1 /*
2 * Copyright (c) 1996, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.security;
27
28 import java.security.spec.AlgorithmParameterSpec;
29 import java.util.*;
30 import java.util.concurrent.ConcurrentHashMap;
31 import java.io.*;
32 import java.security.cert.Certificate;
33 import java.security.cert.X509Certificate;
34
35 import java.nio.ByteBuffer;
36
37 import java.security.Provider.Service;
38
39 import javax.crypto.Cipher;
40 import javax.crypto.IllegalBlockSizeException;
41 import javax.crypto.BadPaddingException;
42 import javax.crypto.NoSuchPaddingException;
43
44 import sun.security.util.Debug;
45 import sun.security.jca.*;
46 import sun.security.jca.GetInstance.Instance;
47
48 /**
49 * The Signature class is used to provide applications the functionality
50 * of a digital signature algorithm. Digital signatures are used for
51 * authentication and integrity assurance of digital data.
52 *
53 * <p> The signature algorithm can be, among others, the NIST standard
54 * DSA, using DSA and SHA-256. The DSA algorithm using the
55 * SHA-256 message digest algorithm can be specified as {@code SHA256withDSA}.
56 * In the case of RSA the signing algorithm could be specified as, for example,
57 * {@code SHA256withRSA}.
58 * The algorithm name must be specified, as there is no default.
59 *
60 * <p> A Signature object can be used to generate and verify digital
61 * signatures.
62 *
63 * <p> There are three phases to the use of a Signature object for
64 * either signing data or verifying a signature:<ol>
65 *
66 * <li>Initialization, with either
67 *
68 * <ul>
69 *
70 * <li>a public key, which initializes the signature for
71 * verification (see {@link #initVerify(PublicKey) initVerify}), or
72 *
73 * <li>a private key (and optionally a Secure Random Number Generator),
74 * which initializes the signature for signing
75 * (see {@link #initSign(PrivateKey)}
76 * and {@link #initSign(PrivateKey, SecureRandom)}).
77 *
78 * </ul>
79 *
80 * <li>Updating
81 *
82 * <p>Depending on the type of initialization, this will update the
83 * bytes to be signed or verified. See the
84 * {@link #update(byte) update} methods.
85 *
86 * <li>Signing or Verifying a signature on all updated bytes. See the
87 * {@link #sign() sign} methods and the {@link #verify(byte[]) verify}
88 * method.
89 *
90 * </ol>
91 *
92 * <p>Note that this class is abstract and extends from
93 * {@code SignatureSpi} for historical reasons.
94 * Application developers should only take notice of the methods defined in
95 * this {@code Signature} class; all the methods in
96 * the superclass are intended for cryptographic service providers who wish to
97 * supply their own implementations of digital signature algorithms.
98 *
99 * <p> Every implementation of the Java platform is required to support the
100 * following standard {@code Signature} algorithms:
101 * <ul>
102 * <li>{@code SHA1withDSA}</li>
103 * <li>{@code SHA256withDSA}</li>
104 * <li>{@code SHA1withRSA}</li>
105 * <li>{@code SHA256withRSA}</li>
106 * </ul>
107 * These algorithms are described in the <a href=
108 * "{@docRoot}/../specs/security/standard-names.html#signature-algorithms">
109 * Signature section</a> of the
110 * Java Security Standard Algorithm Names Specification.
111 * Consult the release documentation for your implementation to see if any
112 * other algorithms are supported.
113 *
114 * @author Benjamin Renaud
115 * @since 1.1
116 *
117 */
118
119 public abstract class Signature extends SignatureSpi {
120
121 private static final Debug debug =
122 Debug.getInstance("jca", "Signature");
123
124 private static final Debug pdebug =
125 Debug.getInstance("provider", "Provider");
126 private static final boolean skipDebug =
127 Debug.isOn("engine=") && !Debug.isOn("signature");
128
129 /*
130 * The algorithm for this signature object.
131 * This value is used to map an OID to the particular algorithm.
132 * The mapping is done in AlgorithmObject.algOID(String algorithm)
133 */
134 private String algorithm;
135
136 // The provider
137 Provider provider;
138
139 /**
140 * Possible {@link #state} value, signifying that
141 * this signature object has not yet been initialized.
142 */
143 protected static final int UNINITIALIZED = 0;
144
145 /**
146 * Possible {@link #state} value, signifying that
147 * this signature object has been initialized for signing.
148 */
149 protected static final int SIGN = 2;
150
151 /**
152 * Possible {@link #state} value, signifying that
153 * this signature object has been initialized for verification.
154 */
155 protected static final int VERIFY = 3;
156
157 /**
158 * Current state of this signature object.
159 */
160 protected int state = UNINITIALIZED;
161
162 /**
163 * Creates a Signature object for the specified algorithm.
164 *
165 * @param algorithm the standard string name of the algorithm.
166 * See the Signature section in the <a href=
167 * "{@docRoot}/../specs/security/standard-names.html#signature-algorithms">
168 * Java Security Standard Algorithm Names Specification</a>
169 * for information about standard algorithm names.
170 */
171 protected Signature(String algorithm) {
172 this.algorithm = algorithm;
173 }
174
175 // name of the special signature alg
176 private static final String RSA_SIGNATURE = "NONEwithRSA";
177
178 // name of the equivalent cipher alg
179 private static final String RSA_CIPHER = "RSA/ECB/PKCS1Padding";
180
181 // all the services we need to lookup for compatibility with Cipher
182 private static final List<ServiceId> rsaIds = List.of(
183 new ServiceId("Signature", "NONEwithRSA"),
184 new ServiceId("Cipher", "RSA/ECB/PKCS1Padding"),
185 new ServiceId("Cipher", "RSA/ECB"),
186 new ServiceId("Cipher", "RSA//PKCS1Padding"),
187 new ServiceId("Cipher", "RSA"));
188
189 /**
190 * Returns a Signature object that implements the specified signature
191 * algorithm.
