Crypto++  8.2
Free C++ class library of cryptographic schemes
pubkey.h
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1 // pubkey.h - originally written and placed in the public domain by Wei Dai
2 
3 /// \file pubkey.h
4 /// \brief This file contains helper classes/functions for implementing public key algorithms.
5 /// \details The class hierachies in this header file tend to look like this:
6 ///
7 /// <pre>
8 /// x1
9 /// +--+
10 /// | |
11 /// y1 z1
12 /// | |
13 /// x2<y1> x2<z1>
14 /// | |
15 /// y2 z2
16 /// | |
17 /// x3<y2> x3<z2>
18 /// | |
19 /// y3 z3
20 /// </pre>
21 ///
22 /// <ul>
23 /// <li>x1, y1, z1 are abstract interface classes defined in cryptlib.h
24 /// <li>x2, y2, z2 are implementations of the interfaces using "abstract policies", which
25 /// are pure virtual functions that should return interfaces to interchangeable algorithms.
26 /// These classes have Base suffixes.
27 /// <li>x3, y3, z3 hold actual algorithms and implement those virtual functions.
28 /// These classes have Impl suffixes.
29 /// </ul>
30 ///
31 /// \details The TF_ prefix means an implementation using trapdoor functions on integers.
32 /// \details The DL_ prefix means an implementation using group operations in groups where discrete log is hard.
33 
34 #ifndef CRYPTOPP_PUBKEY_H
35 #define CRYPTOPP_PUBKEY_H
36 
37 #include "config.h"
38 
39 #if CRYPTOPP_MSC_VERSION
40 # pragma warning(push)
41 # pragma warning(disable: 4702)
42 #endif
43 
44 #include "cryptlib.h"
45 #include "integer.h"
46 #include "algebra.h"
47 #include "modarith.h"
48 #include "filters.h"
49 #include "eprecomp.h"
50 #include "fips140.h"
51 #include "argnames.h"
52 #include "smartptr.h"
53 #include "stdcpp.h"
54 
55 #if defined(__SUNPRO_CC)
56 # define MAYBE_RETURN(x) return x
57 #else
58 # define MAYBE_RETURN(x) CRYPTOPP_UNUSED(x)
59 #endif
60 
61 NAMESPACE_BEGIN(CryptoPP)
62 
63 /// \brief Provides range for plaintext and ciphertext lengths
64 /// \details A trapdoor function is a function that is easy to compute in one direction,
65 /// but difficult to compute in the opposite direction without special knowledge.
66 /// The special knowledge is usually the private key.
67 /// \details Trapdoor functions only handle messages of a limited length or size.
68 /// MaxPreimage is the plaintext's maximum length, and MaxImage is the
69 /// ciphertext's maximum length.
70 /// \sa TrapdoorFunctionBounds(), RandomizedTrapdoorFunction(), TrapdoorFunction(),
71 /// RandomizedTrapdoorFunctionInverse() and TrapdoorFunctionInverse()
72 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE TrapdoorFunctionBounds
73 {
74 public:
75  virtual ~TrapdoorFunctionBounds() {}
76 
77  /// \brief Returns the maximum size of a message before the trapdoor function is applied
78  /// \returns the maximum size of a message before the trapdoor function is applied
79  /// \details Derived classes must implement PreimageBound().
80  virtual Integer PreimageBound() const =0;
81  /// \brief Returns the maximum size of a message after the trapdoor function is applied
82  /// \returns the maximum size of a message after the trapdoor function is applied
83  /// \details Derived classes must implement ImageBound().
84  virtual Integer ImageBound() const =0;
85  /// \brief Returns the maximum size of a message before the trapdoor function is applied bound to a public key
86  /// \returns the maximum size of a message before the trapdoor function is applied bound to a public key
87  /// \details The default implementation returns <tt>PreimageBound() - 1</tt>.
88  virtual Integer MaxPreimage() const {return --PreimageBound();}
89  /// \brief Returns the maximum size of a message after the trapdoor function is applied bound to a public key
90  /// \returns the the maximum size of a message after the trapdoor function is applied bound to a public key
91  /// \details The default implementation returns <tt>ImageBound() - 1</tt>.
92  virtual Integer MaxImage() const {return --ImageBound();}
93 };
94 
95 /// \brief Applies the trapdoor function, using random data if required
96 /// \details ApplyFunction() is the foundation for encrypting a message under a public key.
97 /// Derived classes will override it at some point.
98 /// \sa TrapdoorFunctionBounds(), RandomizedTrapdoorFunction(), TrapdoorFunction(),
99 /// RandomizedTrapdoorFunctionInverse() and TrapdoorFunctionInverse()
100 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE RandomizedTrapdoorFunction : public TrapdoorFunctionBounds
101 {
102 public:
103  virtual ~RandomizedTrapdoorFunction() {}
104 
105  /// \brief Applies the trapdoor function, using random data if required
106  /// \param rng a RandomNumberGenerator derived class
107  /// \param x the message on which the encryption function is applied
108  /// \returns the message x encrypted under the public key
109  /// \details ApplyRandomizedFunction is a generalization of encryption under a public key
110  /// cryptosystem. The RandomNumberGenerator may (or may not) be required.
111  /// Derived classes must implement it.
112  virtual Integer ApplyRandomizedFunction(RandomNumberGenerator &rng, const Integer &x) const =0;
113 
114  /// \brief Determines if the encryption algorithm is randomized
115  /// \returns true if the encryption algorithm is randomized, false otherwise
116  /// \details If IsRandomized() returns false, then NullRNG() can be used.
117  virtual bool IsRandomized() const {return true;}
118 };
119 
120 /// \brief Applies the trapdoor function
121 /// \details ApplyFunction() is the foundation for encrypting a message under a public key.
122 /// Derived classes will override it at some point.
123 /// \sa TrapdoorFunctionBounds(), RandomizedTrapdoorFunction(), TrapdoorFunction(),
124 /// RandomizedTrapdoorFunctionInverse() and TrapdoorFunctionInverse()
125 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE TrapdoorFunction : public RandomizedTrapdoorFunction
126 {
127 public:
128  virtual ~TrapdoorFunction() {}
129 
130  /// \brief Applies the trapdoor function
131  /// \param rng a RandomNumberGenerator derived class
132  /// \param x the message on which the encryption function is applied
133  /// \details ApplyRandomizedFunction is a generalization of encryption under a public key
134  /// cryptosystem. The RandomNumberGenerator may (or may not) be required.
135  /// \details Internally, ApplyRandomizedFunction() calls ApplyFunction() \a
136  /// without the RandomNumberGenerator.
138  {CRYPTOPP_UNUSED(rng); return ApplyFunction(x);}
139  bool IsRandomized() const {return false;}
140 
141  /// \brief Applies the trapdoor
142  /// \param x the message on which the encryption function is applied
143  /// \returns the message x encrypted under the public key
144  /// \details ApplyFunction is a generalization of encryption under a public key
145  /// cryptosystem. Derived classes must implement it.
146  virtual Integer ApplyFunction(const Integer &x) const =0;
147 };
148 
149 /// \brief Applies the inverse of the trapdoor function, using random data if required
150 /// \details CalculateInverse() is the foundation for decrypting a message under a private key
151 /// in a public key cryptosystem. Derived classes will override it at some point.
152 /// \sa TrapdoorFunctionBounds(), RandomizedTrapdoorFunction(), TrapdoorFunction(),
153 /// RandomizedTrapdoorFunctionInverse() and TrapdoorFunctionInverse()
154 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE RandomizedTrapdoorFunctionInverse
155 {
156 public:
158 
159  /// \brief Applies the inverse of the trapdoor function, using random data if required
160  /// \param rng a RandomNumberGenerator derived class
161  /// \param x the message on which the decryption function is applied
162  /// \returns the message x decrypted under the private key
163  /// \details CalculateRandomizedInverse is a generalization of decryption using the private key
164  /// The RandomNumberGenerator may (or may not) be required. Derived classes must implement it.
165  virtual Integer CalculateRandomizedInverse(RandomNumberGenerator &rng, const Integer &x) const =0;
166 
167  /// \brief Determines if the decryption algorithm is randomized
168  /// \returns true if the decryption algorithm is randomized, false otherwise
169  /// \details If IsRandomized() returns false, then NullRNG() can be used.
170  virtual bool IsRandomized() const {return true;}
171 };
172 
173 /// \brief Applies the inverse of the trapdoor function
174 /// \details CalculateInverse() is the foundation for decrypting a message under a private key
175 /// in a public key cryptosystem. Derived classes will override it at some point.
176 /// \sa TrapdoorFunctionBounds(), RandomizedTrapdoorFunction(), TrapdoorFunction(),
177 /// RandomizedTrapdoorFunctionInverse() and TrapdoorFunctionInverse()
178 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE TrapdoorFunctionInverse : public RandomizedTrapdoorFunctionInverse
179 {
180 public:
181  virtual ~TrapdoorFunctionInverse() {}
182 
183  /// \brief Applies the inverse of the trapdoor function
184  /// \param rng a RandomNumberGenerator derived class
185  /// \param x the message on which the decryption function is applied
186  /// \returns the message x decrypted under the private key
187  /// \details CalculateRandomizedInverse is a generalization of decryption using the private key
188  /// \details Internally, CalculateRandomizedInverse() calls CalculateInverse() \a
189  /// without the RandomNumberGenerator.
191  {return CalculateInverse(rng, x);}
192 
193  /// \brief Determines if the decryption algorithm is randomized
194  /// \returns true if the decryption algorithm is randomized, false otherwise
195  /// \details If IsRandomized() returns false, then NullRNG() can be used.
196  bool IsRandomized() const {return false;}
197 
198  /// \brief Calculates the inverse of an element
199  /// \param rng a RandomNumberGenerator derived class
200  /// \param x the element
201  /// \returns the inverse of the element in the group
202  virtual Integer CalculateInverse(RandomNumberGenerator &rng, const Integer &x) const =0;
203 };
204 
205 // ********************************************************
206 
207 /// \brief Message encoding method for public key encryption
208 class CRYPTOPP_NO_VTABLE PK_EncryptionMessageEncodingMethod
209 {
210 public:
212 
213  virtual bool ParameterSupported(const char *name) const
214  {CRYPTOPP_UNUSED(name); return false;}
215 
216  /// max size of unpadded message in bytes, given max size of padded message in bits (1 less than size of modulus)
217  virtual size_t MaxUnpaddedLength(size_t paddedLength) const =0;
218 
219  virtual void Pad(RandomNumberGenerator &rng, const byte *raw, size_t inputLength, byte *padded, size_t paddedBitLength, const NameValuePairs &parameters) const =0;
220 
221  virtual DecodingResult Unpad(const byte *padded, size_t paddedBitLength, byte *raw, const NameValuePairs &parameters) const =0;
222 };
223 
224 // ********************************************************
225 
226 /// \brief The base for trapdoor based cryptosystems
227 /// \tparam TFI trapdoor function interface derived class
228 /// \tparam MEI message encoding interface derived class
229 template <class TFI, class MEI>
230 class CRYPTOPP_NO_VTABLE TF_Base
231 {
232 protected:
233  virtual ~TF_Base() {}
234 
235  virtual const TrapdoorFunctionBounds & GetTrapdoorFunctionBounds() const =0;
236 
237  typedef TFI TrapdoorFunctionInterface;
238  virtual const TrapdoorFunctionInterface & GetTrapdoorFunctionInterface() const =0;
239 
240  typedef MEI MessageEncodingInterface;
241  virtual const MessageEncodingInterface & GetMessageEncodingInterface() const =0;
242 };
243 
244 // ********************************************************
245 
246 /// \brief Public key trapdoor function default implementation
247 /// \tparam BASE public key cryptosystem with a fixed length
248 template <class BASE>
249 class CRYPTOPP_NO_VTABLE PK_FixedLengthCryptoSystemImpl : public BASE
250 {
251 public:
252  virtual ~PK_FixedLengthCryptoSystemImpl() {}
253 
254  size_t MaxPlaintextLength(size_t ciphertextLength) const
255  {return ciphertextLength == FixedCiphertextLength() ? FixedMaxPlaintextLength() : 0;}
256  size_t CiphertextLength(size_t plaintextLength) const
257  {return plaintextLength <= FixedMaxPlaintextLength() ? FixedCiphertextLength() : 0;}
258 
259  virtual size_t FixedMaxPlaintextLength() const =0;
260  virtual size_t FixedCiphertextLength() const =0;
261 };
262 
263 /// \brief Trapdoor function cryptosystem base class
264 /// \tparam INTFACE public key cryptosystem base interface
265 /// \tparam BASE public key cryptosystem implementation base
266 template <class INTFACE, class BASE>
267 class CRYPTOPP_NO_VTABLE TF_CryptoSystemBase : public PK_FixedLengthCryptoSystemImpl<INTFACE>, protected BASE
268 {
269 public:
270  virtual ~TF_CryptoSystemBase() {}
271 
272  bool ParameterSupported(const char *name) const {return this->GetMessageEncodingInterface().ParameterSupported(name);}
273  size_t FixedMaxPlaintextLength() const {return this->GetMessageEncodingInterface().MaxUnpaddedLength(PaddedBlockBitLength());}
274  size_t FixedCiphertextLength() const {return this->GetTrapdoorFunctionBounds().MaxImage().ByteCount();}
275 
276 protected:
277  size_t PaddedBlockByteLength() const {return BitsToBytes(PaddedBlockBitLength());}
278  // Coverity finding on potential overflow/underflow.
279  size_t PaddedBlockBitLength() const {return SaturatingSubtract(this->GetTrapdoorFunctionBounds().PreimageBound().BitCount(),1U);}
280 };
281 
282 /// \brief Trapdoor function cryptosystems decryption base class
283 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE TF_DecryptorBase : public TF_CryptoSystemBase<PK_Decryptor, TF_Base<TrapdoorFunctionInverse, PK_EncryptionMessageEncodingMethod> >
284 {
285 public:
286  virtual ~TF_DecryptorBase() {}
287 
288  DecodingResult Decrypt(RandomNumberGenerator &rng, const byte *ciphertext, size_t ciphertextLength, byte *plaintext, const NameValuePairs &parameters = g_nullNameValuePairs) const;
289 };
290 
291 /// \brief Trapdoor function cryptosystems encryption base class
292 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE TF_EncryptorBase : public TF_CryptoSystemBase<PK_Encryptor, TF_Base<RandomizedTrapdoorFunction, PK_EncryptionMessageEncodingMethod> >
293 {
294 public:
295  virtual ~TF_EncryptorBase() {}
296 
297  void Encrypt(RandomNumberGenerator &rng, const byte *plaintext, size_t plaintextLength, byte *ciphertext, const NameValuePairs &parameters = g_nullNameValuePairs) const;
298 };
299 
300 // ********************************************************
301 
302 // Typedef change due to Clang, http://github.com/weidai11/cryptopp/issues/300
303 typedef std::pair<const byte *, unsigned int> HashIdentifier;
304 
305 /// \brief Interface for message encoding method for public key signature schemes.
306 /// \details PK_SignatureMessageEncodingMethod provides interfaces for message
307 /// encoding method for public key signature schemes. The methods support both
308 /// trapdoor functions (<tt>TF_*</tt>) and discrete logarithm (<tt>DL_*</tt>)
309 /// based schemes.
310 class CRYPTOPP_NO_VTABLE PK_SignatureMessageEncodingMethod
311 {
312 public:
314 
315  virtual size_t MinRepresentativeBitLength(size_t hashIdentifierLength, size_t digestLength) const
316  {CRYPTOPP_UNUSED(hashIdentifierLength); CRYPTOPP_UNUSED(digestLength); return 0;}
317  virtual size_t MaxRecoverableLength(size_t representativeBitLength, size_t hashIdentifierLength, size_t digestLength) const
318  {CRYPTOPP_UNUSED(representativeBitLength); CRYPTOPP_UNUSED(representativeBitLength); CRYPTOPP_UNUSED(hashIdentifierLength); CRYPTOPP_UNUSED(digestLength); return 0;}
319 
320  /// \brief Determines whether an encoding method requires a random number generator
321  /// \return true if the encoding method requires a RandomNumberGenerator()
322  /// \details if IsProbabilistic() returns false, then NullRNG() can be passed to functions that take
323  /// RandomNumberGenerator().
