1 /* FIPS compliance status test for GNU/Linux systems.
2    Copyright (C) 2012-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef _FIPS_PRIVATE_H
20 #define _FIPS_PRIVATE_H
21 
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <stdlib.h>
25 #include <unistd.h>
26 #include <not-cancel.h>
27 #include <stdbool.h>
28 
29 /* Return true if FIPS mode is enabled.  See
30    sysdeps/generic/fips-private.h for more information.  */
31 
32 static bool
fips_enabled_p(void)33 fips_enabled_p (void)
34 {
35   static enum
36   {
37     FIPS_UNTESTED = 0,
38     FIPS_ENABLED = 1,
39     FIPS_DISABLED = -1,
40     FIPS_TEST_FAILED = -2
41   } checked;
42 
43   if (checked == FIPS_UNTESTED)
44     {
45       int fd = __open_nocancel ("/proc/sys/crypto/fips_enabled", O_RDONLY);
46 
47       if (fd != -1)
48 	{
49 	  /* This is more than enough, the file contains a single integer.  */
50 	  char buf[32];
51 	  ssize_t n;
52 	  n = TEMP_FAILURE_RETRY (__read_nocancel (fd, buf, sizeof (buf) - 1));
53 	  __close_nocancel_nostatus (fd);
54 
55 	  if (n > 0)
56 	    {
57 	      /* Terminate the string.  */
58 	      buf[n] = '\0';
59 
60 	      char *endp;
61 	      long int res = strtol (buf, &endp, 10);
62 	      if (endp != buf && (*endp == '\0' || *endp == '\n'))
63 		checked = (res > 0) ? FIPS_ENABLED : FIPS_DISABLED;
64 	    }
65 	}
66 
67       if (checked == FIPS_UNTESTED)
68 	checked = FIPS_TEST_FAILED;
69     }
70 
71   return checked == FIPS_ENABLED;
72 }
73 
74 #endif /* _FIPS_PRIVATE_H */
75