1 files changed, 38 insertions, 0 deletions
diff --git a/crypto/err/err.c b/crypto/err/err.c
index e9ef2156e11f3..5ce774a3f5675 100644
--- a/crypto/err/err.c
+++ b/crypto/err/err.c
@@ -118,6 +118,7 @@
 #include <openssl/buffer.h>
 #include <openssl/bio.h>
 #include <openssl/err.h>
+#include "constant_time_locl.h"
 
 DECLARE_LHASH_OF(ERR_STRING_DATA);
 DECLARE_LHASH_OF(ERR_STATE);
@@ -1156,3 +1157,40 @@ int ERR_pop_to_mark(void)
     es->err_flags[es->top] &= ~ERR_FLAG_MARK;
     return 1;
 }
+
+#ifdef UINTPTR_T
+# undef UINTPTR_T
+#endif
+/*
+ * uintptr_t is the answer, but unformtunately we can't assume that all
+ * compilers supported by 1.0.2 have it :-(
+ */
+#if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE==64
+/*
+ * But we can't use size_t on VMS, because it adheres to sizeof(size_t)==4
+ * even in 64-bit builds, which means that it won't work as mask.
+ */
+# define UINTPTR_T unsigned long long
+#else
+# define UINTPTR_T size_t
+#endif
+
+void err_clear_last_constant_time(int clear)
+{
+    ERR_STATE *es;
+    int top;
+
+    es = ERR_get_state();
+    if (es == NULL)
+        return;
+
+    top = es->top;
+
+    es->err_flags[top] &= ~(0 - clear);
+    es->err_buffer[top] &= ~(0UL - clear);
+    es->err_file[top] = (const char *)((UINTPTR_T)es->err_file[top] &
+                                       ~((UINTPTR_T)0 - clear));
+    es->err_line[top] |= 0 - clear;
+
+    es->top = (top + ERR_NUM_ERRORS - clear) % ERR_NUM_ERRORS;
+}