| 1 | /* |
| 2 | * Pageant client code. |
| 3 | */ |
| 4 | |
| 5 | #include <stdio.h> |
| 6 | #include <stdlib.h> |
| 7 | |
| 8 | #include "putty.h" |
| 9 | |
| 10 | #ifndef NO_SECURITY |
| 11 | #include <aclapi.h> |
| 12 | #endif |
| 13 | |
| 14 | #define AGENT_COPYDATA_ID 0x804e50ba /* random goop */ |
| 15 | #define AGENT_MAX_MSGLEN 8192 |
| 16 | |
| 17 | int agent_exists(void) |
| 18 | { |
| 19 | HWND hwnd; |
| 20 | hwnd = FindWindow("Pageant", "Pageant"); |
| 21 | if (!hwnd) |
| 22 | return FALSE; |
| 23 | else |
| 24 | return TRUE; |
| 25 | } |
| 26 | |
| 27 | /* |
| 28 | * Unfortunately, this asynchronous agent request mechanism doesn't |
| 29 | * appear to work terribly well. I'm going to comment it out for |
| 30 | * the moment, and see if I can come up with a better one :-/ |
| 31 | */ |
| 32 | #ifdef WINDOWS_ASYNC_AGENT |
| 33 | |
| 34 | struct agent_query_data { |
| 35 | COPYDATASTRUCT cds; |
| 36 | unsigned char *mapping; |
| 37 | HANDLE handle; |
| 38 | char *mapname; |
| 39 | HWND hwnd; |
| 40 | void (*callback)(void *, void *, int); |
| 41 | void *callback_ctx; |
| 42 | }; |
| 43 | |
| 44 | DWORD WINAPI agent_query_thread(LPVOID param) |
| 45 | { |
| 46 | struct agent_query_data *data = (struct agent_query_data *)param; |
| 47 | unsigned char *ret; |
| 48 | int id, retlen; |
| 49 | |
| 50 | id = SendMessage(data->hwnd, WM_COPYDATA, (WPARAM) NULL, |
| 51 | (LPARAM) &data->cds); |
| 52 | ret = NULL; |
| 53 | if (id > 0) { |
| 54 | retlen = 4 + GET_32BIT(data->mapping); |
| 55 | ret = snewn(retlen, unsigned char); |
| 56 | if (ret) { |
| 57 | memcpy(ret, data->mapping, retlen); |
| 58 | } |
| 59 | } |
| 60 | if (!ret) |
| 61 | retlen = 0; |
| 62 | UnmapViewOfFile(data->mapping); |
| 63 | CloseHandle(data->handle); |
| 64 | sfree(data->mapname); |
| 65 | |
| 66 | agent_schedule_callback(data->callback, data->callback_ctx, ret, retlen); |
| 67 | |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | #endif |
| 72 | |
| 73 | /* |
| 74 | * Dynamically load advapi32.dll for SID manipulation. In its absence, |
| 75 | * we degrade gracefully. |
| 76 | */ |
| 77 | #ifndef NO_SECURITY |
| 78 | int advapi_initialised = FALSE; |
| 79 | static HMODULE advapi; |
| 80 | DECL_WINDOWS_FUNCTION(static, BOOL, OpenProcessToken, |
| 81 | (HANDLE, DWORD, PHANDLE)); |
| 82 | DECL_WINDOWS_FUNCTION(static, BOOL, GetTokenInformation, |
| 83 | (HANDLE, TOKEN_INFORMATION_CLASS, |
| 84 | LPVOID, DWORD, PDWORD)); |
| 85 | DECL_WINDOWS_FUNCTION(static, BOOL, InitializeSecurityDescriptor, |
| 86 | (PSECURITY_DESCRIPTOR, DWORD)); |
| 87 | DECL_WINDOWS_FUNCTION(static, BOOL, SetSecurityDescriptorOwner, |
| 88 | (PSECURITY_DESCRIPTOR, PSID, BOOL)); |
| 89 | DECL_WINDOWS_FUNCTION(, DWORD, GetSecurityInfo, |
| 90 | (HANDLE, SE_OBJECT_TYPE, SECURITY_INFORMATION, |
| 91 | PSID *, PSID *, PACL *, PACL *, |
| 92 | PSECURITY_DESCRIPTOR *)); |
| 93 | int init_advapi(void) |
| 94 | { |
| 95 | advapi = load_system32_dll("advapi32.dll"); |
| 96 | return advapi && |
