xnu-7195.101.1.tar.gz

[apple/xnu.git] / bsd / dev / random / randomdev.c

diff --git a/bsd/dev/random/randomdev.c b/bsd/dev/random/randomdev.c
index 96f997e24d0324d9da3231448ce3c48ec9d78580..5d0ebe81df1bbfadc2d2eb48220dadf3b986b29a 100644 (file)
--- a/bsd/dev/random/randomdev.c
+++ b/bsd/dev/random/randomdev.c
@@ -1,17 +1,20 @@
 /*
 /*

- * Copyright (c) 1999, 2000-2002 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1999-2009 Apple, Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@

  *
  *

- * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
- * 

  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in

- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- * 
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *

  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,


@@ -19,10 +22,11 @@
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.

- * 
- * @APPLE_LICENSE_HEADER_END@
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@

  */
 
  */
 

+

 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/proc.h>
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/proc.h>


@@ -30,164 +34,120 @@
 #include <sys/ioctl.h>
 #include <sys/conf.h>
 #include <sys/fcntl.h>
 #include <sys/ioctl.h>
 #include <sys/conf.h>
 #include <sys/fcntl.h>

+#include <string.h>

 #include <miscfs/devfs/devfs.h>
 #include <miscfs/devfs/devfs.h>

-#include <kern/lock.h>
+#include <kern/locks.h>
+#include <kern/clock.h>

 #include <sys/time.h>
 #include <sys/malloc.h>
 #include <sys/time.h>
 #include <sys/malloc.h>

+#include <sys/sysproto.h>
+#include <sys/uio_internal.h>

 
 #include <dev/random/randomdev.h>
 
 #include <dev/random/randomdev.h>

-#include <dev/random/YarrowCoreLib/include/yarrow.h>

 
 

-#define RANDOM_MAJOR  -1 /* let the kernel pick the device number */
+#include <libkern/OSByteOrder.h>
+#include <libkern/OSAtomic.h>

 
 

-/*
- * A struct describing which functions will get invoked for certain
- * actions.
- */
-static struct cdevsw random_cdevsw =
-{
-       random_open,            /* open */
-       random_close,           /* close */
-       random_read,            /* read */
-       random_write,           /* write */
-       eno_ioctl,                      /* ioctl */
-       nulldev,                        /* stop */
-       nulldev,                        /* reset */
-       NULL,                           /* tty's */
-       eno_select,                     /* select */
-       eno_mmap,                       /* mmap */
-       eno_strat,                      /* strategy */
-       eno_getc,                       /* getc */
-       eno_putc,                       /* putc */
-       0                                       /* type */
-};
+#include <mach/mach_time.h>

 
 

-/* Used to detect whether we've already been initialized */
-static int gRandomInstalled = 0;
-static PrngRef gPrngRef;
-static int gRandomError = 1;
-static mutex_t *gYarrowMutex = 0;
+#define RANDOM_MAJOR  -1 /* let the kernel pick the device number */
+#define RANDOM_MINOR   0
+#define URANDOM_MINOR  1

 
 

-#define RESEED_TICKS 50 /* how long a reseed operation can take */
+d_ioctl_t       random_ioctl;

 
 

-/*
- *Initialize ONLY the Yarrow generator.
- */
-void PreliminarySetup ()
+static const struct cdevsw random_cdevsw =

 {
 {

-    prng_error_status perr;
-    struct timeval tt;
-    char buffer [16];
-
-    /* create a Yarrow object */
-    perr = prngInitialize(&gPrngRef);
-    if (perr != 0) {
-        printf ("Couldn't initialize Yarrow, /dev/random will not work.\n");
-        return;
-    }
-
-       /* clear the error flag, reads and write should then work */
-    gRandomError = 0;
-
-    /* get a little non-deterministic data as an initial seed. */
-    microtime(&tt);
-
-    /*
-        * So how much of the system clock is entropic?
-        * It's hard to say, but assume that at least the
-        * least significant byte of a 64 bit structure
-        * is entropic.  It's probably more, how can you figure
-        * the exact time the user turned the computer on, for example.
-    */
-    perr = prngInput(gPrngRef, (BYTE*) &tt, sizeof (tt), SYSTEM_SOURCE, 8);
-    if (perr != 0) {
-        /* an error, complain */
-        printf ("Couldn't seed Yarrow.\n");
-        return;
-    }
-    
-    /* turn the data around */
-    perr = prngOutput(gPrngRef, (BYTE*) buffer, sizeof (buffer));
-    
-    /* and scramble it some more */
-    perr = prngForceReseed(gPrngRef, RESEED_TICKS);
-    
-    /* make a mutex to control access */
-    gYarrowMutex = mutex_alloc(0);
-}
+       .d_open = random_open,
+       .d_close = random_close,
+       .d_read = random_read,
+       .d_write = random_write,
+       .d_ioctl = random_ioctl,
+       .d_stop = (stop_fcn_t *)nulldev,
+       .d_reset = (reset_fcn_t *)nulldev,
+       .d_select = eno_select,
+       .d_mmap = eno_mmap,
+       .d_strategy = eno_strat,
+       .d_reserved_1 = eno_getc,
+       .d_reserved_2 = eno_putc,
+};
+