192 *
193 * <p> This method traverses the list of registered security Providers,
194 * starting with the most preferred Provider.
195 * A new Signature object encapsulating the
196 * SignatureSpi implementation from the first
197 * Provider that supports the specified algorithm is returned.
198 *
199 * <p> Note that the list of registered providers may be retrieved via
200 * the {@link Security#getProviders() Security.getProviders()} method.
201 *
202 * @implNote
203 * The JDK Reference Implementation additionally uses the
204 * {@code jdk.security.provider.preferred}
205 * {@link Security#getProperty(String) Security} property to determine
206 * the preferred provider order for the specified algorithm. This
207 * may be different than the order of providers returned by
208 * {@link Security#getProviders() Security.getProviders()}.
209 *
210 * @param algorithm the standard name of the algorithm requested.
211 * See the Signature section in the <a href=
212 * "{@docRoot}/../specs/security/standard-names.html#signature-algorithms">
213 * Java Security Standard Algorithm Names Specification</a>
214 * for information about standard algorithm names.
215 *
216 * @return the new {@code Signature} object
217 *
218 * @throws NoSuchAlgorithmException if no {@code Provider} supports a
219 * {@code Signature} implementation for the
220 * specified algorithm
221 *
222 * @throws NullPointerException if {@code algorithm} is {@code null}
223 *
224 * @see Provider
225 */
226 public static Signature getInstance(String algorithm)
227 throws NoSuchAlgorithmException {
228 Objects.requireNonNull(algorithm, "null algorithm name");
229 List<Service> list;
230 if (algorithm.equalsIgnoreCase(RSA_SIGNATURE)) {
231 list = GetInstance.getServices(rsaIds);
232 } else {
233 list = GetInstance.getServices("Signature", algorithm);
234 }
235 Iterator<Service> t = list.iterator();
236 if (t.hasNext() == false) {
237 throw new NoSuchAlgorithmException
238 (algorithm + " Signature not available");
239 }
240 // try services until we find an Spi or a working Signature subclass
241 NoSuchAlgorithmException failure;
242 do {
243 Service s = t.next();
244 if (isSpi(s)) {
245 return new Delegate(s, t, algorithm);
246 } else {
247 // must be a subclass of Signature, disable dynamic selection
248 try {
249 Instance instance =
250 GetInstance.getInstance(s, SignatureSpi.class);
251 return getInstance(instance, algorithm);
252 } catch (NoSuchAlgorithmException e) {
253 failure = e;
254 }
255 }
256 } while (t.hasNext());
257 throw failure;
258 }
259
260 private static Signature getInstance(Instance instance, String algorithm) {
261 Signature sig;
262 if (instance.impl instanceof Signature) {
263 sig = (Signature)instance.impl;
264 sig.algorithm = algorithm;
265 } else {
266 SignatureSpi spi = (SignatureSpi)instance.impl;
267 sig = new Delegate(spi, algorithm);
268 }
269 sig.provider = instance.provider;
270 return sig;
271 }
272
273 private static final Map<String,Boolean> signatureInfo;
274
275 static {
276 signatureInfo = new ConcurrentHashMap<>();
277 Boolean TRUE = Boolean.TRUE;
278 // pre-initialize with values for our SignatureSpi implementations
279 signatureInfo.put("sun.security.provider.DSA$RawDSA", TRUE);
280 signatureInfo.put("sun.security.provider.DSA$SHA1withDSA", TRUE);
281 signatureInfo.put("sun.security.rsa.RSASignature$MD2withRSA", TRUE);
282 signatureInfo.put("sun.security.rsa.RSASignature$MD5withRSA", TRUE);
283 signatureInfo.put("sun.security.rsa.RSASignature$SHA1withRSA", TRUE);
284 signatureInfo.put("sun.security.rsa.RSASignature$SHA256withRSA", TRUE);
285 signatureInfo.put("sun.security.rsa.RSASignature$SHA384withRSA", TRUE);
286 signatureInfo.put("sun.security.rsa.RSASignature$SHA512withRSA", TRUE);
287 signatureInfo.put("sun.security.rsa.RSAPSSSignature", TRUE);
288 signatureInfo.put("sun.security.pkcs11.P11Signature", TRUE);
289 }
290
291 private static boolean isSpi(Service s) {
292 if (s.getType().equals("Cipher")) {
293 // must be a CipherSpi, which we can wrap with the CipherAdapter
294 return true;
295 }
296 String className = s.getClassName();
297 Boolean result = signatureInfo.get(className);
298 if (result == null) {
299 try {
300 Object instance = s.newInstance(null);
301 // Signature extends SignatureSpi
302 // so it is a "real" Spi if it is an
303 // instance of SignatureSpi but not Signature
304 boolean r = (instance instanceof SignatureSpi)
305 && (instance instanceof Signature == false);
306 if ((debug != null) && (r == false)) {
307 debug.println("Not a SignatureSpi " + className);
308 debug.println("Delayed provider selection may not be "
309 + "available for algorithm " + s.getAlgorithm());
310 }
311 result = Boolean.valueOf(r);
312 signatureInfo.put(className, result);
313 } catch (Exception e) {
314 // something is wrong, assume not an SPI
315 return false;
316 }
317 }
318 return result.booleanValue();
319 }
320
321 /**
322 * Returns a Signature object that implements the specified signature
323 * algorithm.
324 *
325 * <p> A new Signature object encapsulating the
326 * SignatureSpi implementation from the specified provider
327 * is returned. The specified provider must be registered
328 * in the security provider list.
329 *
330 * <p> Note that the list of registered providers may be retrieved via
331 * the {@link Security#getProviders() Security.getProviders()} method.
332 *
333 * @param algorithm the name of the algorithm requested.
