001: /***
002: * ASM: a very small and fast Java bytecode manipulation framework
003: * Copyright (c) 2000-2007 INRIA, France Telecom
004: * All rights reserved.
005: *
006: * Redistribution and use in source and binary forms, with or without
007: * modification, are permitted provided that the following conditions
008: * are met:
009: * 1. Redistributions of source code must retain the above copyright
010: * notice, this list of conditions and the following disclaimer.
011: * 2. Redistributions in binary form must reproduce the above copyright
012: * notice, this list of conditions and the following disclaimer in the
013: * documentation and/or other materials provided with the distribution.
014: * 3. Neither the name of the copyright holders nor the names of its
015: * contributors may be used to endorse or promote products derived from
016: * this software without specific prior written permission.
017: *
018: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
019: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
020: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
021: * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
022: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
023: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
024: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
025: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
026: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
027: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
028: * THE POSSIBILITY OF SUCH DAMAGE.
029: */package org.objectweb.asm.commons;
030:
031: import java.io.ByteArrayOutputStream;
032: import java.io.DataOutput;
033: import java.io.DataOutputStream;
034: import java.io.IOException;
035: import java.security.MessageDigest;
036: import java.util.ArrayList;
037: import java.util.Arrays;
038: import java.util.Collection;
039:
040: import org.objectweb.asm.ClassAdapter;
041: import org.objectweb.asm.ClassVisitor;
042: import org.objectweb.asm.FieldVisitor;
043: import org.objectweb.asm.MethodVisitor;
044: import org.objectweb.asm.Opcodes;
045:
046: /**
047: * A {@link ClassAdapter} that adds a serial version unique identifier to a
048: * class if missing. Here is typical usage of this class:
049: *
050: * <pre>
051: * ClassWriter cw = new ClassWriter(...);
052: * ClassVisitor sv = new SerialVersionUIDAdder(cw);
053: * ClassVisitor ca = new MyClassAdapter(sv);
054: * new ClassReader(orginalClass).accept(ca, false);
055: * </pre>
056: *
057: * The SVUID algorithm can be found <a href=
058: * "http://java.sun.com/j2se/1.4.2/docs/guide/serialization/spec/class.html"
059: * >http://java.sun.com/j2se/1.4.2/docs/guide/serialization/spec/class.html</a>:
060: *
061: * <pre>
062: * The serialVersionUID is computed using the signature of a stream of bytes
063: * that reflect the class definition. The National Institute of Standards and
064: * Technology (NIST) Secure Hash Algorithm (SHA-1) is used to compute a
065: * signature for the stream. The first two 32-bit quantities are used to form a
066: * 64-bit hash. A java.lang.DataOutputStream is used to convert primitive data
067: * types to a sequence of bytes. The values input to the stream are defined by
068: * the Java Virtual Machine (VM) specification for classes.
069: *
070: * The sequence of items in the stream is as follows:
071: *
072: * 1. The class name written using UTF encoding.
073: * 2. The class modifiers written as a 32-bit integer.
074: * 3. The name of each interface sorted by name written using UTF encoding.
075: * 4. For each field of the class sorted by field name (except private static
076: * and private transient fields):
077: * 1. The name of the field in UTF encoding.
078: * 2. The modifiers of the field written as a 32-bit integer.
079: * 3. The descriptor of the field in UTF encoding
080: * 5. If a class initializer exists, write out the following:
081: * 1. The name of the method, <clinit>, in UTF encoding.
082: * 2. The modifier of the method, java.lang.reflect.Modifier.STATIC,
083: * written as a 32-bit integer.
084: * 3. The descriptor of the method, ()V, in UTF encoding.
085: * 6. For each non-private constructor sorted by method name and signature:
086: * 1. The name of the method, <init>, in UTF encoding.
087: * 2. The modifiers of the method written as a 32-bit integer.
088: * 3. The descriptor of the method in UTF encoding.
089: * 7. For each non-private method sorted by method name and signature:
090: * 1. The name of the method in UTF encoding.
091: * 2. The modifiers of the method written as a 32-bit integer.
092: * 3. The descriptor of the method in UTF encoding.
093: * 8. The SHA-1 algorithm is executed on the stream of bytes produced by
094: * DataOutputStream and produces five 32-bit values sha[0..4].
