1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
|
void hmac_sha256(const byte *Key,size_t KeyLength,const byte *Data,
size_t DataLength,byte *ResDigest)
{
const size_t Sha256BlockSize=64; // As defined in RFC 4868.
byte KeyHash[SHA256_DIGEST_SIZE];
if (KeyLength > Sha256BlockSize) // Convert longer keys to key hash.
{
sha256_context KCtx;
sha256_init(&KCtx);
sha256_process(&KCtx, Key, KeyLength);
sha256_done(&KCtx, KeyHash);
Key = KeyHash;
KeyLength = SHA256_DIGEST_SIZE;
}
byte KeyBuf[Sha256BlockSize]; // Store the padded key here.
for (size_t I = 0; I < KeyLength; I++) // Use 0x36 padding for inner digest.
KeyBuf[I] = Key[I] ^ 0x36;
for (size_t I = KeyLength; I < Sha256BlockSize; I++)
KeyBuf[I] = 0x36;
sha256_context ICtx;
sha256_init(&ICtx);
sha256_process(&ICtx, KeyBuf, Sha256BlockSize); // Hash padded key.
sha256_process(&ICtx, Data, DataLength); // Hash data.
byte IDig[SHA256_DIGEST_SIZE]; // Internal digest for padded key and data.
sha256_done(&ICtx, IDig);
sha256_context RCtx;
sha256_init(&RCtx);
for (size_t I = 0; I < KeyLength; I++) // Use 0x5c for outer key padding.
KeyBuf[I] = Key[I] ^ 0x5c;
for (size_t I = KeyLength; I < Sha256BlockSize; I++)
KeyBuf[I] = 0x5c;
sha256_process(&RCtx, KeyBuf, Sha256BlockSize); // Hash padded key.
sha256_process(&RCtx, IDig, SHA256_DIGEST_SIZE); // Hash internal digest.
sha256_done(&RCtx, ResDigest);
}
// PBKDF2 for 32 byte key length. We generate the key for specified number
// of iteration count also as two supplementary values (key for checksums
// and password verification) for iterations+16 and iterations+32.
void pbkdf2(const byte *Pwd, size_t PwdLength,
const byte *Salt, size_t SaltLength,
byte *Key, byte *V1, byte *V2, uint Count)
{
const size_t MaxSalt=64;
byte SaltData[MaxSalt+4];
memcpy(SaltData, Salt, Min(SaltLength,MaxSalt));
SaltData[SaltLength + 0] = 0; // Salt concatenated to 1.
SaltData[SaltLength + 1] = 0;
SaltData[SaltLength + 2] = 0;
SaltData[SaltLength + 3] = 1;
// First iteration: HMAC of password, salt and block index (1).
byte U1[SHA256_DIGEST_SIZE];
hmac_sha256(Pwd, PwdLength, SaltData, SaltLength + 4, U1);
byte Fn[SHA256_DIGEST_SIZE]; // Current function value.
memcpy(Fn, U1, sizeof(Fn)); // Function at first iteration.
uint CurCount[] = { Count-1, 16, 16 };
byte *CurValue[] = { Key , V1, V2 };
byte U2[SHA256_DIGEST_SIZE];
for (uint I = 0; I < 3; I++) // For output key and 2 supplementary values.
{
for (uint J = 0; J < CurCount[I]; J++)
{
hmac_sha256(Pwd, PwdLength, U1, sizeof(U1), U2); // U2 = PRF (P, U1).
memcpy(U1, U2, sizeof(U1));
for (uint K = 0; K < sizeof(Fn); K++) // Function ^= U.