334 * See the Signature section in the <a href=
335 * "{@docRoot}/../specs/security/standard-names.html#signature-algorithms">
336 * Java Security Standard Algorithm Names Specification</a>
337 * for information about standard algorithm names.
338 *
339 * @param provider the name of the provider.
340 *
341 * @return the new {@code Signature} object
342 *
343 * @throws IllegalArgumentException if the provider name is {@code null}
344 * or empty
345 *
346 * @throws NoSuchAlgorithmException if a {@code SignatureSpi}
347 * implementation for the specified algorithm is not
348 * available from the specified provider
349 *
350 * @throws NoSuchProviderException if the specified provider is not
351 * registered in the security provider list
352 *
353 * @throws NullPointerException if {@code algorithm} is {@code null}
354 *
355 * @see Provider
356 */
357 public static Signature getInstance(String algorithm, String provider)
358 throws NoSuchAlgorithmException, NoSuchProviderException {
359 Objects.requireNonNull(algorithm, "null algorithm name");
360 if (algorithm.equalsIgnoreCase(RSA_SIGNATURE)) {
361 // exception compatibility with existing code
362 if (provider == null || provider.isEmpty()) {
363 throw new IllegalArgumentException("missing provider");
364 }
365 Provider p = Security.getProvider(provider);
366 if (p == null) {
367 throw new NoSuchProviderException
368 ("no such provider: " + provider);
369 }
370 return getInstanceRSA(p);
371 }
372 Instance instance = GetInstance.getInstance
373 ("Signature", SignatureSpi.class, algorithm, provider);
374 return getInstance(instance, algorithm);
375 }
376
377 /**
378 * Returns a Signature object that implements the specified
379 * signature algorithm.
380 *
381 * <p> A new Signature object encapsulating the
382 * SignatureSpi implementation from the specified Provider
383 * object is returned. Note that the specified Provider object
384 * does not have to be registered in the provider list.
385 *
386 * @param algorithm the name of the algorithm requested.
387 * See the Signature section in the <a href=
388 * "{@docRoot}/../specs/security/standard-names.html#signature-algorithms">
389 * Java Security Standard Algorithm Names Specification</a>
390 * for information about standard algorithm names.
391 *
392 * @param provider the provider.
393 *
394 * @return the new {@code Signature} object
395 *
396 * @throws IllegalArgumentException if the provider is {@code null}
397 *
398 * @throws NoSuchAlgorithmException if a {@code SignatureSpi}
399 * implementation for the specified algorithm is not available
400 * from the specified {@code Provider} object
401 *
402 * @throws NullPointerException if {@code algorithm} is {@code null}
403 *
404 * @see Provider
405 *
406 * @since 1.4
407 */
408 public static Signature getInstance(String algorithm, Provider provider)
409 throws NoSuchAlgorithmException {
410 Objects.requireNonNull(algorithm, "null algorithm name");
411 if (algorithm.equalsIgnoreCase(RSA_SIGNATURE)) {
412 // exception compatibility with existing code
413 if (provider == null) {
414 throw new IllegalArgumentException("missing provider");
415 }
416 return getInstanceRSA(provider);
417 }
418 Instance instance = GetInstance.getInstance
419 ("Signature", SignatureSpi.class, algorithm, provider);
420 return getInstance(instance, algorithm);
421 }
422
423 // return an implementation for NONEwithRSA, which is a special case
424 // because of the Cipher.RSA/ECB/PKCS1Padding compatibility wrapper
425 private static Signature getInstanceRSA(Provider p)
426 throws NoSuchAlgorithmException {
427 // try Signature first
428 Service s = p.getService("Signature", RSA_SIGNATURE);
429 if (s != null) {
430 Instance instance = GetInstance.getInstance(s, SignatureSpi.class);
431 return getInstance(instance, RSA_SIGNATURE);
432 }
433 // check Cipher
434 try {
435 Cipher c = Cipher.getInstance(RSA_CIPHER, p);
436 return new Delegate(new CipherAdapter(c), RSA_SIGNATURE);
437 } catch (GeneralSecurityException e) {
438 // throw Signature style exception message to avoid confusion,
439 // but append Cipher exception as cause
440 throw new NoSuchAlgorithmException("no such algorithm: "
441 + RSA_SIGNATURE + " for provider " + p.getName(), e);
442 }
443 }
444
445 /**
446 * Returns the provider of this signature object.
447 *
448 * @return the provider of this signature object
449 */
450 public final Provider getProvider() {
451 chooseFirstProvider();
452 return this.provider;
453 }
454
455 private String getProviderName() {
456 return (provider == null) ? "(no provider)" : provider.getName();
457 }
458
459 void chooseFirstProvider() {
460 // empty, overridden in Delegate
461 }
462
463 /**
464 * Initializes this object for verification. If this method is called
465 * again with a different argument, it negates the effect
466 * of this call.
467 *
468 * @param publicKey the public key of the identity whose signature is
469 * going to be verified.
470 *
471 * @exception InvalidKeyException if the key is invalid.
472 */
473 public final void initVerify(PublicKey publicKey)
474 throws InvalidKeyException {
475 engineInitVerify(publicKey);
476 state = VERIFY;
477
478 if (!skipDebug && pdebug != null) {
479 pdebug.println("Signature." + algorithm +
480 " verification algorithm from: " + getProviderName());
481 }
482 }
483
484 /**
485 * Initializes this object for verification, using the public key from
486 * the given certificate.
487 * <p>If the certificate is of type X.509 and has a <i>key usage</i>
488 * extension field marked as critical, and the value of the <i>key usage</i>
489 * extension field implies that the public key in
490 * the certificate and its corresponding private key are not
491 * supposed to be used for digital signatures, an
492 * {@code InvalidKeyException} is thrown.
