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comparison app/src/main/java/com/five_ten_sg/connectbot/util/PubkeyUtils.java @ 438:d29cce60f393

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migrate from Eclipse to Android Studio
author Carl Byington <carl@five-ten-sg.com>
date Thu, 03 Dec 2015 11:23:55 -0800
parents src/com/five_ten_sg/connectbot/util/PubkeyUtils.java@b40bc65fa09a
children
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437:208b31032318 438:d29cce60f393
1 /*
2 * ConnectBot: simple, powerful, open-source SSH client for Android
3 * Copyright 2007 Kenny Root, Jeffrey Sharkey
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package com.five_ten_sg.connectbot.util;
19
20 import java.io.IOException;
21 import java.math.BigInteger;
22 import java.security.AlgorithmParameters;
23 import java.security.InvalidAlgorithmParameterException;
24 import java.security.InvalidKeyException;
25 import java.security.Key;
26 import java.security.KeyFactory;
27 import java.security.KeyPair;
28 import java.security.MessageDigest;
29 import java.security.NoSuchAlgorithmException;
30 import java.security.PrivateKey;
31 import java.security.PublicKey;
32 import java.security.interfaces.DSAParams;
33 import java.security.interfaces.DSAPrivateKey;
34 import java.security.interfaces.DSAPublicKey;
35 import java.security.interfaces.ECPrivateKey;
36 import java.security.interfaces.ECPublicKey;
37 import java.security.interfaces.RSAPrivateCrtKey;
38 import java.security.interfaces.RSAPublicKey;
39 import java.security.spec.DSAPublicKeySpec;
40 import java.security.spec.ECParameterSpec;
41 import java.security.spec.ECPoint;
42 import java.security.spec.ECPublicKeySpec;
43 import java.security.spec.InvalidKeySpecException;
44 import java.security.spec.InvalidParameterSpecException;
45 import java.security.spec.KeySpec;
46 import java.security.spec.PKCS8EncodedKeySpec;
47 import java.security.spec.RSAPublicKeySpec;
48 import java.security.spec.X509EncodedKeySpec;
49 import java.util.Arrays;
50
51 import javax.crypto.BadPaddingException;
52 import javax.crypto.Cipher;
53 import javax.crypto.EncryptedPrivateKeyInfo;
54 import javax.crypto.IllegalBlockSizeException;
55 import javax.crypto.NoSuchPaddingException;
56 import javax.crypto.SecretKeyFactory;
57 import javax.crypto.spec.PBEKeySpec;
58 import javax.crypto.spec.PBEParameterSpec;
59 import javax.crypto.spec.SecretKeySpec;
60
61 import org.keyczar.jce.EcCore;
62
63 import com.five_ten_sg.connectbot.bean.PubkeyBean;
64 import android.util.Log;
65
66 import ch.ethz.ssh2.crypto.Base64;
67 import ch.ethz.ssh2.crypto.SecureRandomFix;
68 import ch.ethz.ssh2.crypto.SimpleDERReader;
69 import ch.ethz.ssh2.signature.DSASHA1Verify;
70 import ch.ethz.ssh2.signature.ECDSASHA2Verify;
71 import ch.ethz.ssh2.signature.RSASHA1Verify;
72
73 public class PubkeyUtils {
74 private static final String TAG = "PubkeyUtils";
75
76 public static final String PKCS8_START = "-----BEGIN PRIVATE KEY-----";
77 public static final String PKCS8_END = "-----END PRIVATE KEY-----";
78
79 // Size in bytes of salt to use.
