Crypto++  5.6.5
Free C++ class library of cryptographic schemes
pkcspad.cpp
1 // pkcspad.cpp - originally written and placed in the public domain by Wei Dai
2 
3 #include "pch.h"
4 
5 #ifndef CRYPTOPP_PKCSPAD_CPP // SunCC workaround: compiler could cause this file to be included twice
6 #define CRYPTOPP_PKCSPAD_CPP
7 
8 #include "pkcspad.h"
9 #include "emsa2.h"
10 #include "hashfwd.h"
11 #include "misc.h"
12 #include "trap.h"
13 
14 NAMESPACE_BEGIN(CryptoPP)
15 
16 // Typedef/cast change due to Clang, http://github.com/weidai11/cryptopp/issues/300
17 template<> const byte PKCS_DigestDecoration<Weak1::MD2>::decoration[] = {0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,0x48,0x86,0xf7,0x0d,0x02,0x02,0x05,0x00,0x04,0x10};
18 template<> const unsigned int PKCS_DigestDecoration<Weak1::MD2>::length = (unsigned int)sizeof(PKCS_DigestDecoration<Weak1::MD2>::decoration);
19 
20 template<> const byte PKCS_DigestDecoration<Weak1::MD5>::decoration[] = {0x30,0x20,0x30,0x0c,0x06,0x08,0x2a,0x86,0x48,0x86,0xf7,0x0d,0x02,0x05,0x05,0x00,0x04,0x10};
21 template<> const unsigned int PKCS_DigestDecoration<Weak1::MD5>::length = (unsigned int)sizeof(PKCS_DigestDecoration<Weak1::MD5>::decoration);
22 
23 template<> const byte PKCS_DigestDecoration<RIPEMD160>::decoration[] = {0x30,0x21,0x30,0x09,0x06,0x05,0x2b,0x24,0x03,0x02,0x01,0x05,0x00,0x04,0x14};
24 template<> const unsigned int PKCS_DigestDecoration<RIPEMD160>::length = (unsigned int)sizeof(PKCS_DigestDecoration<RIPEMD160>::decoration);
25 
26 template<> const byte PKCS_DigestDecoration<Tiger>::decoration[] = {0x30,0x29,0x30,0x0D,0x06,0x09,0x2B,0x06,0x01,0x04,0x01,0xDA,0x47,0x0C,0x02,0x05,0x00,0x04,0x18};
27 template<> const unsigned int PKCS_DigestDecoration<Tiger>::length = (unsigned int)sizeof(PKCS_DigestDecoration<Tiger>::decoration);
28 
29 // Inclusion based on DLL due to Clang, http://github.com/weidai11/cryptopp/issues/300
30 #ifndef CRYPTOPP_IS_DLL
31 template<> const byte PKCS_DigestDecoration<SHA1>::decoration[] = {0x30,0x21,0x30,0x09,0x06,0x05,0x2B,0x0E,0x03,0x02,0x1A,0x05,0x00,0x04,0x14};
32 template<> const unsigned int PKCS_DigestDecoration<SHA1>::length = (unsigned int)sizeof(PKCS_DigestDecoration<SHA1>::decoration);
33 
34 template<> const byte PKCS_DigestDecoration<SHA224>::decoration[] = {0x30,0x2d,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x04,0x05,0x00,0x04,0x1c};
35 template<> const unsigned int PKCS_DigestDecoration<SHA224>::length = (unsigned int)sizeof(PKCS_DigestDecoration<SHA224>::decoration);
36 
37 template<> const byte PKCS_DigestDecoration<SHA256>::decoration[] = {0x30,0x31,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x01,0x05,0x00,0x04,0x20};
38 template<> const unsigned int PKCS_DigestDecoration<SHA256>::length = (unsigned int)sizeof(PKCS_DigestDecoration<SHA256>::decoration);
39 
40 template<> const byte PKCS_DigestDecoration<SHA384>::decoration[] = {0x30,0x41,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,0x01,0x65,0x03,0x04,0x02,0x02,0x05,0x00,0x04,0x30};