095: *
096: * 9. The hash value is assembled from the first and second 32-bit values of
097: * the SHA-1 message digest. If the result of the message digest, the five
098: * 32-bit words H0 H1 H2 H3 H4, is in an array of five int values named
099: * sha, the hash value would be computed as follows:
100: *
101: * long hash = ((sha[0] >>> 24) & 0xFF) |
102: * ((sha[0] >>> 16) & 0xFF) << 8 |
103: * ((sha[0] >>> 8) & 0xFF) << 16 |
104: * ((sha[0] >>> 0) & 0xFF) << 24 |
105: * ((sha[1] >>> 24) & 0xFF) << 32 |
106: * ((sha[1] >>> 16) & 0xFF) << 40 |
107: * ((sha[1] >>> 8) & 0xFF) << 48 |
108: * ((sha[1] >>> 0) & 0xFF) << 56;
109: * </pre>
110: *
111: * @author Rajendra Inamdar, Vishal Vishnoi
112: */
113: public class SerialVersionUIDAdder extends ClassAdapter {
114:
115: /**
116: * Flag that indicates if we need to compute SVUID.
117: */
118: protected boolean computeSVUID;
119:
120: /**
121: * Set to true if the class already has SVUID.
122: */
123: protected boolean hasSVUID;
124:
125: /**
126: * Classes access flags.
127: */
128: protected int access;
129:
130: /**
131: * Internal name of the class
132: */
133: protected String name;
134:
135: /**
136: * Interfaces implemented by the class.
137: */
138: protected String[] interfaces;
139:
140: /**
141: * Collection of fields. (except private static and private transient
142: * fields)
143: */
144: protected Collection svuidFields;
145:
146: /**
147: * Set to true if the class has static initializer.
148: */
149: protected boolean hasStaticInitializer;
150:
151: /**
152: * Collection of non-private constructors.
153: */
154: protected Collection svuidConstructors;
155:
156: /**
157: * Collection of non-private methods.
158: */
159: protected Collection svuidMethods;
160:
161: /**
162: * Creates a new {@link SerialVersionUIDAdder}.
163: *
164: * @param cv a {@link ClassVisitor} to which this visitor will delegate
165: * calls.
166: */
167: public SerialVersionUIDAdder(final ClassVisitor cv) {
168: super (cv);
169: svuidFields = new ArrayList();
170: svuidConstructors = new ArrayList();
171: svuidMethods = new ArrayList();
172: }
173:
174: // ------------------------------------------------------------------------
175: // Overriden methods
176: // ------------------------------------------------------------------------
177:
178: /*
179: * Visit class header and get class name, access , and intefraces
180: * informatoin (step 1,2, and 3) for SVUID computation.
181: */
182: public void visit(final int version, final int access,
183: final String name, final String signature,
184: final String super Name, final String[] interfaces) {
185: computeSVUID = (access & Opcodes.ACC_INTERFACE) == 0;
186:
187: if (computeSVUID) {
188: this .name = name;
189: this .access = access;
190: this .interfaces = interfaces;
191: }
192:
193: super .visit(version, access, name, signature, super Name,
194: interfaces);
195: }
196:
197: /*
198: * Visit the methods and get constructor and method information (step 5 and
199: * 7). Also determince if there is a class initializer (step 6).
200: */
201: public MethodVisitor visitMethod(final int access,
202: final String name, final String desc,
203: final String signature, final String[] exceptions) {
204: if (computeSVUID) {
205: if ("<clinit>".equals(name)) {
206: hasStaticInitializer = true;
207: }
208: /*
209: * Remembers non private constructors and methods for SVUID
210: * computation For constructor and method modifiers, only the
211: * ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC, ACC_FINAL,
212: * ACC_SYNCHRONIZED, ACC_NATIVE, ACC_ABSTRACT and ACC_STRICT flags
213: * are used.
214: */
215: int mods = access
216: & (Opcodes.ACC_PUBLIC | Opcodes.ACC_PRIVATE
217: | Opcodes.ACC_PROTECTED
218: | Opcodes.ACC_STATIC | Opcodes.ACC_FINAL
219: | Opcodes.ACC_SYNCHRONIZED
220: | Opcodes.ACC_NATIVE | Opcodes.ACC_ABSTRACT | Opcodes.ACC_STRICT);
221:
222: // all non private methods
223: if ((access & Opcodes.ACC_PRIVATE) == 0) {
224: if ("<init>".equals(name)) {
225: svuidConstructors.add(new Item(name, mods, desc));
226: } else if (!"<clinit>".equals(name)) {
227: svuidMethods.add(new Item(name, mods, desc));
228: }
229: }
230: }
231:
232: return cv
233: .visitMethod(access, name, desc, signature, exceptions);
234: }
235:
236: /*
237: * Gets class field information for step 4 of the alogrithm. Also determines
238: * if the class already has a SVUID.