324  /// \sa Bellare and Rogaway<a href="http://grouper.ieee.org/groups/1363/P1363a/contributions/pss-submission.pdf">PSS:
325  /// Provably Secure Encoding Method for Digital Signatures</a>
326  bool IsProbabilistic() const
327  {return true;}
328  bool AllowNonrecoverablePart() const
329  {throw NotImplemented("PK_MessageEncodingMethod: this signature scheme does not support message recovery");}
330  virtual bool RecoverablePartFirst() const
331  {throw NotImplemented("PK_MessageEncodingMethod: this signature scheme does not support message recovery");}
332 
333  // for verification, DL
334  virtual void ProcessSemisignature(HashTransformation &hash, const byte *semisignature, size_t semisignatureLength) const
335  {CRYPTOPP_UNUSED(hash); CRYPTOPP_UNUSED(semisignature); CRYPTOPP_UNUSED(semisignatureLength);}
336 
337  // for signature
338  virtual void ProcessRecoverableMessage(HashTransformation &hash,
339  const byte *recoverableMessage, size_t recoverableMessageLength,
340  const byte *presignature, size_t presignatureLength,
341  SecByteBlock &semisignature) const
342  {
343  CRYPTOPP_UNUSED(hash);CRYPTOPP_UNUSED(recoverableMessage); CRYPTOPP_UNUSED(recoverableMessageLength);
344  CRYPTOPP_UNUSED(presignature); CRYPTOPP_UNUSED(presignatureLength); CRYPTOPP_UNUSED(semisignature);
345  if (RecoverablePartFirst())
346  CRYPTOPP_ASSERT(!"ProcessRecoverableMessage() not implemented");
347  }
348 
349  virtual void ComputeMessageRepresentative(RandomNumberGenerator &rng,
350  const byte *recoverableMessage, size_t recoverableMessageLength,
351  HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
352  byte *representative, size_t representativeBitLength) const =0;
353 
354  virtual bool VerifyMessageRepresentative(
355  HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
356  byte *representative, size_t representativeBitLength) const =0;
357 
358  virtual DecodingResult RecoverMessageFromRepresentative( // for TF
359  HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
360  byte *representative, size_t representativeBitLength,
361  byte *recoveredMessage) const
362  {CRYPTOPP_UNUSED(hash);CRYPTOPP_UNUSED(hashIdentifier); CRYPTOPP_UNUSED(messageEmpty);
363  CRYPTOPP_UNUSED(representative); CRYPTOPP_UNUSED(representativeBitLength); CRYPTOPP_UNUSED(recoveredMessage);
364  throw NotImplemented("PK_MessageEncodingMethod: this signature scheme does not support message recovery");}
365 
366  virtual DecodingResult RecoverMessageFromSemisignature( // for DL
367  HashTransformation &hash, HashIdentifier hashIdentifier,
368  const byte *presignature, size_t presignatureLength,
369  const byte *semisignature, size_t semisignatureLength,
370  byte *recoveredMessage) const
371  {CRYPTOPP_UNUSED(hash);CRYPTOPP_UNUSED(hashIdentifier); CRYPTOPP_UNUSED(presignature); CRYPTOPP_UNUSED(presignatureLength);
372  CRYPTOPP_UNUSED(semisignature); CRYPTOPP_UNUSED(semisignatureLength); CRYPTOPP_UNUSED(recoveredMessage);
373  throw NotImplemented("PK_MessageEncodingMethod: this signature scheme does not support message recovery");}
374 
375  // VC60 workaround
377  {
378  template <class H> struct HashIdentifierLookup2
379  {
380  static HashIdentifier CRYPTOPP_API Lookup()
381  {
382  return HashIdentifier(static_cast<const byte *>(NULLPTR), 0);
383  }
384  };
385  };
386 };
387 
388 /// \brief Interface for message encoding method for public key signature schemes.
389 /// \details PK_DeterministicSignatureMessageEncodingMethod provides interfaces
390 /// for message encoding method for public key signature schemes.
392 {
393 public:
394  bool VerifyMessageRepresentative(
395  HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
396  byte *representative, size_t representativeBitLength) const;
397 };
398 
399 /// \brief Interface for message encoding method for public key signature schemes.
400 /// \details PK_RecoverableSignatureMessageEncodingMethod provides interfaces
401 /// for message encoding method for public key signature schemes.
403 {
404 public:
405  bool VerifyMessageRepresentative(
406  HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
407  byte *representative, size_t representativeBitLength) const;
408 };
409 
410 /// \brief Interface for message encoding method for public key signature schemes.
411 /// \details DL_SignatureMessageEncodingMethod_DSA provides interfaces
412 /// for message encoding method for DSA.
414 {
415 public:
416  void ComputeMessageRepresentative(RandomNumberGenerator &rng,
417  const byte *recoverableMessage, size_t recoverableMessageLength,
418  HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
419  byte *representative, size_t representativeBitLength) const;
420 };
421 
422 /// \brief Interface for message encoding method for public key signature schemes.
423 /// \details DL_SignatureMessageEncodingMethod_NR provides interfaces
424 /// for message encoding method for Nyberg-Rueppel.
426 {
427 public:
428  void ComputeMessageRepresentative(RandomNumberGenerator &rng,
429  const byte *recoverableMessage, size_t recoverableMessageLength,
430  HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
431  byte *representative, size_t representativeBitLength) const;
432 };
433 
434 #if 0
435 /// \brief Interface for message encoding method for public key signature schemes.
436 /// \details DL_SignatureMessageEncodingMethod_SM2 provides interfaces
437 /// for message encoding method for SM2.
438 class CRYPTOPP_DLL DL_SignatureMessageEncodingMethod_SM2 : public PK_DeterministicSignatureMessageEncodingMethod
439 {
440 public:
441  void ComputeMessageRepresentative(RandomNumberGenerator &rng,
442  const byte *recoverableMessage, size_t recoverableMessageLength,
443  HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
444  byte *representative, size_t representativeBitLength) const;
445 };
446 #endif
447 
448 /// \brief Interface for message encoding method for public key signature schemes.
449 /// \details PK_MessageAccumulatorBase provides interfaces
450 /// for message encoding method.
451 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE PK_MessageAccumulatorBase : public PK_MessageAccumulator
452 {
453 public:
454  PK_MessageAccumulatorBase() : m_empty(true) {}
455 
456  virtual HashTransformation & AccessHash() =0;
457 
458  void Update(const byte *input, size_t length)
459  {
460  AccessHash().Update(input, length);
461  m_empty = m_empty && length == 0;
462  }
463 
464  SecByteBlock m_recoverableMessage, m_representative, m_presignature, m_semisignature;
465  Integer m_k, m_s;
466  bool m_empty;
467 };
468 
469 /// \brief Interface for message encoding method for public key signature schemes.
470 /// \details PK_MessageAccumulatorBase provides interfaces
471 /// for message encoding method.
472 template <class HASH_ALGORITHM>
473 class PK_MessageAccumulatorImpl : public PK_MessageAccumulatorBase, protected ObjectHolder<HASH_ALGORITHM>
474 {
475 public:
476  HashTransformation & AccessHash() {return this->m_object;}
477 };
478 
479 /// \brief Trapdoor Function (TF) Signature Scheme base class
480 /// \tparam INTFACE interface
481 /// \tparam BASE base class
482 template <class INTFACE, class BASE>
483 class CRYPTOPP_NO_VTABLE TF_SignatureSchemeBase : public INTFACE, protected BASE
484 {
485 public:
486  virtual ~TF_SignatureSchemeBase() {}
487 
488  size_t SignatureLength() const
489  {return this->GetTrapdoorFunctionBounds().MaxPreimage().ByteCount();}
490  size_t MaxRecoverableLength() const
491  {return this->GetMessageEncodingInterface().MaxRecoverableLength(MessageRepresentativeBitLength(), GetHashIdentifier().second, GetDigestSize());}
492  size_t MaxRecoverableLengthFromSignatureLength(size_t signatureLength) const
493  {CRYPTOPP_UNUSED(signatureLength); return this->MaxRecoverableLength();}
494 
495  bool IsProbabilistic() const
496  {return this->GetTrapdoorFunctionInterface().IsRandomized() || this->GetMessageEncodingInterface().IsProbabilistic();}
497  bool AllowNonrecoverablePart() const
498  {return this->GetMessageEncodingInterface().AllowNonrecoverablePart();}
499  bool RecoverablePartFirst() const
500  {return this->GetMessageEncodingInterface().RecoverablePartFirst();}
501 
502 protected:
503  size_t MessageRepresentativeLength() const {return BitsToBytes(MessageRepresentativeBitLength());}
504  // Coverity finding on potential overflow/underflow.
505  size_t MessageRepresentativeBitLength() const {return SaturatingSubtract(this->GetTrapdoorFunctionBounds().ImageBound().BitCount(),1U);}
506  virtual HashIdentifier GetHashIdentifier() const =0;
507  virtual size_t GetDigestSize() const =0;
508 };
509 
510 /// \brief Trapdoor Function (TF) Signer base class
511 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE TF_SignerBase : public TF_SignatureSchemeBase<PK_Signer, TF_Base<RandomizedTrapdoorFunctionInverse, PK_SignatureMessageEncodingMethod> >
512 {
513 public:
514  virtual ~TF_SignerBase() {}
515 
516  void InputRecoverableMessage(PK_MessageAccumulator &messageAccumulator, const byte *recoverableMessage, size_t recoverableMessageLength) const;
517  size_t SignAndRestart(RandomNumberGenerator &rng, PK_MessageAccumulator &messageAccumulator, byte *signature, bool restart=true) const;
518 };
519 
520 /// \brief Trapdoor Function (TF) Verifier base class
521 class CRYPTOPP_DLL CRYPTOPP_NO_VTABLE TF_VerifierBase : public TF_SignatureSchemeBase<PK_Verifier, TF_Base<TrapdoorFunction, PK_SignatureMessageEncodingMethod> >
522 {
523 public:
524  virtual ~TF_VerifierBase() {}
525 
526  void InputSignature(PK_MessageAccumulator &messageAccumulator, const byte *signature, size_t signatureLength) const;
527  bool VerifyAndRestart(PK_MessageAccumulator &messageAccumulator) const;
528  DecodingResult RecoverAndRestart(byte *recoveredMessage, PK_MessageAccumulator &recoveryAccumulator) const;
529 };
530 
531 // ********************************************************
532 
533 /// \brief Trapdoor Function (TF) scheme options
534 /// \tparam T1 algorithm info class
535 /// \tparam T2 keys class with public and private key
536 /// \tparam T3 message encoding class
537 template <class T1, class T2, class T3>
539 {
540  typedef T1 AlgorithmInfo;
541  typedef T2 Keys;
542  typedef typename Keys::PrivateKey PrivateKey;
543  typedef typename Keys::PublicKey PublicKey;
544  typedef T3 MessageEncodingMethod;
545 };
546 
547 /// \brief Trapdoor Function (TF) signature scheme options
548 /// \tparam T1 algorithm info class
549 /// \tparam T2 keys class with public and private key
550 /// \tparam T3 message encoding class
551 /// \tparam T4 HashTransformation class
552 template <class T1, class T2, class T3, class T4>
554 {
555  typedef T4 HashFunction;
556 };
557 
558 /// \brief Trapdoor Function (TF) base implementation
559 /// \tparam BASE base class
560 /// \tparam SCHEME_OPTIONS scheme options class
561 /// \tparam KEY_CLASS key class
562 template <class BASE, class SCHEME_OPTIONS, class KEY_CLASS>
563 class CRYPTOPP_NO_VTABLE TF_ObjectImplBase : public AlgorithmImpl<BASE, typename SCHEME_OPTIONS::AlgorithmInfo>
564 {
565 public:
566  typedef SCHEME_OPTIONS SchemeOptions;
567  typedef KEY_CLASS KeyClass;
568 
569  virtual ~TF_ObjectImplBase() {}
570 
571  PublicKey & AccessPublicKey() {return AccessKey();}
572  const PublicKey & GetPublicKey() const {return GetKey();}
573 
574  PrivateKey & AccessPrivateKey() {return AccessKey();}
575  const PrivateKey & GetPrivateKey() const {return GetKey();}
576 
577  virtual const KeyClass & GetKey() const =0;
578  virtual KeyClass & AccessKey() =0;
579 
580  const KeyClass & GetTrapdoorFunction() const {return GetKey();}
581 
582  PK_MessageAccumulator * NewSignatureAccumulator(RandomNumberGenerator &rng) const
583  {
584  CRYPTOPP_UNUSED(rng);
586  }
587  PK_MessageAccumulator * NewVerificationAccumulator() const
588  {
590  }
591 
592 protected:
593  const typename BASE::MessageEncodingInterface & GetMessageEncodingInterface() const
595  const TrapdoorFunctionBounds & GetTrapdoorFunctionBounds() const
596  {return GetKey();}
597  const typename BASE::TrapdoorFunctionInterface & GetTrapdoorFunctionInterface() const
598  {return GetKey();}
599 
600  // for signature scheme
601  HashIdentifier GetHashIdentifier() const
602  {
603  typedef typename SchemeOptions::MessageEncodingMethod::HashIdentifierLookup::template HashIdentifierLookup2<typename SchemeOptions::HashFunction> L;
604  return L::Lookup();
605  }
606  size_t GetDigestSize() const
607  {
608  typedef typename SchemeOptions::HashFunction H;
609  return H::DIGESTSIZE;
610  }
611 };
612 
613 /// \brief Trapdoor Function (TF) signature with external reference
614 /// \tparam BASE base class
615 /// \tparam SCHEME_OPTIONS scheme options class
616 /// \tparam KEY key class
617 /// \details TF_ObjectImplExtRef() holds a pointer to an external key structure
618 template <class BASE, class SCHEME_OPTIONS, class KEY>
619 class TF_ObjectImplExtRef : public TF_ObjectImplBase<BASE, SCHEME_OPTIONS, KEY>
620 {
621 public:
622  virtual ~TF_ObjectImplExtRef() {}
623 
624  TF_ObjectImplExtRef(const KEY *pKey = NULLPTR) : m_pKey(pKey) {}
625  void SetKeyPtr(const KEY *pKey) {m_pKey = pKey;}
626 
627  const KEY & GetKey() const {return *m_pKey;}
628  KEY & AccessKey() {throw NotImplemented("TF_ObjectImplExtRef: cannot modify refererenced key");}
629 
630 private:
631  const KEY * m_pKey;
632 };
633 
634 /// \brief Trapdoor Function (TF) signature scheme options
635 /// \tparam BASE base class
636 /// \tparam SCHEME_OPTIONS scheme options class
637 /// \tparam KEY_CLASS key class
638 /// \details TF_ObjectImpl() holds a reference to a trapdoor function
639 template <class BASE, class SCHEME_OPTIONS, class KEY_CLASS>
640 class CRYPTOPP_NO_VTABLE TF_ObjectImpl : public TF_ObjectImplBase<BASE, SCHEME_OPTIONS, KEY_CLASS>
641 {
642 public:
643  typedef KEY_CLASS KeyClass;
644 
645  virtual ~TF_ObjectImpl() {}
646 
647  const KeyClass & GetKey() const {return m_trapdoorFunction;}
648  KeyClass & AccessKey() {return m_trapdoorFunction;}
649 
650 private:
651  KeyClass m_trapdoorFunction;
652 };
653 
654 /// \brief Trapdoor Function (TF) decryptor options
655 /// \tparam SCHEME_OPTIONS scheme options class
656 template <class SCHEME_OPTIONS>
657 class TF_DecryptorImpl : public TF_ObjectImpl<TF_DecryptorBase, SCHEME_OPTIONS, typename SCHEME_OPTIONS::PrivateKey>
658 {
659 };
660 
661 /// \brief Trapdoor Function (TF) encryptor options
662 /// \tparam SCHEME_OPTIONS scheme options class
663 template <class SCHEME_OPTIONS>
664 class TF_EncryptorImpl : public TF_ObjectImpl<TF_EncryptorBase, SCHEME_OPTIONS, typename SCHEME_OPTIONS::PublicKey>
665 {
666 };
667 
668 /// \brief Trapdoor Function (TF) encryptor options
669 /// \tparam SCHEME_OPTIONS scheme options class
670 template <class SCHEME_OPTIONS>
671 class TF_SignerImpl : public TF_ObjectImpl<TF_SignerBase, SCHEME_OPTIONS, typename SCHEME_OPTIONS::PrivateKey>
672 {
673 };
674 
675 /// \brief Trapdoor Function (TF) encryptor options
676 /// \tparam SCHEME_OPTIONS scheme options class
677 template <class SCHEME_OPTIONS>
678 class TF_VerifierImpl : public TF_ObjectImpl<TF_VerifierBase, SCHEME_OPTIONS, typename SCHEME_OPTIONS::PublicKey>
679 {
680 };
681 
682 // ********************************************************
683 
684 /// \brief Mask generation function interface
685 class CRYPTOPP_NO_VTABLE MaskGeneratingFunction
686 {
687 public:
688  virtual ~MaskGeneratingFunction() {}
689 
690  /// \brief Generate and apply mask
691  /// \param hash HashTransformation derived class
692  /// \param output the destination byte array
693  /// \param outputLength the size fo the the destination byte array
694  /// \param input the message to hash
695  /// \param inputLength the size of the message
696  /// \param mask flag indicating whether to apply the mask
697  virtual void GenerateAndMask(HashTransformation &hash, byte *output, size_t outputLength, const byte *input, size_t inputLength, bool mask = true) const =0;
698 };
699 
700 /// \fn P1363_MGF1KDF2_Common
701 /// \brief P1363 mask generation function
702 /// \param hash HashTransformation derived class
703 /// \param output the destination byte array
704 /// \param outputLength the size fo the the destination byte array
705 /// \param input the message to hash
706 /// \param inputLength the size of the message
707 /// \param derivationParams additional derivation parameters
708 /// \param derivationParamsLength the size of the additional derivation parameters
709 /// \param mask flag indicating whether to apply the mask
710 /// \param counterStart starting counter value used in generation function
711 CRYPTOPP_DLL void CRYPTOPP_API P1363_MGF1KDF2_Common(HashTransformation &hash, byte *output, size_t outputLength, const byte *input, size_t inputLength, const byte *derivationParams, size_t derivationParamsLength, bool mask, unsigned int counterStart);
712 
713 /// \brief P1363 mask generation function
715 {
716 public:
717  CRYPTOPP_STATIC_CONSTEXPR const char* CRYPTOPP_API StaticAlgorithmName() {return "MGF1";}
718  void GenerateAndMask(HashTransformation &hash, byte *output, size_t outputLength, const byte *input, size_t inputLength, bool mask = true) const
719  {
720  P1363_MGF1KDF2_Common(hash, output, outputLength, input, inputLength, NULLPTR, 0, mask, 0);
721  }
722 };
723 
724 // ********************************************************
725 
726 /// \brief P1363 key derivation function
727 /// \tparam H hash function used in the derivation
728 template <class H>
730 {
731 public:
732  static void CRYPTOPP_API DeriveKey(byte *output, size_t outputLength, const byte *input, size_t inputLength, const byte *derivationParams, size_t derivationParamsLength)
733  {
734  H h;
735  P1363_MGF1KDF2_Common(h, output, outputLength, input, inputLength, derivationParams, derivationParamsLength, false, 1);
736  }
737 };
738 
739 // ********************************************************
740 
741 /// \brief Exception thrown when an invalid group element is encountered
742 /// \details Thrown by DecodeElement and AgreeWithStaticPrivateKey
744 {
745 public:
746  DL_BadElement() : InvalidDataFormat("CryptoPP: invalid group element") {}
747 };
748 
749 /// \brief Interface for Discrete Log (DL) group parameters
750 /// \tparam T element in the group
751 /// \details The element is usually an Integer, \ref ECP "ECP::Point" or \ref EC2N "EC2N::Point"
752 template <class T>
753 class CRYPTOPP_NO_VTABLE DL_GroupParameters : public CryptoParameters
754 {
756 
757 public:
758  typedef T Element;
759 
760  virtual ~DL_GroupParameters() {}
761 
762  DL_GroupParameters() : m_validationLevel(0) {}
763 
764  // CryptoMaterial
765  bool Validate(RandomNumberGenerator &rng, unsigned int level) const
766  {
767  if (!GetBasePrecomputation().IsInitialized())
768  return false;
769 
770  if (m_validationLevel > level)
771  return true;
772 
773  bool pass = ValidateGroup(rng, level);
774  pass = pass && ValidateElement(level, GetSubgroupGenerator(), &GetBasePrecomputation());
775 
776  m_validationLevel = pass ? level+1 : 0;
777 
778  return pass;
779  }
780 
781  bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
782  {
783  return GetValueHelper(this, name, valueType, pValue)
784  CRYPTOPP_GET_FUNCTION_ENTRY(SubgroupOrder)
785  CRYPTOPP_GET_FUNCTION_ENTRY(SubgroupGenerator)
786  ;
787  }
788 
789  /// \brief Determines whether the object supports precomputation
790  /// \return true if the object supports precomputation, false otherwise
791  /// \sa Precompute()
792  bool SupportsPrecomputation() const {return true;}
793 
794  /// \brief Perform precomputation
795  /// \param precomputationStorage the suggested number of objects for the precompute table
796  /// \throws NotImplemented
797  /// \details The exact semantics of Precompute() varies, but it typically means calculate
798  /// a table of n objects that can be used later to speed up computation.