Fn[K] ^= U1[K];
}
memcpy(CurValue[I], Fn, SHA256_DIGEST_SIZE);
}
cleandata(SaltData, sizeof(SaltData));
cleandata(Fn, sizeof(Fn));
cleandata(U1, sizeof(U1));
cleandata(U2, sizeof(U2));
}
void CryptData::SetKey50(bool Encrypt,SecPassword *Password,const wchar *PwdW,
const byte *Salt,const byte *InitV,uint Lg2Cnt,byte *HashKey,
byte *PswCheck)
{
if (Lg2Cnt>CRYPT5_KDF_LG2_COUNT_MAX)
return;
byte Key[32],PswCheckValue[SHA256_DIGEST_SIZE],HashKeyValue[SHA256_DIGEST_SIZE];
bool Found=false;
for (uint I=0;I<ASIZE(KDF5Cache);I++)
{
KDF5CacheItem *Item=KDF5Cache+I;
if (Item->Lg2Count==Lg2Cnt && Item->Pwd==*Password &&
memcmp(Item->Salt,Salt,SIZE_SALT50)==0)
{
SecHideData(Item->Key,sizeof(Item->Key),false,false);
memcpy(Key,Item->Key,sizeof(Key));
SecHideData(Item->Key,sizeof(Item->Key),true,false);
memcpy(PswCheckValue,Item->PswCheckValue,sizeof(PswCheckValue));
memcpy(HashKeyValue,Item->HashKeyValue,sizeof(HashKeyValue));
Found=true;
break;
}
}
if (!Found)
{
char PwdUtf[MAXPASSWORD*4];
WideToUtf(PwdW,PwdUtf,ASIZE(PwdUtf));
pbkdf2((byte *)PwdUtf,strlen(PwdUtf),Salt,SIZE_SALT50,Key,HashKeyValue,PswCheckValue,(1<<Lg2Cnt));
cleandata(PwdUtf,sizeof(PwdUtf));
KDF5CacheItem *Item=KDF5Cache+(KDF5CachePos++ % ASIZE(KDF5Cache));
Item->Lg2Count=Lg2Cnt;
Item->Pwd=*Password;
memcpy(Item->Salt,Salt,SIZE_SALT50);
memcpy(Item->Key,Key,sizeof(Key));
memcpy(Item->PswCheckValue,PswCheckValue,sizeof(PswCheckValue));
memcpy(Item->HashKeyValue,HashKeyValue,sizeof(HashKeyValue));
SecHideData(Item->Key,sizeof(Key),true,false);
}
if (HashKey!=NULL)
memcpy(HashKey,HashKeyValue,SHA256_DIGEST_SIZE);
if (PswCheck!=NULL)
{
memset(PswCheck,0,SIZE_PSWCHECK);
for (uint I=0;I<SHA256_DIGEST_SIZE;I++)
PswCheck[I%SIZE_PSWCHECK]^=PswCheckValue[I];
cleandata(PswCheckValue,sizeof(PswCheckValue));
}
// NULL initialization vector is possible if we only need the password
// check value for archive encryption header.
if (InitV!=NULL)
rin.Init(Encrypt, Key, 256, InitV);
cleandata(Key,sizeof(Key));
}
void ConvertHashToMAC(HashValue *Value,byte *Key)
{
if (Value->Type==HASH_CRC32)
{
byte RawCRC[4];
RawPut4(Value->CRC32,RawCRC);
byte Digest[SHA256_DIGEST_SIZE];
hmac_sha256(Key,SHA256_DIGEST_SIZE,RawCRC,sizeof(RawCRC),Digest);
Value->CRC32=0;
for (uint I=0;I<ASIZE(Digest);I++)
Value->CRC32^=Digest[I] << ((I & 3) * 8);
}
if (Value->Type==HASH_BLAKE2)
{
byte Digest[BLAKE2_DIGEST_SIZE];
hmac_sha256(Key,BLAKE2_DIGEST_SIZE,Value->Digest,sizeof(Value->Digest),Digest);
memcpy(Value->Digest,Digest,sizeof(Value->Digest));
}
}
#if 0
static void TestPBKDF2();
struct TestKDF {TestKDF() {TestPBKDF2();exit(0);}} GlobalTestKDF;
void TestPBKDF2() // Test PBKDF2 HMAC-SHA256
{
byte Key[32],V1[32],V2[32];
pbkdf2((byte *)"password", 8, (byte *)"salt", 4, Key, V1, V2, 1);
byte Res1[32]={0x12, 0x0f, 0xb6, 0xcf, 0xfc, 0xf8, 0xb3, 0x2c, 0x43, 0xe7, 0x22, 0x52, 0x56, 0xc4, 0xf8, 0x37, 0xa8, 0x65, 0x48, 0xc9, 0x2c, 0xcc, 0x35, 0x48, 0x08, 0x05, 0x98, 0x7c, 0xb7, 0x0b, 0xe1, 0x7b };
mprintf(L"\nPBKDF2 test1: %s", memcmp(Key,Res1,32)==0 ? L"OK":L"Failed");
pbkdf2((byte *)"password", 8, (byte *)"salt", 4, Key, V1, V2, 4096);
byte Res2[32]={0xc5, 0xe4, 0x78, 0xd5, 0x92, 0x88, 0xc8, 0x41, 0xaa, 0x53, 0x0d, 0xb6, 0x84, 0x5c, 0x4c, 0x8d, 0x96, 0x28, 0x93, 0xa0, 0x01, 0xce, 0x4e, 0x11, 0xa4, 0x96, 0x38, 0x73, 0xaa, 0x98, 0x13, 0x4a };
mprintf(L"\nPBKDF2 test2: %s", memcmp(Key,Res2,32)==0 ? L"OK":L"Failed");
pbkdf2((byte *)"just some long string pretending to be a password", 49, (byte *)"salt, salt, salt, a lot of salt", 31, Key, V1, V2, 65536);
byte Res3[32]={0x08, 0x0f, 0xa3, 0x1d, 0x42, 0x2d, 0xb0, 0x47, 0x83, 0x9b, 0xce, 0x3a, 0x3b, 0xce, 0x49, 0x51, 0xe2, 0x62, 0xb9, 0xff, 0x76, 0x2f, 0x57, 0xe9, 0xc4, 0x71, 0x96, 0xce, 0x4b, 0x6b, 0x6e, 0xbf};
mprintf(L"\nPBKDF2 test3: %s", memcmp(Key,Res3,32)==0 ? L"OK":L"Failed");
}
#endif
|
