1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package org.conscrypt;
18
19import java.security.AlgorithmParameters;
20import java.security.InvalidAlgorithmParameterException;
21import java.security.InvalidKeyException;
22import java.security.InvalidParameterException;
23import java.security.Key;
24import java.security.KeyFactory;
25import java.security.NoSuchAlgorithmException;
26import java.security.SecureRandom;
27import java.security.SignatureException;
28import java.security.interfaces.RSAPrivateCrtKey;
29import java.security.interfaces.RSAPrivateKey;
30import java.security.interfaces.RSAPublicKey;
31import java.security.spec.AlgorithmParameterSpec;
32import java.security.spec.InvalidKeySpecException;
33import java.security.spec.PKCS8EncodedKeySpec;
34import java.security.spec.X509EncodedKeySpec;
35import java.util.Arrays;
36import java.util.Locale;
37import javax.crypto.BadPaddingException;
38import javax.crypto.Cipher;
39import javax.crypto.CipherSpi;
40import javax.crypto.IllegalBlockSizeException;
41import javax.crypto.NoSuchPaddingException;
42import javax.crypto.ShortBufferException;
43import javax.crypto.spec.SecretKeySpec;
44import org.conscrypt.util.EmptyArray;
45
46public abstract class OpenSSLCipherRSA extends CipherSpi {
47    /**
48     * The current OpenSSL key we're operating on.
49     */
50    private OpenSSLKey key;
51
52    /**
53     * Current key type: private or public.
54     */
55    private boolean usingPrivateKey;
56
57    /**
58     * Current cipher mode: encrypting or decrypting.
59     */
60    private boolean encrypting;
61
62    /**
63     * Buffer for operations
64     */
65    private byte[] buffer;
66
67    /**
68     * Current offset in the buffer.
69     */
70    private int bufferOffset;
71
72    /**
73     * Flag that indicates an exception should be thrown when the input is too
74     * large during doFinal.
75     */
76    private boolean inputTooLarge;
77
78    /**
79     * Current padding mode
80     */
81    private int padding = NativeConstants.RSA_PKCS1_PADDING;
82
83    protected OpenSSLCipherRSA(int padding) {
84        this.padding = padding;
85    }
86
87    @Override
88    protected void engineSetMode(String mode) throws NoSuchAlgorithmException {
89        final String modeUpper = mode.toUpperCase(Locale.ROOT);
90        if ("NONE".equals(modeUpper) || "ECB".equals(modeUpper)) {
91            return;
92        }
93
94        throw new NoSuchAlgorithmException("mode not supported: " + mode);
95    }
96
97    @Override
98    protected void engineSetPadding(String padding) throws NoSuchPaddingException {
99        final String paddingUpper = padding.toUpperCase(Locale.ROOT);
100        if ("PKCS1PADDING".equals(paddingUpper)) {
101            this.padding = NativeConstants.RSA_PKCS1_PADDING;
102            return;
103        }
104        if ("NOPADDING".equals(paddingUpper)) {
105            this.padding = NativeConstants.RSA_NO_PADDING;
106            return;
107        }
108
109        throw new NoSuchPaddingException("padding not supported: " + padding);
110    }
111
112    @Override
113    protected int engineGetBlockSize() {
114        if (encrypting) {
115            return paddedBlockSizeBytes();
116        }
117        return keySizeBytes();
118    }
119
120    @Override
121    protected int engineGetOutputSize(int inputLen) {
122        if (encrypting) {
123            return keySizeBytes();
124        }
125        return paddedBlockSizeBytes();
126    }
127
128    private int paddedBlockSizeBytes() {
129        int paddedBlockSizeBytes = keySizeBytes();
130        if (padding == NativeConstants.RSA_PKCS1_PADDING) {
131            paddedBlockSizeBytes--;  // for 0 prefix
132            paddedBlockSizeBytes -= 10;  // PKCS1 padding header length
133        }
134        return paddedBlockSizeBytes;
135    }
136
137    private int keySizeBytes() {
138        if (key == null) {
139            throw new IllegalStateException("cipher is not initialized");
140        }
141        return NativeCrypto.RSA_size(this.key.getNativeRef());
142    }
143
144    @Override
145    protected byte[] engineGetIV() {
146        return null;
147    }
148
149    @Override
150    protected AlgorithmParameters engineGetParameters() {
151        return null;
152    }
153
154    private void engineInitInternal(int opmode, Key key) throws InvalidKeyException {