41 template<> const unsigned int PKCS_DigestDecoration<SHA384>::length = (unsigned int)sizeof(PKCS_DigestDecoration<SHA384>::decoration);
42 
43 template<> const byte PKCS_DigestDecoration<SHA512>::decoration[] = {0x30,0x51,0x30,0x0d, 0x06,0x09,0x60,0x86, 0x48,0x01,0x65,0x03, 0x04,0x02,0x03,0x05, 0x00,0x04,0x40};
44 template<> const unsigned int PKCS_DigestDecoration<SHA512>::length = (unsigned int)sizeof(PKCS_DigestDecoration<SHA512>::decoration);
45 
46 // http://github.com/weidai11/cryptopp/issues/517. OIDs and encoded prefixes found at
47 // http://www.ietf.org/archive/id/draft-jivsov-openpgp-sha3-01.txt
48 template<> const byte PKCS_DigestDecoration<SHA3_256>::decoration[] = {0x30,0x31,0x30,0x0d, 0x06,0x09,0x60,0x86, 0x48,0x01,0x65,0x03, 0x04,0x02,0x08,0x05, 0x00,0x04,0x20};
49 template<> const unsigned int PKCS_DigestDecoration<SHA3_256>::length = (unsigned int)sizeof(PKCS_DigestDecoration<SHA3_256>::decoration);
50 
51 template<> const byte PKCS_DigestDecoration<SHA3_384>::decoration[] = {0x30,0x41,0x30,0x0d, 0x06,0x09,0x60,0x86, 0x48,0x01,0x65,0x03, 0x04,0x02,0x09,0x05, 0x00,0x04,0x30};
52 template<> const unsigned int PKCS_DigestDecoration<SHA3_384>::length = (unsigned int)sizeof(PKCS_DigestDecoration<SHA3_384>::decoration);
53 
54 template<> const byte PKCS_DigestDecoration<SHA3_512>::decoration[] = {0x30,0x51,0x30,0x0d, 0x06,0x09,0x60,0x86, 0x48,0x01,0x65,0x03, 0x04,0x02,0x0a,0x05, 0x00,0x04,0x40};
55 template<> const unsigned int PKCS_DigestDecoration<SHA3_512>::length = (unsigned int)sizeof(PKCS_DigestDecoration<SHA3_512>::decoration);
56 #endif
57 
58 size_t PKCS_EncryptionPaddingScheme::MaxUnpaddedLength(size_t paddedLength) const
59 {
60  return SaturatingSubtract(paddedLength/8, 10U);
61 }
62 
63 void PKCS_EncryptionPaddingScheme::Pad(RandomNumberGenerator& rng, const byte *input, size_t inputLen, byte *pkcsBlock, size_t pkcsBlockLen, const NameValuePairs& parameters) const
64 {
65  CRYPTOPP_UNUSED(parameters);
66  CRYPTOPP_ASSERT (inputLen <= MaxUnpaddedLength(pkcsBlockLen)); // this should be checked by caller
67 
68  // convert from bit length to byte length
69  if (pkcsBlockLen % 8 != 0)
70  {
71  pkcsBlock[0] = 0;
72  pkcsBlock++;
73  }
74  pkcsBlockLen /= 8;
75 
76  pkcsBlock[0] = 2; // block type 2
77 
78  // pad with non-zero random bytes
79  for (unsigned i = 1; i < pkcsBlockLen-inputLen-1; i++)
80  pkcsBlock[i] = (byte)rng.GenerateWord32(1, 0xff);
81 
82  pkcsBlock[pkcsBlockLen-inputLen-1] = 0; // separator
83  memcpy(pkcsBlock+pkcsBlockLen-inputLen, input, inputLen);
84 }
85 
86 DecodingResult PKCS_EncryptionPaddingScheme::Unpad(const byte *pkcsBlock, size_t pkcsBlockLen, byte *output, const NameValuePairs& parameters) const
87 {
88  CRYPTOPP_UNUSED(parameters);
89  bool invalid = false;
90  size_t maxOutputLen = MaxUnpaddedLength(pkcsBlockLen);
91 
92  // convert from bit length to byte length
93  if (pkcsBlockLen % 8 != 0)
94  {
95  invalid = (pkcsBlock[0] != 0) || invalid;
96  pkcsBlock++;
97  }
98  pkcsBlockLen /= 8;
99 
100  // Require block type 2.
