Fix seeding from random device w/o getrandom syscall

[openssl.git] / crypto / mem_sec.c

diff --git a/crypto/mem_sec.c b/crypto/mem_sec.c
index afd0c26beacb4fad89c6c80d82afdff5ed6fa3cd..9e0f6702f4069d7cdce6098e42877da8b3f417ef 100644 (file)
--- a/crypto/mem_sec.c
+++ b/crypto/mem_sec.c
@@ -20,10 +20,8 @@
 
 #include <string.h>
 
-/* e_os.h includes unistd.h, which defines _POSIX_VERSION */
-#if defined(OPENSSL_SYS_UNIX) \
-    && defined(_POSIX_VERSION) && _POSIX_VERSION >= 200112L
-# define IMPLEMENTED
+/* e_os.h defines OPENSSL_SECURE_MEMORY if secure memory can be implemented */
+#ifdef OPENSSL_SECURE_MEMORY
 # include <stdlib.h>
 # include <assert.h>
 # include <unistd.h>
@@ -31,8 +29,10 @@
 # include <sys/mman.h>
 # if defined(OPENSSL_SYS_LINUX)
 #  include <sys/syscall.h>
-#  include <linux/mman.h>
-#  include <errno.h>
+#  if defined(SYS_mlock2)
+#   include <linux/mman.h>
+#   include <errno.h>
+#  endif
 # endif
 # include <sys/param.h>
 # include <sys/stat.h>
@@ -43,8 +43,11 @@
 #ifndef PAGE_SIZE
 # define PAGE_SIZE    4096
 #endif
+#if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
+# define MAP_ANON MAP_ANONYMOUS
+#endif
 
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
 static size_t secure_mem_used;
 
 static int secure_mem_initialized;
@@ -64,11 +67,11 @@ static int sh_allocated(const char *ptr);
 
 int CRYPTO_secure_malloc_init(size_t size, int minsize)
 {
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
     int ret = 0;
 
     if (!secure_mem_initialized) {
-        sec_malloc_lock = CRYPTO_THREAD_glock_new("sec_malloc");
+        sec_malloc_lock = CRYPTO_THREAD_lock_new();
         if (sec_malloc_lock == NULL)
             return 0;
         if ((ret = sh_init(size, minsize)) != 0) {
@@ -82,12 +85,12 @@ int CRYPTO_secure_malloc_init(size_t size, int minsize)
     return ret;
 #else
     return 0;
-#endif /* IMPLEMENTED */
+#endif /* OPENSSL_SECURE_MEMORY */
 }
 
-int CRYPTO_secure_malloc_done()
+int CRYPTO_secure_malloc_done(void)
 {
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
     if (secure_mem_used == 0) {
         sh_done();
         secure_mem_initialized = 0;
@@ -95,22 +98,22 @@ int CRYPTO_secure_malloc_done()
         sec_malloc_lock = NULL;
         return 1;
     }
-#endif /* IMPLEMENTED */
+#endif /* OPENSSL_SECURE_MEMORY */
     return 0;
 }
 
-int CRYPTO_secure_malloc_initialized()
+int CRYPTO_secure_malloc_initialized(void)
 {
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
     return secure_mem_initialized;
 #else
     return 0;
-#endif /* IMPLEMENTED */
+#endif /* OPENSSL_SECURE_MEMORY */
 }
 
 void *CRYPTO_secure_malloc(size_t num, const char *file, int line)
 {
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
     void *ret;
     size_t actual_size;
 
@@ -125,21 +128,22 @@ void *CRYPTO_secure_malloc(size_t num, const char *file, int line)
     return ret;
 #else
     return CRYPTO_malloc(num, file, line);
-#endif /* IMPLEMENTED */
+#endif /* OPENSSL_SECURE_MEMORY */
 }
 
 void *CRYPTO_secure_zalloc(size_t num, const char *file, int line)
 {
-    void *ret = CRYPTO_secure_malloc(num, file, line);
-
-    if (ret != NULL)
-        memset(ret, 0, num);
-    return ret;
+#ifdef OPENSSL_SECURE_MEMORY
+    if (secure_mem_initialized)
+        /* CRYPTO_secure_malloc() zeroes allocations when it is implemented */
+        return CRYPTO_secure_malloc(num, file, line);
+#endif
+    return CRYPTO_zalloc(num, file, line);
 }
 
 void CRYPTO_secure_free(void *ptr, const char *file, int line)
 {
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
     size_t actual_size;
 
     if (ptr == NULL)
@@ -156,13 +160,13 @@ void CRYPTO_secure_free(void *ptr, const char *file, int line)
     CRYPTO_THREAD_unlock(sec_malloc_lock);
 #else
     CRYPTO_free(ptr, file, line);
-#endif /* IMPLEMENTED */
+#endif /* OPENSSL_SECURE_MEMORY */
 }
 
 void CRYPTO_secure_clear_free(void *ptr, size_t num,
                               const char *file, int line)
 {
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
     size_t actual_size;
 
     if (ptr == NULL)
@@ -183,12 +187,12 @@ void CRYPTO_secure_clear_free(void *ptr, size_t num,
         return;
     OPENSSL_cleanse(ptr, num);
     CRYPTO_free(ptr, file, line);
-#endif /* IMPLEMENTED */
+#endif /* OPENSSL_SECURE_MEMORY */
 }
 
 int CRYPTO_secure_allocated(const void *ptr)
 {
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
     int ret;
 
     if (!secure_mem_initialized)
@@ -199,21 +203,21 @@ int CRYPTO_secure_allocated(const void *ptr)
     return ret;
 #else
     return 0;
-#endif /* IMPLEMENTED */
+#endif /* OPENSSL_SECURE_MEMORY */
 }
 
-size_t CRYPTO_secure_used()
+size_t CRYPTO_secure_used(void)
 {
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
     return secure_mem_used;
 #else
     return 0;
-#endif /* IMPLEMENTED */
+#endif /* OPENSSL_SECURE_MEMORY */
 }
 
 size_t CRYPTO_secure_actual_size(void *ptr)
 {
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
     size_t actual_size;
 
     CRYPTO_THREAD_write_lock(sec_malloc_lock);
@@ -231,7 +235,7 @@ size_t CRYPTO_secure_actual_size(void *ptr)
 /*
  * SECURE HEAP IMPLEMENTATION
  */
-#ifdef IMPLEMENTED
+#ifdef OPENSSL_SECURE_MEMORY
 
 
 /*
@@ -493,7 +497,7 @@ static int sh_init(size_t size, int minsize)
     return 0;
 }
 
-static void sh_done()
+static void sh_done(void)
 {
     OPENSSL_free(sh.freelist);
     OPENSSL_free(sh.bittable);
@@ -581,6 +585,9 @@ static void *sh_malloc(size_t size)
 
     OPENSSL_assert(WITHIN_ARENA(chunk));
 
+    /* zero the free list header as a precaution against information leakage */
+    memset(chunk, 0, sizeof(SH_LIST));
+
     return chunk;
 }
 
@@ -613,6 +620,8 @@ static void sh_free(void *ptr)
 
         list--;
 
+        /* Zero the higher addressed block's free list pointers */
+        memset(ptr > buddy ? ptr : buddy, 0, sizeof(SH_LIST));
         if (ptr > buddy)
             ptr = buddy;
 
@@ -634,4 +643,4 @@ static size_t sh_actual_size(char *ptr)
     OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
     return sh.arena_size / (ONE << list);
 }
-#endif /* IMPLEMENTED */
+#endif /* OPENSSL_SECURE_MEMORY */