1 files changed, 34 insertions, 18 deletions

diff --git a/src/lib/libcrypto/arc4random/getentropy_solaris.c b/src/lib/libcrypto/arc4random/getentropy_solaris.c
index 6aeb8713ab..13afe7e3c9 100644
--- a/src/lib/libcrypto/arc4random/getentropy_solaris.c
+++ b/src/lib/libcrypto/arc4random/getentropy_solaris.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: getentropy_solaris.c,v 1.1 2014/07/08 10:45:35 beck Exp $     */
+/*      $OpenBSD: getentropy_solaris.c,v 1.2 2014/07/12 13:19:44 beck Exp $     */
 
 /*
  * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
@@ -66,7 +66,8 @@ int	getentropy(void *buf, size_t len);
 
 extern int main(int, char *argv[]);
 static int gotdata(char *buf, size_t len);
-static int getentropy_urandom(void *buf, size_t len);
+static int getentropy_urandom(void *buf, size_t len, const char *path,
+    int devfscheck);
 static int getentropy_fallback(void *buf, size_t len);
 
 int
@@ -80,20 +81,39 @@ getentropy(void *buf, size_t len)
         }
 
         /*
-         * Try to get entropy with /dev/urandom
+         * Try to get entropy with /dev/urandom...
+         *
+         * Solaris provides /dev/urandom as a symbolic link to
+         * /devices/pseudo/random@0:urandom which is provided by
+         * a devfs filesystem.  Best practice is to use O_NOFOLLOW,
+         * so we must try the unpublished name directly.
+         *
+         * This can fail if the process is inside a chroot which lacks
+         * the devfs mount, or if file descriptors are exhausted.
+         */
+        ret = getentropy_urandom(buf, len,
+            "/devices/pseudo/random@0:urandom", 1);
+        if (ret != -1)
+                return (ret);
+
+        /*
+         * Unfortunately, chroot spaces on Solaris are sometimes setup
+         * with direct device node of the well-known /dev/urandom name
+         * (perhaps to avoid dragging all of devfs into the space).
          *
          * This can fail if the process is inside a chroot or if file
          * descriptors are exhausted.
          */
-        ret = getentropy_urandom(buf, len);
+        ret = getentropy_urandom(buf, len, "/dev/urandom", 0);
         if (ret != -1)
                 return (ret);
+
         /*
-         * Entropy collection via /dev/urandom and sysctl have failed.
+         * Entropy collection via /dev/urandom has failed.
          *
          * No other API exists for collecting entropy, and we have
-         * no failsafe way to get it on Solaris that is not sensitive
-         * to resource exhaustion.
+         * no failsafe way to get it on Solaris that is not sensitive
+         * to resource exhaustion.
          *
          * We have very few options:
          *     - Even syslog_r is unsafe to call at this low level, so
@@ -141,7 +161,7 @@ gotdata(char *buf, size_t len)
 }
 
 static int
-getentropy_urandom(void *buf, size_t len)
+getentropy_urandom(void *buf, size_t len, const char *path, int devfscheck)
 {
         struct stat st;
         size_t i;
@@ -150,19 +170,14 @@ getentropy_urandom(void *buf, size_t len)
 
 start:
 
-        flags = O_RDONLY;
+        flags = O_RDONLY;
 #ifdef O_NOFOLLOW
-        flags |= O_NOFOLLOW;
+        flags |= O_NOFOLLOW;
 #endif
 #ifdef O_CLOEXEC
-        flags |= O_CLOEXEC;
+        flags |= O_CLOEXEC;
 #endif
-        /* 
-         * Solaris provides /dev/urandom as a symbolic link. 
-         * /devices/pseudo/random@0:urandom should be the
-         * real device path, and we do want O_NOFOLLOW. 
-         */
-        fd = open("/devices/pseudo/random@0:urandom", flags, 0);
+        fd = open(path, flags, 0);
         if (fd == -1) {
                 if (errno == EINTR)
                         goto start;
@@ -173,7 +188,8 @@ start:
 #endif
 
         /* Lightly verify that the device node looks sane */
-        if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) {
+        if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode) ||
+            (devfscheck && (strcmp(st.st_fstype, "devfs") != 0))) {
                 close(fd);
                 goto nodevrandom;
         }