799  /// \details If a derived class does not override Precompute(), then the base class throws
800  /// NotImplemented.
801  /// \sa SupportsPrecomputation(), LoadPrecomputation(), SavePrecomputation()
802  void Precompute(unsigned int precomputationStorage=16)
803  {
804  AccessBasePrecomputation().Precompute(GetGroupPrecomputation(), GetSubgroupOrder().BitCount(), precomputationStorage);
805  }
806 
807  /// \brief Retrieve previously saved precomputation
808  /// \param storedPrecomputation BufferedTransformation with the saved precomputation
809  /// \throws NotImplemented
810  /// \sa SupportsPrecomputation(), Precompute()
811  void LoadPrecomputation(BufferedTransformation &storedPrecomputation)
812  {
813  AccessBasePrecomputation().Load(GetGroupPrecomputation(), storedPrecomputation);
814  m_validationLevel = 0;
815  }
816 
817  /// \brief Save precomputation for later use
818  /// \param storedPrecomputation BufferedTransformation to write the precomputation
819  /// \throws NotImplemented
820  /// \sa SupportsPrecomputation(), Precompute()
821  void SavePrecomputation(BufferedTransformation &storedPrecomputation) const
822  {
823  GetBasePrecomputation().Save(GetGroupPrecomputation(), storedPrecomputation);
824  }
825 
826  /// \brief Retrieves the subgroup generator
827  /// \return the subgroup generator
828  /// \details The subgroup generator is retrieved from the base precomputation
829  virtual const Element & GetSubgroupGenerator() const {return GetBasePrecomputation().GetBase(GetGroupPrecomputation());}
830 
831  /// \brief Sets the subgroup generator
832  /// \param base the new subgroup generator
833  /// \details The subgroup generator is set in the base precomputation
834  virtual void SetSubgroupGenerator(const Element &base) {AccessBasePrecomputation().SetBase(GetGroupPrecomputation(), base);}
835 
836  /// \brief Exponentiates the base
837  /// \return the element after exponentiation
838  /// \details ExponentiateBase() calls GetBasePrecomputation() and then exponentiates.
839  virtual Element ExponentiateBase(const Integer &exponent) const
840  {
841  return GetBasePrecomputation().Exponentiate(GetGroupPrecomputation(), exponent);
842  }
843 
844  /// \brief Exponentiates an element
845  /// \param base the base elemenet
846  /// \param exponent the exponent to raise the base
847  /// \return the result of the exponentiation
848  /// \details Internally, ExponentiateElement() calls SimultaneousExponentiate().
849  virtual Element ExponentiateElement(const Element &base, const Integer &exponent) const
850  {
851  Element result;
852  SimultaneousExponentiate(&result, base, &exponent, 1);
853  return result;
854  }
855 
856  /// \brief Retrieves the group precomputation
857  /// \return a const reference to the group precomputation
858  virtual const DL_GroupPrecomputation<Element> & GetGroupPrecomputation() const =0;
859 
860  /// \brief Retrieves the group precomputation
861  /// \return a const reference to the group precomputation using a fixed base
862  virtual const DL_FixedBasePrecomputation<Element> & GetBasePrecomputation() const =0;
863 
864  /// \brief Retrieves the group precomputation
865  /// \return a non-const reference to the group precomputation using a fixed base
866  virtual DL_FixedBasePrecomputation<Element> & AccessBasePrecomputation() =0;
867 
868  /// \brief Retrieves the subgroup order
869  /// \return the order of subgroup generated by the base element
870  virtual const Integer & GetSubgroupOrder() const =0;
871 
872  /// \brief Retrieves the maximum exponent for the group
873  /// \return the maximum exponent for the group
874  virtual Integer GetMaxExponent() const =0;
875 
876  /// \brief Retrieves the order of the group
877  /// \return the order of the group
878  /// \details Either GetGroupOrder() or GetCofactor() must be overridden in a derived class.
879  virtual Integer GetGroupOrder() const {return GetSubgroupOrder()*GetCofactor();}
880 
881  /// \brief Retrieves the cofactor
882  /// \return the cofactor
883  /// \details Either GetGroupOrder() or GetCofactor() must be overridden in a derived class.
884  virtual Integer GetCofactor() const {return GetGroupOrder()/GetSubgroupOrder();}
885 
886  /// \brief Retrieves the encoded element's size
887  /// \param reversible flag indicating the encoding format
888  /// \return encoded element's size, in bytes
889  /// \details The format of the encoded element varies by the underlyinhg type of the element and the
890  /// reversible flag. GetEncodedElementSize() must be implemented in a derived class.
891  /// \sa GetEncodedElementSize(), EncodeElement(), DecodeElement()
892  virtual unsigned int GetEncodedElementSize(bool reversible) const =0;
893 
894  /// \brief Encodes the element
895  /// \param reversible flag indicating the encoding format
896  /// \param element reference to the element to encode
897  /// \param encoded destination byte array for the encoded element
898  /// \details EncodeElement() must be implemented in a derived class.
899  /// \pre <tt>COUNTOF(encoded) == GetEncodedElementSize()</tt>
900  virtual void EncodeElement(bool reversible, const Element &element, byte *encoded) const =0;
901 
902  /// \brief Decodes the element
903  /// \param encoded byte array with the encoded element
904  /// \param checkForGroupMembership flag indicating if the element should be validated
905  /// \return Element after decoding
906  /// \details DecodeElement() must be implemented in a derived class.
907  /// \pre <tt>COUNTOF(encoded) == GetEncodedElementSize()</tt>
908  virtual Element DecodeElement(const byte *encoded, bool checkForGroupMembership) const =0;
909 
910  /// \brief Converts an element to an Integer
911  /// \param element the element to convert to an Integer
912  /// \return Element after converting to an Integer
913  /// \details ConvertElementToInteger() must be implemented in a derived class.
914  virtual Integer ConvertElementToInteger(const Element &element) const =0;
915 
916  /// \brief Check the group for errors
917  /// \param rng RandomNumberGenerator for objects which use randomized testing
918  /// \param level level of thoroughness
919  /// \return true if the tests succeed, false otherwise
920  /// \details There are four levels of thoroughness:
921  /// <ul>
922  /// <li>0 - using this object won't cause a crash or exception
923  /// <li>1 - this object will probably function, and encrypt, sign, other operations correctly
924  /// <li>2 - ensure this object will function correctly, and perform reasonable security checks
925  /// <li>3 - perform reasonable security checks, and do checks that may take a long time
926  /// </ul>
927  /// \details Level 0 does not require a RandomNumberGenerator. A NullRNG() can be used for level 0.
928  /// Level 1 may not check for weak keys and such. Levels 2 and 3 are recommended.
929  /// \details ValidateGroup() must be implemented in a derived class.
930  virtual bool ValidateGroup(RandomNumberGenerator &rng, unsigned int level) const =0;
931 
932  /// \brief Check the element for errors
933  /// \param level level of thoroughness
934  /// \param element element to check
935  /// \param precomp optional pointer to DL_FixedBasePrecomputation
936  /// \return true if the tests succeed, false otherwise
937  /// \details There are four levels of thoroughness:
938  /// <ul>
939  /// <li>0 - using this object won't cause a crash or exception
940  /// <li>1 - this object will probably function, and encrypt, sign, other operations correctly
941  /// <li>2 - ensure this object will function correctly, and perform reasonable security checks
942  /// <li>3 - perform reasonable security checks, and do checks that may take a long time
943  /// </ul>
944  /// \details Level 0 performs group membership checks. Level 1 may not check for weak keys and such.
945  /// Levels 2 and 3 are recommended.
946  /// \details ValidateElement() must be implemented in a derived class.
947  virtual bool ValidateElement(unsigned int level, const Element &element, const DL_FixedBasePrecomputation<Element> *precomp) const =0;
948 
949  virtual bool FastSubgroupCheckAvailable() const =0;
950 
951  /// \brief Determines if an element is an identity
952  /// \param element element to check
953  /// \return true if the element is an identity, false otherwise
954  /// \details The identity element or or neutral element is a special element in a group that leaves
955  /// other elements unchanged when combined with it.
956  /// \details IsIdentity() must be implemented in a derived class.
957  virtual bool IsIdentity(const Element &element) const =0;
958 
959  /// \brief Exponentiates a base to multiple exponents
960  /// \param results an array of Elements
961  /// \param base the base to raise to the exponents
962  /// \param exponents an array of exponents
963  /// \param exponentsCount the number of exponents in the array
964  /// \details SimultaneousExponentiate() raises the base to each exponent in the exponents array and stores the
965  /// result at the respective position in the results array.
966  /// \details SimultaneousExponentiate() must be implemented in a derived class.
967  /// \pre <tt>COUNTOF(results) == exponentsCount</tt>
968  /// \pre <tt>COUNTOF(exponents) == exponentsCount</tt>
969  virtual void SimultaneousExponentiate(Element *results, const Element &base, const Integer *exponents, unsigned int exponentsCount) const =0;
970 
971 protected:
972  void ParametersChanged() {m_validationLevel = 0;}
973 
974 private:
975  mutable unsigned int m_validationLevel;
976 };
977 
978 /// \brief Base implementation of Discrete Log (DL) group parameters
979 /// \tparam GROUP_PRECOMP group precomputation class
980 /// \tparam BASE_PRECOMP fixed base precomputation class
981 /// \tparam BASE class or type of an element
982 template <class GROUP_PRECOMP, class BASE_PRECOMP = DL_FixedBasePrecomputationImpl<typename GROUP_PRECOMP::Element>, class BASE = DL_GroupParameters<typename GROUP_PRECOMP::Element> >
983 class DL_GroupParametersImpl : public BASE
984 {
985 public:
986  typedef GROUP_PRECOMP GroupPrecomputation;
987  typedef typename GROUP_PRECOMP::Element Element;
988  typedef BASE_PRECOMP BasePrecomputation;
989 
990  virtual ~DL_GroupParametersImpl() {}
991 
992  /// \brief Retrieves the group precomputation
993  /// \return a const reference to the group precomputation
994  const DL_GroupPrecomputation<Element> & GetGroupPrecomputation() const {return m_groupPrecomputation;}
995 
996  /// \brief Retrieves the group precomputation
997  /// \return a const reference to the group precomputation using a fixed base
999 
1000  /// \brief Retrieves the group precomputation
1001  /// \return a non-const reference to the group precomputation using a fixed base
1003 
1004 protected:
1005  GROUP_PRECOMP m_groupPrecomputation;
1006  BASE_PRECOMP m_gpc;
1007 };
1008 
1009 /// \brief Base class for a Discrete Log (DL) key
1010 /// \tparam T class or type of an element
1011 /// \details The element is usually an Integer, \ref ECP "ECP::Point" or \ref EC2N "EC2N::Point"
1012 template <class T>
1013 class CRYPTOPP_NO_VTABLE DL_Key
1014 {
1015 public:
1016  virtual ~DL_Key() {}
1017 
1018  /// \brief Retrieves abstract group parameters
1019  /// \return a const reference to the group parameters
1020  virtual const DL_GroupParameters<T> & GetAbstractGroupParameters() const =0;
1021  /// \brief Retrieves abstract group parameters
1022  /// \return a non-const reference to the group parameters
1023  virtual DL_GroupParameters<T> & AccessAbstractGroupParameters() =0;
1024 };
1025 
1026 /// \brief Interface for Discrete Log (DL) public keys
1027 template <class T>
1028 class CRYPTOPP_NO_VTABLE DL_PublicKey : public DL_Key<T>
1029 {
1030  typedef DL_PublicKey<T> ThisClass;
1031 
1032 public:
1033  typedef T Element;
1034 
1035  virtual ~DL_PublicKey();
1036 
1037  /// \brief Get a named value
1038  /// \param name the name of the object or value to retrieve
1039  /// \param valueType reference to a variable that receives the value
1040  /// \param pValue void pointer to a variable that receives the value
1041  /// \returns true if the value was retrieved, false otherwise
1042  /// \details GetVoidValue() retrieves the value of name if it exists.
1043  /// \note GetVoidValue() is an internal function and should be implemented
1044  /// by derived classes. Users should use one of the other functions instead.
1045  /// \sa GetValue(), GetValueWithDefault(), GetIntValue(), GetIntValueWithDefault(),
1046  /// GetRequiredParameter() and GetRequiredIntParameter()
1047  bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
1048  {
1049  return GetValueHelper(this, name, valueType, pValue, &this->GetAbstractGroupParameters())
1050  CRYPTOPP_GET_FUNCTION_ENTRY(PublicElement);
1051  }
1052 
1053  /// \brief Initialize or reinitialize this key
1054  /// \param source NameValuePairs to assign
1055  void AssignFrom(const NameValuePairs &source);
1056 
1057  /// \brief Retrieves the public element
1058  /// \returns the public element
1059  virtual const Element & GetPublicElement() const {return GetPublicPrecomputation().GetBase(this->GetAbstractGroupParameters().GetGroupPrecomputation());}
1060 
1061  /// \brief Sets the public element
1062  /// \param y the public element
1063  virtual void SetPublicElement(const Element &y) {AccessPublicPrecomputation().SetBase(this->GetAbstractGroupParameters().GetGroupPrecomputation(), y);}
1064 
1065  /// \brief Exponentiates this element
1066  /// \param exponent the exponent to raise the base
1067  /// \returns the public element raised to the exponent
1068  virtual Element ExponentiatePublicElement(const Integer &exponent) const
1069  {
1070  const DL_GroupParameters<T> &params = this->GetAbstractGroupParameters();
1071  return GetPublicPrecomputation().Exponentiate(params.GetGroupPrecomputation(), exponent);
1072  }
1073 
1074  /// \brief Exponentiates an element
1075  /// \param baseExp the first exponent
1076  /// \param publicExp the second exponent
1077  /// \returns the public element raised to the exponent
1078  /// \details CascadeExponentiateBaseAndPublicElement raises the public element to
1079  /// the base element and precomputation.
