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
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
/**
* PKCS #5 PBES2
* (C) 1999-2008 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/
#include <botan/pbes2.h>
#include <botan/pbkdf2.h>
#include <botan/hmac.h>
#include <botan/cbc.h>
#include <botan/algo_factory.h>
#include <botan/libstate.h>
#include <botan/der_enc.h>
#include <botan/ber_dec.h>
#include <botan/parsing.h>
#include <botan/asn1_obj.h>
#include <botan/oids.h>
#include <algorithm>
#include <memory>
namespace Botan {
/**
* Encrypt some bytes using PBES2
*/
void PBE_PKCS5v20::write(const byte input[], u32bit length)
{
while(length)
{
u32bit put = std::min(DEFAULT_BUFFERSIZE, length);
pipe.write(input, length);
flush_pipe(true);
length -= put;
}
}
/**
* Start encrypting with PBES2
*/
void PBE_PKCS5v20::start_msg()
{
if(direction == ENCRYPTION)
pipe.append(new CBC_Encryption(block_cipher->clone(),
new PKCS7_Padding,
key, iv));
else
pipe.append(new CBC_Decryption(block_cipher->clone(),
new PKCS7_Padding,
key, iv));
pipe.start_msg();
if(pipe.message_count() > 1)
pipe.set_default_msg(pipe.default_msg() + 1);
}
/**
* Finish encrypting with PBES2
*/
void PBE_PKCS5v20::end_msg()
{
pipe.end_msg();
flush_pipe(false);
pipe.reset();
}
/**
* Flush the pipe
*/
void PBE_PKCS5v20::flush_pipe(bool safe_to_skip)
{
if(safe_to_skip && pipe.remaining() < 64)
return;
SecureVector<byte> buffer(DEFAULT_BUFFERSIZE);
while(pipe.remaining())
{
u32bit got = pipe.read(buffer, buffer.size());
send(buffer, got);
}
}
/**
* Set the passphrase to use
*/
void PBE_PKCS5v20::set_key(const std::string& passphrase)
{
PKCS5_PBKDF2 pbkdf(new HMAC(hash_function->clone()));
pbkdf.set_iterations(iterations);
pbkdf.change_salt(salt, salt.size());
key = pbkdf.derive_key(key_length, passphrase).bits_of();
}
/**
* Create a new set of PBES2 parameters
*/
void PBE_PKCS5v20::new_params(RandomNumberGenerator& rng)
{
iterations = 2048;
key_length = block_cipher->MAXIMUM_KEYLENGTH;
salt.create(8);
rng.randomize(salt, salt.size());
iv.create(block_cipher->BLOCK_SIZE);
rng.randomize(iv, iv.size());
}
/**
* Encode PKCS#5 PBES2 parameters
*/
MemoryVector<byte> PBE_PKCS5v20::encode_params() const
{
return DER_Encoder()
.start_cons(SEQUENCE)
.encode(
AlgorithmIdentifier("PKCS5.PBKDF2",
DER_Encoder()
.start_cons(SEQUENCE)
.encode(salt, OCTET_STRING)
.encode(iterations)
.encode(key_length)
.end_cons()
.get_contents()
)
)
.encode(
AlgorithmIdentifier(block_cipher->name() + "/CBC",
DER_Encoder()
.encode(iv, OCTET_STRING)
.get_contents()
)
)
.end_cons()
.get_contents();
}
/**
* Decode PKCS#5 PBES2 parameters
*/
void PBE_PKCS5v20::decode_params(DataSource& source)
{
AlgorithmIdentifier kdf_algo, enc_algo;
BER_Decoder(source)
.start_cons(SEQUENCE)
.decode(kdf_algo)
.decode(enc_algo)
.verify_end()
.end_cons();
if(kdf_algo.oid == OIDS::lookup("PKCS5.PBKDF2"))
{
BER_Decoder(kdf_algo.parameters)
.start_cons(SEQUENCE)
.decode(salt, OCTET_STRING)
.decode(iterations)
.decode_optional(key_length, INTEGER, UNIVERSAL)
.verify_end()
.end_cons();
}
else
throw Decoding_Error("PBE-PKCS5 v2.0: Unknown KDF algorithm " +
kdf_algo.oid.as_string());
Algorithm_Factory& af = global_state().algorithm_factory();
std::string cipher = OIDS::lookup(enc_algo.oid);
std::vector<std::string> cipher_spec = split_on(cipher, '/');
if(cipher_spec.size() != 2)
throw Decoding_Error("PBE-PKCS5 v2.0: Invalid cipher spec " + cipher);
if(!known_cipher(cipher_spec[0]) || cipher_spec[1] != "CBC")
throw Decoding_Error("PBE-PKCS5 v2.0: Don't know param format for " +
cipher);
BER_Decoder(enc_algo.parameters).decode(iv, OCTET_STRING).verify_end();
block_cipher = af.make_block_cipher(cipher_spec[0]);
hash_function = af.make_hash_function("SHA-160");
if(key_length == 0)
key_length = block_cipher->MAXIMUM_KEYLENGTH;
if(salt.size() < 8)
throw Decoding_Error("PBE-PKCS5 v2.0: Encoded salt is too small");
}
/**
* Return an OID for PBES2
*/
OID PBE_PKCS5v20::get_oid() const
{
return OIDS::lookup("PBE-PKCS5v20");
}
/**
* Check if this is a known PBES2 cipher
*/
bool PBE_PKCS5v20::known_cipher(const std::string& algo)
{
if(algo == "AES-128" || algo == "AES-192" || algo == "AES-256")
return true;
if(algo == "DES" || algo == "TripleDES")
return true;
return false;
}
/**
* PKCS#5 v2.0 PBE Constructor
*/
PBE_PKCS5v20::PBE_PKCS5v20(BlockCipher* cipher,
HashFunction* digest) :
direction(ENCRYPTION), block_cipher(cipher), hash_function(digest)
{
if(!known_cipher(block_cipher->name()))
throw Invalid_Argument("PBE-PKCS5 v2.0: Invalid cipher " + cipher->name());
if(hash_function->name() != "SHA-160")
throw Invalid_Argument("PBE-PKCS5 v2.0: Invalid digest " + digest->name());
}
/**
* PKCS#5 v2.0 PBE Constructor
*/
PBE_PKCS5v20::PBE_PKCS5v20(DataSource& params) : direction(DECRYPTION)
{
hash_function = 0;
block_cipher = 0;
decode_params(params);
}
PBE_PKCS5v20::~PBE_PKCS5v20()
{
delete hash_function;
delete block_cipher;
}
}
|
