src/TortoisePlink/Windows/utils/get_username.c

   1 /*
   2  * Implementation of get_username() for Windows.
   3  */
   4
   5 #include "putty.h"
   6
   7 #ifndef SECURITY_WIN32
   8 #define SECURITY_WIN32
   9 #endif
  10 #include <security.h>
  11
  12 char *get_username(void)
  13 {
  14     DWORD namelen;
  15     char *user;
  16     bool got_username = false;
  17     DECL_WINDOWS_FUNCTION(static, BOOLEAN, GetUserNameExA,
  18                           (EXTENDED_NAME_FORMAT, LPSTR, PULONG));
  19
  20     {
  21         static bool tried_usernameex = false;
  22         if (!tried_usernameex) {
  23             /* Not available on Win9x, so load dynamically */
  24             HMODULE secur32 = load_system32_dll("secur32.dll");
  25             /* If MIT Kerberos is installed, the following call to
  26                GET_WINDOWS_FUNCTION makes Windows implicitly load
  27                sspicli.dll WITHOUT proper path sanitizing, so better
  28                load it properly before */
  29             HMODULE sspicli = load_system32_dll("sspicli.dll");
  30             (void)sspicli; /* squash compiler warning about unused variable */
  31             GET_WINDOWS_FUNCTION(secur32, GetUserNameExA);
  32             tried_usernameex = true;
  33         }
  34     }
  35
  36     if (p_GetUserNameExA) {
  37         /*
  38          * If available, use the principal -- this avoids the problem
  39          * that the local username is case-insensitive but Kerberos
  40          * usernames are case-sensitive.
  41          */
  42
  43         /* Get the length */
  44         namelen = 0;
  45         (void) p_GetUserNameExA(NameUserPrincipal, NULL, &namelen);
  46
  47         user = snewn(namelen, char);
  48         got_username = p_GetUserNameExA(NameUserPrincipal, user, &namelen);
  49         if (got_username) {
  50             char *p = strchr(user, '@');
  51             if (p) *p = 0;
  52         } else {
  53             sfree(user);
  54         }
  55     }
  56
  57     if (!got_username) {
  58         /* Fall back to local user name */
  59         namelen = 0;
  60         if (!GetUserName(NULL, &namelen)) {
  61             /*
  62              * Apparently this doesn't work at least on Windows XP SP2.
  63              * Thus assume a maximum of 256. It will fail again if it
  64              * doesn't fit.
  65              */
  66             namelen = 256;
  67         }
  68
  69         user = snewn(namelen, char);
  70         got_username = GetUserName(user, &namelen);
  71         if (!got_username) {
  72             sfree(user);
  73         }
  74     }
  75
  76     return got_username ? user : NULL;
  77 }