1080  virtual Element CascadeExponentiateBaseAndPublicElement(const Integer &baseExp, const Integer &publicExp) const
1081  {
1082  const DL_GroupParameters<T> &params = this->GetAbstractGroupParameters();
1083  return params.GetBasePrecomputation().CascadeExponentiate(params.GetGroupPrecomputation(), baseExp, GetPublicPrecomputation(), publicExp);
1084  }
1085 
1086  /// \brief Accesses the public precomputation
1087  /// \details GetPublicPrecomputation returns a const reference, while
1088  /// AccessPublicPrecomputation returns a non-const reference. Must be
1089  /// overridden in derived classes.
1090  virtual const DL_FixedBasePrecomputation<T> & GetPublicPrecomputation() const =0;
1091 
1092  /// \brief Accesses the public precomputation
1093  /// \details GetPublicPrecomputation returns a const reference, while
1094  /// AccessPublicPrecomputation returns a non-const reference. Must be
1095  /// overridden in derived classes.
1096  virtual DL_FixedBasePrecomputation<T> & AccessPublicPrecomputation() =0;
1097 };
1098 
1099 // Out-of-line dtor due to AIX and GCC, http://github.com/weidai11/cryptopp/issues/499
1100 template<class T>
1102 
1103 /// \brief Interface for Discrete Log (DL) private keys
1104 template <class T>
1105 class CRYPTOPP_NO_VTABLE DL_PrivateKey : public DL_Key<T>
1106 {
1107  typedef DL_PrivateKey<T> ThisClass;
1108 
1109 public:
1110  typedef T Element;
1111 
1112  virtual ~DL_PrivateKey();
1113 
1114  /// \brief Initializes a public key from this key
1115  /// \param pub reference to a public key
1117  {
1119  pub.SetPublicElement(this->GetAbstractGroupParameters().ExponentiateBase(GetPrivateExponent()));
1120  }
1121 
1122  /// \brief Get a named value
1123  /// \param name the name of the object or value to retrieve
1124  /// \param valueType reference to a variable that receives the value
1125  /// \param pValue void pointer to a variable that receives the value
1126  /// \returns true if the value was retrieved, false otherwise
1127  /// \details GetVoidValue() retrieves the value of name if it exists.
1128  /// \note GetVoidValue() is an internal function and should be implemented
1129  /// by derived classes. Users should use one of the other functions instead.
1130  /// \sa GetValue(), GetValueWithDefault(), GetIntValue(), GetIntValueWithDefault(),
1131  /// GetRequiredParameter() and GetRequiredIntParameter()
1132  bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
1133  {
1134  return GetValueHelper(this, name, valueType, pValue, &this->GetAbstractGroupParameters())
1135  CRYPTOPP_GET_FUNCTION_ENTRY(PrivateExponent);
1136  }
1137 
1138  /// \brief Initialize or reinitialize this key
1139  /// \param source NameValuePairs to assign
1140  void AssignFrom(const NameValuePairs &source)
1141  {
1142  this->AccessAbstractGroupParameters().AssignFrom(source);
1143  AssignFromHelper(this, source)
1144  CRYPTOPP_SET_FUNCTION_ENTRY(PrivateExponent);
1145  }
1146 
1147  /// \brief Retrieves the private exponent
1148  /// \returns the private exponent
1149  /// \details Must be overridden in derived classes.
1150  virtual const Integer & GetPrivateExponent() const =0;
1151  /// \brief Sets the private exponent
1152  /// \param x the private exponent
1153  /// \details Must be overridden in derived classes.
1154  virtual void SetPrivateExponent(const Integer &x) =0;
1155 };
1156 
1157 // Out-of-line dtor due to AIX and GCC, http://github.com/weidai11/cryptopp/issues/499
1158 template<class T>
1160 
1161 template <class T>
1163 {
1164  DL_PrivateKey<T> *pPrivateKey = NULLPTR;
1165  if (source.GetThisPointer(pPrivateKey))
1166  pPrivateKey->MakePublicKey(*this);
1167  else
1168  {
1169  this->AccessAbstractGroupParameters().AssignFrom(source);
1170  AssignFromHelper(this, source)
1171  CRYPTOPP_SET_FUNCTION_ENTRY(PublicElement);
1172  }
1173 }
1174 
1175 class OID;
1176 
1177 /// \brief Discrete Log (DL) key base implementation
1178 /// \tparam PK Key class
1179 /// \tparam GP GroupParameters class
1180 /// \tparam O OID class
1181 template <class PK, class GP, class O = OID>
1182 class DL_KeyImpl : public PK
1183 {
1184 public:
1185  typedef GP GroupParameters;
1186 
1187  virtual ~DL_KeyImpl() {}
1188 
1189  O GetAlgorithmID() const {return GetGroupParameters().GetAlgorithmID();}
1190  bool BERDecodeAlgorithmParameters(BufferedTransformation &bt)
1191  {AccessGroupParameters().BERDecode(bt); return true;}
1192  bool DEREncodeAlgorithmParameters(BufferedTransformation &bt) const
1193  {GetGroupParameters().DEREncode(bt); return true;}
1194 
1195  const GP & GetGroupParameters() const {return m_groupParameters;}
1196  GP & AccessGroupParameters() {return m_groupParameters;}
1197 
1198 private:
1199  GP m_groupParameters;
1200 };
1201 
1202 class X509PublicKey;
1203 class PKCS8PrivateKey;
1204 
1205 /// \brief Discrete Log (DL) private key base implementation
1206 /// \tparam GP GroupParameters class
1207 template <class GP>
1208 class DL_PrivateKeyImpl : public DL_PrivateKey<typename GP::Element>, public DL_KeyImpl<PKCS8PrivateKey, GP>
1209 {
1210 public:
1211  typedef typename GP::Element Element;
1212 
1213  virtual ~DL_PrivateKeyImpl() {}
1214 
1215  // GeneratableCryptoMaterial
1216  bool Validate(RandomNumberGenerator &rng, unsigned int level) const
1217  {
1218  bool pass = GetAbstractGroupParameters().Validate(rng, level);
1219 
1220  const Integer &q = GetAbstractGroupParameters().GetSubgroupOrder();
1221  const Integer &x = GetPrivateExponent();
1222 
1223  pass = pass && x.IsPositive() && x < q;
1224  if (level >= 1)
1225  pass = pass && Integer::Gcd(x, q) == Integer::One();
1226  return pass;
1227  }
1228 
1229  bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
1230  {
1231  return GetValueHelper<DL_PrivateKey<Element> >(this, name, valueType, pValue).Assignable();
1232  }
1233 
1234  void AssignFrom(const NameValuePairs &source)
1235  {
1236  AssignFromHelper<DL_PrivateKey<Element> >(this, source);
1237  }
1238 
1240  {
1241  if (!params.GetThisObject(this->AccessGroupParameters()))
1242  this->AccessGroupParameters().GenerateRandom(rng, params);
1243  Integer x(rng, Integer::One(), GetAbstractGroupParameters().GetMaxExponent());
1244  SetPrivateExponent(x);
1245  }
1246 
1247  bool SupportsPrecomputation() const {return true;}
1248 
1249  void Precompute(unsigned int precomputationStorage=16)
1250  {AccessAbstractGroupParameters().Precompute(precomputationStorage);}
1251 
1252  void LoadPrecomputation(BufferedTransformation &storedPrecomputation)
1253  {AccessAbstractGroupParameters().LoadPrecomputation(storedPrecomputation);}
1254 
1255  void SavePrecomputation(BufferedTransformation &storedPrecomputation) const
1256  {GetAbstractGroupParameters().SavePrecomputation(storedPrecomputation);}
1257 
1258  // DL_Key
1259  const DL_GroupParameters<Element> & GetAbstractGroupParameters() const {return this->GetGroupParameters();}
1260  DL_GroupParameters<Element> & AccessAbstractGroupParameters() {return this->AccessGroupParameters();}
1261 
1262  // DL_PrivateKey
1263  const Integer & GetPrivateExponent() const {return m_x;}
1264  void SetPrivateExponent(const Integer &x) {m_x = x;}
1265 
1266  // PKCS8PrivateKey
1268  {m_x.BERDecode(bt);}
1270  {m_x.DEREncode(bt);}
1271 
1272 private:
1273  Integer m_x;
1274 };
1275 
1276 template <class BASE, class SIGNATURE_SCHEME>
1278 {
1279 public:
1281 
1282  void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &params)
1283  {
1284  BASE::GenerateRandom(rng, params);
1285 
1287  {
1288  typename SIGNATURE_SCHEME::Signer signer(*this);
1289  typename SIGNATURE_SCHEME::Verifier verifier(signer);
1290  SignaturePairwiseConsistencyTest_FIPS_140_Only(signer, verifier);
1291  }
1292  }
1293 };
1294 
1295 /// \brief Discrete Log (DL) public key base implementation
1296 /// \tparam GP GroupParameters class
1297 template <class GP>
1298 class DL_PublicKeyImpl : public DL_PublicKey<typename GP::Element>, public DL_KeyImpl<X509PublicKey, GP>
1299 {
1300 public:
1301  typedef typename GP::Element Element;
1302 
1303  virtual ~DL_PublicKeyImpl();
1304 
1305  // CryptoMaterial
1306  bool Validate(RandomNumberGenerator &rng, unsigned int level) const
1307  {
1308  bool pass = GetAbstractGroupParameters().Validate(rng, level);
1309  pass = pass && GetAbstractGroupParameters().ValidateElement(level, this->GetPublicElement(), &GetPublicPrecomputation());
1310  return pass;
1311  }
1312 
1313  bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
1314  {
1315  return GetValueHelper<DL_PublicKey<Element> >(this, name, valueType, pValue).Assignable();
1316  }
1317 
1318  void AssignFrom(const NameValuePairs &source)
1319  {
1320  AssignFromHelper<DL_PublicKey<Element> >(this, source);
1321  }
1322 
1323  bool SupportsPrecomputation() const {return true;}
1324 
1325  void Precompute(unsigned int precomputationStorage=16)
1326  {
1327  AccessAbstractGroupParameters().Precompute(precomputationStorage);
1328  AccessPublicPrecomputation().Precompute(GetAbstractGroupParameters().GetGroupPrecomputation(), GetAbstractGroupParameters().GetSubgroupOrder().BitCount(), precomputationStorage);
1329  }
1330 
1331  void LoadPrecomputation(BufferedTransformation &storedPrecomputation)
1332  {
1333  AccessAbstractGroupParameters().LoadPrecomputation(storedPrecomputation);
1334  AccessPublicPrecomputation().Load(GetAbstractGroupParameters().GetGroupPrecomputation(), storedPrecomputation);
1335  }
1336 
1337  void SavePrecomputation(BufferedTransformation &storedPrecomputation) const
1338  {
1339  GetAbstractGroupParameters().SavePrecomputation(storedPrecomputation);
1340  GetPublicPrecomputation().Save(GetAbstractGroupParameters().GetGroupPrecomputation(), storedPrecomputation);
1341  }
1342 
1343  // DL_Key
1344  const DL_GroupParameters<Element> & GetAbstractGroupParameters() const {return this->GetGroupParameters();}
1345  DL_GroupParameters<Element> & AccessAbstractGroupParameters() {return this->AccessGroupParameters();}
1346 
1347  // DL_PublicKey
1350 
1351  // non-inherited
1352  bool operator==(const DL_PublicKeyImpl<GP> &rhs) const
1353  {return this->GetGroupParameters() == rhs.GetGroupParameters() && this->GetPublicElement() == rhs.GetPublicElement();}
1354 
1355 private:
1356  typename GP::BasePrecomputation m_ypc;
1357 };
1358 
1359 // Out-of-line dtor due to AIX and GCC, http://github.com/weidai11/cryptopp/issues/499
1360 template<class GP>
1362 
1363 /// \brief Interface for Elgamal-like signature algorithms
1364 /// \tparam T Field element
1365 template <class T>
1366 class CRYPTOPP_NO_VTABLE DL_ElgamalLikeSignatureAlgorithm
1367 {
1368 public:
1369  virtual ~DL_ElgamalLikeSignatureAlgorithm() {}
1370 
1371  /// \brief Sign a message using a private key
1372  /// \param params GroupParameters
1373  /// \param privateKey private key
1374  /// \param k signing exponent
1375  /// \param e encoded message
1376  /// \param r r part of signature
1377  /// \param s s part of signature
1378  virtual void Sign(const DL_GroupParameters<T> &params, const Integer &privateKey, const Integer &k, const Integer &e, Integer &r, Integer &s) const =0;
1379 
1380  /// \brief Verify a message using a public key
1381  /// \param params GroupParameters
1382  /// \param publicKey public key
1383  /// \param e encoded message
1384  /// \param r r part of signature
1385  /// \param s s part of signature
1386  virtual bool Verify(const DL_GroupParameters<T> &params, const DL_PublicKey<T> &publicKey, const Integer &e, const Integer &r, const Integer &s) const =0;
1387 
1388  /// \brief Recover a Presignature
1389  /// \param params GroupParameters
1390  /// \param publicKey public key
1391  /// \param r r part of signature
1392  /// \param s s part of signature
1393  virtual Integer RecoverPresignature(const DL_GroupParameters<T> &params, const DL_PublicKey<T> &publicKey, const Integer &r, const Integer &s) const
1394  {
1395  CRYPTOPP_UNUSED(params); CRYPTOPP_UNUSED(publicKey); CRYPTOPP_UNUSED(r); CRYPTOPP_UNUSED(s);
1396  throw NotImplemented("DL_ElgamalLikeSignatureAlgorithm: this signature scheme does not support message recovery");
1397  MAYBE_RETURN(Integer::Zero());
1398  }
1399 
1400  /// \brief Retrieve R length
1401  /// \param params GroupParameters
1402  virtual size_t RLen(const DL_GroupParameters<T> &params) const
1403  {return params.GetSubgroupOrder().ByteCount();}
1404 
1405  /// \brief Retrieve S length
1406  /// \param params GroupParameters
1407  virtual size_t SLen(const DL_GroupParameters<T> &params) const
1408  {return params.GetSubgroupOrder().ByteCount();}
1409 
1410  /// \brief Signature scheme flag
1411  /// \returns true if the signature scheme is deterministic, false otherwise
1412  /// \details IsDeterministic() is provided for DL signers. It is used by RFC 6979 signature schemes.
1413  virtual bool IsDeterministic() const
1414  {return false;}
1415 };
1416 
1417 /// \brief Interface for deterministic signers
1418 /// \details RFC 6979 signers which generate k based on the encoded message and private key
1419 class CRYPTOPP_NO_VTABLE DeterministicSignatureAlgorithm
1420 {
1421 public:
1422  virtual ~DeterministicSignatureAlgorithm() {}
1423 
1424  /// \brief Generate k
1425  /// \param x private key
1426  /// \param q subgroup generator
1427  /// \param e encoded message
1428  virtual Integer GenerateRandom(const Integer &x, const Integer &q, const Integer &e) const =0;
1429 };
1430 
1431 /// \brief Interface for DL key agreement algorithms
1432 /// \tparam T Field element
1433 template <class T>
1434 class CRYPTOPP_NO_VTABLE DL_KeyAgreementAlgorithm
1435 {
1436 public:
1437  typedef T Element;
1438 
1439  virtual ~DL_KeyAgreementAlgorithm() {}
1440 
1441  virtual Element AgreeWithEphemeralPrivateKey(const DL_GroupParameters<Element> &params, const DL_FixedBasePrecomputation<Element> &publicPrecomputation, const Integer &privateExponent) const =0;
1442  virtual Element AgreeWithStaticPrivateKey(const DL_GroupParameters<Element> &params, const Element &publicElement, bool validateOtherPublicKey, const Integer &privateExponent) const =0;
1443 };
1444 
1445 /// \brief Interface for key derivation algorithms used in DL cryptosystems
1446 /// \tparam T Field element
1447 template <class T>
1448 class CRYPTOPP_NO_VTABLE DL_KeyDerivationAlgorithm
1449 {
1450 public:
1451  virtual ~DL_KeyDerivationAlgorithm() {}
1452 
1453  virtual bool ParameterSupported(const char *name) const
1454  {CRYPTOPP_UNUSED(name); return false;}
1455  virtual void Derive(const DL_GroupParameters<T> &groupParams, byte *derivedKey, size_t derivedLength, const T &agreedElement, const T &ephemeralPublicKey, const NameValuePairs &derivationParams) const =0;
1456 };
1457 
1458 /// \brief Interface for symmetric encryption algorithms used in DL cryptosystems
1459 class CRYPTOPP_NO_VTABLE DL_SymmetricEncryptionAlgorithm
1460 {
1461 public:
1462  virtual ~DL_SymmetricEncryptionAlgorithm() {}
1463 
1464  virtual bool ParameterSupported(const char *name) const
1465  {CRYPTOPP_UNUSED(name); return false;}
1466  virtual size_t GetSymmetricKeyLength(size_t plaintextLength) const =0;
1467  virtual size_t GetSymmetricCiphertextLength(size_t plaintextLength) const =0;
1468  virtual size_t GetMaxSymmetricPlaintextLength(size_t ciphertextLength) const =0;
1469  virtual void SymmetricEncrypt(RandomNumberGenerator &rng, const byte *key, const byte *plaintext, size_t plaintextLength, byte *ciphertext, const NameValuePairs &parameters) const =0;
1470  virtual DecodingResult SymmetricDecrypt(const byte *key, const byte *ciphertext, size_t ciphertextLength, byte *plaintext, const NameValuePairs &parameters) const =0;
1471 };
1472 
1473 /// \brief Discrete Log (DL) base interface
1474 /// \tparam KI public or private key interface
1475 template <class KI>
1476 class CRYPTOPP_NO_VTABLE DL_Base
1477 {
1478 protected:
1479  typedef KI KeyInterface;
1480  typedef typename KI::Element Element;
1481 
1482  virtual ~DL_Base() {}
1483 
1484  const DL_GroupParameters<Element> & GetAbstractGroupParameters() const {return GetKeyInterface().GetAbstractGroupParameters();}
1485  DL_GroupParameters<Element> & AccessAbstractGroupParameters() {return AccessKeyInterface().AccessAbstractGroupParameters();}
1486 
1487  virtual KeyInterface & AccessKeyInterface() =0;
1488  virtual const KeyInterface & GetKeyInterface() const =0;
1489 };
1490 
1491 /// \brief Discrete Log (DL) signature scheme base implementation
1492 /// \tparam INTFACE PK_Signer or PK_Verifier derived class
1493 /// \tparam KEY_INTFACE DL_Base key base used in the scheme
1494 /// \details DL_SignatureSchemeBase provides common functions for signers and verifiers.
