1 files changed, 80 insertions, 78 deletions

diff --git a/src/lib/libcrypto/crypto/getentropy_linux.c b/src/lib/libcrypto/crypto/getentropy_linux.c
index 1a22d2d306..993c1d2a83 100644
--- a/src/lib/libcrypto/crypto/getentropy_linux.c
+++ b/src/lib/libcrypto/crypto/getentropy_linux.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: getentropy_linux.c,v 1.1 2014/06/20 19:08:11 beck Exp $       */
+/*      $OpenBSD: getentropy_linux.c,v 1.2 2014/06/20 19:53:36 otto Exp $       */
 
 /*
  * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
@@ -61,8 +61,86 @@
 
 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_sysctl(void *buf, size_t len);
+static int getentropy_fallback(void *buf, size_t len);
+
+int
+getentropy(void *buf, size_t len)
+{
+        int ret = -1;
+
+        if (len > 256) {
+                errno = EIO;
+                return -1;
+        }
+
+        /*
+         * Try to get entropy with /dev/urandom
+         *
+         * This can fail if the process is inside a chroot or if file
+         * descriptors are exhausted.
+         */
+        ret = getentropy_urandom(buf, len);
+        if (ret != -1)
+                return (ret);
+
+#ifdef RANDOM_UUID
+        /*
+         * Try to use sysctl CTL_KERN, KERN_RANDOM, RANDOM_UUID.  sysctl is
+         * a failsafe API, so it guarantees a result.  This should work
+         * inside a chroot, or when file descriptors are exhuasted.
+         *
+         * However this can fail if the Linux kernel removes support for sysctl.
+         * Starting in 2007, there have been efforts to deprecate the sysctl
+         * API/ABI, and push callers towards use of the chroot-unavailable
+         * fd-using /proc mechanism -- essentially the same problems as
+         * /dev/urandom.
+         *
+         * Numerous setbacks have been encountered in their deprecation
+         * schedule, so as of June 2014 the kernel ABI still exists. The
+         * sysctl() stub in libc is missing on some systems.  There are
+         * also reports that some kernels spew messages to the console.
+         */
+        ret = getentropy_sysctl(buf, len);
+        if (ret != -1)
+                return (ret);
+#endif /* RANDOM_UUID */
+
+        /*
+         * Entropy collection via /dev/urandom and sysctl have failed.
+         *
+         * No other API exists for collecting entropy.  See the large
+         * comment block above.
+         *
+         * We have very few options:
+         *     - Even syslog_r is unsafe to call at this low level, so
+         *       there is no way to alert the user or program.
+         *     - Cannot call abort() because some systems have unsafe corefiles.
+         *     - Could raise(SIGKILL) resulting in silent program termination.
+         *     - Return EIO, to hint that arc4random's stir function
+         *       should raise(SIGKILL)
+         *     - Do the best under the circumstances....
+         *
+         * This code path exists to bring light to the issue that Linux
+         * does not provide a failsafe API for entropy collection.
+         *
+         * We hope this demonstrates that Linux should either retain their
+         * sysctl ABI, or consider providing a new failsafe API which
+         * works in a chroot or when file descriptors are exhausted.
+         */
+#undef FAIL_HARD_WHEN_LINUX_DEPRECATES_SYSCTL
+#ifdef FAIL_HARD_WHEN_LINUX_DEPRECATES_SYSCTL
+        raise(SIGKILL);
+#endif
+        ret = getentropy_fallback(buf, len);
+        if (ret != -1)
+                return (ret);
+
+        errno = EIO;
+        return (ret);
+}
 
 /*
  * XXX Should be replaced with a proper entropy measure.
@@ -361,79 +439,3 @@ getentropy_fallback(void *buf, size_t len)
         errno = EIO;
         return -1;
 }
-
-int
-getentropy(void *buf, size_t len)
-{
-        int ret = -1;
-
-        if (len > 256) {
-                errno = EIO;
-                return -1;
-        }
-
-        /*
-         * Try to get entropy with /dev/urandom
-         *
-         * This can fail if the process is inside a chroot or if file
-         * descriptors are exhausted.
-         */
-        ret = getentropy_urandom(buf, len);
-        if (ret != -1)
-                return (ret);
-
-#ifdef RANDOM_UUID
-        /*
-         * Try to use sysctl CTL_KERN, KERN_RANDOM, RANDOM_UUID.  sysctl is
-         * a failsafe API, so it guarantees a result.  This should work
-         * inside a chroot, or when file descriptors are exhuasted.
-         *
-         * However this can fail if the Linux kernel removes support for sysctl.
-         * Starting in 2007, there have been efforts to deprecate the sysctl
-         * API/ABI, and push callers towards use of the chroot-unavailable
-         * fd-using /proc mechanism -- essentially the same problems as
-         * /dev/urandom.
-         *
-         * Numerous setbacks have been encountered in their deprecation
-         * schedule, so as of June 2014 the kernel ABI still exists. The
-         * sysctl() stub in libc is missing on some systems.  There are
-         * also reports that some kernels spew messages to the console.
-         */
-        ret = getentropy_sysctl(buf, len);
-        if (ret != -1)
-                return (ret);
-#endif /* RANDOM_UUID */
-
-        /*
-         * Entropy collection via /dev/urandom and sysctl have failed.
-         *
-         * No other API exists for collecting entropy.  See the large
-         * comment block above.
-         *
-         * We have very few options:
-         *     - Even syslog_r is unsafe to call at this low level, so
-         *       there is no way to alert the user or program.
-         *     - Cannot call abort() because some systems have unsafe corefiles.
-         *     - Could raise(SIGKILL) resulting in silent program termination.
-         *     - Return EIO, to hint that arc4random's stir function
-         *       should raise(SIGKILL)
-         *     - Do the best under the circumstances....
-         *
-         * This code path exists to bring light to the issue that Linux
-         * does not provide a failsafe API for entropy collection.
-         *
-         * We hope this demonstrates that Linux should either retain their
-         * sysctl ABI, or consider providing a new failsafe API which
-         * works in a chroot or when file descriptors are exhausted.
-         */
-#undef FAIL_HARD_WHEN_LINUX_DEPRECATES_SYSCTL
-#ifdef FAIL_HARD_WHEN_LINUX_DEPRECATES_SYSCTL
-        raise(SIGKILL);
-#endif
-        ret = getentropy_fallback(buf, len);
-        if (ret != -1)
-                return (ret);
-
-        errno = EIO;
-        return (ret);
-}