80 private static final int SALT_SIZE = 8;
81
82 // Number of iterations for password hashing. PKCS#5 recommends 1000
83 private static final int ITERATIONS = 1000;
84
85 // Cannot be instantiated
86 private PubkeyUtils() {
87 }
88
89 public static String formatKey(Key key) {
90 String algo = key.getAlgorithm();
91 String fmt = key.getFormat();
92 byte[] encoded = key.getEncoded();
93 return "Key[algorithm=" + algo + ", format=" + fmt +
94 ", bytes=" + encoded.length + "]";
95 }
96
97 public static byte[] sha256(byte[] data) throws NoSuchAlgorithmException {
98 return MessageDigest.getInstance("SHA-256").digest(data);
99 }
100
101 public static byte[] cipher(int mode, byte[] data, byte[] secret) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
102 SecretKeySpec secretKeySpec = new SecretKeySpec(sha256(secret), "AES");
103 Cipher c = Cipher.getInstance("AES");
104 c.init(mode, secretKeySpec);
105 return c.doFinal(data);
106 }
107
108 public static byte[] encrypt(byte[] cleartext, String secret) throws Exception {
109 byte[] salt = new byte[SALT_SIZE];
110 byte[] ciphertext = Encryptor.encrypt(salt, ITERATIONS, secret, cleartext);
111 byte[] complete = new byte[salt.length + ciphertext.length];
112 System.arraycopy(salt, 0, complete, 0, salt.length);
113 System.arraycopy(ciphertext, 0, complete, salt.length, ciphertext.length);
114 Arrays.fill(salt, (byte) 0x00);
115 Arrays.fill(ciphertext, (byte) 0x00);
116 return complete;
117 }
118
119 public static byte[] decrypt(byte[] saltAndCiphertext, String secret) throws Exception {
120 try {
121 byte[] salt = new byte[SALT_SIZE];
122 byte[] ciphertext = new byte[saltAndCiphertext.length - salt.length];
123 System.arraycopy(saltAndCiphertext, 0, salt, 0, salt.length);
124 System.arraycopy(saltAndCiphertext, salt.length, ciphertext, 0, ciphertext.length);
125 return Encryptor.decrypt(salt, ITERATIONS, secret, ciphertext);
126 }
127 catch (Exception e) {
128 Log.d("decrypt", "Could not decrypt with new method", e);
129 // We might be using the old encryption method.
130 return cipher(Cipher.DECRYPT_MODE, saltAndCiphertext, secret.getBytes());
131 }
132 }
133
134 public static byte[] getEncodedPrivate(PrivateKey pk, String secret) throws Exception {
135 final byte[] encoded = pk.getEncoded();
136
137 if (secret == null || secret.length() == 0) {
138 return encoded;
139 }
140
141 return encrypt(pk.getEncoded(), secret);
142 }
143
144 public static PrivateKey decodePrivate(byte[] encoded, String keyType) throws NoSuchAlgorithmException, InvalidKeySpecException {
145 PKCS8EncodedKeySpec privKeySpec = new PKCS8EncodedKeySpec(encoded);
146 KeyFactory kf = KeyFactory.getInstance(keyType);
147 return kf.generatePrivate(privKeySpec);
148 }
149
150 public static PrivateKey decodePrivate(byte[] encoded, String keyType, String secret) throws Exception {
151 if (secret != null && secret.length() > 0)
152 return decodePrivate(decrypt(encoded, secret), keyType);
153 else
154 return decodePrivate(encoded, keyType);
155 }
156
157 public static PublicKey decodePublic(byte[] encoded, String keyType) throws NoSuchAlgorithmException, InvalidKeySpecException {
158 X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(encoded);
159 KeyFactory kf = KeyFactory.getInstance(keyType);
160 return kf.generatePublic(pubKeySpec);
161 }
162
163 static String getAlgorithmForOid(String oid) throws NoSuchAlgorithmException {
164 if ("1.2.840.10045.2.1".equals(oid)) {
165 return "EC";
166 }
167 else if ("1.2.840.113549.1.1.1".equals(oid)) {
168 return "RSA";
169 }
170 else if ("1.2.840.10040.4.1".equals(oid)) {
171 return "DSA";
172 }
173 else {