1495 /// DL_Base<DL_PrivateKey> is used for signers, and DL_Base<DL_PublicKey> is used for verifiers.
1496 template <class INTFACE, class KEY_INTFACE>
1497 class CRYPTOPP_NO_VTABLE DL_SignatureSchemeBase : public INTFACE, public DL_Base<KEY_INTFACE>
1498 {
1499 public:
1500  virtual ~DL_SignatureSchemeBase() {}
1501 
1502  /// \brief Provides the signature length
1503  /// \returns signature length, in bytes
1504  /// \details SignatureLength returns the size required for <tt>r+s</tt>.
1505  size_t SignatureLength() const
1506  {
1507  return GetSignatureAlgorithm().RLen(this->GetAbstractGroupParameters())
1508  + GetSignatureAlgorithm().SLen(this->GetAbstractGroupParameters());
1509  }
1510 
1511  /// \brief Provides the maximum recoverable length
1512  /// \returns maximum recoverable length, in bytes
1513  size_t MaxRecoverableLength() const
1514  {return GetMessageEncodingInterface().MaxRecoverableLength(0, GetHashIdentifier().second, GetDigestSize());}
1515 
1516  /// \brief Provides the maximum recoverable length
1517  /// \param signatureLength the size fo the signature
1518  /// \returns maximum recoverable length based on signature length, in bytes
1519  /// \details this function is not implemented and always returns 0.
1520  size_t MaxRecoverableLengthFromSignatureLength(size_t signatureLength) const
1521  {CRYPTOPP_UNUSED(signatureLength); CRYPTOPP_ASSERT(false); return 0;} // TODO
1522 
1523  /// \brief Determines if the scheme is probabilistic
1524  /// \returns true if the scheme is probabilistic, false otherwise
1525  bool IsProbabilistic() const
1526  {return true;}
1527 
1528  /// \brief Determines if the scheme has non-recoverable part
1529  /// \returns true if the message encoding has a non-recoverable part, false otherwise.
1531  {return GetMessageEncodingInterface().AllowNonrecoverablePart();}
1532 
1533  /// \brief Determines if the scheme allows recoverable part first
1534  /// \returns true if the message encoding allows the recoverable part, false otherwise.
1536  {return GetMessageEncodingInterface().RecoverablePartFirst();}
1537 
1538 protected:
1539  size_t MessageRepresentativeLength() const {return BitsToBytes(MessageRepresentativeBitLength());}
1540  size_t MessageRepresentativeBitLength() const {return this->GetAbstractGroupParameters().GetSubgroupOrder().BitCount();}
1541 
1542  // true if the scheme conforms to RFC 6979
1543  virtual bool IsDeterministic() const {return false;}
1544 
1545  virtual const DL_ElgamalLikeSignatureAlgorithm<typename KEY_INTFACE::Element> & GetSignatureAlgorithm() const =0;
1546  virtual const PK_SignatureMessageEncodingMethod & GetMessageEncodingInterface() const =0;
1547  virtual HashIdentifier GetHashIdentifier() const =0;
1548  virtual size_t GetDigestSize() const =0;
1549 };
1550 
1551 /// \brief Discrete Log (DL) signature scheme signer base implementation
1552 /// \tparam T Field element
1553 template <class T>
1554 class CRYPTOPP_NO_VTABLE DL_SignerBase : public DL_SignatureSchemeBase<PK_Signer, DL_PrivateKey<T> >
1555 {
1556 public:
1557  virtual ~DL_SignerBase() {}
1558 
1559  /// \brief Testing interface
1560  /// \param k Integer
1561  /// \param e Integer
1562  /// \param r Integer
1563  /// \param s Integer
1564  void RawSign(const Integer &k, const Integer &e, Integer &r, Integer &s) const
1565  {
1566  const DL_ElgamalLikeSignatureAlgorithm<T> &alg = this->GetSignatureAlgorithm();
1567  const DL_GroupParameters<T> &params = this->GetAbstractGroupParameters();
1568  const DL_PrivateKey<T> &key = this->GetKeyInterface();
1569 
1570  r = params.ConvertElementToInteger(params.ExponentiateBase(k));
1571  alg.Sign(params, key.GetPrivateExponent(), k, e, r, s);
1572  }
1573 
1574  void InputRecoverableMessage(PK_MessageAccumulator &messageAccumulator, const byte *recoverableMessage, size_t recoverableMessageLength) const
1575  {
1576  PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator);
1577  ma.m_recoverableMessage.Assign(recoverableMessage, recoverableMessageLength);
1578  this->GetMessageEncodingInterface().ProcessRecoverableMessage(ma.AccessHash(),
1579  recoverableMessage, recoverableMessageLength,
1580  ma.m_presignature, ma.m_presignature.size(),
1581  ma.m_semisignature);
1582  }
1583 
1584  size_t SignAndRestart(RandomNumberGenerator &rng, PK_MessageAccumulator &messageAccumulator, byte *signature, bool restart) const
1585  {
1586  this->GetMaterial().DoQuickSanityCheck();
1587 
1588  PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator);
1589  const DL_ElgamalLikeSignatureAlgorithm<T> &alg = this->GetSignatureAlgorithm();
1590  const DL_GroupParameters<T> &params = this->GetAbstractGroupParameters();
1591  const DL_PrivateKey<T> &key = this->GetKeyInterface();
1592 
1593  SecByteBlock representative(this->MessageRepresentativeLength());
1594  this->GetMessageEncodingInterface().ComputeMessageRepresentative(
1595  rng,
1596  ma.m_recoverableMessage, ma.m_recoverableMessage.size(),
1597  ma.AccessHash(), this->GetHashIdentifier(), ma.m_empty,
1598  representative, this->MessageRepresentativeBitLength());
1599  ma.m_empty = true;
1600  Integer e(representative, representative.size());
1601 
1602  // hash message digest into random number k to prevent reusing the same k on
1603  // different messages after virtual machine rollback
1604  if (rng.CanIncorporateEntropy())
1605  rng.IncorporateEntropy(representative, representative.size());
1606 
1607  Integer k;
1608  if (alg.IsDeterministic())
1609  {
1610  const Integer& q = params.GetSubgroupOrder();
1611  const Integer& x = key.GetPrivateExponent();
1612  const DeterministicSignatureAlgorithm& det = dynamic_cast<const DeterministicSignatureAlgorithm&>(alg);
1613  k = det.GenerateRandom(x, q, e);
1614  }
1615  else
1616  {
1617  k.Randomize(rng, 1, params.GetSubgroupOrder()-1);
1618  }
1619 
1620  Integer r, s;
1621  r = params.ConvertElementToInteger(params.ExponentiateBase(k));
1622  alg.Sign(params, key.GetPrivateExponent(), k, e, r, s);
1623 
1624  /*
1625  Integer r, s;
1626  if (this->MaxRecoverableLength() > 0)
1627  r.Decode(ma.m_semisignature, ma.m_semisignature.size());
1628  else
1629  r.Decode(ma.m_presignature, ma.m_presignature.size());
1630  alg.Sign(params, key.GetPrivateExponent(), ma.m_k, e, r, s);
1631  */
1632 
1633  size_t rLen = alg.RLen(params);
1634  r.Encode(signature, rLen);
1635  s.Encode(signature+rLen, alg.SLen(params));
1636 
1637  if (restart)
1638  RestartMessageAccumulator(rng, ma);
1639 
1640  return this->SignatureLength();
1641  }
1642 
1643 protected:
1644  void RestartMessageAccumulator(RandomNumberGenerator &rng, PK_MessageAccumulatorBase &ma) const
1645  {
1646  // k needs to be generated before hashing for signature schemes with recovery
1647  // but to defend against VM rollbacks we need to generate k after hashing.
1648  // so this code is commented out, since no DL-based signature scheme with recovery
1649  // has been implemented in Crypto++ anyway
1650  /*
1651  const DL_ElgamalLikeSignatureAlgorithm<T> &alg = this->GetSignatureAlgorithm();
1652  const DL_GroupParameters<T> &params = this->GetAbstractGroupParameters();
1653  ma.m_k.Randomize(rng, 1, params.GetSubgroupOrder()-1);
1654  ma.m_presignature.New(params.GetEncodedElementSize(false));
1655  params.ConvertElementToInteger(params.ExponentiateBase(ma.m_k)).Encode(ma.m_presignature, ma.m_presignature.size());
1656  */
1657  CRYPTOPP_UNUSED(rng); CRYPTOPP_UNUSED(ma);
1658  }
1659 };
1660 
1661 /// \brief Discret Log (DL) Verifier base class
1662 /// \tparam T Field element
1663 template <class T>
1664 class CRYPTOPP_NO_VTABLE DL_VerifierBase : public DL_SignatureSchemeBase<PK_Verifier, DL_PublicKey<T> >
1665 {
1666 public:
1667  virtual ~DL_VerifierBase() {}
1668 
1669  void InputSignature(PK_MessageAccumulator &messageAccumulator, const byte *signature, size_t signatureLength) const
1670  {
1671  CRYPTOPP_UNUSED(signature); CRYPTOPP_UNUSED(signatureLength);
1672  PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator);
1673  const DL_ElgamalLikeSignatureAlgorithm<T> &alg = this->GetSignatureAlgorithm();
1674  const DL_GroupParameters<T> &params = this->GetAbstractGroupParameters();
1675 
1676  size_t rLen = alg.RLen(params);
1677  ma.m_semisignature.Assign(signature, rLen);
1678  ma.m_s.Decode(signature+rLen, alg.SLen(params));
1679 
1680  this->GetMessageEncodingInterface().ProcessSemisignature(ma.AccessHash(), ma.m_semisignature, ma.m_semisignature.size());
1681  }
1682 
1683  bool VerifyAndRestart(PK_MessageAccumulator &messageAccumulator) const
1684  {
1685  this->GetMaterial().DoQuickSanityCheck();
1686 
1687  PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator);
1688  const DL_ElgamalLikeSignatureAlgorithm<T> &alg = this->GetSignatureAlgorithm();
1689  const DL_GroupParameters<T> &params = this->GetAbstractGroupParameters();
1690  const DL_PublicKey<T> &key = this->GetKeyInterface();
1691 
1692  SecByteBlock representative(this->MessageRepresentativeLength());
1693  this->GetMessageEncodingInterface().ComputeMessageRepresentative(NullRNG(), ma.m_recoverableMessage, ma.m_recoverableMessage.size(),
1694  ma.AccessHash(), this->GetHashIdentifier(), ma.m_empty,
1695  representative, this->MessageRepresentativeBitLength());
1696  ma.m_empty = true;
1697  Integer e(representative, representative.size());
1698 
1699  Integer r(ma.m_semisignature, ma.m_semisignature.size());
1700  return alg.Verify(params, key, e, r, ma.m_s);
1701  }
1702 
1703  DecodingResult RecoverAndRestart(byte *recoveredMessage, PK_MessageAccumulator &messageAccumulator) const
1704  {
1705  this->GetMaterial().DoQuickSanityCheck();
1706 
1707  PK_MessageAccumulatorBase &ma = static_cast<PK_MessageAccumulatorBase &>(messageAccumulator);
1708  const DL_ElgamalLikeSignatureAlgorithm<T> &alg = this->GetSignatureAlgorithm();
1709  const DL_GroupParameters<T> &params = this->GetAbstractGroupParameters();
1710  const DL_PublicKey<T> &key = this->GetKeyInterface();
1711 
1712  SecByteBlock representative(this->MessageRepresentativeLength());
1713  this->GetMessageEncodingInterface().ComputeMessageRepresentative(
1714  NullRNG(),
1715  ma.m_recoverableMessage, ma.m_recoverableMessage.size(),
1716  ma.AccessHash(), this->GetHashIdentifier(), ma.m_empty,
1717  representative, this->MessageRepresentativeBitLength());
1718  ma.m_empty = true;
1719  Integer e(representative, representative.size());
1720 
1721  ma.m_presignature.New(params.GetEncodedElementSize(false));
1722  Integer r(ma.m_semisignature, ma.m_semisignature.size());
1723  alg.RecoverPresignature(params, key, r, ma.m_s).Encode(ma.m_presignature, ma.m_presignature.size());
1724 
1725  return this->GetMessageEncodingInterface().RecoverMessageFromSemisignature(
1726  ma.AccessHash(), this->GetHashIdentifier(),
1727  ma.m_presignature, ma.m_presignature.size(),
1728  ma.m_semisignature, ma.m_semisignature.size(),
1729  recoveredMessage);
1730  }
1731 };
1732 
1733 /// \brief Discrete Log (DL) cryptosystem base implementation
1734 /// \tparam PK field element type
1735 /// \tparam KI public or private key interface
1736 template <class PK, class KI>
1737 class CRYPTOPP_NO_VTABLE DL_CryptoSystemBase : public PK, public DL_Base<KI>
1738 {
1739 public:
1740  typedef typename DL_Base<KI>::Element Element;
1741 
1742  virtual ~DL_CryptoSystemBase() {}
1743 
1744  size_t MaxPlaintextLength(size_t ciphertextLength) const
1745  {
1746  unsigned int minLen = this->GetAbstractGroupParameters().GetEncodedElementSize(true);
1747  return ciphertextLength < minLen ? 0 : GetSymmetricEncryptionAlgorithm().GetMaxSymmetricPlaintextLength(ciphertextLength - minLen);
1748  }
1749 
1750  size_t CiphertextLength(size_t plaintextLength) const
1751  {
1752  size_t len = GetSymmetricEncryptionAlgorithm().GetSymmetricCiphertextLength(plaintextLength);
1753  return len == 0 ? 0 : this->GetAbstractGroupParameters().GetEncodedElementSize(true) + len;
1754  }
1755 
1756  bool ParameterSupported(const char *name) const
1757  {return GetKeyDerivationAlgorithm().ParameterSupported(name) || GetSymmetricEncryptionAlgorithm().ParameterSupported(name);}
1758 
1759 protected:
1760  virtual const DL_KeyAgreementAlgorithm<Element> & GetKeyAgreementAlgorithm() const =0;
1761  virtual const DL_KeyDerivationAlgorithm<Element> & GetKeyDerivationAlgorithm() const =0;
1762  virtual const DL_SymmetricEncryptionAlgorithm & GetSymmetricEncryptionAlgorithm() const =0;
1763 };
1764 
1765 /// \brief Discrete Log (DL) decryptor base implementation
1766 /// \tparam T Field element
1767 template <class T>
1768 class CRYPTOPP_NO_VTABLE DL_DecryptorBase : public DL_CryptoSystemBase<PK_Decryptor, DL_PrivateKey<T> >
1769 {
1770 public:
1771  typedef T Element;
1772 
1773  virtual ~DL_DecryptorBase() {}
1774 
1775  DecodingResult Decrypt(RandomNumberGenerator &rng, const byte *ciphertext, size_t ciphertextLength, byte *plaintext, const NameValuePairs &parameters = g_nullNameValuePairs) const
1776  {
1777  try
1778  {
1779  CRYPTOPP_UNUSED(rng);
1780  const DL_KeyAgreementAlgorithm<T> &agreeAlg = this->GetKeyAgreementAlgorithm();
1781  const DL_KeyDerivationAlgorithm<T> &derivAlg = this->GetKeyDerivationAlgorithm();
1782  const DL_SymmetricEncryptionAlgorithm &encAlg = this->GetSymmetricEncryptionAlgorithm();
1783  const DL_GroupParameters<T> &params = this->GetAbstractGroupParameters();
1784  const DL_PrivateKey<T> &key = this->GetKeyInterface();
1785 
1786  Element q = params.DecodeElement(ciphertext, true);
1787  size_t elementSize = params.GetEncodedElementSize(true);
1788  ciphertext += elementSize;
1789  ciphertextLength -= elementSize;
1790 
1791  Element z = agreeAlg.AgreeWithStaticPrivateKey(params, q, true, key.GetPrivateExponent());
1792 
1793  SecByteBlock derivedKey(encAlg.GetSymmetricKeyLength(encAlg.GetMaxSymmetricPlaintextLength(ciphertextLength)));
1794  derivAlg.Derive(params, derivedKey, derivedKey.size(), z, q, parameters);
1795 
1796  return encAlg.SymmetricDecrypt(derivedKey, ciphertext, ciphertextLength, plaintext, parameters);
1797  }
1798  catch (DL_BadElement &)
1799  {
1800  return DecodingResult();
1801  }
1802  }
1803 };
1804 
1805 /// \brief Discrete Log (DL) encryptor base implementation
1806 /// \tparam T Field element
1807 template <class T>
1808 class CRYPTOPP_NO_VTABLE DL_EncryptorBase : public DL_CryptoSystemBase<PK_Encryptor, DL_PublicKey<T> >
1809 {
1810 public:
1811  typedef T Element;
1812 
1813  virtual ~DL_EncryptorBase() {}
1814 
1815  void Encrypt(RandomNumberGenerator &rng, const byte *plaintext, size_t plaintextLength, byte *ciphertext, const NameValuePairs &parameters = g_nullNameValuePairs) const
1816  {
1817  const DL_KeyAgreementAlgorithm<T> &agreeAlg = this->GetKeyAgreementAlgorithm();
1818  const DL_KeyDerivationAlgorithm<T> &derivAlg = this->GetKeyDerivationAlgorithm();
1819  const DL_SymmetricEncryptionAlgorithm &encAlg = this->GetSymmetricEncryptionAlgorithm();
1820  const DL_GroupParameters<T> &params = this->GetAbstractGroupParameters();
1821  const DL_PublicKey<T> &key = this->GetKeyInterface();
1822 
1823  Integer x(rng, Integer::One(), params.GetMaxExponent());
1824  Element q = params.ExponentiateBase(x);
1825  params.EncodeElement(true, q, ciphertext);
1826  unsigned int elementSize = params.GetEncodedElementSize(true);
1827  ciphertext += elementSize;
1828 
