexString(iqmp_array[i]&0xff)+":");

                }

                System.out.println("");

                */

            }

            catch

            {

                //System.out.println(e);

                return false;

            }

            return true;

        }



        bool Decrypt_dss()

        {

            try

            {

                byte[] plain;

                if (m_encrypted)

                {

                    if (m_keytype == OPENSSH)

                    {

                        m_cipher.Init(Cipher.DECRYPT_MODE, m_key, m_iv);

                        plain = new byte[m_encoded_data.Length];

                        m_cipher.Update(m_encoded_data, 0, m_encoded_data.Length, plain, 0);

                        /*

                        for(int i=0; i<plain.Length; i++){

                        System.out.print(Integer.toHexString(plain[i]&0xff)+":");

                        }

                        System.out.println("");

                        */

                    }

                    else if (m_keytype == FSECURE)

                    {

                        for (int i = 0; i < m_iv.Length; i++) m_iv[i] = 0;

                        m_cipher.Init(Cipher.DECRYPT_MODE, m_key, m_iv);

                        plain = new byte[m_encoded_data.Length];

                        m_cipher.Update(m_encoded_data, 0, m_encoded_data.Length, plain, 0);

                    }

                    else

                    {

                        return false;

                    }

                }

                else

                {

                    if (m_P != null) return true;

                    plain = m_encoded_data;

                }



                if (m_keytype == FSECURE)

                {              // FSecure   

                    ByteBuffer buf = new ByteBuffer(plain);

                    int foo = buf.GetInt();

                    if (plain.Length != foo + 4)

                    {

                        return false;

                    }

                    m_P = buf.GetMPIntBits();

                    m_G_array = buf.GetMPIntBits();

                    m_Q = buf.GetMPIntBits();

                    m_pub = buf.GetMPIntBits();

                    m_prv = buf.GetMPIntBits();

                    return true;

                }



                int index = 0;

                int Length = 0;



                if (plain[index] != 0x30) return false;

                index++; // SEQUENCE

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }



                if (plain[index] != 0x02) return false;

                index++; // INTEGER

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                index += Length;



                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_P = new byte[Length];

                Array.Copy(plain, index, m_P, 0, Length);

                index += Length;



                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_Q = new byte[Length];

                Array.Copy(plain, index, m_Q, 0, Length);

                index += Length;



                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_G_array = new byte[Length];

                Array.Copy(plain, index, m_G_array, 0, Length);

                index += Length;



                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_pub = new byte[Length];

                Array.Copy(plain, index, m_pub, 0, Length);

                index += Length;



                index++;

                Length = plain[index++] & 0xff;

                if ((Length & 0x80) != 0)

                {

                    int foo = Length & 0x7f; Length = 0;

                    while (foo-- > 0) { Length = (Length << 8) + (plain[index++] & 0xff); }

                }

                m_prv = new byte[Length];

                Array.Copy(plain, index, m_prv, 0, Length);

                index += Length;

            }

            catch

            {

                //System.out.println(e);

                //e.printStackTrace();

                return false;

            }

            return true;

        }



        public bool isEncrypted { get { return m_encrypted; } }



        public string Name { get { return m_identity; } }



        private int WriteSEQUENCE(byte[] buf, int index, int len)

        {

            buf[index++] = 0x30;

            index = WriteLength(buf, index, len);

            return index;

        }



        private int WriteINTEGER(byte[] buf, int index, byte[] data)

        {

            buf[index++] = 0x02;

            index = WriteLength(buf, index, data.Length);

            Array.Copy(data, 0, buf, index, data.Length);

            index += data.Length;

            return index;

        }



        private int CountLength(int i_len)

        {

            uint len = (uint)i_len;

            int i = 1;

            if (len <= 0x7f) return i;

            while (len > 0)

            {

                len >>= 8;

                i++;

            }

            return i;

        }



        private int WriteLength(byte[] data, int index, int i_len)

        {

            int len = (int)i_len;

            int i = CountLength(len) - 1;

            if (i == 0)

            {

                data[index++] = (byte)len;

                return index;

            }

            data[index++] = (byte)(0x80 | i);

            int j = index + i;

            while (i > 0)

            {

                data[index + i - 1] = (byte)(len & 0xff);

                len >>= 8;

                i--;

            }

            return j;

        }



        private byte a2b(byte c)

        {

            if ('0' <= c && c <= '9')

                return (byte)(c - '0');

            if ('a' <= c && c <= 'z')

                return (byte)(c - 'a' + 10);

            return (byte)(c - 'A' + 10);

        }



        private byte b2a(byte c)

        {

            if (0 <= c && c <= 9)

                return (byte)(c + '0');

            return (byte)(c - 10 + 'A');

        }

    }



}