174 throw new NoSuchAlgorithmException("Unknown algorithm OID " + oid);
175 }
176 }
177
178 static String getOidFromPkcs8Encoded(byte[] encoded) throws NoSuchAlgorithmException {
179 if (encoded == null) {
180 throw new NoSuchAlgorithmException("encoding is null");
181 }
182
183 try {
184 SimpleDERReader reader = new SimpleDERReader(encoded);
185 reader.resetInput(reader.readSequenceAsByteArray());
186 reader.readInt();
187 reader.resetInput(reader.readSequenceAsByteArray());
188 return reader.readOid();
189 }
190 catch (IOException e) {
191 Log.w(TAG, "Could not read OID", e);
192 throw new NoSuchAlgorithmException("Could not read key", e);
193 }
194 }
195
196 public static KeyPair recoverKeyPair(byte[] encoded) throws NoSuchAlgorithmException,
197 InvalidKeySpecException {
198 final String algo = getAlgorithmForOid(getOidFromPkcs8Encoded(encoded));
199 final KeySpec privKeySpec = new PKCS8EncodedKeySpec(encoded);
200 final KeyFactory kf = KeyFactory.getInstance(algo);
201 final PrivateKey priv = kf.generatePrivate(privKeySpec);
202 return new KeyPair(recoverPublicKey(kf, priv), priv);
203 }
204
205
206 static PublicKey recoverPublicKey(KeyFactory kf, PrivateKey priv)
207 throws NoSuchAlgorithmException, InvalidKeySpecException {
208 if (priv instanceof RSAPrivateCrtKey) {
209 RSAPrivateCrtKey rsaPriv = (RSAPrivateCrtKey) priv;
210 return kf.generatePublic(new RSAPublicKeySpec(rsaPriv.getModulus(), rsaPriv
211 .getPublicExponent()));
212 }
213 else if (priv instanceof DSAPrivateKey) {
214 DSAPrivateKey dsaPriv = (DSAPrivateKey) priv;
215 DSAParams params = dsaPriv.getParams();
216 // Calculate public key Y
217 BigInteger y = params.getG().modPow(dsaPriv.getX(), params.getP());
218 return kf.generatePublic(new DSAPublicKeySpec(y, params.getP(), params.getQ(), params
219 .getG()));
220 }
221 else if (priv instanceof ECPrivateKey) {
222 ECPrivateKey ecPriv = (ECPrivateKey) priv;
223 ECParameterSpec params = ecPriv.getParams();
224 // Calculate public key Y
225 ECPoint generator = params.getGenerator();
226 BigInteger[] wCoords = EcCore.multiplyPointA(new BigInteger[] { generator.getAffineX(),
227 generator.getAffineY()
228 }, ecPriv.getS(), params);
229 ECPoint w = new ECPoint(wCoords[0], wCoords[1]);
230 return kf.generatePublic(new ECPublicKeySpec(w, params));
231 }
232 else {
233 throw new NoSuchAlgorithmException("Key type must be RSA, DSA, or EC");
234 }
235 }
236
237 /*
238 * OpenSSH compatibility methods
239 */
240
241 public static String convertToOpenSSHFormat(PublicKey pk, String origNickname) throws IOException, InvalidKeyException {
242 String nickname = origNickname;
243
244 if (nickname == null)
245 nickname = "connectbot@android";
246
247 if (pk instanceof RSAPublicKey) {
248 String data = "ssh-rsa ";
249 data += String.valueOf(Base64.encode(RSASHA1Verify.encodeSSHRSAPublicKey((RSAPublicKey) pk)));
250 return data + " " + nickname;
251 }
252 else if (pk instanceof DSAPublicKey) {
253 String data = "ssh-dss ";
254 data += String.valueOf(Base64.encode(DSASHA1Verify.encodeSSHDSAPublicKey((DSAPublicKey) pk)));
255 return data + " " + nickname;
256 }
257 else if (pk instanceof ECPublicKey) {
258 ECPublicKey ecPub = (ECPublicKey) pk;
259 String keyType = ECDSASHA2Verify.getCurveName(ecPub.getParams().getCurve().getField().getFieldSize());
260 String keyData = String.valueOf(Base64.encode(ECDSASHA2Verify.encodeSSHECDSAPublicKey(ecPub)));
261 return ECDSASHA2Verify.ECDSA_SHA2_PREFIX + keyType + " " + keyData + " " + nickname;
262 }
263
264 throw new InvalidKeyException("Unknown key type");
265 }
266
267 /*
268 * OpenSSH compatibility methods
269 */
270
271 /**
272 * @param pair