239: */
240: public FieldVisitor visitField(final int access, final String name,
241: final String desc, final String signature,
242: final Object value) {
243: if (computeSVUID) {
244: if ("serialVersionUID".equals(name)) {
245: // since the class already has SVUID, we won't be computing it.
246: computeSVUID = false;
247: hasSVUID = true;
248: }
249: /*
250: * Remember field for SVUID computation For field modifiers, only
251: * the ACC_PUBLIC, ACC_PRIVATE, ACC_PROTECTED, ACC_STATIC,
252: * ACC_FINAL, ACC_VOLATILE, and ACC_TRANSIENT flags are used when
253: * computing serialVersionUID values.
254: */
255: int mods = access
256: & (Opcodes.ACC_PUBLIC | Opcodes.ACC_PRIVATE
257: | Opcodes.ACC_PROTECTED
258: | Opcodes.ACC_STATIC | Opcodes.ACC_FINAL
259: | Opcodes.ACC_VOLATILE | Opcodes.ACC_TRANSIENT);
260:
261: if ((access & Opcodes.ACC_PRIVATE) == 0
262: || (access & (Opcodes.ACC_STATIC | Opcodes.ACC_TRANSIENT)) == 0) {
263: svuidFields.add(new Item(name, mods, desc));
264: }
265: }
266:
267: return super .visitField(access, name, desc, signature, value);
268: }
269:
270: /*
271: * Add the SVUID if class doesn't have one
272: */
273: public void visitEnd() {
274: // compute SVUID and add it to the class
275: if (computeSVUID && !hasSVUID) {
276: try {
277: cv.visitField(Opcodes.ACC_FINAL + Opcodes.ACC_STATIC,
278: "serialVersionUID", "J", null, new Long(
279: computeSVUID()));
280: } catch (Throwable e) {
281: throw new RuntimeException(
282: "Error while computing SVUID for " + name, e);
283: }
284: }
285:
286: super .visitEnd();
287: }
288:
289: // ------------------------------------------------------------------------
290: // Utility methods
291: // ------------------------------------------------------------------------
292:
293: /**
294: * Returns the value of SVUID if the class doesn't have one already. Please
295: * note that 0 is returned if the class already has SVUID, thus use
296: * <code>isHasSVUID</code> to determine if the class already had an SVUID.
297: *
298: * @return Returns the serial version UID
299: */
300: protected long computeSVUID() throws IOException {
301: ByteArrayOutputStream bos;
302: DataOutputStream dos = null;
303: long svuid = 0;
304:
305: try {
306: bos = new ByteArrayOutputStream();
307: dos = new DataOutputStream(bos);
308:
309: /*
310: * 1. The class name written using UTF encoding.
311: */
312: dos.writeUTF(name.replace('/', '.'));
313:
314: /*
315: * 2. The class modifiers written as a 32-bit integer.
316: */
317: dos
318: .writeInt(access
319: & (Opcodes.ACC_PUBLIC | Opcodes.ACC_FINAL
320: | Opcodes.ACC_INTERFACE | Opcodes.ACC_ABSTRACT));
321:
322: /*
323: * 3. The name of each interface sorted by name written using UTF
324: * encoding.
325: */
326: Arrays.sort(interfaces);
327: for (int i = 0; i < interfaces.length; i++) {
328: dos.writeUTF(interfaces[i].replace('/', '.'));
329: }
330:
331: /*
332: * 4. For each field of the class sorted by field name (except
333: * private static and private transient fields):
334: *
335: * 1. The name of the field in UTF encoding. 2. The modifiers of the
336: * field written as a 32-bit integer. 3. The descriptor of the field
337: * in UTF encoding
338: *
339: * Note that field signatutes are not dot separated. Method and
340: * constructor signatures are dot separated. Go figure...
341: */
342: writeItems(svuidFields, dos, false);
343:
344: /*
345: * 5. If a class initializer exists, write out the following: 1. The
346: * name of the method, <clinit>, in UTF encoding. 2. The modifier of
347: * the method, java.lang.reflect.Modifier.STATIC, written as a
348: * 32-bit integer. 3. The descriptor of the method, ()V, in UTF
349: * encoding.