1829  Element z = agreeAlg.AgreeWithEphemeralPrivateKey(params, key.GetPublicPrecomputation(), x);
1830 
1831  SecByteBlock derivedKey(encAlg.GetSymmetricKeyLength(plaintextLength));
1832  derivAlg.Derive(params, derivedKey, derivedKey.size(), z, q, parameters);
1833 
1834  encAlg.SymmetricEncrypt(rng, derivedKey, plaintext, plaintextLength, ciphertext, parameters);
1835  }
1836 };
1837 
1838 /// \brief Discrete Log (DL) scheme options
1839 /// \tparam T1 algorithm information
1840 /// \tparam T2 group parameters for the scheme
1841 template <class T1, class T2>
1843 {
1844  typedef T1 AlgorithmInfo;
1845  typedef T2 GroupParameters;
1846  typedef typename GroupParameters::Element Element;
1847 };
1848 
1849 /// \brief Discrete Log (DL) key options
1850 /// \tparam T1 algorithm information
1851 /// \tparam T2 keys used in the scheme
1852 template <class T1, class T2>
1853 struct DL_KeyedSchemeOptions : public DL_SchemeOptionsBase<T1, typename T2::PublicKey::GroupParameters>
1854 {
1855  typedef T2 Keys;
1856  typedef typename Keys::PrivateKey PrivateKey;
1857  typedef typename Keys::PublicKey PublicKey;
1858 };
1859 
1860 /// \brief Discrete Log (DL) signature scheme options
1861 /// \tparam T1 algorithm information
1862 /// \tparam T2 keys used in the scheme
1863 /// \tparam T3 signature algorithm
1864 /// \tparam T4 message encoding method
1865 /// \tparam T5 hash function
1866 template <class T1, class T2, class T3, class T4, class T5>
1868 {
1869  typedef T3 SignatureAlgorithm;
1870  typedef T4 MessageEncodingMethod;
1871  typedef T5 HashFunction;
1872 };
1873 
1874 /// \brief Discrete Log (DL) crypto scheme options
1875 /// \tparam T1 algorithm information
1876 /// \tparam T2 keys used in the scheme
1877 /// \tparam T3 key agreement algorithm
1878 /// \tparam T4 key derivation algorithm
1879 /// \tparam T5 symmetric encryption algorithm
1880 template <class T1, class T2, class T3, class T4, class T5>
1882 {
1883  typedef T3 KeyAgreementAlgorithm;
1884  typedef T4 KeyDerivationAlgorithm;
1885  typedef T5 SymmetricEncryptionAlgorithm;
1886 };
1887 
1888 /// \brief Discrete Log (DL) base object implementation
1889 /// \tparam BASE TODO
1890 /// \tparam SCHEME_OPTIONS options for the scheme
1891 /// \tparam KEY key used in the scheme
1892 template <class BASE, class SCHEME_OPTIONS, class KEY>
1893 class CRYPTOPP_NO_VTABLE DL_ObjectImplBase : public AlgorithmImpl<BASE, typename SCHEME_OPTIONS::AlgorithmInfo>
1894 {
1895 public:
1896  typedef SCHEME_OPTIONS SchemeOptions;
1897  typedef typename KEY::Element Element;
1898 
1899  virtual ~DL_ObjectImplBase() {}
1900 
1901  PrivateKey & AccessPrivateKey() {return m_key;}
1902  PublicKey & AccessPublicKey() {return m_key;}
1903 
1904  // KeyAccessor
1905  const KEY & GetKey() const {return m_key;}
1906  KEY & AccessKey() {return m_key;}
1907 
1908 protected:
1909  typename BASE::KeyInterface & AccessKeyInterface() {return m_key;}
1910  const typename BASE::KeyInterface & GetKeyInterface() const {return m_key;}
1911 
1912  // for signature scheme
1913  HashIdentifier GetHashIdentifier() const
1914  {
1915  typedef typename SchemeOptions::MessageEncodingMethod::HashIdentifierLookup HashLookup;
1916  return HashLookup::template HashIdentifierLookup2<typename SchemeOptions::HashFunction>::Lookup();
1917  }
1918  size_t GetDigestSize() const
1919  {
1920  typedef typename SchemeOptions::HashFunction H;
1921  return H::DIGESTSIZE;
1922  }
1923 
1924 private:
1925  KEY m_key;
1926 };
1927 
1928 /// \brief Discrete Log (DL) object implementation
1929 /// \tparam BASE TODO
1930 /// \tparam SCHEME_OPTIONS options for the scheme
1931 /// \tparam KEY key used in the scheme
1932 template <class BASE, class SCHEME_OPTIONS, class KEY>
1933 class CRYPTOPP_NO_VTABLE DL_ObjectImpl : public DL_ObjectImplBase<BASE, SCHEME_OPTIONS, KEY>
1934 {
1935 public:
1936  typedef typename KEY::Element Element;
1937 
1938  virtual ~DL_ObjectImpl() {}
1939 
1940 protected:
1941  const DL_ElgamalLikeSignatureAlgorithm<Element> & GetSignatureAlgorithm() const
1943  const DL_KeyAgreementAlgorithm<Element> & GetKeyAgreementAlgorithm() const
1945  const DL_KeyDerivationAlgorithm<Element> & GetKeyDerivationAlgorithm() const
1947  const DL_SymmetricEncryptionAlgorithm & GetSymmetricEncryptionAlgorithm() const
1949  HashIdentifier GetHashIdentifier() const
1950  {return HashIdentifier();}
1951  const PK_SignatureMessageEncodingMethod & GetMessageEncodingInterface() const
1953 };
1954 
1955 /// \brief Discrete Log (DL) signer implementation
1956 /// \tparam SCHEME_OPTIONS options for the scheme
1957 template <class SCHEME_OPTIONS>
1958 class DL_SignerImpl : public DL_ObjectImpl<DL_SignerBase<typename SCHEME_OPTIONS::Element>, SCHEME_OPTIONS, typename SCHEME_OPTIONS::PrivateKey>
1959 {
1960 public:
1962  {
1964  this->RestartMessageAccumulator(rng, *p);
1965  return p.release();
1966  }
1967 };
1968 
1969 /// \brief Discrete Log (DL) verifier implementation
1970 /// \tparam SCHEME_OPTIONS options for the scheme
1971 template <class SCHEME_OPTIONS>
1972 class DL_VerifierImpl : public DL_ObjectImpl<DL_VerifierBase<typename SCHEME_OPTIONS::Element>, SCHEME_OPTIONS, typename SCHEME_OPTIONS::PublicKey>
1973 {
1974 public:
1976  {
1978  }
1979 };
1980 
1981 /// \brief Discrete Log (DL) encryptor implementation
1982 /// \tparam SCHEME_OPTIONS options for the scheme
1983 template <class SCHEME_OPTIONS>
1984 class DL_EncryptorImpl : public DL_ObjectImpl<DL_EncryptorBase<typename SCHEME_OPTIONS::Element>, SCHEME_OPTIONS, typename SCHEME_OPTIONS::PublicKey>
1985 {
1986 };
1987 
1988 /// \brief Discrete Log (DL) decryptor implementation
1989 /// \tparam SCHEME_OPTIONS options for the scheme
1990 template <class SCHEME_OPTIONS>
1991 class DL_DecryptorImpl : public DL_ObjectImpl<DL_DecryptorBase<typename SCHEME_OPTIONS::Element>, SCHEME_OPTIONS, typename SCHEME_OPTIONS::PrivateKey>
1992 {
1993 };
1994 
1995 // ********************************************************
1996 
1997 /// \brief Discrete Log (DL) simple key agreement base implementation
1998 /// \tparam T class or type
1999 template <class T>
2001 {
2002 public:
2003  typedef T Element;
2004 
2005  virtual ~DL_SimpleKeyAgreementDomainBase() {}
2006 
2007  CryptoParameters & AccessCryptoParameters() {return AccessAbstractGroupParameters();}
2008  unsigned int AgreedValueLength() const {return GetAbstractGroupParameters().GetEncodedElementSize(false);}
2009  unsigned int PrivateKeyLength() const {return GetAbstractGroupParameters().GetSubgroupOrder().ByteCount();}
2010  unsigned int PublicKeyLength() const {return GetAbstractGroupParameters().GetEncodedElementSize(true);}
2011 
2012  void GeneratePrivateKey(RandomNumberGenerator &rng, byte *privateKey) const
2013  {
2014  Integer x(rng, Integer::One(), GetAbstractGroupParameters().GetMaxExponent());
2015  x.Encode(privateKey, PrivateKeyLength());
2016  }
2017 
2018  void GeneratePublicKey(RandomNumberGenerator &rng, const byte *privateKey, byte *publicKey) const
2019  {
2020  CRYPTOPP_UNUSED(rng);
2021  const DL_GroupParameters<T> &params = GetAbstractGroupParameters();
2022  Integer x(privateKey, PrivateKeyLength());
2023  Element y = params.ExponentiateBase(x);
2024  params.EncodeElement(true, y, publicKey);
2025  }
2026 
2027  bool Agree(byte *agreedValue, const byte *privateKey, const byte *otherPublicKey, bool validateOtherPublicKey=true) const
2028  {
2029  try
2030  {
2031  const DL_GroupParameters<T> &params = GetAbstractGroupParameters();
2032  Integer x(privateKey, PrivateKeyLength());
2033  Element w = params.DecodeElement(otherPublicKey, validateOtherPublicKey);
2034 
2035  Element z = GetKeyAgreementAlgorithm().AgreeWithStaticPrivateKey(
2036  GetAbstractGroupParameters(), w, validateOtherPublicKey, x);
2037  params.EncodeElement(false, z, agreedValue);
2038  }
2039  catch (DL_BadElement &)
2040  {
2041  return false;
2042  }
2043  return true;
2044  }
2045 
2046  /// \brief Retrieves a reference to the group generator
2047  /// \returns const reference to the group generator
2048  const Element &GetGenerator() const {return GetAbstractGroupParameters().GetSubgroupGenerator();}
2049 
2050 protected:
2051  virtual const DL_KeyAgreementAlgorithm<Element> & GetKeyAgreementAlgorithm() const =0;
2052  virtual DL_GroupParameters<Element> & AccessAbstractGroupParameters() =0;
2053  const DL_GroupParameters<Element> & GetAbstractGroupParameters() const {return const_cast<DL_SimpleKeyAgreementDomainBase<Element> *>(this)->AccessAbstractGroupParameters();}
2054 };
2055 
2056 /// \brief Methods for avoiding "Small-Subgroup" attacks on Diffie-Hellman Key Agreement
2057 /// \details Additional methods exist and include public key validation and choice of prime p.
2058 /// \sa <A HREF="http://tools.ietf.org/html/rfc2785">Methods for Avoiding the "Small-Subgroup" Attacks on the
2059 /// Diffie-Hellman Key Agreement Method for S/MIME</A>
2061  /// \brief No cofactor multiplication applied
2063  /// \brief Cofactor multiplication compatible with ordinary Diffie-Hellman
2064  /// \details Modifies the computation of ZZ by including j (the cofactor) in the computations and is
2065  /// compatible with ordinary Diffie-Hellman.
2067  /// \brief Cofactor multiplication incompatible with ordinary Diffie-Hellman
2068  /// \details Modifies the computation of ZZ by including j (the cofactor) in the computations but is
2069  /// not compatible with ordinary Diffie-Hellman.
2071 
2075 
2076 /// \brief Diffie-Hellman key agreement algorithm
2077 template <class ELEMENT, class COFACTOR_OPTION>
2079 {
2080 public:
2081  typedef ELEMENT Element;
2082 
2083  CRYPTOPP_STATIC_CONSTEXPR const char* CRYPTOPP_API StaticAlgorithmName()
2084  {return COFACTOR_OPTION::ToEnum() == INCOMPATIBLE_COFACTOR_MULTIPLICTION ? "DHC" : "DH";}
2085 
2086  virtual ~DL_KeyAgreementAlgorithm_DH() {}
2087 
2088  Element AgreeWithEphemeralPrivateKey(const DL_GroupParameters<Element> &params, const DL_FixedBasePrecomputation<Element> &publicPrecomputation, const Integer &privateExponent) const
2089  {
2090  return publicPrecomputation.Exponentiate(params.GetGroupPrecomputation(),
2091  COFACTOR_OPTION::ToEnum() == INCOMPATIBLE_COFACTOR_MULTIPLICTION ? privateExponent*params.GetCofactor() : privateExponent);
2092  }
2093 
2094  Element AgreeWithStaticPrivateKey(const DL_GroupParameters<Element> &params, const Element &publicElement, bool validateOtherPublicKey, const Integer &privateExponent) const
2095  {
2096  if (COFACTOR_OPTION::ToEnum() == COMPATIBLE_COFACTOR_MULTIPLICTION)
2097  {
2098  const Integer &k = params.GetCofactor();
2099  return params.ExponentiateElement(publicElement,
2100  ModularArithmetic(params.GetSubgroupOrder()).Divide(privateExponent, k)*k);
2101  }
2102  else if (COFACTOR_OPTION::ToEnum() == INCOMPATIBLE_COFACTOR_MULTIPLICTION)
2103  return params.ExponentiateElement(publicElement, privateExponent*params.GetCofactor());
2104  else
2105  {
2106  CRYPTOPP_ASSERT(COFACTOR_OPTION::ToEnum() == NO_COFACTOR_MULTIPLICTION);
2107 
2108  if (!validateOtherPublicKey)
2109  return params.ExponentiateElement(publicElement, privateExponent);
2110 
2111  if (params.FastSubgroupCheckAvailable())
2112  {
2113  if (!params.ValidateElement(2, publicElement, NULLPTR))
2114  throw DL_BadElement();
2115  return params.ExponentiateElement(publicElement, privateExponent);
2116  }
2117  else
2118  {
2119  const Integer e[2] = {params.GetSubgroupOrder(), privateExponent};
2120  Element r[2];
2121  params.SimultaneousExponentiate(r, publicElement, e, 2);
2122  if (!params.IsIdentity(r[0]))
2123  throw DL_BadElement();
2124  return r[1];
2125  }
2126  }
2127  }
2128 };
2129 
2130 // ********************************************************
2131 
2132 /// \brief Template implementing constructors for public key algorithm classes
2133 template <class BASE>
2134 class CRYPTOPP_NO_VTABLE PK_FinalTemplate : public BASE
2135 {
2136 public:
2137  PK_FinalTemplate() {}
2138 
2139  PK_FinalTemplate(const CryptoMaterial &key)
2140  {this->AccessKey().AssignFrom(key);}
2141 
2143  {this->AccessKey().BERDecode(bt);}
2144 
2145  PK_FinalTemplate(const AsymmetricAlgorithm &algorithm)
2146  {this->AccessKey().AssignFrom(algorithm.GetMaterial());}
2147 
2148  PK_FinalTemplate(const Integer &v1)
2149  {this->AccessKey().Initialize(v1);}
2150 
2151  template <class T1, class T2>
2152  PK_FinalTemplate(const T1 &v1, const T2 &v2)
2153  {this->AccessKey().Initialize(v1, v2);}
2154 
2155  template <class T1, class T2, class T3>
2156  PK_FinalTemplate(const T1 &v1, const T2 &v2, const T3 &v3)
2157  {this->AccessKey().Initialize(v1, v2, v3);}
2158 
2159  template <class T1, class T2, class T3, class T4>
2160  PK_FinalTemplate(const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4)
2161  {this->AccessKey().Initialize(v1, v2, v3, v4);}
2162 
2163  template <class T1, class T2, class T3, class T4, class T5>
2164  PK_FinalTemplate(const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5)
2165  {this->AccessKey().Initialize(v1, v2, v3, v4, v5);}
2166 
2167  template <class T1, class T2, class T3, class T4, class T5, class T6>
2168  PK_FinalTemplate(const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, const T6 &v6)
2169  {this->AccessKey().Initialize(v1, v2, v3, v4, v5, v6);}
2170 
2171  template <class T1, class T2, class T3, class T4, class T5, class T6, class T7>
2172  PK_FinalTemplate(const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, const T6 &v6, const T7 &v7)
2173  {this->AccessKey().Initialize(v1, v2, v3, v4, v5, v6, v7);}
2174 
2175  template <class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8>
2176  PK_FinalTemplate(const T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, const T6 &v6, const T7 &v7, const T8 &v8)
2177  {this->AccessKey().Initialize(v1, v2, v3, v4, v5, v6, v7, v8);}
2178 
2179  template <class T1, class T2>
2180  PK_FinalTemplate(T1 &v1, const T2 &v2)
2181  {this->AccessKey().Initialize(v1, v2);}
2182 
2183  template <class T1, class T2, class T3>
2184  PK_FinalTemplate(T1 &v1, const T2 &v2, const T3 &v3)
2185  {this->AccessKey().Initialize(v1, v2, v3);}
2186 
2187  template <class T1, class T2, class T3, class T4>
2188  PK_FinalTemplate(T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4)
2189  {this->AccessKey().Initialize(v1, v2, v3, v4);}
2190 
2191  template <class T1, class T2, class T3, class T4, class T5>
2192  PK_FinalTemplate(T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5)
2193  {this->AccessKey().Initialize(v1, v2, v3, v4, v5);}
2194 
2195  template <class T1, class T2, class T3, class T4, class T5, class T6>
2196  PK_FinalTemplate(T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, const T6 &v6)
2197  {this->AccessKey().Initialize(v1, v2, v3, v4, v5, v6);}
2198 
2199  template <class T1, class T2, class T3, class T4, class T5, class T6, class T7>
2200  PK_FinalTemplate(T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, const T6 &v6, const T7 &v7)
2201  {this->AccessKey().Initialize(v1, v2, v3, v4, v5, v6, v7);}
2202 
2203  template <class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8>
2204  PK_FinalTemplate(T1 &v1, const T2 &v2, const T3 &v3, const T4 &v4, const T5 &v5, const T6 &v6, const T7 &v7, const T8 &v8)
2205  {this->AccessKey().Initialize(v1, v2, v3, v4, v5, v6, v7, v8);}
2206 };
2207 
2208 /// \brief Base class for public key encryption standard classes.