155        if (opmode == Cipher.ENCRYPT_MODE || opmode == Cipher.WRAP_MODE) {
156            encrypting = true;
157        } else if (opmode == Cipher.DECRYPT_MODE || opmode == Cipher.UNWRAP_MODE) {
158            encrypting = false;
159        } else {
160            throw new InvalidParameterException("Unsupported opmode " + opmode);
161        }
162
163        if (key instanceof OpenSSLRSAPrivateKey) {
164            OpenSSLRSAPrivateKey rsaPrivateKey = (OpenSSLRSAPrivateKey) key;
165            usingPrivateKey = true;
166            this.key = rsaPrivateKey.getOpenSSLKey();
167        } else if (key instanceof RSAPrivateCrtKey) {
168            RSAPrivateCrtKey rsaPrivateKey = (RSAPrivateCrtKey) key;
169            usingPrivateKey = true;
170            this.key = OpenSSLRSAPrivateCrtKey.getInstance(rsaPrivateKey);
171        } else if (key instanceof RSAPrivateKey) {
172            RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) key;
173            usingPrivateKey = true;
174            this.key = OpenSSLRSAPrivateKey.getInstance(rsaPrivateKey);
175        } else if (key instanceof OpenSSLRSAPublicKey) {
176            OpenSSLRSAPublicKey rsaPublicKey = (OpenSSLRSAPublicKey) key;
177            usingPrivateKey = false;
178            this.key = rsaPublicKey.getOpenSSLKey();
179        } else if (key instanceof RSAPublicKey) {
180            RSAPublicKey rsaPublicKey = (RSAPublicKey) key;
181            usingPrivateKey = false;
182            this.key = OpenSSLRSAPublicKey.getInstance(rsaPublicKey);
183        } else {
184            throw new InvalidKeyException("Need RSA private or public key");
185        }
186
187        buffer = new byte[NativeCrypto.RSA_size(this.key.getNativeRef())];
188        bufferOffset = 0;
189        inputTooLarge = false;
190    }
191
192    @Override
193    protected void engineInit(int opmode, Key key, SecureRandom random) throws InvalidKeyException {
194        engineInitInternal(opmode, key);
195    }
196
197    @Override
198    protected void engineInit(int opmode, Key key, AlgorithmParameterSpec params,
199            SecureRandom random) throws InvalidKeyException, InvalidAlgorithmParameterException {
200        if (params != null) {
201            throw new InvalidAlgorithmParameterException("unknown param type: "
202                    + params.getClass().getName());
203        }
204
205        engineInitInternal(opmode, key);
206    }
207
208    @Override
209    protected void engineInit(int opmode, Key key, AlgorithmParameters params, SecureRandom random)
210            throws InvalidKeyException, InvalidAlgorithmParameterException {
211        if (params != null) {
212            throw new InvalidAlgorithmParameterException("unknown param type: "
213                    + params.getClass().getName());
214        }
215
216        engineInitInternal(opmode, key);
217    }
218
219    @Override
220    protected byte[] engineUpdate(byte[] input, int inputOffset, int inputLen) {
221        if (bufferOffset + inputLen > buffer.length) {
222            inputTooLarge = true;
223            return EmptyArray.BYTE;
224        }
225
226        System.arraycopy(input, inputOffset, buffer, bufferOffset, inputLen);
227        bufferOffset += inputLen;
228        return EmptyArray.BYTE;
229    }
230
231    @Override
232    protected int engineUpdate(byte[] input, int inputOffset, int inputLen, byte[] output,
233            int outputOffset) throws ShortBufferException {
234        engineUpdate(input, inputOffset, inputLen);
235        return 0;
236    }
237
238    @Override
239    protected byte[] engineDoFinal(byte[] input, int inputOffset, int inputLen)
240            throws IllegalBlockSizeException, BadPaddingException {
241        if (input != null) {
242            engineUpdate(input, inputOffset, inputLen);
243        }
244
245        if (inputTooLarge) {
246            throw new IllegalBlockSizeException("input must be under " + buffer.length + " bytes");
247        }
248
249        final byte[] tmpBuf;
250        if (bufferOffset != buffer.length) {
251            if (padding == NativeConstants.RSA_NO_PADDING) {
252                tmpBuf = new byte[buffer.length];
253                System.arraycopy(buffer, 0, tmpBuf, buffer.length - bufferOffset, bufferOffset);
254            } else {
255                tmpBuf = Arrays.copyOf(buffer, bufferOffset);
256            }
257        } else {
