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

   1 /*
   2  * Pageant client code.
   3  */
   4
   5 #include <windows.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8
   9 #include "putty.h"
  10
  11 #define AGENT_COPYDATA_ID 0x804e50ba   /* random goop */
  12 #define AGENT_MAX_MSGLEN  8192
  13
  14 #define GET_32BIT(cp) \
  15     (((unsigned long)(unsigned char)(cp)[0] << 24) | \
  16     ((unsigned long)(unsigned char)(cp)[1] << 16) | \
  17     ((unsigned long)(unsigned char)(cp)[2] << 8) | \
  18     ((unsigned long)(unsigned char)(cp)[3]))
  19
  20 int agent_exists(void)
  21 {
  22     HWND hwnd;
  23     hwnd = FindWindow("Pageant", "Pageant");
  24     if (!hwnd)
  25         return FALSE;
  26     else
  27         return TRUE;
  28 }
  29
  30 struct agent_query_data {
  31     COPYDATASTRUCT cds;
  32     unsigned char *mapping;
  33     HANDLE handle;
  34     char *mapname;
  35     HWND hwnd;
  36     void (*callback)(void *, void *, int);
  37     void *callback_ctx;
  38 };
  39
  40 DWORD WINAPI agent_query_thread(LPVOID param)
  41 {
  42     struct agent_query_data *data = (struct agent_query_data *)param;
  43     unsigned char *ret;
  44     int id, retlen;
  45
  46     id = SendMessage(data->hwnd, WM_COPYDATA, (WPARAM) NULL,
  47                      (LPARAM) &data->cds);
  48     ret = NULL;
  49     if (id > 0) {
  50         retlen = 4 + GET_32BIT(data->mapping);
  51         ret = snewn(retlen, unsigned char);
  52         if (ret) {
  53             memcpy(ret, data->mapping, retlen);
  54         }
  55     }
  56     if (!ret)
  57         retlen = 0;
  58     UnmapViewOfFile(data->mapping);
  59     CloseHandle(data->handle);
  60     sfree(data->mapname);
  61
  62     agent_schedule_callback(data->callback, data->callback_ctx, ret, retlen);
  63
  64     return 0;
  65 }
  66
  67 int agent_query(void *in, int inlen, void **out, int *outlen,
  68                 void (*callback)(void *, void *, int), void *callback_ctx)
  69 {
  70     HWND hwnd;
  71     char *mapname;
  72     HANDLE filemap;
  73     unsigned char *p, *ret;
  74     int id, retlen;
  75     COPYDATASTRUCT cds;
  76
  77     *out = NULL;
  78     *outlen = 0;
  79
  80     hwnd = FindWindow("Pageant", "Pageant");
  81     if (!hwnd)
  82         return 1;                      /* *out == NULL, so failure */
  83     mapname = dupprintf("PageantRequest%08x", (unsigned)GetCurrentThreadId());
  84     filemap = CreateFileMapping(INVALID_HANDLE_VALUE, NULL, PAGE_READWRITE,
  85                                 0, AGENT_MAX_MSGLEN, mapname);
  86     if (!filemap)
  87         return 1;                      /* *out == NULL, so failure */
  88     p = MapViewOfFile(filemap, FILE_MAP_WRITE, 0, 0, 0);
  89     memcpy(p, in, inlen);
  90     cds.dwData = AGENT_COPYDATA_ID;
  91     cds.cbData = 1 + strlen(mapname);
  92     cds.lpData = mapname;
  93     if (callback != NULL && !(flags & FLAG_SYNCAGENT)) {
  94         /*
  95          * We need an asynchronous Pageant request. Since I know of
  96          * no way to stop SendMessage from blocking the thread it's
  97          * called in, I see no option but to start a fresh thread.
  98          * When we're done we'll PostMessage the result back to our
  99          * main window, so that the callback is done in the primary
 100          * thread to avoid concurrency.
 101          */
 102         struct agent_query_data *data = snew(struct agent_query_data);
 103         DWORD threadid;
 104         data->mapping = p;
 105         data->handle = filemap;
 106         data->mapname = mapname;
 107         data->callback = callback;
 108         data->callback_ctx = callback_ctx;
 109         data->cds = cds;               /* structure copy */
 110         data->hwnd = hwnd;
 111         if (CreateThread(NULL, 0, agent_query_thread, data, 0, &threadid))
 112             return 0;
 113         sfree(data);
 114     }
 115
 116     /*
 117      * The user either passed a null callback (indicating that the
 118      * query is required to be synchronous) or CreateThread failed.
 119      * Either way, we need a synchronous request.
 120      */
 121     id = SendMessage(hwnd, WM_COPYDATA, (WPARAM) NULL, (LPARAM) & cds);
 122     if (id > 0) {
 123         retlen = 4 + GET_32BIT(p);
 124         ret = snewn(retlen, unsigned char);
 125         if (ret) {
 126             memcpy(ret, p, retlen);
 127             *out = ret;
 128             *outlen = retlen;
 129         }
 130     }
 131     UnmapViewOfFile(p);
 132     CloseHandle(filemap);
 133     return 1;
 134 }