--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/com/five_ten_sg/connectbot/util/PubkeyUtils.java	Thu May 22 10:41:19 2014 -0700
@@ -0,0 +1,392 @@
+/*
+ * ConnectBot: simple, powerful, open-source SSH client for Android
+ * Copyright 2007 Kenny Root, Jeffrey Sharkey
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.five_ten_sg.connectbot.util;
+
+import java.io.IOException;
+import java.math.BigInteger;
+import java.security.AlgorithmParameters;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.Key;
+import java.security.KeyFactory;
+import java.security.KeyPair;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.security.PrivateKey;
+import java.security.PublicKey;
+import java.security.SecureRandom;
+import java.security.interfaces.DSAParams;
+import java.security.interfaces.DSAPrivateKey;
+import java.security.interfaces.DSAPublicKey;
+import java.security.interfaces.ECPrivateKey;
+import java.security.interfaces.ECPublicKey;
+import java.security.interfaces.RSAPrivateCrtKey;
+import java.security.interfaces.RSAPublicKey;
+import java.security.spec.DSAPublicKeySpec;
+import java.security.spec.ECParameterSpec;
+import java.security.spec.ECPoint;
+import java.security.spec.ECPublicKeySpec;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.InvalidParameterSpecException;
+import java.security.spec.KeySpec;
+import java.security.spec.PKCS8EncodedKeySpec;
+import java.security.spec.RSAPublicKeySpec;
+import java.security.spec.X509EncodedKeySpec;
+import java.util.Arrays;
+
+import javax.crypto.BadPaddingException;
+import javax.crypto.Cipher;
+import javax.crypto.EncryptedPrivateKeyInfo;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.PBEKeySpec;
+import javax.crypto.spec.PBEParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+import org.keyczar.jce.EcCore;
+
+import com.five_ten_sg.connectbot.bean.PubkeyBean;
+import android.util.Log;
+
+import com.trilead.ssh2.crypto.Base64;
+import com.trilead.ssh2.crypto.SimpleDERReader;
+import com.trilead.ssh2.signature.DSASHA1Verify;
+import com.trilead.ssh2.signature.ECDSASHA2Verify;
+import com.trilead.ssh2.signature.RSASHA1Verify;
+
+public class PubkeyUtils {
+    private static final String TAG = "PubkeyUtils";
+
+    public static final String PKCS8_START = "-----BEGIN PRIVATE KEY-----";
+    public static final String PKCS8_END = "-----END PRIVATE KEY-----";
+
+    // Size in bytes of salt to use.
+    private static final int SALT_SIZE = 8;
+
+    // Number of iterations for password hashing. PKCS#5 recommends 1000
+    private static final int ITERATIONS = 1000;
+
+    // Cannot be instantiated
+    private PubkeyUtils() {
+    }
+
+    public static String formatKey(Key key) {
+        String algo = key.getAlgorithm();
+        String fmt = key.getFormat();
+        byte[] encoded = key.getEncoded();
+        return "Key[algorithm=" + algo + ", format=" + fmt +
+               ", bytes=" + encoded.length + "]";
+    }
+
+    public static byte[] sha256(byte[] data) throws NoSuchAlgorithmException {
+        return MessageDigest.getInstance("SHA-256").digest(data);
+    }
+
+    public static byte[] cipher(int mode, byte[] data, byte[] secret) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
+        SecretKeySpec secretKeySpec = new SecretKeySpec(sha256(secret), "AES");
+        Cipher c = Cipher.getInstance("AES");
+        c.init(mode, secretKeySpec);
+        return c.doFinal(data);
+    }
+
+    public static byte[] encrypt(byte[] cleartext, String secret) throws Exception {
+        byte[] salt = new byte[SALT_SIZE];
+        byte[] ciphertext = Encryptor.encrypt(salt, ITERATIONS, secret, cleartext);
+        byte[] complete = new byte[salt.length + ciphertext.length];
+        System.arraycopy(salt, 0, complete, 0, salt.length);
+        System.arraycopy(ciphertext, 0, complete, salt.length, ciphertext.length);
+        Arrays.fill(salt, (byte) 0x00);
+        Arrays.fill(ciphertext, (byte) 0x00);
+        return complete;
+    }
+
+    public static byte[] decrypt(byte[] saltAndCiphertext, String secret) throws Exception {
+        try {
+            byte[] salt = new byte[SALT_SIZE];
+            byte[] ciphertext = new byte[saltAndCiphertext.length - salt.length];
+            System.arraycopy(saltAndCiphertext, 0, salt, 0, salt.length);
+            System.arraycopy(saltAndCiphertext, salt.length, ciphertext, 0, ciphertext.length);
+            return Encryptor.decrypt(salt, ITERATIONS, secret, ciphertext);
+        }
+        catch (Exception e) {
+            Log.d("decrypt", "Could not decrypt with new method", e);
+            // We might be using the old encryption method.