493 *
494 * @param certificate the certificate of the identity whose signature is
495 * going to be verified.
496 *
497 * @exception InvalidKeyException if the public key in the certificate
498 * is not encoded properly or does not include required parameter
499 * information or cannot be used for digital signature purposes.
500 * @since 1.3
501 */
502 public final void initVerify(Certificate certificate)
503 throws InvalidKeyException {
504 // If the certificate is of type X509Certificate,
505 // we should check whether it has a Key Usage
506 // extension marked as critical.
507 if (certificate instanceof java.security.cert.X509Certificate) {
508 // Check whether the cert has a key usage extension
509 // marked as a critical extension.
510 // The OID for KeyUsage extension is 2.5.29.15.
511 X509Certificate cert = (X509Certificate)certificate;
512 Set<String> critSet = cert.getCriticalExtensionOIDs();
513
514 if (critSet != null && !critSet.isEmpty()
515 && critSet.contains("2.5.29.15")) {
516 boolean[] keyUsageInfo = cert.getKeyUsage();
517 // keyUsageInfo[0] is for digitalSignature.
518 if ((keyUsageInfo != null) && (keyUsageInfo[0] == false))
519 throw new InvalidKeyException("Wrong key usage");
520 }
521 }
522
523 PublicKey publicKey = certificate.getPublicKey();
524 engineInitVerify(publicKey);
525 state = VERIFY;
526
527 if (!skipDebug && pdebug != null) {
528 pdebug.println("Signature." + algorithm +
529 " verification algorithm from: " + getProviderName());
530 }
531 }
532
533 /**
534 * Initialize this object for signing. If this method is called
535 * again with a different argument, it negates the effect
536 * of this call.
537 *
538 * @param privateKey the private key of the identity whose signature
539 * is going to be generated.
540 *
541 * @exception InvalidKeyException if the key is invalid.
542 */
543 public final void initSign(PrivateKey privateKey)
544 throws InvalidKeyException {
545 engineInitSign(privateKey);
546 state = SIGN;
547
548 if (!skipDebug && pdebug != null) {
549 pdebug.println("Signature." + algorithm +
550 " signing algorithm from: " + getProviderName());
551 }
552 }
553
554 /**
555 * Initialize this object for signing. If this method is called
556 * again with a different argument, it negates the effect
557 * of this call.
558 *
559 * @param privateKey the private key of the identity whose signature
560 * is going to be generated.
561 *
562 * @param random the source of randomness for this signature.
563 *
564 * @exception InvalidKeyException if the key is invalid.
565 */
566 public final void initSign(PrivateKey privateKey, SecureRandom random)
567 throws InvalidKeyException {
568 engineInitSign(privateKey, random);
569 state = SIGN;
570
571 if (!skipDebug && pdebug != null) {
572 pdebug.println("Signature." + algorithm +
573 " signing algorithm from: " + getProviderName());
574 }
575 }
576
577 /**
578 * Returns the signature bytes of all the data updated.
579 * The format of the signature depends on the underlying
580 * signature scheme.
581 *
582 * <p>A call to this method resets this signature object to the state
583 * it was in when previously initialized for signing via a
584 * call to {@code initSign(PrivateKey)}. That is, the object is
585 * reset and available to generate another signature from the same
586 * signer, if desired, via new calls to {@code update} and
587 * {@code sign}.
588 *
589 * @return the signature bytes of the signing operation's result.
590 *
591 * @exception SignatureException if this signature object is not
592 * initialized properly or if this signature algorithm is unable to
593 * process the input data provided.
594 */
595 public final byte[] sign() throws SignatureException {
596 if (state == SIGN) {
597 return engineSign();
598 }
599 throw new SignatureException("object not initialized for " +
600 "signing");
601 }
602
603 /**
604 * Finishes the signature operation and stores the resulting signature
605 * bytes in the provided buffer {@code outbuf}, starting at
606 * {@code offset}.
607 * The format of the signature depends on the underlying
608 * signature scheme.
609 *
610 * <p>This signature object is reset to its initial state (the state it
611 * was in after a call to one of the {@code initSign} methods) and
612 * can be reused to generate further signatures with the same private key.
613 *
614 * @param outbuf buffer for the signature result.
615 *
616 * @param offset offset into {@code outbuf} where the signature is
617 * stored.
618 *
619 * @param len number of bytes within {@code outbuf} allotted for the
620 * signature.
621 *
622 * @return the number of bytes placed into {@code outbuf}.
623 *
624 * @exception SignatureException if this signature object is not
625 * initialized properly, if this signature algorithm is unable to
626 * process the input data provided, or if {@code len} is less
627 * than the actual signature length.
628 * @exception IllegalArgumentException if {@code outbuf} is {@code null},
629 * or {@code offset} or {@code len} is less than 0, or the sum of
630 * {@code offset} and {@code len} is greater than the length of
631 * {@code outbuf}.
632 *
633 * @since 1.2
634 */
635 public final int sign(byte[] outbuf, int offset, int len)
636 throws SignatureException {
637 if (outbuf == null) {
638 throw new IllegalArgumentException("No output buffer given");
639 }
640 if (offset < 0 || len < 0) {
641 throw new IllegalArgumentException("offset or len is less than 0");
642 }
643 if (outbuf.length - offset < len) {
644 throw new IllegalArgumentException
645 ("Output buffer too small for specified offset and length");
646 }
647 if (state != SIGN) {
648 throw new SignatureException("object not initialized for " +
649 "signing");
650 }
651 return engineSign(outbuf, offset, len);
652 }
653
654 /**
655 * Verifies the passed-in signature.
656 *
657 * <p>A call to this method resets this signature object to the state
658 * it was in when previously initialized for verification via a
659 * call to {@code initVerify(PublicKey)}. That is, the object is
660 * reset and available to verify another signature from the identity
661 * whose public key was specified in the call to {@code initVerify}.
