Elliptic curve key pair
Inheritance: KeyPair, ISigner, IVerifier
        /// <summary>
        /// Read private key parameters.
        /// </summary>
        /// <param name="passphrase">passphrase for decrypt the key file</param>
        /// <param name="keyPair">key pair</param>
        /// <param name="comment">comment or empty if it didn't exist</param>
        public void Load(string passphrase, out KeyPair keyPair, out string comment)
        {
            PEMKeyType keyType;
            String base64Text;
            bool encrypted = false;
            CipherAlgorithm? encryption = null;
            byte[] iv = null;
            int keySize = 0;
            int ivSize = 0;

            using (StreamReader sreader = GetStreamReader()) {
                string line = sreader.ReadLine();
                if (line == null)
                    throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (unexpected eof)");

                if (line == PrivateKeyFileHeader.SSH2_OPENSSH_HEADER_RSA)
                    keyType = PEMKeyType.RSA;
                else if (line == PrivateKeyFileHeader.SSH2_OPENSSH_HEADER_DSA)
                    keyType = PEMKeyType.DSA;
                else if (line == PrivateKeyFileHeader.SSH2_OPENSSH_HEADER_ECDSA)
                    keyType = PEMKeyType.ECDSA;
                else
                    throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (unexpected key type)");

                string footer = line.Replace("BEGIN", "END");

                StringBuilder buf = new StringBuilder();
                comment = String.Empty;
                while (true) {
                    line = sreader.ReadLine();
                    if (line == null)
                        throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (unexpected eof)");
                    if (line == footer)
                        break;
                    if (line.IndexOf(':') >= 0) {
                        if (line.StartsWith("Proc-Type:")) {
                            string[] w = line.Substring("Proc-Type:".Length).Trim().Split(',');
                            if (w.Length < 1)
                                throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid Proc-Type)");
                            if (w[0] != "4")
                                throw new SSHException(Strings.GetString("UnsupportedPrivateKeyFormat")
                                            + " (" + Strings.GetString("Reason_UnsupportedProcType") + ")");
                            if (w.Length >= 2 && w[1] == "ENCRYPTED")
                                encrypted = true;
                        }
                        else if (line.StartsWith("DEK-Info:")) {
                            string[] w = line.Substring("DEK-Info:".Length).Trim().Split(',');
                            if (w.Length < 2)
                                throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid DEK-Info)");
                            switch (w[0]) {
                                case "DES-EDE3-CBC":
                                    encryption = CipherAlgorithm.TripleDES;
                                    ivSize = 8;
                                    keySize = 24;
                                    break;
                                case "AES-128-CBC":
                                    encryption = CipherAlgorithm.AES128;
                                    ivSize = 16;
                                    keySize = 16;
                                    break;
                                default:
                                    throw new SSHException(Strings.GetString("UnsupportedPrivateKeyFormat")
                                            + " (" + Strings.GetString("Reason_UnsupportedEncryptionType") + ")");
                            }
                            iv = HexToByteArray(w[1]);
                            if (iv == null || iv.Length != ivSize)
                                throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid IV)");
                        }
                    }
                    else
                        buf.Append(line);
                }
                base64Text = buf.ToString();
            }

            byte[] keydata = Base64.Decode(Encoding.ASCII.GetBytes(base64Text));

            if (encrypted) {
                if (!encryption.HasValue || iv == null)
                    throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (missing encryption type or IV)");
                byte[] key = PassphraseToKey(passphrase, iv, keySize);
                Cipher cipher = CipherFactory.CreateCipher(SSHProtocol.SSH2, encryption.Value, key, iv);
                if (keydata.Length % cipher.BlockSize != 0)
                    throw new SSHException(Strings.GetString("NotValidPrivateKeyFile") + " (invalid key data size)");
                cipher.Decrypt(keydata, 0, keydata.Length, keydata, 0);
            }

            using (MemoryStream keyDataStream = new MemoryStream(keydata, false)) {
                BERReader reader = new BERReader(keyDataStream);
                if (!reader.ReadSequence())
                    throw new SSHException(Strings.GetString("WrongPassphrase"));
                if (keyType == PEMKeyType.RSA) {
                    /* from OpenSSL rsa_asn1.c
                     *
                     * ASN1_SIMPLE(RSA, version, LONG),
                     * ASN1_SIMPLE(RSA, n, BIGNUM),
                     * ASN1_SIMPLE(RSA, e, BIGNUM),
                     * ASN1_SIMPLE(RSA, d, BIGNUM),
                     * ASN1_SIMPLE(RSA, p, BIGNUM),
                     * ASN1_SIMPLE(RSA, q, BIGNUM),
                     * ASN1_SIMPLE(RSA, dmp1, BIGNUM),
                     * ASN1_SIMPLE(RSA, dmq1, BIGNUM),
                     * ASN1_SIMPLE(RSA, iqmp, BIGNUM)
                     */
                    BigInteger v, n, e, d, p, q, dmp1, dmq1, iqmp;
                    if (!reader.ReadInteger(out v) ||
                        !reader.ReadInteger(out n) ||
                        !reader.ReadInteger(out e) ||
                        !reader.ReadInteger(out d) ||
                        !reader.ReadInteger(out p) ||
                        !reader.ReadInteger(out q) ||
                        !reader.ReadInteger(out dmp1) ||
                        !reader.ReadInteger(out dmq1) ||
                        !reader.ReadInteger(out iqmp)) {

                        throw new SSHException(Strings.GetString("WrongPassphrase"));
                    }

