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..0f69c8f95f60551810cb441a520cab3ccb325533 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_;
@@ -72,9 +79,24 @@ 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.
+// are send to VLOG(1), on a release build they are disregarded. An optional
+// |message| can be passed, which will be prepended to the error stack output
+// if present.
+void ClearOpenSSLERRStack(const char* message);

[wtc, 2010/11/17 20:30:48]

Please consult the Style Guide's recommendations on
function overloading and optional arguments.  I remember
they're discouraged in general but allowed in some cases,
but I don't remember the details.

[joth, 2010/11/18 12:52:47]

Done.
It falls under the "overloads must be obvious" subjectiveness test.
I had a better idea though and removed the overload, and updated all callsites
to pass FROM_HERE instead as this seems generally better.

 void ClearOpenSSLERRStack();
 
+// Place an instance of this class on the call stack to automatically clear
+// the OpenSSL error stack on function exit. If |message| is not null it will
+// be included in any error dump.
+class OpenSSLErrStackTracer {
+ public:
+  explicit OpenSSLErrStackTracer(const char* message) : message_(message) {}
+  ~OpenSSLErrStackTracer() { ClearOpenSSLERRStack(message_); }
+
+ private:
+  const char* const message_;
+};
+
 }  // namespace base
 
 #endif  // BASE_OPENSSL_UTIL_H_