662 *
663 * @param signature the signature bytes to be verified.
664 *
665 * @return true if the signature was verified, false if not.
666 *
667 * @exception SignatureException if this signature object is not
668 * initialized properly, the passed-in signature is improperly
669 * encoded or of the wrong type, if this signature algorithm is unable to
670 * process the input data provided, etc.
671 */
672 public final boolean verify(byte[] signature) throws SignatureException {
673 if (state == VERIFY) {
674 return engineVerify(signature);
675 }
676 throw new SignatureException("object not initialized for " +
677 "verification");
678 }
679
680 /**
681 * Verifies the passed-in signature in the specified array
682 * of bytes, starting at the specified offset.
683 *
684 * <p>A call to this method resets this signature object to the state
685 * it was in when previously initialized for verification via a
686 * call to {@code initVerify(PublicKey)}. That is, the object is
687 * reset and available to verify another signature from the identity
688 * whose public key was specified in the call to {@code initVerify}.
689 *
690 *
691 * @param signature the signature bytes to be verified.
692 * @param offset the offset to start from in the array of bytes.
693 * @param length the number of bytes to use, starting at offset.
694 *
695 * @return true if the signature was verified, false if not.
696 *
697 * @exception SignatureException if this signature object is not
698 * initialized properly, the passed-in signature is improperly
699 * encoded or of the wrong type, if this signature algorithm is unable to
700 * process the input data provided, etc.
701 * @exception IllegalArgumentException if the {@code signature}
702 * byte array is {@code null}, or the {@code offset} or {@code length}
703 * is less than 0, or the sum of the {@code offset} and
704 * {@code length} is greater than the length of the
705 * {@code signature} byte array.
706 * @since 1.4
707 */
708 public final boolean verify(byte[] signature, int offset, int length)
709 throws SignatureException {
710 if (state == VERIFY) {
711 if (signature == null) {
712 throw new IllegalArgumentException("signature is null");
713 }
714 if (offset < 0 || length < 0) {
715 throw new IllegalArgumentException
716 ("offset or length is less than 0");
717 }
718 if (signature.length - offset < length) {
719 throw new IllegalArgumentException
720 ("signature too small for specified offset and length");
721 }
722
723 return engineVerify(signature, offset, length);
724 }
725 throw new SignatureException("object not initialized for " +
726 "verification");
727 }
728
729 /**
730 * Updates the data to be signed or verified by a byte.
731 *
732 * @param b the byte to use for the update.
733 *
734 * @exception SignatureException if this signature object is not
735 * initialized properly.
736 */
737 public final void update(byte b) throws SignatureException {
738 if (state == VERIFY || state == SIGN) {
739 engineUpdate(b);
740 } else {
741 throw new SignatureException("object not initialized for "
742 + "signature or verification");
743 }
744 }
745
746 /**
747 * Updates the data to be signed or verified, using the specified
748 * array of bytes.
749 *
750 * @param data the byte array to use for the update.
751 *
752 * @exception SignatureException if this signature object is not
753 * initialized properly.
754 */
755 public final void update(byte[] data) throws SignatureException {
756 update(data, 0, data.length);
757 }
758
759 /**
760 * Updates the data to be signed or verified, using the specified
761 * array of bytes, starting at the specified offset.
762 *
763 * @param data the array of bytes.
764 * @param off the offset to start from in the array of bytes.
765 * @param len the number of bytes to use, starting at offset.
766 *
767 * @exception SignatureException if this signature object is not
768 * initialized properly.
769 * @exception IllegalArgumentException if {@code data} is {@code null},
770 * or {@code off} or {@code len} is less than 0, or the sum of
771 * {@code off} and {@code len} is greater than the length of
772 * {@code data}.
773 */
774 public final void update(byte[] data, int off, int len)
775 throws SignatureException {
776 if (state == SIGN || state == VERIFY) {
777 if (data == null) {
778 throw new IllegalArgumentException("data is null");
779 }
780 if (off < 0 || len < 0) {
781 throw new IllegalArgumentException("off or len is less than 0");
782 }
783 if (data.length - off < len) {
784 throw new IllegalArgumentException
785 ("data too small for specified offset and length");
786 }
787 engineUpdate(data, off, len);
788 } else {
789 throw new SignatureException("object not initialized for "
790 + "signature or verification");
791 }
792 }
793
794 /**
795 * Updates the data to be signed or verified using the specified
796 * ByteBuffer. Processes the {@code data.remaining()} bytes
797 * starting at {@code data.position()}.
798 * Upon return, the buffer's position will be equal to its limit;
799 * its limit will not have changed.
800 *
801 * @param data the ByteBuffer
802 *
803 * @exception SignatureException if this signature object is not
804 * initialized properly.
805 * @since 1.5
806 */
807 public final void update(ByteBuffer data) throws SignatureException {
808 if ((state != SIGN) && (state != VERIFY)) {
809 throw new SignatureException("object not initialized for "
810 + "signature or verification");
811 }
812 if (data == null) {
813 throw new NullPointerException();
814 }
815 engineUpdate(data);
816 }
817
818 /**
819 * Returns the name of the algorithm for this signature object.
820 *
821 * @return the name of the algorithm for this signature object.
822 */
823 public final String getAlgorithm() {
824 return this.algorithm;
825 }
826
827 /**
828 * Returns a string representation of this signature object,
829 * providing information that includes the state of the object
830 * and the name of the algorithm used.
831 *
832 * @return a string representation of this signature object.
833 */
834 public String toString() {
835 String initState = "";
836 switch (state) {
837 case UNINITIALIZED:
838 initState = "<not initialized>";
839 break;
840 case VERIFY:
841 initState = "<initialized for verifying>";
842 break;
843 case SIGN:
844 initState = "<initialized for signing>";
845 break;
846 }
847 return "Signature object: " + getAlgorithm() + initState;
848 }
849
850 /**
851 * Sets the specified algorithm parameter to the specified value.
