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

   1 /*
   2  * SSH agent client code.
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <assert.h>
   8 #include <unistd.h>
   9 #include <sys/socket.h>
  10 #include <sys/un.h>
  11
  12 #include "misc.h"
  13 #include "puttymem.h"
  14
  15 #define GET_32BIT(cp) \
  16     (((unsigned long)(unsigned char)(cp)[0] << 24) | \
  17     ((unsigned long)(unsigned char)(cp)[1] << 16) | \
  18     ((unsigned long)(unsigned char)(cp)[2] << 8) | \
  19     ((unsigned long)(unsigned char)(cp)[3]))
  20
  21 int agent_exists(void)
  22 {
  23     if (getenv("SSH_AUTH_SOCK") != NULL)
  24         return TRUE;
  25     return FALSE;
  26 }
  27
  28 void agent_query(void *in, int inlen, void **out, int *outlen)
  29 {
  30     char *name;
  31     int sock;
  32     struct sockaddr_un addr;
  33     int done;
  34     int retsize, retlen;
  35     char sizebuf[4], *retbuf;
  36
  37     name = getenv("SSH_AUTH_SOCK");
  38     if (!name)
  39         goto failure;
  40
  41     sock = socket(PF_UNIX, SOCK_STREAM, 0);
  42     if (sock < 0) {
  43         perror("socket(PF_UNIX)");
  44         exit(1);
  45     }
  46
  47     addr.sun_family = AF_UNIX;
  48     strncpy(addr.sun_path, name, sizeof(addr.sun_path));
  49     if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
  50         close(sock);
  51         goto failure;
  52     }
  53
  54     for (done = 0; done < inlen ;) {
  55         int ret = write(sock, (char *)in + done, inlen - done);
  56         if (ret <= 0) {
  57             close(sock);
  58             goto failure;
  59         }
  60         done += ret;
  61     }
  62
  63     retbuf = sizebuf;
  64     retsize = 4;
  65     retlen = 0;
  66
  67     while (retlen < retsize) {
  68         int ret = read(sock, retbuf + retlen, retsize - retlen);
  69         if (ret <= 0) {
  70             close(sock);
  71             if (retbuf != sizebuf) sfree(retbuf);
  72             goto failure;
  73         }
  74         retlen += ret;
  75         if (retsize == 4 && retlen == 4) {
  76             retsize = GET_32BIT(retbuf);
  77             if (retsize <= 0) {
  78                 close(sock);
  79                 goto failure;
  80             }
  81             retsize += 4;
  82             assert(retbuf == sizebuf);
  83             retbuf = snewn(retsize, char);
  84             memcpy(retbuf, sizebuf, 4);
  85         }
  86     }
  87
  88     assert(retbuf != sizebuf);
  89     *out = retbuf;
  90     *outlen = retlen;
  91     return;
  92
  93     failure:
  94     *out = NULL;
  95     *outlen = 0;
  96 }