Fix seeding from random device w/o getrandom syscall

[oweals/openssl.git] / crypto / rand / rand_unix.c

diff --git a/crypto/rand/rand_unix.c b/crypto/rand/rand_unix.c
index 35777fffbae9e476253687907f66fc1cb21fafff..39c4e7e7417a627640cdc0fae68cd682d5de6541 100644 (file)
--- a/crypto/rand/rand_unix.c
+++ b/crypto/rand/rand_unix.c
@@ -19,7 +19,7 @@
 #include <stdio.h>
 #include "internal/dso.h"
 #if defined(__linux)
-# include <sys/syscall.h>
+# include <asm/unistd.h>
 #endif
 #if defined(__FreeBSD__)
 # include <sys/types.h>
@@ -324,8 +324,8 @@ static ssize_t syscall_random(void *buf, size_t buflen)
 #  endif
 
     /* Linux supports this since version 3.17 */
-#  if defined(__linux) && defined(SYS_getrandom)
-    return syscall(SYS_getrandom, buf, buflen, 0);
+#  if defined(__linux) && defined(__NR_getrandom)
+    return syscall(__NR_getrandom, buf, buflen, 0);
 #  elif (defined(__FreeBSD__) || defined(__NetBSD__)) && defined(KERN_ARND)
     return sysctl_random(buf, buflen);
 #  else
@@ -510,6 +510,29 @@ size_t rand_pool_acquire_entropy(RAND_POOL *pool)
     bytes_needed = rand_pool_bytes_needed(pool, 1 /*entropy_factor*/);
     {
         size_t i;
+#ifdef DEVRANDOM_WAIT
+        static int wait_done = 0;
+
+        /*
+         * On some implementations reading from /dev/urandom is possible
+         * before it is initialized. Therefore we wait for /dev/random
+         * to be readable to make sure /dev/urandom is initialized.
+         */
+        if (!wait_done && bytes_needed > 0) {
+             int f = open(DEVRANDOM_WAIT, O_RDONLY);
+
+             if (f >= 0) {
+                 fd_set fds;
+
+                 FD_ZERO(&fds);
+                 FD_SET(f, &fds);
+                 while (select(f+1, &fds, NULL, NULL, NULL) < 0
+                        && errno == EINTR);
+                 close(f);
+             }
+             wait_done = 1;
+        }
+#endif
 
         for (i = 0; bytes_needed > 0 && i < OSSL_NELEM(random_device_paths); i++) {
             ssize_t bytes = 0;