+            return cipher(Cipher.DECRYPT_MODE, saltAndCiphertext, secret.getBytes());
+        }
+    }
+
+    public static byte[] getEncodedPrivate(PrivateKey pk, String secret) throws Exception {
+        final byte[] encoded = pk.getEncoded();
+
+        if (secret == null || secret.length() == 0) {
+            return encoded;
+        }
+
+        return encrypt(pk.getEncoded(), secret);
+    }
+
+    public static PrivateKey decodePrivate(byte[] encoded, String keyType) throws NoSuchAlgorithmException, InvalidKeySpecException {
+        PKCS8EncodedKeySpec privKeySpec = new PKCS8EncodedKeySpec(encoded);
+        KeyFactory kf = KeyFactory.getInstance(keyType);
+        return kf.generatePrivate(privKeySpec);
+    }
+
+    public static PrivateKey decodePrivate(byte[] encoded, String keyType, String secret) throws Exception {
+        if (secret != null && secret.length() > 0)
+            return decodePrivate(decrypt(encoded, secret), keyType);
+        else
+            return decodePrivate(encoded, keyType);
+    }
+
+    public static PublicKey decodePublic(byte[] encoded, String keyType) throws NoSuchAlgorithmException, InvalidKeySpecException {
+        X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(encoded);
+        KeyFactory kf = KeyFactory.getInstance(keyType);
+        return kf.generatePublic(pubKeySpec);
+    }
+
+    static String getAlgorithmForOid(String oid) throws NoSuchAlgorithmException {
+        if ("1.2.840.10045.2.1".equals(oid)) {
+            return "EC";
+        }
+        else if ("1.2.840.113549.1.1.1".equals(oid)) {
+            return "RSA";
+        }
+        else if ("1.2.840.10040.4.1".equals(oid)) {
+            return "DSA";
+        }
+        else {
+            throw new NoSuchAlgorithmException("Unknown algorithm OID " + oid);
+        }
+    }
+
+    static String getOidFromPkcs8Encoded(byte[] encoded) throws NoSuchAlgorithmException {
+        if (encoded == null) {
+            throw new NoSuchAlgorithmException("encoding is null");
+        }
+
+        try {
+            SimpleDERReader reader = new SimpleDERReader(encoded);
+            reader.resetInput(reader.readSequenceAsByteArray());
+            reader.readInt();
+            reader.resetInput(reader.readSequenceAsByteArray());
+            return reader.readOid();
+        }
+        catch (IOException e) {
+            Log.w(TAG, "Could not read OID", e);
+            throw new NoSuchAlgorithmException("Could not read key", e);
+        }
+    }
+
+    public static KeyPair recoverKeyPair(byte[] encoded) throws NoSuchAlgorithmException,
+        InvalidKeySpecException {
+        final String algo = getAlgorithmForOid(getOidFromPkcs8Encoded(encoded));
+        final KeySpec privKeySpec = new PKCS8EncodedKeySpec(encoded);
+        final KeyFactory kf = KeyFactory.getInstance(algo);
+        final PrivateKey priv = kf.generatePrivate(privKeySpec);
+        return new KeyPair(recoverPublicKey(kf, priv), priv);
+    }
+
+
+    static PublicKey recoverPublicKey(KeyFactory kf, PrivateKey priv)
+    throws NoSuchAlgorithmException, InvalidKeySpecException {
+        if (priv instanceof RSAPrivateCrtKey) {
+            RSAPrivateCrtKey rsaPriv = (RSAPrivateCrtKey) priv;
+            return kf.generatePublic(new RSAPublicKeySpec(rsaPriv.getModulus(), rsaPriv
+                                     .getPublicExponent()));
+        }
+        else if (priv instanceof DSAPrivateKey) {