101  invalid = (pkcsBlock[0] != 2) || invalid;
102 
103  // skip past the padding until we find the separator
104  size_t i=1;
105  while (i<pkcsBlockLen && pkcsBlock[i++]) { // null body
106  }
107  CRYPTOPP_ASSERT(i==pkcsBlockLen || pkcsBlock[i-1]==0);
108 
109  size_t outputLen = pkcsBlockLen - i;
110  invalid = (outputLen > maxOutputLen) || invalid;
111 
112  if (invalid)
113  return DecodingResult();
114 
115  memcpy (output, pkcsBlock+i, outputLen);
116  return DecodingResult(outputLen);
117 }
118 
119 // ********************************************************
120 
121 #ifndef CRYPTOPP_IMPORTS
122 
123 void PKCS1v15_SignatureMessageEncodingMethod::ComputeMessageRepresentative(RandomNumberGenerator &rng,
124  const byte *recoverableMessage, size_t recoverableMessageLength,
125  HashTransformation &hash, HashIdentifier hashIdentifier, bool messageEmpty,
126  byte *representative, size_t representativeBitLength) const
127 {
128  CRYPTOPP_UNUSED(rng), CRYPTOPP_UNUSED(recoverableMessage), CRYPTOPP_UNUSED(recoverableMessageLength);
129  CRYPTOPP_UNUSED(messageEmpty), CRYPTOPP_UNUSED(hashIdentifier);
130  CRYPTOPP_ASSERT(representativeBitLength >= MinRepresentativeBitLength(hashIdentifier.second, hash.DigestSize()));
131 
132  size_t pkcsBlockLen = representativeBitLength;
133  // convert from bit length to byte length
134  if (pkcsBlockLen % 8 != 0)
135  {
136  representative[0] = 0;
137  representative++;
138  }
139  pkcsBlockLen /= 8;
140 
141  representative[0] = 1; // block type 1
142 
143  unsigned int digestSize = hash.DigestSize();
144  byte *pPadding = representative + 1;
145  byte *pDigest = representative + pkcsBlockLen - digestSize;
146  byte *pHashId = pDigest - hashIdentifier.second;
147  byte *pSeparator = pHashId - 1;
148 
149  // pad with 0xff
150  memset(pPadding, 0xff, pSeparator-pPadding);
151  *pSeparator = 0;
152  memcpy(pHashId, hashIdentifier.first, hashIdentifier.second);
153  hash.Final(pDigest);
154 }
155 
156 #endif
157 
158 NAMESPACE_END
159 
160 #endif
Utility functions for the Crypto++ library.
Forward declarations for hash functions used in signature encoding methods.
Classes and functions for various padding schemes used in public key algorithms.
virtual word32 GenerateWord32(word32 min=0, word32 max=0xffffffffUL)
Generate a random 32 bit word in the range min to max, inclusive.
Definition: cryptlib.cpp:281
Interface for random number generators.
Definition: cryptlib.h:1327
Returns a decoding results.
Definition: cryptlib.h:253
Classes for PKCS padding schemes.
T1 SaturatingSubtract(const T1 &a, const T2 &b)
Performs a saturating subtract clamped at 0.
Definition: misc.h:886
#define CRYPTOPP_ASSERT(exp)
Debugging and diagnostic assertion.
Definition: trap.h:60
virtual unsigned int DigestSize() const =0
Provides the digest size of the hash.
Debugging and diagnostic assertions.
Interface for hash functions and data processing part of MACs.
Definition: cryptlib.h:1065
PKCS #1 decoration data structure.
Definition: pkcspad.h:34
size_t MaxUnpaddedLength(size_t paddedLength) const
max size of unpadded message in bytes, given max size of padded message in bits (1 less than size of ...
Definition: pkcspad.cpp:58
Crypto++ library namespace.
virtual void Final(byte *digest)
Computes the hash of the current message.
Definition: cryptlib.h:1095
Interface for retrieving values given their names.
Definition: cryptlib.h:291