 
 /*
  * Called to initialize our device,
  * and to register ourselves with devfs
  */
 void
 
 /*
  * Called to initialize our device,
  * and to register ourselves with devfs
  */
 void

-random_init()
+random_init(void)

 {
        int ret;
 
 {
        int ret;
 

-       if (gRandomInstalled)
-               return;
-
-       /* install us in the file system */
-       gRandomInstalled = 1;
-
-       /* setup yarrow and the mutex */
-       PreliminarySetup();
-

        ret = cdevsw_add(RANDOM_MAJOR, &random_cdevsw);
        if (ret < 0) {
        ret = cdevsw_add(RANDOM_MAJOR, &random_cdevsw);
        if (ret < 0) {

-               printf("random_init: failed to allocate a major number!\n");
-               gRandomInstalled = 0;
-               return;
+               panic("random_init: failed to allocate a major number!");

        }
 
        }
 

-       devfs_make_node(makedev (ret, 0), DEVFS_CHAR,
-               UID_ROOT, GID_WHEEL, 0644, "random", 0);
+       devfs_make_node(makedev(ret, RANDOM_MINOR), DEVFS_CHAR,
+           UID_ROOT, GID_WHEEL, 0666, "random", 0);

 
        /*
 
        /*

-        * also make urandom 
+        * also make urandom

         * (which is exactly the same thing in our context)
         */
         * (which is exactly the same thing in our context)
         */

-       devfs_make_node(makedev (ret, 1), DEVFS_CHAR,
-               UID_ROOT, GID_WHEEL, 0644, "urandom", 0);
+       devfs_make_node(makedev(ret, URANDOM_MINOR), DEVFS_CHAR,
+           UID_ROOT, GID_WHEEL, 0666, "urandom", 0);
+}
+
+int
+random_ioctl(   __unused dev_t dev, u_long cmd, __unused caddr_t data,
+    __unused int flag, __unused struct proc *p  )
+{
+       switch (cmd) {
+       case FIONBIO:
+       case FIOASYNC:
+               break;
+       default:
+               return ENODEV;
+       }
+
+       return 0;

 }
 
 /*
  * Open the device.  Make sure init happened, and make sure the caller is
  * authorized.
  */
 }
 
 /*
  * Open the device.  Make sure init happened, and make sure the caller is
  * authorized.
  */

- 
+

 int
 int

-random_open(dev_t dev, int flags, int devtype, struct proc *p)
+random_open(__unused dev_t dev, int flags, __unused int devtype, __unused struct proc *p)

 {
 {

-       if (gRandomError != 0) {
-               /* forget it, yarrow didn't come up */
-               return (ENOTSUP);
-       }
-

        /*
         * if we are being opened for write,
         * make sure that we have privledges do so
         */
        if (flags & FWRITE) {
        /*
         * if we are being opened for write,
         * make sure that we have privledges do so
         */
        if (flags & FWRITE) {

-               if (securelevel >= 2)
-                       return (EPERM);
-               if ((securelevel >= 1) && suser(p->p_ucred, &p->p_acflag))
-                       return (EPERM);
+               if (securelevel >= 2) {
+                       return EPERM;
+               }
+#ifndef __APPLE__
+               if ((securelevel >= 1) && proc_suser(p)) {
+                       return EPERM;
+               }
+#endif  /* !__APPLE__ */

        }
 
        }
 

-       return (0);
+       return 0;

 }
 
 
 /*
  * close the device.
  */
 }
 
 
 /*
  * close the device.
  */

- 
+

 int
 int

-random_close(dev_t dev, int flags, int mode, struct proc *p)
+random_close(__unused dev_t dev, __unused int flags, __unused int mode, __unused struct proc *p)

 {
 {

-       return (0);
+       return 0;

 }
 
 
 }
 
 


@@ -196,111 +156,85 @@ random_close(dev_t dev, int flags, int mode, struct proc *p)
  * prng.
  */
 int
  * prng.
  */
 int

-random_write (dev_t dev, struct uio *uio, int ioflag)
+random_write(dev_t dev, struct uio *uio, __unused int ioflag)

