git.distorted.org.uk Git - u/mdw/putty/blob - windows/winpgntc.c

   1 /*
   2  * Pageant client code.
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7
   8 #include "putty.h"
   9
  10 #define AGENT_COPYDATA_ID 0x804e50ba   /* random goop */
  11 #define AGENT_MAX_MSGLEN  8192
  12
  13 #define GET_32BIT(cp) \
  14     (((unsigned long)(unsigned char)(cp)[0] << 24) | \
  15     ((unsigned long)(unsigned char)(cp)[1] << 16) | \
  16     ((unsigned long)(unsigned char)(cp)[2] << 8) | \
  17     ((unsigned long)(unsigned char)(cp)[3]))
  18
  19 int agent_exists(void)
  20 {
  21     HWND hwnd;
  22     hwnd = FindWindow("Pageant", "Pageant");
  23     if (!hwnd)
  24         return FALSE;
  25     else
  26         return TRUE;
  27 }
  28
  29 /*
  30  * Unfortunately, this asynchronous agent request mechanism doesn't
  31  * appear to work terribly well. I'm going to comment it out for
  32  * the moment, and see if I can come up with a better one :-/
  33  */
  34 #ifdef WINDOWS_ASYNC_AGENT
  35
  36 struct agent_query_data {
  37     COPYDATASTRUCT cds;
  38     unsigned char *mapping;
  39     HANDLE handle;
  40     char *mapname;
  41     HWND hwnd;
  42     void (*callback)(void *, void *, int);
  43     void *callback_ctx;
  44 };
  45
  46 DWORD WINAPI agent_query_thread(LPVOID param)
  47 {
  48     struct agent_query_data *data = (struct agent_query_data *)param;
  49     unsigned char *ret;
  50     int id, retlen;
  51
  52     id = SendMessage(data->hwnd, WM_COPYDATA, (WPARAM) NULL,
  53                      (LPARAM) &data->cds);
  54     ret = NULL;
  55     if (id > 0) {
  56         retlen = 4 + GET_32BIT(data->mapping);
  57         ret = snewn(retlen, unsigned char);
  58         if (ret) {
  59             memcpy(ret, data->mapping, retlen);
  60         }
  61     }
  62     if (!ret)
  63         retlen = 0;
  64     UnmapViewOfFile(data->mapping);
  65     CloseHandle(data->handle);
  66     sfree(data->mapname);
  67
  68     agent_schedule_callback(data->callback, data->callback_ctx, ret, retlen);
  69
  70     return 0;
  71 }
  72
  73 #endif
  74
  75 int agent_query(void *in, int inlen, void **out, int *outlen,
  76                 void (*callback)(void *, void *, int), void *callback_ctx)
  77 {
  78     HWND hwnd;
  79     char *mapname;
  80     HANDLE filemap;
  81     unsigned char *p, *ret;
  82     int id, retlen;
  83     COPYDATASTRUCT cds;
  84
  85     *out = NULL;
  86     *outlen = 0;
  87
  88     hwnd = FindWindow("Pageant", "Pageant");
  89     if (!hwnd)
  90         return 1;                      /* *out == NULL, so failure */
  91     mapname = dupprintf("PageantRequest%08x", (unsigned)GetCurrentThreadId());
  92     filemap = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE,
  93                                 0, AGENT_MAX_MSGLEN, mapname);
  94     if (!filemap)
  95         return 1;                      /* *out == NULL, so failure */
  96     p = MapViewOfFile(filemap, FILE_MAP_WRITE, 0, 0, 0);
  97     memcpy(p, in, inlen);
  98     cds.dwData = AGENT_COPYDATA_ID;
  99     cds.cbData = 1 + strlen(mapname);
 100     cds.lpData = mapname;
 101 #ifdef WINDOWS_ASYNC_AGENT
 102     if (callback != NULL && !(flags & FLAG_SYNCAGENT)) {
 103         /*
 104          * We need an asynchronous Pageant request. Since I know of
 105          * no way to stop SendMessage from blocking the thread it's
 106          * called in, I see no option but to start a fresh thread.
 107          * When we're done we'll PostMessage the result back to our
 108          * main window, so that the callback is done in the primary
 109          * thread to avoid concurrency.
 110          */
 111         struct agent_query_data *data = snew(struct agent_query_data);
 112         DWORD threadid;
 113         data->mapping = p;
 114         data->handle = filemap;
 115         data->mapname = mapname;
 116         data->callback = callback;
 117         data->callback_ctx = callback_ctx;
 118         data->cds = cds;               /* structure copy */
 119         data->hwnd = hwnd;
 120         if (CreateThread(NULL, 0, agent_query_thread, data, 0, &threadid))
 121             return 0;
 122         sfree(data);
 123     }
 124 #endif
 125
 126     /*
 127      * The user either passed a null callback (indicating that the
 128      * query is required to be synchronous) or CreateThread failed.
 129      * Either way, we need a synchronous request.
 130      */
 131     id = SendMessage(hwnd, WM_COPYDATA, (WPARAM) NULL, (LPARAM) & cds);
 132     if (id > 0) {
 133         retlen = 4 + GET_32BIT(p);
 134         ret = snewn(retlen, unsigned char);
 135         if (ret) {
 136             memcpy(ret, p, retlen);
 137             *out = ret;
 138             *outlen = retlen;
 139         }
 140     }
 141     UnmapViewOfFile(p);
 142     CloseHandle(filemap);
 143     return 1;
 144 }