Implements Signature Creator & Verifier for openssl

base/openssl_util.h

Index: base/openssl_util.h
diff --git a/base/openssl_util.h b/base/openssl_util.h
index 1d290ae3ad0cd6dcb13206d943961ceb75bd2a8b..366c00c1f98ef0ddd61696ee5c682c2235a3dd24 100644
--- a/base/openssl_util.h
+++ b/base/openssl_util.h
@@ -16,10 +16,17 @@ namespace base {
 template <typename T, void (*destructor)(T*)>
 class ScopedOpenSSL {
  public:
-  explicit ScopedOpenSSL(T* ptr_) : ptr_(ptr_) { }
+  ScopedOpenSSL() : ptr_(NULL) { }
+  explicit ScopedOpenSSL(T* ptr) : ptr_(ptr) { }
   ~ScopedOpenSSL() { if (ptr_) (*destructor)(ptr_); }
 
   T* get() const { return ptr_; }
+  void reset(T* ptr) {
+    if (ptr != ptr_) {
+      if (ptr_) (*destructor)(ptr_);
+      ptr_ = ptr;
+    }
+  }
 
  private:
   T* ptr_;
@@ -72,8 +79,27 @@ class ScopedOpenSSLSafeSizeBuffer {
 void EnsureOpenSSLInit();
 
 // Drains the OpenSSL ERR_get_error stack. On a debug build the error codes
-// are send to VLOG(1), on a release build they are disregarded.
-void ClearOpenSSLERRStack();
+// are send to VLOG(1), on a release build they are disregarded. In most
+// cases you should pass FROM_HERE as the |location|.
+void ClearOpenSSLERRStack(const tracked_objects::Location& location);
+
+// Place an instance of this class on the call stack to automatically clear
+// the OpenSSL error stack on function exit. Note any diagnostic will be emitted
+// with the location of construction, as it's not possible to track the callsite
+// of the destructor.
+class OpenSSLErrStackTracer {
+ public:
+  explicit OpenSSLErrStackTracer(const tracked_objects::Location& location)
+      : location_(location) {
+    EnsureOpenSSLInit();
+  }
+  ~OpenSSLErrStackTracer() { ClearOpenSSLERRStack(location_); }
+
+ private:
+  const tracked_objects::Location location_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(OpenSSLErrStackTracer);
+};
 
 }  // namespace base