852 * This method supplies a general-purpose mechanism through
853 * which it is possible to set the various parameters of this object.
854 * A parameter may be any settable parameter for the algorithm, such as
855 * a parameter size, or a source of random bits for signature generation
856 * (if appropriate), or an indication of whether or not to perform
857 * a specific but optional computation. A uniform algorithm-specific
858 * naming scheme for each parameter is desirable but left unspecified
859 * at this time.
860 *
861 * @param param the string identifier of the parameter.
862 * @param value the parameter value.
863 *
864 * @exception InvalidParameterException if {@code param} is an
865 * invalid parameter for this signature algorithm engine,
866 * the parameter is already set
867 * and cannot be set again, a security exception occurs, and so on.
868 *
869 * @see #getParameter
870 *
871 * @deprecated Use
872 * {@link #setParameter(java.security.spec.AlgorithmParameterSpec)
873 * setParameter}.
874 */
875 @Deprecated
876 public final void setParameter(String param, Object value)
877 throws InvalidParameterException {
878 engineSetParameter(param, value);
879 }
880
881 /**
882 * Initializes this signature engine with the specified parameter set.
883 *
884 * @param params the parameters
885 *
886 * @exception InvalidAlgorithmParameterException if the given parameters
887 * are inappropriate for this signature engine
888 *
889 * @see #getParameters
890 */
891 public final void setParameter(AlgorithmParameterSpec params)
892 throws InvalidAlgorithmParameterException {
893 engineSetParameter(params);
894 }
895
896 /**
897 * Returns the parameters used with this signature object.
898 *
899 * <p> If this signature has been previously initialized with parameters
900 * (by calling the {@code setParameter} method), this method returns
901 * the same parameters. If this signature has not been initialized with
902 * parameters, this method may return a combination of default and
903 * randomly generated parameter values if the underlying
904 * signature implementation supports it and can successfully generate
905 * them. Otherwise, {@code null} is returned.
906 *
907 * @return the parameters used with this signature, or {@code null}
908 *
909 * @see #setParameter(AlgorithmParameterSpec)
910 * @since 1.4
911 */
912 public final AlgorithmParameters getParameters() {
913 return engineGetParameters();
914 }
915
916 /**
917 * Gets the value of the specified algorithm parameter. This method
918 * supplies a general-purpose mechanism through which it is possible to
919 * get the various parameters of this object. A parameter may be any
920 * settable parameter for the algorithm, such as a parameter size, or
921 * a source of random bits for signature generation (if appropriate),
922 * or an indication of whether or not to perform a specific but optional
923 * computation. A uniform algorithm-specific naming scheme for each
924 * parameter is desirable but left unspecified at this time.
925 *
926 * @param param the string name of the parameter.
927 *
928 * @return the object that represents the parameter value, or {@code null} if
929 * there is none.
930 *
931 * @exception InvalidParameterException if {@code param} is an invalid
932 * parameter for this engine, or another exception occurs while
933 * trying to get this parameter.
934 *
935 * @see #setParameter(String, Object)
936 *
937 * @deprecated
938 */
939 @Deprecated
940 public final Object getParameter(String param)
941 throws InvalidParameterException {
942 return engineGetParameter(param);
943 }
944
945 /**
946 * Returns a clone if the implementation is cloneable.
947 *
948 * @return a clone if the implementation is cloneable.
949 *
950 * @exception CloneNotSupportedException if this is called
951 * on an implementation that does not support {@code Cloneable}.
952 */
953 public Object clone() throws CloneNotSupportedException {
954 if (this instanceof Cloneable) {
955 return super.clone();
956 } else {
957 throw new CloneNotSupportedException();
958 }
959 }
960
961 /*
962 * The following class allows providers to extend from SignatureSpi
963 * rather than from Signature. It represents a Signature with an
964 * encapsulated, provider-supplied SPI object (of type SignatureSpi).
965 * If the provider implementation is an instance of SignatureSpi, the
966 * getInstance() methods above return an instance of this class, with
967 * the SPI object encapsulated.
968 *
969 * Note: All SPI methods from the original Signature class have been
970 * moved up the hierarchy into a new class (SignatureSpi), which has
971 * been interposed in the hierarchy between the API (Signature)
972 * and its original parent (Object).
973 */
974
975 @SuppressWarnings("deprecation")
976 private static class Delegate extends Signature {
977
978 // The provider implementation (delegate)
979 // filled in once the provider is selected
980 private SignatureSpi sigSpi;
981
982 // lock for mutex during provider selection
983 private final Object lock;
984
985 // next service to try in provider selection
986 // null once provider is selected
987 private Service firstService;
988
989 // remaining services to try in provider selection
990 // null once provider is selected
991 private Iterator<Service> serviceIterator;
992
993 // constructor
994 Delegate(SignatureSpi sigSpi, String algorithm) {
995 super(algorithm);
996 this.sigSpi = sigSpi;
997 this.lock = null; // no lock needed
998 }
999
1000 // used with delayed provider selection
1001 Delegate(Service service,
1002 Iterator<Service> iterator, String algorithm) {
1003 super(algorithm);
1004 this.firstService = service;
1005 this.serviceIterator = iterator;
1006 this.lock = new Object();
1007 }
1008
1009 /**
1010 * Returns a clone if the delegate is cloneable.
1011 *
1012 * @return a clone if the delegate is cloneable.
1013 *
1014 * @exception CloneNotSupportedException if this is called on a
1015 * delegate that does not support {@code Cloneable}.
1016 */
1017 public Object clone() throws CloneNotSupportedException {
1018 chooseFirstProvider();
1019 if (sigSpi instanceof Cloneable) {
1020 SignatureSpi sigSpiClone = (SignatureSpi)sigSpi.clone();
1021 // Because 'algorithm' and 'provider' are private
1022 // members of our supertype, we must perform a cast to
1023 // access them.
