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/*
* Pageant client code.
*/
#include <stdio.h>
#include <stdlib.h>
#include "putty.h"
#ifndef NO_SECURITY
#include <aclapi.h>
#endif
#define AGENT_COPYDATA_ID 0x804e50ba /* random goop */
#define AGENT_MAX_MSGLEN 8192
int agent_exists(void)
{
HWND hwnd;
hwnd = FindWindow("Pageant", "Pageant");
if (!hwnd)
return FALSE;
else
return TRUE;
}
/*
* Unfortunately, this asynchronous agent request mechanism doesn't
* appear to work terribly well. I'm going to comment it out for
* the moment, and see if I can come up with a better one :-/
*/
#ifdef WINDOWS_ASYNC_AGENT
struct agent_query_data {
COPYDATASTRUCT cds;
unsigned char *mapping;
HANDLE handle;
char *mapname;
HWND hwnd;
void (*callback)(void *, void *, int);
void *callback_ctx;
};
DWORD WINAPI agent_query_thread(LPVOID param)
{
struct agent_query_data *data = (struct agent_query_data *)param;
unsigned char *ret;
int id, retlen;
id = SendMessage(data->hwnd, WM_COPYDATA, (WPARAM) NULL,
(LPARAM) &data->cds);
ret = NULL;
if (id > 0) {
retlen = 4 + GET_32BIT(data->mapping);
ret = snewn(retlen, unsigned char);
if (ret) {
memcpy(ret, data->mapping, retlen);
}
}
if (!ret)
retlen = 0;
UnmapViewOfFile(data->mapping);
CloseHandle(data->handle);
sfree(data->mapname);
agent_schedule_callback(data->callback, data->callback_ctx, ret, retlen);
return 0;
}
#endif
/*
* Dynamically load advapi32.dll for SID manipulation. In its absence,
* we degrade gracefully.
*/
#ifndef NO_SECURITY
int advapi_initialised = FALSE;
static HMODULE advapi;
DECL_WINDOWS_FUNCTION(static, BOOL, OpenProcessToken,
(HANDLE, DWORD, PHANDLE));
DECL_WINDOWS_FUNCTION(static, BOOL, GetTokenInformation,
(HANDLE, TOKEN_INFORMATION_CLASS,
LPVOID, DWORD, PDWORD));
DECL_WINDOWS_FUNCTION(static, BOOL, InitializeSecurityDescriptor,
(PSECURITY_DESCRIPTOR, DWORD));
DECL_WINDOWS_FUNCTION(static, BOOL, SetSecurityDescriptorOwner,
(PSECURITY_DESCRIPTOR, PSID, BOOL));
DECL_WINDOWS_FUNCTION(, DWORD, GetSecurityInfo,
(HANDLE, SE_OBJECT_TYPE, SECURITY_INFORMATION,
PSID *, PSID *, PACL *, PACL *,
PSECURITY_DESCRIPTOR *));
int init_advapi(void)
{
advapi = load_system32_dll("advapi32.dll");
return 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);
}
PSID get_user_sid(void)
{
HANDLE proc = NULL, tok = NULL;
TOKEN_USER *user = NULL;
DWORD toklen, sidlen;
PSID sid = NULL, ret = NULL;
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;
}
#endif
int agent_query(void *in, int inlen, void **out, int *outlen,
void (*callback)(void *, void *, int), void *callback_ctx)
{
HWND hwnd;
char *mapname;
HANDLE filemap;
unsigned char *p, *ret;
int id, retlen;
COPYDATASTRUCT cds;
SECURITY_ATTRIBUTES sa, *psa;
PSECURITY_DESCRIPTOR psd = NULL;
PSID usersid = NULL;
*out = NULL;
*outlen = 0;
hwnd = FindWindow("Pageant", "Pageant");
if (!hwnd)
return 1; /* *out == NULL, so failure */
mapname = dupprintf("PageantRequest%08x", (unsigned)GetCurrentThreadId());
#ifndef NO_SECURITY
if (advapi_initialised || init_advapi()) {
/*
* Make the file mapping we create for communication with
* Pageant owned by the user SID rather than the default. This
* should make communication between processes with slightly
* different contexts more reliable: in particular, command
* prompts launched as administrator should still be able to
* run PSFTPs which refer back to the owning user's
* unprivileged Pageant.
*/
usersid = get_user_sid();
psa = NULL;
if (usersid) {
psd = (PSECURITY_DESCRIPTOR)
LocalAlloc(LPTR, SECURITY_DESCRIPTOR_MIN_LENGTH);
if (psd) {
if (p_InitializeSecurityDescriptor
(psd, SECURITY_DESCRIPTOR_REVISION) &&
p_SetSecurityDescriptorOwner(psd, usersid, FALSE)) {
sa.nLength = sizeof(sa);
sa.bInheritHandle = TRUE;
sa.lpSecurityDescriptor = psd;
psa = &sa;
} else {
LocalFree(psd);
psd = NULL;
}
}
}
}
#endif /* NO_SECURITY */
filemap = CreateFileMapping(INVALID_HANDLE_VALUE, psa, PAGE_READWRITE,
0, AGENT_MAX_MSGLEN, mapname);
if (filemap == NULL || filemap == INVALID_HANDLE_VALUE)
return 1; /* *out == NULL, so failure */
p = MapViewOfFile(filemap, FILE_MAP_WRITE, 0, 0, 0);
memcpy(p, in, inlen);
cds.dwData = AGENT_COPYDATA_ID;
cds.cbData = 1 + strlen(mapname);
cds.lpData = mapname;
#ifdef WINDOWS_ASYNC_AGENT
if (callback != NULL && !(flags & FLAG_SYNCAGENT)) {
/*
* We need an asynchronous Pageant request. Since I know of
* no way to stop SendMessage from blocking the thread it's
* called in, I see no option but to start a fresh thread.
* When we're done we'll PostMessage the result back to our
* main window, so that the callback is done in the primary
* thread to avoid concurrency.
*/
struct agent_query_data *data = snew(struct agent_query_data);
DWORD threadid;
data->mapping = p;
data->handle = filemap;
data->mapname = mapname;
data->callback = callback;
data->callback_ctx = callback_ctx;
data->cds = cds; /* structure copy */
data->hwnd = hwnd;
if (CreateThread(NULL, 0, agent_query_thread, data, 0, &threadid))
return 0;
sfree(data);
}
#endif
/*
* The user either passed a null callback (indicating that the
* query is required to be synchronous) or CreateThread failed.
* Either way, we need a synchronous request.
*/
id = SendMessage(hwnd, WM_COPYDATA, (WPARAM) NULL, (LPARAM) &cds);
if (id > 0) {
retlen = 4 + GET_32BIT(p);
ret = snewn(retlen, unsigned char);
if (ret) {
memcpy(ret, p, retlen);
*out = ret;
*outlen = retlen;
}
}
UnmapViewOfFile(p);
CloseHandle(filemap);
if (psd)
LocalFree(psd);
sfree(usersid);
return 1;
}
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