258            tmpBuf = buffer;
259        }
260
261        byte[] output = new byte[buffer.length];
262        int resultSize;
263        if (encrypting) {
264            if (usingPrivateKey) {
265                resultSize = NativeCrypto.RSA_private_encrypt(tmpBuf.length, tmpBuf, output,
266                                                              key.getNativeRef(), padding);
267            } else {
268                resultSize = NativeCrypto.RSA_public_encrypt(tmpBuf.length, tmpBuf, output,
269                                                             key.getNativeRef(), padding);
270            }
271        } else {
272            try {
273                if (usingPrivateKey) {
274                    resultSize = NativeCrypto.RSA_private_decrypt(tmpBuf.length, tmpBuf, output,
275                                                                  key.getNativeRef(), padding);
276                } else {
277                    resultSize = NativeCrypto.RSA_public_decrypt(tmpBuf.length, tmpBuf, output,
278                                                                 key.getNativeRef(), padding);
279                }
280            } catch (SignatureException e) {
281                IllegalBlockSizeException newE = new IllegalBlockSizeException();
282                newE.initCause(e);
283                throw newE;
284            }
285        }
286        if (!encrypting && resultSize != output.length) {
287            output = Arrays.copyOf(output, resultSize);
288        }
289
290        bufferOffset = 0;
291        return output;
292    }
293
294    @Override
295    protected int engineDoFinal(byte[] input, int inputOffset, int inputLen, byte[] output,
296            int outputOffset) throws ShortBufferException, IllegalBlockSizeException,
297            BadPaddingException {
298        byte[] b = engineDoFinal(input, inputOffset, inputLen);
299
300        final int lastOffset = outputOffset + b.length;
301        if (lastOffset > output.length) {
302            throw new ShortBufferException("output buffer is too small " + output.length + " < "
303                    + lastOffset);
304        }
305
306        System.arraycopy(b, 0, output, outputOffset, b.length);
307        return b.length;
308    }
309
310    @Override
311    protected byte[] engineWrap(Key key) throws IllegalBlockSizeException, InvalidKeyException {
312        try {
313            byte[] encoded = key.getEncoded();
314            return engineDoFinal(encoded, 0, encoded.length);
315        } catch (BadPaddingException e) {
316            IllegalBlockSizeException newE = new IllegalBlockSizeException();
317            newE.initCause(e);
318            throw newE;
319        }
320    }
321
322    @Override
323    protected Key engineUnwrap(byte[] wrappedKey, String wrappedKeyAlgorithm,
324            int wrappedKeyType) throws InvalidKeyException, NoSuchAlgorithmException {
325        try {
326            byte[] encoded = engineDoFinal(wrappedKey, 0, wrappedKey.length);
327            if (wrappedKeyType == Cipher.PUBLIC_KEY) {
328                KeyFactory keyFactory = KeyFactory.getInstance(wrappedKeyAlgorithm);
329                return keyFactory.generatePublic(new X509EncodedKeySpec(encoded));
330            } else if (wrappedKeyType == Cipher.PRIVATE_KEY) {
331                KeyFactory keyFactory = KeyFactory.getInstance(wrappedKeyAlgorithm);
332                return keyFactory.generatePrivate(new PKCS8EncodedKeySpec(encoded));
333            } else if (wrappedKeyType == Cipher.SECRET_KEY) {
334                return new SecretKeySpec(encoded, wrappedKeyAlgorithm);
335            } else {
336                throw new UnsupportedOperationException("wrappedKeyType == " + wrappedKeyType);
337            }
338        } catch (IllegalBlockSizeException e) {
339            throw new InvalidKeyException(e);
340        } catch (BadPaddingException e) {
341            throw new InvalidKeyException(e);
342        } catch (InvalidKeySpecException e) {
343            throw new InvalidKeyException(e);
344        }
345    }
346
347    public static class PKCS1 extends OpenSSLCipherRSA {
348        public PKCS1() {
349            super(NativeConstants.RSA_PKCS1_PADDING);
350        }
351    }
352
353    public static class Raw extends OpenSSLCipherRSA {
354        public Raw() {
355            super(NativeConstants.RSA_NO_PADDING);
356        }
357    }
358}
359