1024 Signature that =
1025 new Delegate(sigSpiClone, ((Signature)this).algorithm);
1026 that.provider = ((Signature)this).provider;
1027 return that;
1028 } else {
1029 throw new CloneNotSupportedException();
1030 }
1031 }
1032
1033 private static SignatureSpi newInstance(Service s)
1034 throws NoSuchAlgorithmException {
1035 if (s.getType().equals("Cipher")) {
1036 // must be NONEwithRSA
1037 try {
1038 Cipher c = Cipher.getInstance(RSA_CIPHER, s.getProvider());
1039 return new CipherAdapter(c);
1040 } catch (NoSuchPaddingException e) {
1041 throw new NoSuchAlgorithmException(e);
1042 }
1043 } else {
1044 Object o = s.newInstance(null);
1045 if (o instanceof SignatureSpi == false) {
1046 throw new NoSuchAlgorithmException
1047 ("Not a SignatureSpi: " + o.getClass().getName());
1048 }
1049 return (SignatureSpi)o;
1050 }
1051 }
1052
1053 // max number of debug warnings to print from chooseFirstProvider()
1054 private static int warnCount = 10;
1055
1056 /**
1057 * Choose the Spi from the first provider available. Used if
1058 * delayed provider selection is not possible because initSign()/
1059 * initVerify() is not the first method called.
1060 */
1061 void chooseFirstProvider() {
1062 if (sigSpi != null) {
1063 return;
1064 }
1065 synchronized (lock) {
1066 if (sigSpi != null) {
1067 return;
1068 }
1069 if (debug != null) {
1070 int w = --warnCount;
1071 if (w >= 0) {
1072 debug.println("Signature.init() not first method "
1073 + "called, disabling delayed provider selection");
1074 if (w == 0) {
1075 debug.println("Further warnings of this type will "
1076 + "be suppressed");
1077 }
1078 new Exception("Debug call trace").printStackTrace();
1079 }
1080 }
1081 Exception lastException = null;
1082 while ((firstService != null) || serviceIterator.hasNext()) {
1083 Service s;
1084 if (firstService != null) {
1085 s = firstService;
1086 firstService = null;
1087 } else {
1088 s = serviceIterator.next();
1089 }
1090 if (isSpi(s) == false) {
1091 continue;
1092 }
1093 try {
1094 sigSpi = newInstance(s);
1095 provider = s.getProvider();
1096 // not needed any more
1097 firstService = null;
1098 serviceIterator = null;
1099 return;
1100 } catch (NoSuchAlgorithmException e) {
1101 lastException = e;
1102 }
1103 }
1104 ProviderException e = new ProviderException
1105 ("Could not construct SignatureSpi instance");
1106 if (lastException != null) {
1107 e.initCause(lastException);
1108 }
1109 throw e;
1110 }
1111 }
1112
1113 private void chooseProvider(int type, Key key, SecureRandom random)
1114 throws InvalidKeyException {
1115 synchronized (lock) {
1116 if (sigSpi != null) {
1117 init(sigSpi, type, key, random);
1118 return;
1119 }
1120 Exception lastException = null;
1121 while ((firstService != null) || serviceIterator.hasNext()) {
1122 Service s;
1123 if (firstService != null) {
1124 s = firstService;
1125 firstService = null;
1126 } else {
1127 s = serviceIterator.next();
1128 }
1129 // if provider says it does not support this key, ignore it
1130 if (s.supportsParameter(key) == false) {
1131 continue;
1132 }
1133 // if instance is not a SignatureSpi, ignore it
1134 if (isSpi(s) == false) {
1135 continue;
1136 }
1137 try {
1138 SignatureSpi spi = newInstance(s);
1139 init(spi, type, key, random);
1140 provider = s.getProvider();
1141 sigSpi = spi;
1142 firstService = null;
1143 serviceIterator = null;
1144 return;
1145 } catch (Exception e) {
1146 // NoSuchAlgorithmException from newInstance()
1147 // InvalidKeyException from init()
1148 // RuntimeException (ProviderException) from init()
1149 if (lastException == null) {
1150 lastException = e;
1151 }
1152 }
1153 }
1154 // no working provider found, fail
1155 if (lastException instanceof InvalidKeyException) {
1156 throw (InvalidKeyException)lastException;
1157 }
1158 if (lastException instanceof RuntimeException) {
1159 throw (RuntimeException)lastException;
1160 }
1161 String k = (key != null) ? key.getClass().getName() : "(null)";
1162 throw new InvalidKeyException
1163 ("No installed provider supports this key: "
1164 + k, lastException);
1165 }
1166 }
1167
1168 private static final int I_PUB = 1;
1169 private static final int I_PRIV = 2;
1170 private static final int I_PRIV_SR = 3;
1171
1172 private void init(SignatureSpi spi, int type, Key key,
1173 SecureRandom random) throws InvalidKeyException {
1174 switch (type) {
1175 case I_PUB:
1176 spi.engineInitVerify((PublicKey)key);
1177 break;
1178 case I_PRIV:
1179 spi.engineInitSign((PrivateKey)key);
1180 break;
1181 case I_PRIV_SR:
1182 spi.engineInitSign((PrivateKey)key, random);
1183 break;
1184 default:
1185 throw new AssertionError("Internal error: " + type);
1186 }
1187 }
1188
1189 protected void engineInitVerify(PublicKey publicKey)
1190 throws InvalidKeyException {
1191 if (sigSpi != null) {
1192 sigSpi.engineInitVerify(publicKey);
1193 } else {
1194 chooseProvider(I_PUB, publicKey, null);
1195 }
1196 }
1197
1198 protected void engineInitSign(PrivateKey privateKey)