+            DSAPrivateKey dsaPriv = (DSAPrivateKey) priv;
+            DSAParams params = dsaPriv.getParams();
+            // Calculate public key Y
+            BigInteger y = params.getG().modPow(dsaPriv.getX(), params.getP());
+            return kf.generatePublic(new DSAPublicKeySpec(y, params.getP(), params.getQ(), params
+                                     .getG()));
+        }
+        else if (priv instanceof ECPrivateKey) {
+            ECPrivateKey ecPriv = (ECPrivateKey) priv;
+            ECParameterSpec params = ecPriv.getParams();
+            // Calculate public key Y
+            ECPoint generator = params.getGenerator();
+            BigInteger[] wCoords = EcCore.multiplyPointA(new BigInteger[] { generator.getAffineX(),
+                                   generator.getAffineY()
+                                                                          }, ecPriv.getS(), params);
+            ECPoint w = new ECPoint(wCoords[0], wCoords[1]);
+            return kf.generatePublic(new ECPublicKeySpec(w, params));
+        }
+        else {
+            throw new NoSuchAlgorithmException("Key type must be RSA, DSA, or EC");
+        }
+    }
+
+    /*
+     * OpenSSH compatibility methods
+     */
+
+    public static String convertToOpenSSHFormat(PublicKey pk, String origNickname) throws IOException, InvalidKeyException {
+        String nickname = origNickname;
+
+        if (nickname == null)
+            nickname = "connectbot@android";
+
+        if (pk instanceof RSAPublicKey) {
+            String data = "ssh-rsa ";
+            data += String.valueOf(Base64.encode(RSASHA1Verify.encodeSSHRSAPublicKey((RSAPublicKey) pk)));
+            return data + " " + nickname;
+        }
+        else if (pk instanceof DSAPublicKey) {
+            String data = "ssh-dss ";
+            data += String.valueOf(Base64.encode(DSASHA1Verify.encodeSSHDSAPublicKey((DSAPublicKey) pk)));
+            return data + " " + nickname;
+        }
+        else if (pk instanceof ECPublicKey) {
+            ECPublicKey ecPub = (ECPublicKey) pk;
+            String keyType = ECDSASHA2Verify.getCurveName(ecPub.getParams().getCurve().getField().getFieldSize());
+            String keyData = String.valueOf(Base64.encode(ECDSASHA2Verify.encodeSSHECDSAPublicKey(ecPub)));
+            return ECDSASHA2Verify.ECDSA_SHA2_PREFIX + keyType + " " + keyData + " " + nickname;
+        }
+
+        throw new InvalidKeyException("Unknown key type");
+    }
+
+    /*
+     * OpenSSH compatibility methods
+     */
+
+    /**
+     * @param pair
+     * @return OpenSSH-encoded pubkey
+     */
+    public static byte[] extractOpenSSHPublic(KeyPair pair) {
+        try {
+            PublicKey pubKey = pair.getPublic();
+
+            if (pubKey instanceof RSAPublicKey) {
+                return RSASHA1Verify.encodeSSHRSAPublicKey((RSAPublicKey) pair.getPublic());
+            }
+            else if (pubKey instanceof DSAPublicKey) {
+                return DSASHA1Verify.encodeSSHDSAPublicKey((DSAPublicKey) pair.getPublic());
+            }
+            else if (pubKey instanceof ECPublicKey) {
+                return ECDSASHA2Verify.encodeSSHECDSAPublicKey((ECPublicKey) pair.getPublic());
+            }
+            else {
+                return null;
+            }
+        }
+        catch (IOException e) {
+            return null;
+        }
+    }
+
