commit 74aff357261879dfa8366528a42c59b042c7bd05
author Shawn Willden <swillden@google.com> Mon Aug 11 14:08:31 2014 -0600
committer Shawn Willden <swillden@google.com> Mon Aug 11 15:53:07 2014 -0600
tree 34aa425c1eaea6bc59d29a3fc425ec6537f2d2e3
parent 39b970bea81461af88f83e1c2329eb1b0f4d2e73

Implement and use secure memset to clear sensitive buffers.

Ordinary memset can be optimized away, leaking sensitive data to other
processes.

Change-Id: If4b51e342ef1f21d7e5fa8907bb0534b17bf295b

key_blob.cpp

diff --git a/key_blob.cpp b/key_blob.cpp
index 451ecae..101d158 100644
--- a/key_blob.cpp
+++ b/key_blob.cpp
@@ -136,7 +136,7 @@
     if (ae_err == AE_INVALID) {
         // Authentication failed!  Decryption probably succeeded(ish), but we don't want to return
         // any data when the authentication fails, so clear it.
-        memset(key_material_.get(), 0, key_material_length());
+        memset_s(key_material_.get(), 0, key_material_length());
         error_ = KM_ERROR_INVALID_KEY_BLOB;
         return;
     } else if (ae_err < 0) {
@@ -192,7 +192,7 @@
         AE_SUCCESS)
         return ctx.release();
     else {
-        memset(ctx.get(), 0, ae_ctx_sizeof());
+        memset_s(ctx.get(), 0, ae_ctx_sizeof());
         return NULL;
     }
 }