2209 /// \details These classes are used to select from variants of algorithms.
2210 /// Not all standards apply to all algorithms.
2212 
2213 /// \brief Base class for public key signature standard classes.
2214 /// \details These classes are used to select from variants of algorithms.
2215 /// Not all standards apply to all algorithms.
2217 
2218 /// \brief Trapdoor Function (TF) encryption scheme
2219 /// \tparam STANDARD standard
2220 /// \tparam KEYS keys used in the encryption scheme
2221 /// \tparam ALG_INFO algorithm information
2222 template <class KEYS, class STANDARD, class ALG_INFO>
2223 class TF_ES;
2224 
2225 template <class KEYS, class STANDARD, class ALG_INFO = TF_ES<KEYS, STANDARD, int> >
2226 class TF_ES : public KEYS
2227 {
2228  typedef typename STANDARD::EncryptionMessageEncodingMethod MessageEncodingMethod;
2229 
2230 public:
2231  /// see EncryptionStandard for a list of standards
2232  typedef STANDARD Standard;
2234 
2235  static std::string CRYPTOPP_API StaticAlgorithmName() {return std::string(KEYS::StaticAlgorithmName()) + "/" + MessageEncodingMethod::StaticAlgorithmName();}
2236 
2237  /// implements PK_Decryptor interface
2239  /// implements PK_Encryptor interface
2241 };
2242 
2243 /// \brief Trapdoor Function (TF) Signature Scheme
2244 /// \tparam STANDARD standard
2245 /// \tparam H hash function
2246 /// \tparam KEYS keys used in the signature scheme
2247 /// \tparam ALG_INFO algorithm information
2248 template <class KEYS, class STANDARD, class H, class ALG_INFO>
2249 class TF_SS;
2250 
2251 template <class KEYS, class STANDARD, class H, class ALG_INFO = TF_SS<KEYS, STANDARD, H, int> >
2252 class TF_SS : public KEYS
2253 {
2254 public:
2255  /// see SignatureStandard for a list of standards
2256  typedef STANDARD Standard;
2259 
2260  static std::string CRYPTOPP_API StaticAlgorithmName() {return std::string(KEYS::StaticAlgorithmName()) + "/" + MessageEncodingMethod::StaticAlgorithmName() + "(" + H::StaticAlgorithmName() + ")";}
2261 
2262  /// implements PK_Signer interface
2264  /// implements PK_Verifier interface
2266 };
2267 
2268 /// \brief Discrete Log (DL) signature scheme
2269 /// \tparam KEYS keys used in the signature scheme
2270 /// \tparam SA signature algorithm
2271 /// \tparam MEM message encoding method
2272 /// \tparam H hash function
2273 /// \tparam ALG_INFO algorithm information
2274 template <class KEYS, class SA, class MEM, class H, class ALG_INFO>
2275 class DL_SS;
2276 
2277 template <class KEYS, class SA, class MEM, class H, class ALG_INFO = DL_SS<KEYS, SA, MEM, H, int> >
2278 class DL_SS : public KEYS
2279 {
2281 
2282 public:
2283  static std::string StaticAlgorithmName() {return SA::StaticAlgorithmName() + std::string("/EMSA1(") + H::StaticAlgorithmName() + ")";}
2284 
2285  /// implements PK_Signer interface
2287  /// implements PK_Verifier interface
2289 };
2290 
2291 /// \brief Discrete Log (DL) encryption scheme
2292 /// \tparam KEYS keys used in the encryption scheme
2293 /// \tparam AA key agreement algorithm
2294 /// \tparam DA key derivation algorithm
2295 /// \tparam EA encryption algorithm
2296 /// \tparam ALG_INFO algorithm information
2297 template <class KEYS, class AA, class DA, class EA, class ALG_INFO>
2298 class DL_ES : public KEYS
2299 {
2301 
2302 public:
2303  /// implements PK_Decryptor interface
2305  /// implements PK_Encryptor interface
2307 };
2308 
2309 NAMESPACE_END
2310 
2311 #if CRYPTOPP_MSC_VERSION
2312 # pragma warning(pop)
2313 #endif
2314 
2315 #endif
Integer ApplyRandomizedFunction(RandomNumberGenerator &rng, const Integer &x) const
Applies the trapdoor function.
Definition: pubkey.h:137
Standard names for retrieving values by name when working with NameValuePairs.
virtual const CryptoMaterial & GetMaterial() const =0
Retrieves a reference to CryptoMaterial.
Discrete Log (DL) key options.
Definition: pubkey.h:1853
Applies the trapdoor function, using random data if required.
Definition: pubkey.h:100
const Element & GetGenerator() const
Retrieves a reference to the group generator.
Definition: pubkey.h:2048
PK_FinalTemplate< DL_DecryptorImpl< SchemeOptions > > Decryptor
implements PK_Decryptor interface
Definition: pubkey.h:2304
virtual Element Exponentiate(const DL_GroupPrecomputation< Element > &group, const Integer &exponent) const =0
Exponentiates an element.
size_t SignatureLength() const
Provides the signature length.
Definition: pubkey.h:1505
Interface for asymmetric algorithms.
Definition: cryptlib.h:2444
virtual Integer GetCofactor() const
Retrieves the cofactor.
Definition: pubkey.h:884
Interface for message encoding method for public key signature schemes.
Definition: pubkey.h:413
Trapdoor Function (TF) encryption scheme.
Definition: pubkey.h:2223
Diffie-Hellman key agreement algorithm.
Definition: pubkey.h:2078
void SetPrivateExponent(const Integer &x)
Sets the private exponent.
Definition: pubkey.h:1264
const char * Pad()
bool
Definition: argnames.h:72
const DL_GroupPrecomputation< Element > & GetGroupPrecomputation() const
Retrieves the group precomputation.
Definition: pubkey.h:994
Restricts the instantiation of a class to one static object without locks.
Definition: misc.h:263
Discrete Log (DL) signer implementation.
Definition: pubkey.h:1958
DL_GroupPrecomputation interface.
Definition: eprecomp.h:19
void AssignFrom(const NameValuePairs &source)
Assign values to this object.
Definition: pubkey.h:1234
void DEREncode(BufferedTransformation &bt) const
Encode in DER format.
Definition: integer.cpp:3432
size_t BitsToBytes(size_t bitCount)
Returns the number of 8-bit bytes or octets required for the specified number of bits.
Definition: misc.h:850
bool IsProbabilistic() const
Determines if the scheme is probabilistic.
Definition: pubkey.h:1525
Interface for deterministic signers.
Definition: pubkey.h:1419
PK_FinalTemplate< TF_VerifierImpl< SchemeOptions > > Verifier
implements PK_Verifier interface
Definition: pubkey.h:2265
void InputSignature(PK_MessageAccumulator &messageAccumulator, const byte *signature, size_t signatureLength) const
Input signature into a message accumulator.
Definition: pubkey.h:1669
size_t MaxRecoverableLengthFromSignatureLength(size_t signatureLength) const
Provides the maximum recoverable length.
Definition: pubkey.h:1520
void DEREncodePrivateKey(BufferedTransformation &bt) const
encode privateKey part of privateKeyInfo, without the OCTET STRING header
Definition: pubkey.h:1269
PK_FinalTemplate< TF_EncryptorImpl< SchemeOptions > > Encryptor
implements PK_Encryptor interface
Definition: pubkey.h:2240
static Integer CRYPTOPP_API Gcd(const Integer &a, const Integer &n)
Calculate greatest common divisor.
Definition: integer.cpp:4425
Encodes and Decodes privateKeyInfo.
Definition: asn.h:421
Trapdoor Function (TF) Signer base class.
Definition: pubkey.h:511
void BERDecodePrivateKey(BufferedTransformation &bt, bool, size_t)
decode privateKey part of privateKeyInfo, without the OCTET STRING header
Definition: pubkey.h:1267
virtual void SetSubgroupGenerator(const Element &base)
Sets the subgroup generator.
Definition: pubkey.h:834
The base for trapdoor based cryptosystems.
Definition: pubkey.h:230
Interface for Discrete Log (DL) group parameters.
Definition: pubkey.h:753
Trapdoor Function (TF) base implementation.
Definition: pubkey.h:563
Trapdoor Function (TF) Signature Scheme base class.
Definition: pubkey.h:483
Discrete Log (DL) key base implementation.
Definition: pubkey.h:1182
Converts an enumeration to a type suitable for use as a template parameter.
Definition: cryptlib.h:135
bool GetThisObject(T &object) const
Get a copy of this object or subobject.
Definition: cryptlib.h:328
Interface for message encoding method for public key signature schemes.
Definition: pubkey.h:310
Trapdoor Function (TF) signature with external reference.
Definition: pubkey.h:619
Abstract base classes that provide a uniform interface to this library.
const DL_GroupParameters< Element > & GetAbstractGroupParameters() const
Retrieves abstract group parameters.
Definition: pubkey.h:1344
virtual Integer ConvertElementToInteger(const Element &element) const =0
Converts an element to an Integer.
void MakePublicKey(DL_PublicKey< T > &pub) const
Initializes a public key from this key.
Definition: pubkey.h:1116
void GenerateAndMask(HashTransformation &hash, byte *output, size_t outputLength, const byte *input, size_t inputLength, bool mask=true) const
Generate and apply mask.
Definition: pubkey.h:718
virtual unsigned int PrivateKeyLength() const =0
Provides the size of the private key.
Message encoding method for public key encryption.
Definition: pubkey.h:208
Interface for key derivation algorithms used in DL cryptosystems.
Definition: pubkey.h:1448
virtual void Sign(const DL_GroupParameters< T > &params, const Integer &privateKey, const Integer &k, const Integer &e, Integer &r, Integer &s) const =0
Sign a message using a private key.
Classes for automatic resource management.
void SavePrecomputation(BufferedTransformation &storedPrecomputation) const
Save precomputation for later use.
Definition: pubkey.h:1255
Library configuration file.
Interface for Discrete Log (DL) private keys.
Definition: pubkey.h:1105
virtual Integer GetGroupOrder() const
Retrieves the order of the group.
Definition: pubkey.h:879
Ring of congruence classes modulo n.
Definition: modarith.h:38
Interface for random number generators.
Definition: cryptlib.h:1383
Common C++ header files.
bool Validate(RandomNumberGenerator &rng, unsigned int level) const
Check this object for errors.
Definition: pubkey.h:1216
void Randomize(RandomNumberGenerator &rng, size_t bitCount)
Set this Integer to random integer.
Definition: integer.cpp:3503
virtual Integer MaxPreimage() const
Returns the maximum size of a message before the trapdoor function is applied bound to a public key...
Definition: pubkey.h:88
bool Validate(RandomNumberGenerator &rng, unsigned int level) const
Check this object for errors.
Definition: pubkey.h:1306
Discrete Log (DL) base interface.
Definition: pubkey.h:1476
void New(size_type newSize)
Change size without preserving contents.
Definition: secblock.h:965
Trapdoor function cryptosystems decryption base class.
Definition: pubkey.h:283
Discrete Log (DL) scheme options.
Definition: pubkey.h:1842
bool IsProbabilistic() const
Determines whether an encoding method requires a random number generator.
Definition: pubkey.h:326
bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
Get a named value.
Definition: pubkey.h:781
Discrete Log (DL) encryption scheme.
Definition: pubkey.h:2298
SecBlock<byte> typedef.
Definition: secblock.h:1058
Discrete Log (DL) crypto scheme options.
Definition: pubkey.h:1881
void GeneratePrivateKey(RandomNumberGenerator &rng, byte *privateKey) const
Generate private key in this domain.
Definition: pubkey.h:2012
Classes for performing mathematics over different fields.
unsigned int AgreedValueLength() const
Provides the size of the agreed value.
Definition: pubkey.h:2008
STANDARD Standard
see SignatureStandard for a list of standards
Definition: pubkey.h:2256
Interface for buffered transformations.
Definition: cryptlib.h:1598
void RawSign(const Integer &k, const Integer &e, Integer &r, Integer &s) const
Testing interface.
Definition: pubkey.h:1564
EMSA2 padding method.
Definition: emsa2.h:71
Provides range for plaintext and ciphertext lengths.
Definition: pubkey.h:72
Interface for private keys.
Definition: cryptlib.h:2430
virtual Element ExponentiateBase(const Integer &exponent) const
Exponentiates the base.
Definition: pubkey.h:839
bool SupportsPrecomputation() const
Determines whether the object supports precomputation.
Definition: pubkey.h:1323
const DL_FixedBasePrecomputation< Element > & GetBasePrecomputation() const
Retrieves the group precomputation.
Definition: pubkey.h:998
static const Integer &CRYPTOPP_API One()
Integer representing 1.
Definition: integer.cpp:4877
Interface for Discrete Log (DL) public keys.
Definition: pubkey.h:1028
Discret Log (DL) Verifier base class.
Definition: pubkey.h:1664
P1363 key derivation function.
Definition: pubkey.h:729
Base class for public key signature standard classes.
Definition: pubkey.h:2216
const char * PrivateExponent()
Integer.
Definition: argnames.h:35
CRYPTOPP_DLL RandomNumberGenerator &CRYPTOPP_API NullRNG()
Random Number Generator that does not produce random numbers.
Definition: cryptlib.cpp:400
CryptoParameters & AccessCryptoParameters()
Retrieves a reference to Crypto Parameters.
Definition: pubkey.h:2007
Pointer that overloads operator ->
Definition: smartptr.h:36
void Precompute(unsigned int precomputationStorage=16)
Perform precomputation.
Definition: pubkey.h:1325
virtual void SetPublicElement(const Element &y)
Sets the public element.
Definition: pubkey.h:1063
Discrete Log (DL) signature scheme.
Definition: pubkey.h:2275
unsigned int ByteCount() const
Determines the number of bytes required to represent the Integer.
Definition: integer.cpp:3336
virtual bool IsRandomized() const
Determines if the encryption algorithm is randomized.
Definition: pubkey.h:117
Base class for a Discrete Log (DL) key.
Definition: pubkey.h:1013
Interface for domains of simple key agreement protocols.
Definition: cryptlib.h:2897
Trapdoor Function (TF) encryptor options.
Definition: pubkey.h:664
Applies the inverse of the trapdoor function.
Definition: pubkey.h:178
Returns a decoding results.
