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