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
|
/*
* Copyright (C) 2012 Tobias Brunner
* HSR Hochschule fuer Technik Rapperswil
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*/
#include "pkcs8_builder.h"
#include <utils/debug.h>
#include <asn1/oid.h>
#include <asn1/asn1.h>
#include <asn1/asn1_parser.h>
#include <crypto/pkcs5.h>
#include <credentials/keys/private_key.h>
/**
* ASN.1 definition of a privateKeyInfo structure
*/
static const asn1Object_t pkinfoObjects[] = {
{ 0, "privateKeyInfo", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */
{ 1, "version", ASN1_INTEGER, ASN1_BODY }, /* 1 */
{ 1, "privateKeyAlgorithm", ASN1_EOC, ASN1_RAW }, /* 2 */
{ 1, "privateKey", ASN1_OCTET_STRING, ASN1_BODY }, /* 3 */
{ 1, "attributes", ASN1_CONTEXT_C_0, ASN1_OPT }, /* 4 */
{ 1, "end opt", ASN1_EOC, ASN1_END }, /* 5 */
{ 0, "exit", ASN1_EOC, ASN1_EXIT }
};
#define PKINFO_PRIVATE_KEY_ALGORITHM 2
#define PKINFO_PRIVATE_KEY 3
/**
* Load a generic private key from an ASN.1 encoded blob
*/
static private_key_t *parse_private_key(chunk_t blob)
{
asn1_parser_t *parser;
chunk_t object, params = chunk_empty;
int objectID;
private_key_t *key = NULL;
key_type_t type = KEY_ANY;
builder_part_t part = BUILD_BLOB_ASN1_DER;
parser = asn1_parser_create(pkinfoObjects, blob);
parser->set_flags(parser, FALSE, TRUE);
while (parser->iterate(parser, &objectID, &object))
{
switch (objectID)
{
case PKINFO_PRIVATE_KEY_ALGORITHM:
{
int oid = asn1_parse_algorithmIdentifier(object,
parser->get_level(parser) + 1, ¶ms);
switch (oid)
{
case OID_RSASSA_PSS:
/* TODO: parameters associated with such keys should be
* treated as restrictions later when signing (the type
* itself is already a restriction). However, the
* builders currently don't expect any parameters for
* RSA keys (we also only pass along the params, not the
* exact type, so we'd have to guess that params
* indicate RSA/PSS, but they are optional so that won't
* work for keys without specific restrictions) */
params = chunk_empty;
/* fall-through */
case OID_RSA_ENCRYPTION:
type = KEY_RSA;
break;
case OID_EC_PUBLICKEY:
type = KEY_ECDSA;
break;
case OID_ED25519:
type = KEY_ED25519;
part = BUILD_EDDSA_PRIV_ASN1_DER;
break;
case OID_ED448:
type = KEY_ED448;
part = BUILD_EDDSA_PRIV_ASN1_DER;
break;
default:
/* key type not supported */
goto end;
}
break;
}
case PKINFO_PRIVATE_KEY:
{
DBG2(DBG_ASN, "-- > --");
if (params.ptr)
{
key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY,
type, BUILD_BLOB_ALGID_PARAMS,
params, part, object, BUILD_END);
}
else
{
key = lib->creds->create(lib->creds, CRED_PRIVATE_KEY,
type, part, object, BUILD_END);
}
DBG2(DBG_ASN, "-- < --");
break;
}
}
}
end:
parser->destroy(parser);
return key;
}
/**
* Try to decrypt the given blob with multiple passwords using the given
* pkcs5 object.
*/
static private_key_t *decrypt_private_key(pkcs5_t *pkcs5, chunk_t blob)
{
enumerator_t *enumerator;
shared_key_t *shared;
private_key_t *private_key = NULL;
enumerator = lib->credmgr->create_shared_enumerator(lib->credmgr,
SHARED_PRIVATE_KEY_PASS, NULL, NULL);
while (enumerator->enumerate(enumerator, &shared, NULL, NULL))
{
chunk_t decrypted;
if (!pkcs5->decrypt(pkcs5, shared->get_key(shared), blob, &decrypted))
{
continue;
}
private_key = parse_private_key(decrypted);
if (private_key)
{
chunk_clear(&decrypted);
break;
}
chunk_free(&decrypted);
}
enumerator->destroy(enumerator);
return private_key;
}
/**
* ASN.1 definition of an encryptedPrivateKeyInfo structure
*/
static const asn1Object_t encryptedPKIObjects[] = {
{ 0, "encryptedPrivateKeyInfo", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */
{ 1, "encryptionAlgorithm", ASN1_EOC, ASN1_RAW }, /* 1 */
{ 1, "encryptedData", ASN1_OCTET_STRING, ASN1_BODY }, /* 2 */
{ 0, "exit", ASN1_EOC, ASN1_EXIT }
};
#define EPKINFO_ENCRYPTION_ALGORITHM 1
#define EPKINFO_ENCRYPTED_DATA 2
/**
* Load an encrypted private key from an ASN.1 encoded blob
* Schemes per PKCS#5 (RFC 2898)
*/
static private_key_t *parse_encrypted_private_key(chunk_t blob)
{
asn1_parser_t *parser;
chunk_t object;
int objectID;
private_key_t *key = NULL;
pkcs5_t *pkcs5 = NULL;
parser = asn1_parser_create(encryptedPKIObjects, blob);
while (parser->iterate(parser, &objectID, &object))
{
switch (objectID)
{
case EPKINFO_ENCRYPTION_ALGORITHM:
{
pkcs5 = pkcs5_from_algorithmIdentifier(object,
parser->get_level(parser) + 1);
if (!pkcs5)
{
goto end;
}
break;
}
case EPKINFO_ENCRYPTED_DATA:
{
key = decrypt_private_key(pkcs5, object);
break;
}
}
}
end:
DESTROY_IF(pkcs5);
parser->destroy(parser);
return key;
}
/**
* See header.
*/
private_key_t *pkcs8_private_key_load(key_type_t type, va_list args)
{
chunk_t blob = chunk_empty;
private_key_t *key;
while (TRUE)
{
switch (va_arg(args, builder_part_t))
{
case BUILD_BLOB_ASN1_DER:
blob = va_arg(args, chunk_t);
continue;
case BUILD_END:
break;
default:
return NULL;
}
break;
}
/* we don't know whether it is encrypted or not, try both ways */
key = parse_encrypted_private_key(blob);
if (!key)
{
key = parse_private_key(blob);
}
return key;
}
|