                    BigInteger u = p.ModInverse(q);	// inverse of p mod q
                    keyPair = new RSAKeyPair(e, d, n, u, p, q);
                }
                else if (keyType == PEMKeyType.DSA) {
                    /* from OpenSSL dsa_asn1.c
                     *
                     * ASN1_SIMPLE(DSA, version, LONG),
                     * ASN1_SIMPLE(DSA, p, BIGNUM),
                     * ASN1_SIMPLE(DSA, q, BIGNUM),
                     * ASN1_SIMPLE(DSA, g, BIGNUM),
                     * ASN1_SIMPLE(DSA, pub_key, BIGNUM),
                     * ASN1_SIMPLE(DSA, priv_key, BIGNUM)
                     */
                    BigInteger v, p, q, g, y, x;
                    if (!reader.ReadInteger(out v) ||
                        !reader.ReadInteger(out p) ||
                        !reader.ReadInteger(out q) ||
                        !reader.ReadInteger(out g) ||
                        !reader.ReadInteger(out y) ||
                        !reader.ReadInteger(out x)) {

                        throw new SSHException(Strings.GetString("WrongPassphrase"));
                    }
                    keyPair = new DSAKeyPair(p, g, q, y, x);
                }
                else if (keyType == PEMKeyType.ECDSA) {
                    /* from OpenSSL ec_asn1.c
                     *
                     * ASN1_SIMPLE(EC_PRIVATEKEY, version, LONG),
                     * ASN1_SIMPLE(EC_PRIVATEKEY, privateKey, ASN1_OCTET_STRING),
                     * ASN1_EXP_OPT(EC_PRIVATEKEY, parameters, ECPKPARAMETERS, 0),
                     *   ------
                     *   ASN1_SIMPLE(ECPKPARAMETERS, value.named_curve, ASN1_OBJECT),
                     *   ------
                     * ASN1_EXP_OPT(EC_PRIVATEKEY, publicKey, ASN1_BIT_STRING, 1)
                     */
                    int len;
                    byte[] privateKey;
                    byte[] publicKey;
                    string namedCurve;
                    BigInteger v;
                    if (!reader.ReadInteger(out v) ||
                        !reader.ReadOctetString(out privateKey) ||
                        !reader.ReadTag(BERReader.TagClass.ContextSpecific, true, 0, out len) ||
                        !reader.ReadObjectIdentifier(out namedCurve) ||
                        !reader.ReadTag(BERReader.TagClass.ContextSpecific, true, 1, out len) ||
                        !reader.ReadBitString(out publicKey)) {

                        throw new SSHException(Strings.GetString("WrongPassphrase"));
                    }

                    EllipticCurve curve = EllipticCurve.FindByOID(namedCurve);
                    if (curve == null) {
                        throw new SSHException(Strings.GetString("UnsupportedEllipticCurveInKeyPair"));
                    }

                    ECPoint ecPublicKeyPoint;
                    if (!ECPoint.Parse(publicKey, curve, out ecPublicKeyPoint)) {
                        throw new SSHException(Strings.GetString("KeysAreBroken"));
                    }

                    var ecKeyPair = new ECDSAKeyPair(curve, new ECDSAPublicKey(curve, ecPublicKeyPoint), new BigInteger(privateKey));

                    if (!ecKeyPair.CheckKeyConsistency()) {
                        throw new SSHException(Strings.GetString("KeysAreBroken"));
                    }

                    keyPair = ecKeyPair;
                }
                else {
                    throw new SSHException("Unknown file type. This should not happen.");
                }
            }
        }
Esempio n. 2
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        // Tests key pair validation using test vectors from NIST CAVP.
        // http://csrc.nist.gov/groups/STM/cavp/digital-signatures.html
        internal static void TestKeyPair() {
            using (var reader = new System.IO.StreamReader(@"186-3ecdsatestvectors\KeyPair.rsp")) {
                EllipticCurve curve = null;
                string ds = null;
                BigInteger d = null;
                BigInteger qx = null;
                BigInteger qy = null;
                int testCount = 0;

                while (true) {
                    string line = reader.ReadLine();
                    if (line == null) {
                        break;
                    }
                    var match = System.Text.RegularExpressions.Regex.Match(line, @"\[([-\w]+)\]");
                    if (match.Success) {
                        string curveName = "nist" + match.Groups[1].Value.ToLowerInvariant().Replace("-", "");
                        curve = FindByName(curveName);
                        if (curve != null) {
                            Debug.WriteLine("Test " + curve.CurveName);
                        }
                        d = qx = qy = null;
                        ds = null;
                        testCount = 0;
                        continue;
                    }

                    if (line.StartsWith("d = ") && curve != null) {
                        ds = line.Substring(4).Trim();
                        d = new BigInteger(BigIntegerConverter.ParseHex(ds));
                        continue;
                    }

                    if (line.StartsWith("Qx = ") && curve != null) {
                        qx = new BigInteger(BigIntegerConverter.ParseHex(line.Substring(5).Trim()));
                        continue;
                    }

                    if (line.StartsWith("Qy = ") && curve != null) {
                        qy = new BigInteger(BigIntegerConverter.ParseHex(line.Substring(5).Trim()));

                        if (d != null && qx != null) {
                            var pk = new ECDSAPublicKey(curve, new ECPoint(qx, qy));
                            var kp = new ECDSAKeyPair(curve, pk, d);
                            if (!kp.CheckKeyConsistency()) {
                                throw new Exception("validation failed");
                            }
                            ++testCount;
                            Debug.WriteLine("Pass #{0} : {1}", testCount, ds);
                        }

                        d = qx = qy = null;
                        ds = null;
                    }
                }
            }
        }