+    public static String exportPEM(PrivateKey key, String secret) throws NoSuchAlgorithmException, InvalidParameterSpecException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, InvalidKeySpecException, IllegalBlockSizeException, IOException {
+        StringBuilder sb = new StringBuilder();
+        byte[] data = key.getEncoded();
+        sb.append(PKCS8_START);
+        sb.append('\n');
+
+        if (secret != null) {
+            byte[] salt = new byte[8];
+            SecureRandom random = new SecureRandom();
+            random.nextBytes(salt);
+            PBEParameterSpec defParams = new PBEParameterSpec(salt, 1);
+            AlgorithmParameters params = AlgorithmParameters.getInstance(key.getAlgorithm());
+            params.init(defParams);
+            PBEKeySpec pbeSpec = new PBEKeySpec(secret.toCharArray());
+            SecretKeyFactory keyFact = SecretKeyFactory.getInstance(key.getAlgorithm());
+            Cipher cipher = Cipher.getInstance(key.getAlgorithm());
+            cipher.init(Cipher.WRAP_MODE, keyFact.generateSecret(pbeSpec), params);
+            byte[] wrappedKey = cipher.wrap(key);
+            EncryptedPrivateKeyInfo pinfo = new EncryptedPrivateKeyInfo(params, wrappedKey);
+            data = pinfo.getEncoded();
+            sb.append("Proc-Type: 4,ENCRYPTED\n");
+            sb.append("DEK-Info: DES-EDE3-CBC,");
+            sb.append(encodeHex(salt));
+            sb.append("\n\n");
+        }
+
+        int i = sb.length();
+        sb.append(Base64.encode(data));
+
+        for (i += 63; i < sb.length(); i += 64) {
+            sb.insert(i, "\n");
+        }
+
+        sb.append('\n');
+        sb.append(PKCS8_END);
+        sb.append('\n');
+        return sb.toString();
+    }
+
+    private static final char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5', '6',
+                                               '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
+                                             };
+    protected static String encodeHex(byte[] bytes) {
+        final char[] hex = new char[bytes.length * 2];
+        int i = 0;
+
+        for (byte b : bytes) {
+            hex[i++] = HEX_DIGITS[(b >> 4) & 0x0f];
+            hex[i++] = HEX_DIGITS[b & 0x0f];
+        }
+
+        return String.valueOf(hex);
+    }
+
+    public static String getPubkeyString(PubkeyBean pubkey) {
+        try {
+            PublicKey pk = decodePublic(pubkey.getPublicKey(), pubkey.getType());
+            return convertToOpenSSHFormat(pk, pubkey.getNickname());
+        }
+        catch (Exception e) {
+            e.printStackTrace();
+        }
+
+        return null;
+    }
+
+    public static String getPrivkeyString(PubkeyBean pubkey, String passphrase) {
+        String data = null;
+        boolean imported = PubkeyDatabase.KEY_TYPE_IMPORTED.equals(pubkey.getType());
+
+        if (imported)
+            try {
+                data = new String(pubkey.getPrivateKey());
+            }
+            catch (Exception e) {
+                e.printStackTrace();
+            }
+        else {
+            try {
+                PrivateKey pk = null;
+
+                if (passphrase == null)
+                    pk = decodePrivate(pubkey.getPrivateKey(), pubkey.getType());
+                else
+                    pk = decodePrivate(pubkey.getPrivateKey(), pubkey.getType(), passphrase);
+
+                data = exportPEM(pk, passphrase);
+            }
+            catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+
+        return data;
+    }
+}