* crypt/crypt-entry.c: Include fips-private.h.

(__crypt_r, __crypt): Disable MD5 and DES if FIPS is enabled.
* crypt/md5c-test.c (main): Tolerate disabled MD5.
* sysdeps/unix/sysv/linux/fips-private.h: New file.
* sysdeps/generic/fips-private.h: New file, dummy fallback.

ChangeLog

@@ -1,3 +1,11 @@
+2012-10-10  Alexandre Oliva <aoliva@redhat.com>
+
+	* crypt/crypt-entry.c: Include fips-private.h.
+	(__crypt_r, __crypt): Disable MD5 and DES if FIPS is enabled.
+	* crypt/md5c-test.c (main): Tolerate disabled MD5.
+	* sysdeps/unix/sysv/linux/fips-private.h: New file.
+	* sysdeps/generic/fips-private.h: New file, dummy fallback.
+
 2012-10-10  Alexandre Oliva <aoliva@redhat.com>
 
 	* crypt/crypt-private.h: Include stdbool.h.

crypt/crypt-entry.c

@@ -28,6 +28,7 @@
 #endif
 #include <string.h>
 #include <errno.h>
+#include <fips-private.h>
 
 #ifndef STATIC
 #define STATIC static
@@ -92,8 +93,16 @@ __crypt_r (key, salt, data)
 #ifdef _LIBC
   /* Try to find out whether we have to use MD5 encryption replacement.  */
   if (strncmp (md5_salt_prefix, salt, sizeof (md5_salt_prefix) - 1) == 0)
-    return __md5_crypt_r (key, salt, (char *) data,
-			  sizeof (struct crypt_data));
+    {
+      /* FIPS rules out MD5 password encryption.  */
+      if (fips_enabled_p ())
+	{
+	  __set_errno (EPERM);
+	  return NULL;
+	}
+      return __md5_crypt_r (key, salt, (char *) data,
+			    sizeof (struct crypt_data));
+    }
 
   /* Try to find out whether we have to use SHA256 encryption replacement.  */
   if (strncmp (sha256_salt_prefix, salt, sizeof (sha256_salt_prefix) - 1) == 0)
@@ -115,6 +124,13 @@ __crypt_r (key, salt, data)
       return NULL;
     }
 
+  /* FIPS rules out DES password encryption.  */
+  if (fips_enabled_p ())
+    {
+      __set_errno (EPERM);
+      return NULL;
+    }
+
   /*
    * Setup key schedule
    */
@@ -148,7 +164,9 @@ crypt (key, salt)
 {
 #ifdef _LIBC
   /* Try to find out whether we have to use MD5 encryption replacement.  */
-  if (strncmp (md5_salt_prefix, salt, sizeof (md5_salt_prefix) - 1) == 0)
+  if (strncmp (md5_salt_prefix, salt, sizeof (md5_salt_prefix) - 1) == 0
+      /* Let __crypt_r deal with the error code if FIPS is enabled.  */
+      && !fips_enabled_p ())
     return __md5_crypt (key, salt);
 
   /* Try to find out whether we have to use SHA256 encryption replacement.  */

crypt/md5c-test.c

@@ -9,7 +9,10 @@ main (int argc, char *argv[])
   int result = 0;
 
   cp = crypt ("Hello world!", salt);
-  result |= strcmp ("$1$saltstri$YMyguxXMBpd2TEZ.vS/3q1", cp);
+
+  /* MD5 is disabled in FIPS mode.  */
+  if (cp)
+    result |= strcmp ("$1$saltstri$YMyguxXMBpd2TEZ.vS/3q1", cp);
 
   return result;
 }

sysdeps/generic/fips-private.h

@@ -0,0 +1,36 @@
+/* Dummy implementation of FIPS compliance status test.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _FIPS_PRIVATE_H
+#define _FIPS_PRIVATE_H
+
+#include <stdbool.h>
+
+/* Return true if compliance with the FIPS security standards is
+   enabled.
+
+   This is only relevant within crypt, to tell whether MD5 and DES
+   algorithms should be rejected.  */
+
+static inline bool
+fips_enabled_p (void)
+{
+  return false;
+}
+
+#endif /* _FIPS_PRIVATE_H */

sysdeps/unix/sysv/linux/fips-private.h

@@ -0,0 +1,74 @@
+/* FIPS compliance status test for GNU/Linux systems.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _FIPS_PRIVATE_H
+#define _FIPS_PRIVATE_H
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <not-cancel.h>
+#include <stdbool.h>
+
+/* Return true if FIPS mode is enabled.  See
+   sysdeps/generic/fips-private.h for more information.  */
+
+static inline bool
+fips_enabled_p (void)
+{
+  static enum
+  {
+    FIPS_UNTESTED = 0,
+    FIPS_ENABLED = 1,
+    FIPS_DISABLED = -1,
+    FIPS_TEST_FAILED = -2
+  } checked;
+
+  if (checked == FIPS_UNTESTED)
+    {
+      int fd = open_not_cancel_2 ("/proc/sys/crypto/fips_enabled", O_RDONLY);
+
+      if (fd != -1)
+	{
+	  /* This is more than enough, the file contains a single integer.  */
+	  char buf[32];
+	  ssize_t n;
+	  n = TEMP_FAILURE_RETRY (read_not_cancel (fd, buf, sizeof (buf) - 1));
+	  close_not_cancel_no_status (fd);
+
+	  if (n > 0)
+	    {
+	      /* Terminate the string.  */
+	      buf[n] = '\0';
+
+	      char *endp;
+	      long int res = strtol (buf, &endp, 10);
+	      if (endp != buf && (*endp == '\0' || *endp == '\n'))
+		checked = (res > 0) ? FIPS_ENABLED : FIPS_DISABLED;
+	    }
+	}
+
+      if (checked == FIPS_UNTESTED)
+	checked = FIPS_TEST_FAILED;
+    }
+
+  return checked == FIPS_ENABLED;
+}
+
+#endif /* _FIPS_PRIVATE_H */