Definition: cryptlib.h:255
Trapdoor Function (TF) decryptor options.
Definition: pubkey.h:657
Uses encapsulation to hide an object in derived classes.
Definition: misc.h:189
Discrete Log (DL) private key base implementation.
Definition: pubkey.h:1208
void GeneratePublicKey(RandomNumberGenerator &rng, const byte *privateKey, byte *publicKey) const
Generate a public key from a private key in this domain.
Definition: pubkey.h:2018
virtual const DL_GroupParameters< T > & GetAbstractGroupParameters() const =0
Retrieves abstract group parameters.
virtual const DL_FixedBasePrecomputation< T > & GetPublicPrecomputation() const =0
Accesses the public precomputation.
void Encrypt(RandomNumberGenerator &rng, const byte *plaintext, size_t plaintextLength, byte *ciphertext, const NameValuePairs &parameters=g_nullNameValuePairs) const
Encrypt a byte string.
Definition: pubkey.h:1815
DL_FixedBasePrecomputation< Element > & AccessBasePrecomputation()
Retrieves the group precomputation.
Definition: pubkey.h:1002
P1363 mask generation function.
Definition: pubkey.h:714
void LoadPrecomputation(BufferedTransformation &storedPrecomputation)
Retrieve previously saved precomputation.
Definition: pubkey.h:1252
Cofactor multiplication compatible with ordinary Diffie-Hellman.
Definition: pubkey.h:2066
Trapdoor Function (TF) encryptor options.
Definition: pubkey.h:678
PK_FinalTemplate< TF_SignerImpl< SchemeOptions > > Signer
implements PK_Signer interface
Definition: pubkey.h:2263
A method was called which was not implemented.
Definition: cryptlib.h:223
bool VerifyAndRestart(PK_MessageAccumulator &messageAccumulator) const
Check whether messageAccumulator contains a valid signature and message, and restart messageAccumulat...
Definition: pubkey.h:1683
bool RecoverablePartFirst() const
Determines if the scheme allows recoverable part first.
Definition: pubkey.h:1535
Trapdoor Function (TF) signature scheme options.
Definition: pubkey.h:640
No cofactor multiplication applied.
Definition: pubkey.h:2062
Interface for Elgamal-like signature algorithms.
Definition: pubkey.h:1366
Discrete Log (DL) signature scheme signer base implementation.
Definition: pubkey.h:1554
Interface for message encoding method for public key signature schemes.
Definition: pubkey.h:391
virtual bool Verify(const DL_GroupParameters< T > &params, const DL_PublicKey< T > &publicKey, const Integer &e, const Integer &r, const Integer &s) const =0
Verify a message using a public key.
virtual size_t RLen(const DL_GroupParameters< T > &params) const
Retrieve R length.
Definition: pubkey.h:1402
PK_MessageAccumulator * NewSignatureAccumulator(RandomNumberGenerator &rng) const
Create a new HashTransformation to accumulate the message to be signed.
Definition: pubkey.h:1961
virtual const DL_FixedBasePrecomputation< Element > & GetBasePrecomputation() const =0
Retrieves the group precomputation.
bool IsRandomized() const
Determines if the encryption algorithm is randomized.
Definition: pubkey.h:139
Interface for message encoding method for public key signature schemes.
Definition: pubkey.h:451
virtual void SimultaneousExponentiate(Element *results, const Element &base, const Integer *exponents, unsigned int exponentsCount) const =0
Exponentiates a base to multiple exponents.
void Assign(const T *ptr, size_type len)
Set contents and size from an array.
Definition: secblock.h:841
Base class for public key encryption standard classes.
Definition: pubkey.h:2211
virtual Integer MaxImage() const
Returns the maximum size of a message after the trapdoor function is applied bound to a public key...
Definition: pubkey.h:92
virtual const Element & GetSubgroupGenerator() const
Retrieves the subgroup generator.
Definition: pubkey.h:829
Discrete Log (DL) object implementation.
Definition: pubkey.h:1933
bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
Get a named value.
Definition: pubkey.h:1229
bool AllowNonrecoverablePart() const
Determines if the scheme has non-recoverable part.
Definition: pubkey.h:1530
void LoadPrecomputation(BufferedTransformation &storedPrecomputation)
Retrieve previously saved precomputation.
Definition: pubkey.h:1331
Multiple precision integer with arithmetic operations.
Definition: integer.h:49
const DL_FixedBasePrecomputation< Element > & GetPublicPrecomputation() const
Accesses the public precomputation.
Definition: pubkey.h:1348
Discrete Log (DL) verifier implementation.
Definition: pubkey.h:1972
void Precompute(unsigned int precomputationStorage=16)
Perform precomputation.
Definition: pubkey.h:1249
T1 SaturatingSubtract(const T1 &a, const T2 &b)
Performs a saturating subtract clamped at 0.
Definition: misc.h:1004
Discrete Log (DL) signature scheme base implementation.
Definition: pubkey.h:1497
Trapdoor function cryptosystems encryption base class.
Definition: pubkey.h:292
Discrete Log (DL) base object implementation.
Definition: pubkey.h:1893
Integer CalculateRandomizedInverse(RandomNumberGenerator &rng, const Integer &x) const
Applies the inverse of the trapdoor function.
Definition: pubkey.h:190
const NameValuePairs & g_nullNameValuePairs
An empty set of name-value pairs.
Definition: cryptlib.h:500
const char * SubgroupGenerator()
Integer, ECP::Point, or EC2N::Point.
Definition: argnames.h:39
Applies the trapdoor function.
Definition: pubkey.h:125
virtual bool CanIncorporateEntropy() const
Determines if a generator can accept additional entropy.
Definition: cryptlib.h:1404
bool IsRandomized() const
Determines if the decryption algorithm is randomized.
Definition: pubkey.h:196
unsigned int PublicKeyLength() const
Provides the size of the public key.
Definition: pubkey.h:2010
Discrete Log (DL) cryptosystem base implementation.
Definition: pubkey.h:1737
virtual Element DecodeElement(const byte *encoded, bool checkForGroupMembership) const =0
Decodes the element.
void Precompute(unsigned int precomputationStorage=16)
Perform precomputation.
Definition: pubkey.h:802
Mask generation function interface.
Definition: pubkey.h:685
bool Agree(byte *agreedValue, const byte *privateKey, const byte *otherPublicKey, bool validateOtherPublicKey=true) const
Derive agreed value.
Definition: pubkey.h:2027
PK_FinalTemplate< DL_EncryptorImpl< SchemeOptions > > Encryptor
implements PK_Encryptor interface
Definition: pubkey.h:2306
void AssignFrom(const NameValuePairs &source)
Initialize or reinitialize this key.
Definition: pubkey.h:1140
Public key trapdoor function default implementation.
Definition: pubkey.h:249
Trapdoor Function (TF) encryptor options.
Definition: pubkey.h:671
virtual Element ExponentiatePublicElement(const Integer &exponent) const
Exponentiates this element.
Definition: pubkey.h:1068
bool Validate(RandomNumberGenerator &rng, unsigned int level) const
Check this object for errors.
Definition: pubkey.h:765
Exception thrown when an invalid group element is encountered.
Definition: pubkey.h:743
Trapdoor Function (TF) signature scheme options.
Definition: pubkey.h:553
void AssignFrom(const NameValuePairs &source)
Initialize or reinitialize this key.
Definition: pubkey.h:1162
#define CRYPTOPP_ASSERT(exp)
Debugging and diagnostic assertion.
Definition: trap.h:69
virtual bool ValidateElement(unsigned int level, const Element &element, const DL_FixedBasePrecomputation< Element > *precomp) const =0
Check the element for errors.
CRYPTOPP_DLL bool CRYPTOPP_API FIPS_140_2_ComplianceEnabled()
Determines whether the library provides FIPS validated cryptography.
Definition: fips140.cpp:24
DecodingResult Decrypt(RandomNumberGenerator &rng, const byte *ciphertext, size_t ciphertextLength, byte *plaintext, const NameValuePairs &parameters=g_nullNameValuePairs) const
Decrypt a byte string.
Definition: pubkey.h:1775
DL_FixedBasePrecomputation interface.
Definition: eprecomp.h:60
virtual Integer GenerateRandom(const Integer &x, const Integer &q, const Integer &e) const =0
Generate k.
void Update(const byte *input, size_t length)
Updates a hash with additional input.
Definition: pubkey.h:458
Implementation of BufferedTransformation&#39;s attachment interface.
DL_GroupParameters< Element > & AccessAbstractGroupParameters()
Retrieves abstract group parameters.
Definition: pubkey.h:1345
DL_FixedBasePrecomputation< Element > & AccessPublicPrecomputation()
Accesses the public precomputation.
Definition: pubkey.h:1349
Interface for accumulating messages to be signed or verified.
Definition: cryptlib.h:2745
Interface for key agreement algorithms.
Definition: cryptlib.h:2522
Discrete Log (DL) encryptor base implementation.
Definition: pubkey.h:1808
virtual Element CascadeExponentiateBaseAndPublicElement(const Integer &baseExp, const Integer &publicExp) const
Exponentiates an element.
Definition: pubkey.h:1080
Classes for precomputation in a group.
void Encode(byte *output, size_t outputLen, Signedness sign=UNSIGNED) const
Encode in big-endian format.
Definition: integer.cpp:3410
void AssignFrom(const NameValuePairs &source)
Assign values to this object.
Definition: pubkey.h:1318
Trapdoor Function (TF) Verifier base class.
Definition: pubkey.h:521
virtual const Integer & GetPrivateExponent() const =0
Retrieves the private exponent.
PK_FinalTemplate< DL_SignerImpl< SchemeOptions > > Signer
implements PK_Signer interface
Definition: pubkey.h:2286
virtual const DL_GroupPrecomputation< Element > & GetGroupPrecomputation() const =0
Retrieves the group precomputation.
bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
Get a named value.
Definition: pubkey.h:1313
Classes and functions for the FIPS 140-2 validated library.
virtual Integer RecoverPresignature(const DL_GroupParameters< T > &params, const DL_PublicKey< T > &publicKey, const Integer &r, const Integer &s) const
Recover a Presignature.
Definition: pubkey.h:1393
size_t MaxRecoverableLength() const
Provides the maximum recoverable length.
Definition: pubkey.h:1513
PK_FinalTemplate< TF_DecryptorImpl< SchemeOptions > > Decryptor
implements PK_Decryptor interface
Definition: pubkey.h:2238
Interface for hash functions and data processing part of MACs.
Definition: cryptlib.h:1084
Interface for crypto material, such as public and private keys, and crypto parameters.
Definition: cryptlib.h:2283
virtual void EncodeElement(bool reversible, const Element &element, byte *encoded) const =0
Encodes the element.
CofactorMultiplicationOption
Methods for avoiding "Small-Subgroup" attacks on Diffie-Hellman Key Agreement.
Definition: pubkey.h:2060
unsigned int PrivateKeyLength() const
Provides the size of the private key.
Definition: pubkey.h:2009
DL_GroupParameters< Element > & AccessAbstractGroupParameters()
Retrieves abstract group parameters.
Definition: pubkey.h:1260
virtual unsigned int GetEncodedElementSize(bool reversible) const =0
Retrieves the encoded element&#39;s size.
void Decode(const byte *input, size_t inputLen, Signedness sign=UNSIGNED)
Decode from big-endian byte array.
Definition: integer.cpp:3354
Discrete Log (DL) encryptor implementation.
Definition: pubkey.h:1984
bool SupportsPrecomputation() const
Determines whether the object supports precomputation.
Definition: pubkey.h:792
Discrete Log (DL) public key base implementation.
Definition: pubkey.h:1298
Multiple precision integer with arithmetic operations.
Cofactor multiplication incompatible with ordinary Diffie-Hellman.
Definition: pubkey.h:2070
static const Integer &CRYPTOPP_API Zero()
Integer representing 0.
Definition: integer.cpp:4865
Interface for crypto prameters.
Definition: cryptlib.h:2435
bool GetThisPointer(T *&ptr) const
Get a pointer to this object.
Definition: cryptlib.h:337
virtual Integer GetMaxExponent() const =0
Retrieves the maximum exponent for the group.
Discrete Log (DL) decryptor implementation.
Definition: pubkey.h:1991
void InputRecoverableMessage(PK_MessageAccumulator &messageAccumulator, const byte *recoverableMessage, size_t recoverableMessageLength) const
Input a recoverable message to an accumulator.
Definition: pubkey.h:1574
void BERDecode(const byte *input, size_t inputLen)
Decode from BER format.
Definition: integer.cpp:3439
size_t SignAndRestart(RandomNumberGenerator &rng, PK_MessageAccumulator &messageAccumulator, byte *signature, bool restart) const
Sign and restart messageAccumulator.
Definition: pubkey.h:1584
Class file for performing modular arithmetic.
Interface for public keys.
Definition: cryptlib.h:2425
Crypto++ library namespace.
PK_MessageAccumulator * NewVerificationAccumulator() const
Create a new HashTransformation to accumulate the message to be verified.
Definition: pubkey.h:1975
Applies the inverse of the trapdoor function, using random data if required.
Definition: pubkey.h:154
virtual const Element & GetPublicElement() const
Retrieves the public element.
Definition: pubkey.h:1059
Interface for symmetric encryption algorithms used in DL cryptosystems.
Definition: pubkey.h:1459
bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
Get a named value.
Definition: pubkey.h:1132
Base implementation of Discrete Log (DL) group parameters.
Definition: pubkey.h:983
void GenerateRandom(RandomNumberGenerator &rng, const NameValuePairs &params)
Generate a random key or crypto parameters.
Definition: pubkey.h:1239
virtual bool IsRandomized() const
Determines if the decryption algorithm is randomized.
Definition: pubkey.h:170
Encodes and decodes subjectPublicKeyInfo.
Definition: asn.h:398
Trapdoor function cryptosystem base class.
Definition: pubkey.h:267
virtual DL_GroupParameters< T > & AccessAbstractGroupParameters()=0
Retrieves abstract group parameters.
Input data was received that did not conform to expected format.
Definition: cryptlib.h:209
Trapdoor Function (TF) scheme options.
Definition: pubkey.h:538
void LoadPrecomputation(BufferedTransformation &storedPrecomputation)
Retrieve previously saved precomputation.
Definition: pubkey.h:811
bool SupportsPrecomputation() const
Determines whether the object supports precomputation.
Definition: pubkey.h:1247
PK_FinalTemplate< DL_VerifierImpl< SchemeOptions > > Verifier
implements PK_Verifier interface
Definition: pubkey.h:2288
Discrete Log (DL) signature scheme options.
Definition: pubkey.h:1867
virtual Element ExponentiateElement(const Element &base, const Integer &exponent) const
Exponentiates an element.
Definition: pubkey.h:849
Object Identifier.
Definition: asn.h:166
Interface for message encoding method for public key signature schemes.
Definition: pubkey.h:402
virtual bool IsDeterministic() const
Signature scheme flag.
Definition: pubkey.h:1413
const char * SubgroupOrder()
Integer.
Definition: argnames.h:37
Discrete Log (DL) decryptor base implementation.
Definition: pubkey.h:1768
Interface for message encoding method for public key signature schemes.
Definition: pubkey.h:473
const char * PublicElement()
Integer.
Definition: argnames.h:36
Interface for DL key agreement algorithms.
Definition: pubkey.h:1434
DecodingResult RecoverAndRestart(byte *recoveredMessage, PK_MessageAccumulator &messageAccumulator) const
Recover a message from its signature.
Definition: pubkey.h:1703
const Integer & GetPrivateExponent() const
Retrieves the private exponent.
Definition: pubkey.h:1263
size_type size() const
Provides the count of elements in the SecBlock.
Definition: secblock.h:797
Discrete Log (DL) simple key agreement base implementation.
Definition: pubkey.h:2000
bool GetVoidValue(const char *name, const std::type_info &valueType, void *pValue) const
Get a named value.
Definition: pubkey.h:1047
virtual bool IsIdentity(const Element &element) const =0
Determines if an element is an identity.
virtual size_t SLen(const DL_GroupParameters< T > &params) const
Retrieve S length.
Definition: pubkey.h:1407
STANDARD Standard
see EncryptionStandard for a list of standards
Definition: pubkey.h:2232
virtual void IncorporateEntropy(const byte *input, size_t length)
Update RNG state with additional unpredictable values.
Definition: cryptlib.h:1396
void SavePrecomputation(BufferedTransformation &storedPrecomputation) const
Save precomputation for later use.
Definition: pubkey.h:821
void SavePrecomputation(BufferedTransformation &storedPrecomputation) const
Save precomputation for later use.
Definition: pubkey.h:1337
Interface for message encoding method for public key signature schemes.
Definition: pubkey.h:425
const DL_GroupParameters< Element > & GetAbstractGroupParameters() const
Retrieves abstract group parameters.
Definition: pubkey.h:1259
Interface for retrieving values given their names.
Definition: cryptlib.h:293
Template implementing constructors for public key algorithm classes.
Definition: pubkey.h:2134
Trapdoor Function (TF) Signature Scheme.
Definition: pubkey.h:2249
virtual const Integer & GetSubgroupOrder() const =0
Retrieves the subgroup order.
Base class information.
Definition: simple.h:36