8 files changed, 38 insertions, 30 deletions
diff --git a/crypto/include/internal/rand_int.h b/crypto/include/internal/rand_int.h
index ea3b1a4311..a4947bc465 100644
--- a/crypto/include/internal/rand_int.h
+++ b/crypto/include/internal/rand_int.h
@@ -26,7 +26,6 @@ typedef struct rand_pool_st RAND_POOL;
 void rand_cleanup_int(void);
 void rand_drbg_cleanup_int(void);
 void drbg_delete_thread_state(void);
-void rand_fork(void);
 
 /* Hardware-based seeding functions. */
 size_t rand_acquire_entropy_from_tsc(RAND_POOL *pool);
diff --git a/crypto/init.c b/crypto/init.c
index 46839e768f..9fc0e8ef68 100644
--- a/crypto/init.c
+++ b/crypto/init.c
@@ -847,6 +847,5 @@ void OPENSSL_fork_parent(void)
 
 void OPENSSL_fork_child(void)
 {
-    rand_fork();
 }
 #endif
diff --git a/crypto/rand/drbg_lib.c b/crypto/rand/drbg_lib.c
index 7d0c8027fd..12bb627a04 100644
--- a/crypto/rand/drbg_lib.c
+++ b/crypto/rand/drbg_lib.c
@@ -197,7 +197,7 @@ static RAND_DRBG *rand_drbg_new(int secure,
     }
 
     drbg->secure = secure && CRYPTO_secure_allocated(drbg);
-    drbg->fork_count = rand_fork_count;
+    drbg->fork_id = openssl_get_fork_id();
     drbg->parent = parent;
 
     if (parent == NULL) {
@@ -578,6 +578,7 @@ int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
                        int prediction_resistance,
                        const unsigned char *adin, size_t adinlen)
 {
+    int fork_id;
     int reseed_required = 0;
 
     if (drbg->state != DRBG_READY) {
@@ -603,8 +604,10 @@ int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
         return 0;
     }
 
-    if (drbg->fork_count != rand_fork_count) {
-        drbg->fork_count = rand_fork_count;
+    fork_id = openssl_get_fork_id();
+
+    if (drbg->fork_id != fork_id) {
+        drbg->fork_id = fork_id;
         reseed_required = 1;
     }
 
diff --git a/crypto/rand/rand_lcl.h b/crypto/rand/rand_lcl.h
index f28642e425..1c2b266330 100644
--- a/crypto/rand/rand_lcl.h
+++ b/crypto/rand/rand_lcl.h
@@ -186,12 +186,12 @@ struct rand_drbg_st {
     int secure; /* 1: allocated on the secure heap, 0: otherwise */
     int type; /* the nid of the underlying algorithm */
     /*
-     * Stores the value of the rand_fork_count global as of when we last
-     * reseeded.  The DRBG reseeds automatically whenever drbg->fork_count !=
-     * rand_fork_count.  Used to provide fork-safety and reseed this DRBG in
-     * the child process.
+     * Stores the return value of openssl_get_fork_id() as of when we last
+     * reseeded.  The DRBG reseeds automatically whenever drbg->fork_id !=
+     * openssl_get_fork_id().  Used to provide fork-safety and reseed this
+     * DRBG in the child process.
      */
-    int fork_count;
+    int fork_id;
     unsigned short flags; /* various external flags */
 
     /*
@@ -283,19 +283,6 @@ struct rand_drbg_st {
 /* The global RAND method, and the global buffer and DRBG instance. */
 extern RAND_METHOD rand_meth;
 
-/*
- * A "generation count" of forks.  Incremented in the child process after a
- * fork.  Since rand_fork_count is increment-only, and only ever written to in
- * the child process of the fork, which is guaranteed to be single-threaded, no
- * locking is needed for normal (read) accesses; the rest of pthread fork
- * processing is assumed to introduce the necessary memory barriers.  Sibling
- * children of a given parent will produce duplicate values, but this is not
- * problematic because the reseeding process pulls input from the system CSPRNG
- * and/or other global sources, so the siblings will end up generating
- * different output streams.
- */
-extern int rand_fork_count;
-
 /* DRBG helpers */
 int rand_drbg_restart(RAND_DRBG *drbg,
                       const unsigned char *buffer, size_t len, size_t entropy);
diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c
index 23bb2e68b1..ce4e17c414 100644
--- a/crypto/rand/rand_lib.c
+++ b/crypto/rand/rand_lib.c
@@ -26,8 +26,6 @@ static CRYPTO_RWLOCK *rand_meth_lock;
 static const RAND_METHOD *default_RAND_meth;
 static CRYPTO_ONCE rand_init = CRYPTO_ONCE_STATIC_INIT;
 
-int rand_fork_count;
-
 static CRYPTO_RWLOCK *rand_nonce_lock;
 static int rand_nonce_count;
 
@@ -303,11 +301,6 @@ void rand_drbg_cleanup_additional_data(RAND_POOL *pool, unsigned char *out)
     rand_pool_reattach(pool, out);
 }
 
-void rand_fork(void)
-{
-    rand_fork_count++;
-}
-
 DEFINE_RUN_ONCE_STATIC(do_rand_init)
 {
 #ifndef OPENSSL_NO_ENGINE
diff --git a/crypto/threads_none.c b/crypto/threads_none.c
index 4b1940ae44..7348af02c1 100644
--- a/crypto/threads_none.c
+++ b/crypto/threads_none.c
@@ -12,6 +12,11 @@
 
 #if !defined(OPENSSL_THREADS) || defined(CRYPTO_TDEBUG)
 
+# if defined(OPENSSL_SYS_UNIX)
+#  include <sys/types.h>
+#  include <unistd.h>
+# endif
+
 CRYPTO_RWLOCK *CRYPTO_THREAD_lock_new(void)
 {
     CRYPTO_RWLOCK *lock;
@@ -133,4 +138,12 @@ int openssl_init_fork_handlers(void)
     return 0;
 }
 
+int openssl_get_fork_id(void)
+{
+# if defined(OPENSSL_SYS_UNIX)
+    return getpid();
+# else
+    return return 0;
+# endif
+}
 #endif
diff --git a/crypto/threads_pthread.c b/crypto/threads_pthread.c
index 5a59779ebb..7e8603de66 100644
--- a/crypto/threads_pthread.c
+++ b/crypto/threads_pthread.c
@@ -12,6 +12,11 @@
 
 #if defined(OPENSSL_THREADS) && !defined(CRYPTO_TDEBUG) && !defined(OPENSSL_SYS_WINDOWS)
 
+# if defined(OPENSSL_SYS_UNIX)
+#  include <sys/types.h>
+#  include <unistd.h>
+#endif
+
 # ifdef PTHREAD_RWLOCK_INITIALIZER
 #  define USE_RWLOCK
 # endif
@@ -193,4 +198,9 @@ int openssl_init_fork_handlers(void)
 # endif
     return 0;
 }
+
+int openssl_get_fork_id(void)
+{
+    return getpid();
+}
 #endif
diff --git a/crypto/threads_win.c b/crypto/threads_win.c
index b0b16fd330..44a360fcab 100644
--- a/crypto/threads_win.c
+++ b/crypto/threads_win.c
@@ -164,4 +164,8 @@ int openssl_init_fork_handlers(void)
     return 0;
 }
 
+int openssl_get_fork_id(void)
+{
+    return 0;
+}
 #endif