1199 throws InvalidKeyException {
1200 if (sigSpi != null) {
1201 sigSpi.engineInitSign(privateKey);
1202 } else {
1203 chooseProvider(I_PRIV, privateKey, null);
1204 }
1205 }
1206
1207 protected void engineInitSign(PrivateKey privateKey, SecureRandom sr)
1208 throws InvalidKeyException {
1209 if (sigSpi != null) {
1210 sigSpi.engineInitSign(privateKey, sr);
1211 } else {
1212 chooseProvider(I_PRIV_SR, privateKey, sr);
1213 }
1214 }
1215
1216 protected void engineUpdate(byte b) throws SignatureException {
1217 chooseFirstProvider();
1218 sigSpi.engineUpdate(b);
1219 }
1220
1221 protected void engineUpdate(byte[] b, int off, int len)
1222 throws SignatureException {
1223 chooseFirstProvider();
1224 sigSpi.engineUpdate(b, off, len);
1225 }
1226
1227 protected void engineUpdate(ByteBuffer data) {
1228 chooseFirstProvider();
1229 sigSpi.engineUpdate(data);
1230 }
1231
1232 protected byte[] engineSign() throws SignatureException {
1233 chooseFirstProvider();
1234 return sigSpi.engineSign();
1235 }
1236
1237 protected int engineSign(byte[] outbuf, int offset, int len)
1238 throws SignatureException {
1239 chooseFirstProvider();
1240 return sigSpi.engineSign(outbuf, offset, len);
1241 }
1242
1243 protected boolean engineVerify(byte[] sigBytes)
1244 throws SignatureException {
1245 chooseFirstProvider();
1246 return sigSpi.engineVerify(sigBytes);
1247 }
1248
1249 protected boolean engineVerify(byte[] sigBytes, int offset, int length)
1250 throws SignatureException {
1251 chooseFirstProvider();
1252 return sigSpi.engineVerify(sigBytes, offset, length);
1253 }
1254
1255 protected void engineSetParameter(String param, Object value)
1256 throws InvalidParameterException {
1257 chooseFirstProvider();
1258 sigSpi.engineSetParameter(param, value);
1259 }
1260
1261 protected void engineSetParameter(AlgorithmParameterSpec params)
1262 throws InvalidAlgorithmParameterException {
1263 chooseFirstProvider();
1264 sigSpi.engineSetParameter(params);
1265 }
1266
1267 protected Object engineGetParameter(String param)
1268 throws InvalidParameterException {
1269 chooseFirstProvider();
1270 return sigSpi.engineGetParameter(param);
1271 }
1272
1273 protected AlgorithmParameters engineGetParameters() {
1274 chooseFirstProvider();
1275 return sigSpi.engineGetParameters();
1276 }
1277 }
1278
1279 // adapter for RSA/ECB/PKCS1Padding ciphers
1280 @SuppressWarnings("deprecation")
1281 private static class CipherAdapter extends SignatureSpi {
1282
1283 private final Cipher cipher;
1284
1285 private ByteArrayOutputStream data;
1286
1287 CipherAdapter(Cipher cipher) {
1288 this.cipher = cipher;
1289 }
1290
1291 protected void engineInitVerify(PublicKey publicKey)
1292 throws InvalidKeyException {
1293 cipher.init(Cipher.DECRYPT_MODE, publicKey);
1294 if (data == null) {
1295 data = new ByteArrayOutputStream(128);
1296 } else {
1297 data.reset();
1298 }
1299 }
1300
1301 protected void engineInitSign(PrivateKey privateKey)
1302 throws InvalidKeyException {
1303 cipher.init(Cipher.ENCRYPT_MODE, privateKey);
1304 data = null;
1305 }
1306
1307 protected void engineInitSign(PrivateKey privateKey,
1308 SecureRandom random) throws InvalidKeyException {
1309 cipher.init(Cipher.ENCRYPT_MODE, privateKey, random);
1310 data = null;
1311 }
1312
1313 protected void engineUpdate(byte b) throws SignatureException {
1314 engineUpdate(new byte[] {b}, 0, 1);
1315 }
1316
1317 protected void engineUpdate(byte[] b, int off, int len)
1318 throws SignatureException {
1319 if (data != null) {
1320 data.write(b, off, len);
1321 return;
1322 }
1323 byte[] out = cipher.update(b, off, len);
1324 if ((out != null) && (out.length != 0)) {
1325 throw new SignatureException
1326 ("Cipher unexpectedly returned data");
1327 }
1328 }
1329
1330 protected byte[] engineSign() throws SignatureException {
1331 try {
1332 return cipher.doFinal();
1333 } catch (IllegalBlockSizeException e) {
1334 throw new SignatureException("doFinal() failed", e);
1335 } catch (BadPaddingException e) {
1336 throw new SignatureException("doFinal() failed", e);
1337 }
1338 }
1339
1340 protected boolean engineVerify(byte[] sigBytes)
1341 throws SignatureException {
1342 try {
1343 byte[] out = cipher.doFinal(sigBytes);
1344 byte[] dataBytes = data.toByteArray();
1345 data.reset();
1346 return MessageDigest.isEqual(out, dataBytes);
1347 } catch (BadPaddingException e) {
1348 // e.g. wrong public key used
1349 // return false rather than throwing exception
1350 return false;
1351 } catch (IllegalBlockSizeException e) {
1352 throw new SignatureException("doFinal() failed", e);
1353 }
1354 }
1355
1356 protected void engineSetParameter(String param, Object value)
1357 throws InvalidParameterException {
1358 throw new InvalidParameterException("Parameters not supported");
1359 }
1360
1361 protected Object engineGetParameter(String param)
1362 throws InvalidParameterException {
1363 throw new InvalidParameterException("Parameters not supported");
1364 }
1365
1366 }
1367
1368 }