 {
 {

-    int retCode = 0;
-    char rdBuffer[256];
-
-    if (gRandomError != 0) {
-        return (ENOTSUP);
-    }
-    
-    /* get control of the Yarrow instance, Yarrow is NOT thread safe */
-    mutex_lock(gYarrowMutex);
-    
-    /* Security server is sending us entropy */
-
-    while (uio->uio_resid > 0 && retCode == 0) {
-        /* get the user's data */
-        int bytesToInput = min(uio->uio_resid, sizeof (rdBuffer));
-        retCode = uiomove(rdBuffer, bytesToInput, uio);
-        if (retCode != 0)
-            goto /*ugh*/ error_exit;
-        
-        /* put it in Yarrow */
-        if (prngInput(gPrngRef, (BYTE*) rdBuffer,
-                       sizeof (rdBuffer), SYSTEM_SOURCE,
-               sizeof (rdBuffer) * 8) != 0) {
-            retCode = EIO;
-            goto error_exit;
-        }
-    }
-    
-    /* force a reseed */
-    if (prngForceReseed(gPrngRef, RESEED_TICKS) != 0) {
-        retCode = EIO;
-        goto error_exit;
-    }
-    
-    /* retCode should be 0 at this point */
-    
-error_exit: /* do this to make sure the mutex unlocks. */
-    mutex_unlock(gYarrowMutex);
-    return (retCode);
+       int retCode = 0;
+       char rdBuffer[256];
+
+       if (minor(dev) != RANDOM_MINOR) {
+               return EPERM;
+       }
+
+       /* Security server is sending us entropy */
+
+       while ((size_t)uio_resid(uio) > 0 && retCode == 0) {
+               /* get the user's data */
+               size_t bytesToInput = MIN((size_t)uio_resid(uio), sizeof(rdBuffer));
+               retCode = uiomove(rdBuffer, (int)bytesToInput, uio);
+               if (retCode != 0) {
+                       break;
+               }
+               retCode = write_random(rdBuffer, (u_int)bytesToInput);
+               if (retCode != 0) {
+                       break;
+               }
+       }
+
+       return retCode;

 }
 
 /*
  * return data to the caller.  Results unpredictable.
 }
 
 /*
  * return data to the caller.  Results unpredictable.

- */ 
+ */

 int
 int

-random_read(dev_t dev, struct uio *uio, int ioflag)
+random_read(__unused dev_t dev, struct uio *uio, __unused int ioflag)

 {
 {

-    int retCode = 0;
-    char wrBuffer[512];
-
-    if (gRandomError != 0)
-        return (ENOTSUP);
-
-   /* lock down the mutex */
-    mutex_lock(gYarrowMutex);
-
-    while (uio->uio_resid > 0 && retCode == 0) {
-        /* get the user's data */
-        int bytesToRead = min(uio->uio_resid, sizeof (wrBuffer));
-        
-        /* get the data from Yarrow */
-        if (prngOutput(gPrngRef, (BYTE *) wrBuffer, sizeof (wrBuffer)) != 0) {
-            printf ("Couldn't read data from Yarrow.\n");
-            
-            /* something's really weird */
-            retCode = EIO;
-            goto error_exit;
-        }
-        
-        retCode = uiomove(wrBuffer, bytesToRead, uio);
-        
-        if (retCode != 0)
-            goto error_exit;
-    }
-    
-    retCode = 0;
-    
-error_exit:
-    mutex_unlock(gYarrowMutex);
-    return retCode;
-}
+       int retCode = 0;
+       char buffer[512];

 
 

-/* export good random numbers to the rest of the kernel */
-void
-read_random(void* buffer, u_int numbytes)
-{
-    if (gYarrowMutex == 0) { /* are we initialized? */
-        PreliminarySetup ();
-    }
-    
-    mutex_lock(gYarrowMutex);
-    prngOutput(gPrngRef, (BYTE *) buffer, numbytes);
-    mutex_unlock(gYarrowMutex);
+       size_t bytes_remaining = (size_t)uio_resid(uio);
+       while (bytes_remaining > 0 && retCode == 0) {
+               size_t bytesToRead = MIN(bytes_remaining, sizeof(buffer));
+               read_random(buffer, (u_int)bytesToRead);
+
+               retCode = uiomove(buffer, (int)bytesToRead, uio);
+               if (retCode != 0) {
+                       break;
+               }
+
+               bytes_remaining = (size_t)uio_resid(uio);
+       }
+
+       return retCode;

 }
 
 /*
 }
 
 /*

- * Return an unsigned long pseudo-random number.
+ * Return an u_int32_t pseudo-random number.

  */
  */

-u_long
-RandomULong()
+u_int32_t
+RandomULong(void)

 {
 {

-       u_long buf;
-       read_random(&buf, sizeof (buf));
-       return (buf);
+       u_int32_t buf;
+       read_random(&buf, sizeof(buf));
+       return buf;

 }
 
 }
 

+
+int
+getentropy(__unused struct proc * p, struct getentropy_args *gap, __unused int * ret)
+{
+       user_addr_t user_addr;
+       user_size_t user_size;
+       char buffer[256];
+
+       user_addr = (user_addr_t)gap->buffer;
+       user_size = gap->size;
+       /* Can't request more than 256 random bytes
+        * at once. Complying with openbsd getentropy()
+        */
+       if (user_size > sizeof(buffer)) {
+               return EINVAL;
+       }
+       read_random(buffer, (u_int)user_size);
+       return copyout(buffer, user_addr, user_size);
+}