| 97 | GET_WINDOWS_FUNCTION(advapi, GetSecurityInfo) && |
| 98 | GET_WINDOWS_FUNCTION(advapi, OpenProcessToken) && |
| 99 | GET_WINDOWS_FUNCTION(advapi, GetTokenInformation) && |
| 100 | GET_WINDOWS_FUNCTION(advapi, InitializeSecurityDescriptor) && |
| 101 | GET_WINDOWS_FUNCTION(advapi, SetSecurityDescriptorOwner); |
| 102 | } |
| 103 | |
| 104 | PSID get_user_sid(void) |
| 105 | { |
| 106 | HANDLE proc = NULL, tok = NULL; |
| 107 | TOKEN_USER *user = NULL; |
| 108 | DWORD toklen, sidlen; |
| 109 | PSID sid = NULL, ret = NULL; |
| 110 | |
| 111 | if ((proc = OpenProcess(MAXIMUM_ALLOWED, FALSE, |
| 112 | GetCurrentProcessId())) == NULL) |
| 113 | goto cleanup; |
| 114 | |
| 115 | if (!p_OpenProcessToken(proc, TOKEN_QUERY, &tok)) |
| 116 | goto cleanup; |
| 117 | |
| 118 | if (!p_GetTokenInformation(tok, TokenUser, NULL, 0, &toklen) && |
| 119 | GetLastError() != ERROR_INSUFFICIENT_BUFFER) |
| 120 | goto cleanup; |
| 121 | |
| 122 | if ((user = (TOKEN_USER *)LocalAlloc(LPTR, toklen)) == NULL) |
| 123 | goto cleanup; |
| 124 | |
| 125 | if (!p_GetTokenInformation(tok, TokenUser, user, toklen, &toklen)) |
| 126 | goto cleanup; |
| 127 | |
| 128 | sidlen = GetLengthSid(user->User.Sid); |
| 129 | |
| 130 | sid = (PSID)smalloc(sidlen); |
| 131 | |
| 132 | if (!CopySid(sidlen, sid, user->User.Sid)) |
| 133 | goto cleanup; |
| 134 | |
| 135 | /* Success. Move sid into the return value slot, and null it out |
| 136 | * to stop the cleanup code freeing it. */ |
| 137 | ret = sid; |
| 138 | sid = NULL; |
| 139 | |
| 140 | cleanup: |
| 141 | if (proc != NULL) |
| 142 | CloseHandle(proc); |
| 143 | if (tok != NULL) |
| 144 | CloseHandle(tok); |
| 145 | if (user != NULL) |
| 146 | LocalFree(user); |
| 147 | if (sid != NULL) |
| 148 | sfree(sid); |
| 149 | |
| 150 | return ret; |
| 151 | } |
| 152 | |
| 153 | #endif |
| 154 | |
| 155 | int agent_query(void *in, int inlen, void **out, int *outlen, |
| 156 | void (*callback)(void *, void *, int), void *callback_ctx) |
| 157 | { |
| 158 | HWND hwnd; |
| 159 | char *mapname; |
| 160 | HANDLE filemap; |
| 161 | unsigned char *p, *ret; |
| 162 | int id, retlen; |
| 163 | COPYDATASTRUCT cds; |
| 164 | SECURITY_ATTRIBUTES sa, *psa; |
| 165 | PSECURITY_DESCRIPTOR psd = NULL; |
| 166 | PSID usersid = NULL; |
| 167 | |
| 168 | *out = NULL; |
| 169 | *outlen = 0; |
| 170 | |
| 171 | hwnd = FindWindow("Pageant", "Pageant"); |
| 172 | if (!hwnd) |
| 173 | return 1; /* *out == NULL, so failure */ |
| 174 | mapname = dupprintf("PageantRequest%08x", (unsigned)GetCurrentThreadId()); |
| 175 | |
| 176 | #ifndef NO_SECURITY |
| 177 | if (advapi_initialised || init_advapi()) { |
| 178 | /* |
| 179 | * Make the file mapping we create for communication with |
| 180 | * Pageant owned by the user SID rather than the default. This |
| 181 | * should make communication between processes with slightly |
| 182 | * different contexts more reliable: in particular, command |
| 183 | * prompts launched as administrator should still be able to |
