initial top-level import of subdirectories

2 files changed, 53 insertions, 0 deletions

diff --git a/crypto/compat/issetugid_linux.c b/crypto/compat/issetugid_linux.c
new file mode 100644
index 0000000..669edce
--- /dev/null
+++ b/crypto/compat/issetugid_linux.c
@@ -0,0 +1,47 @@
+/*
+ * issetugid implementation for Linux
+ * Public domain
+ */
+
+#include <errno.h>
+#include <gnu/libc-version.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+/*
+ * Linux-specific glibc 2.16+ interface for determining if a process was
+ * launched setuid/setgid or with additional capabilities.
+ */
+#ifdef HAVE_GETAUXVAL
+#include <sys/auxv.h>
+#endif
+
+int issetugid(void)
+{
+#ifdef HAVE_GETAUXVAL
+        /*
+         * The API for glibc < 2.19 does not indicate if there is an error with
+         * getauxval. While it should not be the case that any 2.6 or greater
+         * kernel ever does not supply AT_SECURE, an emulated software environment
+         * might rewrite the aux vector.
+         *
+         * See https://sourceware.org/bugzilla/show_bug.cgi?id=15846
+         *
+         * Perhaps this code should just read the aux vector itself, so we have
+         * backward-compatibility and error handling in older glibc versions.
+         * info: http://lwn.net/Articles/519085/
+         *
+         */
+        const char *glcv = gnu_get_libc_version();
+        if (strverscmp(glcv, "2.19") >= 0) {
+                errno = 0;
+                if (getauxval(AT_SECURE) == 0) {
+                        if (errno != ENOENT) {
+                                return 0;
+                        }
+                }
+        }
+#endif
+        return 1;
+}
diff --git a/crypto/compat/thread_private.h b/crypto/compat/thread_private.h
new file mode 100644
index 0000000..3286a7c
--- /dev/null
+++ b/crypto/compat/thread_private.h
@@ -0,0 +1,6 @@
+#include <pthread.h>
+
+static pthread_mutex_t arc4random_mtx = PTHREAD_MUTEX_INITIALIZER;
+
+#define _ARC4_LOCK()   pthread_mutex_lock(&arc4random_mtx)
+#define _ARC4_UNLOCK() pthread_mutex_unlock(&arc4random_mtx)