273 * @return OpenSSH-encoded pubkey
274 */
275 public static byte[] extractOpenSSHPublic(KeyPair pair) {
276 try {
277 PublicKey pubKey = pair.getPublic();
278
279 if (pubKey instanceof RSAPublicKey) {
280 return RSASHA1Verify.encodeSSHRSAPublicKey((RSAPublicKey) pair.getPublic());
281 }
282 else if (pubKey instanceof DSAPublicKey) {
283 return DSASHA1Verify.encodeSSHDSAPublicKey((DSAPublicKey) pair.getPublic());
284 }
285 else if (pubKey instanceof ECPublicKey) {
286 return ECDSASHA2Verify.encodeSSHECDSAPublicKey((ECPublicKey) pair.getPublic());
287 }
288 else {
289 return null;
290 }
291 }
292 catch (IOException e) {
293 return null;
294 }
295 }
296
297 public static String exportPEM(PrivateKey key, String secret) throws NoSuchAlgorithmException, InvalidParameterSpecException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, InvalidKeySpecException, IllegalBlockSizeException, IOException {
298 StringBuilder sb = new StringBuilder();
299 byte[] data = key.getEncoded();
300 sb.append(PKCS8_START);
301 sb.append('\n');
302
303 if (secret != null) {
304 byte[] salt = new byte[8];
305 SecureRandomFix random = new SecureRandomFix();
306 random.nextBytes(salt);
307 PBEParameterSpec defParams = new PBEParameterSpec(salt, 1);
308 AlgorithmParameters params = AlgorithmParameters.getInstance(key.getAlgorithm());
309 params.init(defParams);
310 PBEKeySpec pbeSpec = new PBEKeySpec(secret.toCharArray());
311 SecretKeyFactory keyFact = SecretKeyFactory.getInstance(key.getAlgorithm());
312 Cipher cipher = Cipher.getInstance(key.getAlgorithm());
313 cipher.init(Cipher.WRAP_MODE, keyFact.generateSecret(pbeSpec), params);
314 byte[] wrappedKey = cipher.wrap(key);
315 EncryptedPrivateKeyInfo pinfo = new EncryptedPrivateKeyInfo(params, wrappedKey);
316 data = pinfo.getEncoded();
317 sb.append("Proc-Type: 4,ENCRYPTED\n");
318 sb.append("DEK-Info: DES-EDE3-CBC,");
319 sb.append(encodeHex(salt));
320 sb.append("\n\n");
321 }
322
323 int i = sb.length();
324 sb.append(Base64.encode(data));
325
326 for (i += 63; i < sb.length(); i += 64) {
327 sb.insert(i, "\n");
328 }
329
330 sb.append('\n');
331 sb.append(PKCS8_END);
332 sb.append('\n');
333 return sb.toString();
334 }
335
336 private static final char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5', '6',
337 '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
338 };
339 protected static String encodeHex(byte[] bytes) {
340 final char[] hex = new char[bytes.length * 2];
341 int i = 0;
342
343 for (byte b : bytes) {
344 hex[i++] = HEX_DIGITS[(b >> 4) & 0x0f];
345 hex[i++] = HEX_DIGITS[b & 0x0f];
346 }
347
348 return String.valueOf(hex);
349 }
350
351 public static String getPubkeyString(PubkeyBean pubkey) {
352 try {
353 PublicKey pk = decodePublic(pubkey.getPublicKey(), pubkey.getType());
354 return convertToOpenSSHFormat(pk, pubkey.getNickname());
355 }
356 catch (Exception e) {
357 e.printStackTrace();
358 }
359
360 return null;
361 }
362
363 public static String getPrivkeyString(PubkeyBean pubkey, String passphrase) {
364 String data = null;
365 boolean imported = PubkeyDatabase.KEY_TYPE_IMPORTED.equals(pubkey.getType());
366
367 if (imported)
368 try {
369 data = new String(pubkey.getPrivateKey());
370 }
371 catch (Exception e) {
372 e.printStackTrace();
373 }
374 else {
375 try {
376 PrivateKey pk = null;
377
378 if (passphrase == null)
379 pk = decodePrivate(pubkey.getPrivateKey(), pubkey.getType());
380 else
381 pk = decodePrivate(pubkey.getPrivateKey(), pubkey.getType(), passphrase);
382
383 data = exportPEM(pk, passphrase);
384 }
385 catch (Exception e) {
386 e.printStackTrace();
387 }
388 }
389
390 return data;
391 }
392 }