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
|
/*
* winsecur.c: implementation of winsecur.h.
*/
#include <stdio.h>
#include <stdlib.h>
#include "putty.h"
#if !defined NO_SECURITY
#define WINSECUR_GLOBAL
#include "winsecur.h"
int got_advapi(void)
{
static int attempted = FALSE;
static int successful;
static HMODULE advapi;
if (!attempted) {
attempted = TRUE;
advapi = load_system32_dll("advapi32.dll");
successful = advapi &&
GET_WINDOWS_FUNCTION(advapi, GetSecurityInfo) &&
GET_WINDOWS_FUNCTION(advapi, OpenProcessToken) &&
GET_WINDOWS_FUNCTION(advapi, GetTokenInformation) &&
GET_WINDOWS_FUNCTION(advapi, InitializeSecurityDescriptor) &&
GET_WINDOWS_FUNCTION(advapi, SetSecurityDescriptorOwner) &&
GET_WINDOWS_FUNCTION(advapi, SetEntriesInAclA);
}
return successful;
}
int got_crypt(void)
{
static int attempted = FALSE;
static int successful;
static HMODULE crypt;
if (!attempted) {
attempted = TRUE;
crypt = load_system32_dll("crypt32.dll");
successful = crypt &&
GET_WINDOWS_FUNCTION(crypt, CryptProtectMemory);
}
return successful;
}
PSID get_user_sid(void)
{
HANDLE proc = NULL, tok = NULL;
TOKEN_USER *user = NULL;
DWORD toklen, sidlen;
PSID sid = NULL, ret = NULL;
if (!got_advapi())
goto cleanup;
if ((proc = OpenProcess(MAXIMUM_ALLOWED, FALSE,
GetCurrentProcessId())) == NULL)
goto cleanup;
if (!p_OpenProcessToken(proc, TOKEN_QUERY, &tok))
goto cleanup;
if (!p_GetTokenInformation(tok, TokenUser, NULL, 0, &toklen) &&
GetLastError() != ERROR_INSUFFICIENT_BUFFER)
goto cleanup;
if ((user = (TOKEN_USER *)LocalAlloc(LPTR, toklen)) == NULL)
goto cleanup;
if (!p_GetTokenInformation(tok, TokenUser, user, toklen, &toklen))
goto cleanup;
sidlen = GetLengthSid(user->User.Sid);
sid = (PSID)smalloc(sidlen);
if (!CopySid(sidlen, sid, user->User.Sid))
goto cleanup;
/* Success. Move sid into the return value slot, and null it out
* to stop the cleanup code freeing it. */
ret = sid;
sid = NULL;
cleanup:
if (proc != NULL)
CloseHandle(proc);
if (tok != NULL)
CloseHandle(tok);
if (user != NULL)
LocalFree(user);
if (sid != NULL)
sfree(sid);
return ret;
}
int make_private_security_descriptor(DWORD permissions,
PSECURITY_DESCRIPTOR *psd,
PACL *acl,
char **error)
{
SID_IDENTIFIER_AUTHORITY world_auth = SECURITY_WORLD_SID_AUTHORITY;
SID_IDENTIFIER_AUTHORITY nt_auth = SECURITY_NT_AUTHORITY;
EXPLICIT_ACCESS ea[3];
int acl_err;
int ret = FALSE;
/* Initialised once, then kept around to reuse forever */
static PSID worldsid, networksid, usersid;
*psd = NULL;
*acl = NULL;
*error = NULL;
if (!got_advapi()) {
*error = dupprintf("unable to load advapi32.dll");
goto cleanup;
}
if (!usersid) {
if ((usersid = get_user_sid()) == NULL) {
*error = dupprintf("unable to construct SID for current user: %s",
win_strerror(GetLastError()));
goto cleanup;
}
}
if (!worldsid) {
if (!AllocateAndInitializeSid(&world_auth, 1, SECURITY_WORLD_RID,
0, 0, 0, 0, 0, 0, 0, &worldsid)) {
*error = dupprintf("unable to construct SID for world: %s",
win_strerror(GetLastError()));
goto cleanup;
}
}
if (!networksid) {
if (!AllocateAndInitializeSid(&nt_auth, 1, SECURITY_NETWORK_RID,
0, 0, 0, 0, 0, 0, 0, &networksid)) {
*error = dupprintf("unable to construct SID for "
"local same-user access only: %s",
win_strerror(GetLastError()));
goto cleanup;
}
}
memset(ea, 0, sizeof(ea));
ea[0].grfAccessPermissions = permissions;
ea[0].grfAccessMode = REVOKE_ACCESS;
ea[0].grfInheritance = NO_INHERITANCE;
ea[0].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[0].Trustee.ptstrName = (LPTSTR)worldsid;
ea[1].grfAccessPermissions = permissions;
ea[1].grfAccessMode = GRANT_ACCESS;
ea[1].grfInheritance = NO_INHERITANCE;
ea[1].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[1].Trustee.ptstrName = (LPTSTR)usersid;
ea[2].grfAccessPermissions = permissions;
ea[2].grfAccessMode = REVOKE_ACCESS;
ea[2].grfInheritance = NO_INHERITANCE;
ea[2].Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea[2].Trustee.ptstrName = (LPTSTR)networksid;
acl_err = p_SetEntriesInAclA(3, ea, NULL, acl);
if (acl_err != ERROR_SUCCESS || *acl == NULL) {
*error = dupprintf("unable to construct ACL: %s",
win_strerror(acl_err));
goto cleanup;
}
*psd = (PSECURITY_DESCRIPTOR)
LocalAlloc(LPTR, SECURITY_DESCRIPTOR_MIN_LENGTH);
if (!*psd) {
*error = dupprintf("unable to allocate security descriptor: %s",
win_strerror(GetLastError()));
goto cleanup;
}
if (!InitializeSecurityDescriptor(*psd, SECURITY_DESCRIPTOR_REVISION)) {
*error = dupprintf("unable to initialise security descriptor: %s",
win_strerror(GetLastError()));
goto cleanup;
}
if (!SetSecurityDescriptorDacl(*psd, TRUE, *acl, FALSE)) {
*error = dupprintf("unable to set DACL in security descriptor: %s",
win_strerror(GetLastError()));
goto cleanup;
}
ret = TRUE;
cleanup:
if (!ret) {
if (*psd) {
LocalFree(*psd);
*psd = NULL;
}
if (*acl) {
LocalFree(*acl);
*acl = NULL;
}
} else {
sfree(*error);
*error = NULL;
}
return ret;
}
#endif /* !defined NO_SECURITY */
|