| 184 | * run PSFTPs which refer back to the owning user's |
| 185 | * unprivileged Pageant. |
| 186 | */ |
| 187 | usersid = get_user_sid(); |
| 188 | |
| 189 | psa = NULL; |
| 190 | if (usersid) { |
| 191 | psd = (PSECURITY_DESCRIPTOR) |
| 192 | LocalAlloc(LPTR, SECURITY_DESCRIPTOR_MIN_LENGTH); |
| 193 | if (psd) { |
| 194 | if (p_InitializeSecurityDescriptor |
| 195 | (psd, SECURITY_DESCRIPTOR_REVISION) && |
| 196 | p_SetSecurityDescriptorOwner(psd, usersid, FALSE)) { |
| 197 | sa.nLength = sizeof(sa); |
| 198 | sa.bInheritHandle = TRUE; |
| 199 | sa.lpSecurityDescriptor = psd; |
| 200 | psa = &sa; |
| 201 | } else { |
| 202 | LocalFree(psd); |
| 203 | psd = NULL; |
| 204 | } |
| 205 | } |
| 206 | } |
| 207 | } |
| 208 | #endif /* NO_SECURITY */ |
| 209 | |
| 210 | filemap = CreateFileMapping(INVALID_HANDLE_VALUE, psa, PAGE_READWRITE, |
| 211 | 0, AGENT_MAX_MSGLEN, mapname); |
| 212 | if (filemap == NULL || filemap == INVALID_HANDLE_VALUE) |
| 213 | return 1; /* *out == NULL, so failure */ |
| 214 | p = MapViewOfFile(filemap, FILE_MAP_WRITE, 0, 0, 0); |
| 215 | memcpy(p, in, inlen); |
| 216 | cds.dwData = AGENT_COPYDATA_ID; |
| 217 | cds.cbData = 1 + strlen(mapname); |
| 218 | cds.lpData = mapname; |
| 219 | #ifdef WINDOWS_ASYNC_AGENT |
| 220 | if (callback != NULL && !(flags & FLAG_SYNCAGENT)) { |
| 221 | /* |
| 222 | * We need an asynchronous Pageant request. Since I know of |
| 223 | * no way to stop SendMessage from blocking the thread it's |
| 224 | * called in, I see no option but to start a fresh thread. |
| 225 | * When we're done we'll PostMessage the result back to our |
| 226 | * main window, so that the callback is done in the primary |
| 227 | * thread to avoid concurrency. |
| 228 | */ |
| 229 | struct agent_query_data *data = snew(struct agent_query_data); |
| 230 | DWORD threadid; |
| 231 | data->mapping = p; |
| 232 | data->handle = filemap; |
| 233 | data->mapname = mapname; |
| 234 | data->callback = callback; |
| 235 | data->callback_ctx = callback_ctx; |
| 236 | data->cds = cds; /* structure copy */ |
| 237 | data->hwnd = hwnd; |
| 238 | if (CreateThread(NULL, 0, agent_query_thread, data, 0, &threadid)) |
| 239 | return 0; |
| 240 | sfree(data); |
| 241 | } |
| 242 | #endif |
| 243 | |
| 244 | /* |
| 245 | * The user either passed a null callback (indicating that the |
| 246 | * query is required to be synchronous) or CreateThread failed. |
| 247 | * Either way, we need a synchronous request. |
| 248 | */ |
| 249 | id = SendMessage(hwnd, WM_COPYDATA, (WPARAM) NULL, (LPARAM) &cds); |
| 250 | if (id > 0) { |
| 251 | retlen = 4 + GET_32BIT(p); |
| 252 | ret = snewn(retlen, unsigned char); |
| 253 | if (ret) { |
| 254 | memcpy(ret, p, retlen); |
| 255 | *out = ret; |
| 256 | *outlen = retlen; |
| 257 | } |
| 258 | } |
| 259 | UnmapViewOfFile(p); |
| 260 | CloseHandle(filemap); |
| 261 | if (psd) |
| 262 | LocalFree(psd); |
| 263 | sfree(usersid); |
| 264 | return 1; |
| 265 | } |