350: */
351: if (hasStaticInitializer) {
352: dos.writeUTF("<clinit>");
353: dos.writeInt(Opcodes.ACC_STATIC);
354: dos.writeUTF("()V");
355: } // if..
356:
357: /*
358: * 6. For each non-private constructor sorted by method name and
359: * signature: 1. The name of the method, <init>, in UTF encoding. 2.
360: * The modifiers of the method written as a 32-bit integer. 3. The
361: * descriptor of the method in UTF encoding.
362: */
363: writeItems(svuidConstructors, dos, true);
364:
365: /*
366: * 7. For each non-private method sorted by method name and
367: * signature: 1. The name of the method in UTF encoding. 2. The
368: * modifiers of the method written as a 32-bit integer. 3. The
369: * descriptor of the method in UTF encoding.
370: */
371: writeItems(svuidMethods, dos, true);
372:
373: dos.flush();
374:
375: /*
376: * 8. The SHA-1 algorithm is executed on the stream of bytes
377: * produced by DataOutputStream and produces five 32-bit values
378: * sha[0..4].
379: */
380: byte[] hashBytes = computeSHAdigest(bos.toByteArray());
381:
382: /*
383: * 9. The hash value is assembled from the first and second 32-bit
384: * values of the SHA-1 message digest. If the result of the message
385: * digest, the five 32-bit words H0 H1 H2 H3 H4, is in an array of
386: * five int values named sha, the hash value would be computed as
387: * follows:
388: *
389: * long hash = ((sha[0] >>> 24) & 0xFF) | ((sha[0] >>> 16) & 0xFF) <<
390: * 8 | ((sha[0] >>> 8) & 0xFF) << 16 | ((sha[0] >>> 0) & 0xFF) <<
391: * 24 | ((sha[1] >>> 24) & 0xFF) << 32 | ((sha[1] >>> 16) & 0xFF) <<
392: * 40 | ((sha[1] >>> 8) & 0xFF) << 48 | ((sha[1] >>> 0) & 0xFF) <<
393: * 56;
394: */
395: for (int i = Math.min(hashBytes.length, 8) - 1; i >= 0; i--) {
396: svuid = (svuid << 8) | (hashBytes[i] & 0xFF);
397: }
398: } finally {
399: // close the stream (if open)
400: if (dos != null) {
401: dos.close();
402: }
403: }
404:
405: return svuid;
406: }
407:
408: /**
409: * Returns the SHA-1 message digest of the given value.
410: *
411: * @param value the value whose SHA message digest must be computed.
412: * @return the SHA-1 message digest of the given value.
413: */
414: protected byte[] computeSHAdigest(final byte[] value) {
415: try {
416: return MessageDigest.getInstance("SHA").digest(value);
417: } catch (Exception e) {
418: throw new UnsupportedOperationException(e.toString());
419: }
420: }
421:
422: /**
423: * Sorts the items in the collection and writes it to the data output stream
424: *
425: * @param itemCollection collection of items
426: * @param dos a <code>DataOutputStream</code> value
427: * @param dotted a <code>boolean</code> value
428: * @exception IOException if an error occurs
429: */
430: private static void writeItems(final Collection itemCollection,
431: final DataOutput dos, final boolean dotted)
432: throws IOException {
433: int size = itemCollection.size();
434: Item[] items = (Item[]) itemCollection.toArray(new Item[size]);
435: Arrays.sort(items);
436: for (int i = 0; i < size; i++) {
437: dos.writeUTF(items[i].name);
438: dos.writeInt(items[i].access);
439: dos.writeUTF(dotted ? items[i].desc.replace('/', '.')
440: : items[i].desc);
441: }
442: }
443:
444: // ------------------------------------------------------------------------
445: // Inner classes
446: // ------------------------------------------------------------------------
447:
448: static class Item implements Comparable {
449:
450: final String name;
451:
452: final int access;
453:
454: final String desc;
455:
456: Item(final String name, final int access, final String desc) {
457: this .name = name;
458: this .access = access;
459: this .desc = desc;
460: }
461:
462: public int compareTo(final Object o) {
463: Item other = (Item) o;
464: int retVal = name.compareTo(other.name);
465: if (retVal == 0) {
466: retVal = desc.compareTo(other.desc);
467: }
468: return retVal;
469: }
470: }
471: }
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