Index: crypto/openssl_util.h |
=================================================================== |
--- crypto/openssl_util.h (revision 0) |
+++ crypto/openssl_util.h (revision 0) |
@@ -0,0 +1,113 @@ |
+// Copyright (c) 2011 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#ifndef CRYPTO_OPENSSL_UTIL_H_ |
+#define CRYPTO_OPENSSL_UTIL_H_ |
+#pragma once |
+ |
+#include "base/basictypes.h" |
+#include "base/tracked.h" |
+ |
+namespace crypto { |
+ |
+// A helper class that takes care of destroying OpenSSL objects when it goes out |
+// of scope. |
+template <typename T, void (*destructor)(T*)> |
+class ScopedOpenSSL { |
+ public: |
+ ScopedOpenSSL() : ptr_(NULL) { } |
+ explicit ScopedOpenSSL(T* ptr) : ptr_(ptr) { } |
+ ~ScopedOpenSSL() { |
+ reset(NULL); |
+ } |
+ |
+ T* get() const { return ptr_; } |
+ void reset(T* ptr) { |
+ if (ptr != ptr_) { |
+ if (ptr_) (*destructor)(ptr_); |
+ ptr_ = ptr; |
+ } |
+ } |
+ |
+ private: |
+ T* ptr_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(ScopedOpenSSL); |
+}; |
+ |
+// Provides a buffer of at least MIN_SIZE bytes, for use when calling OpenSSL's |
+// SHA256, HMAC, etc functions, adapting the buffer sizing rules to meet those |
+// of the our base wrapper APIs. |
+// This allows the library to write directly to the caller's buffer if it is of |
+// sufficient size, but if not it will write to temporary |min_sized_buffer_| |
+// of required size and then its content is automatically copied out on |
+// destruction, with truncation as appropriate. |
+template<int MIN_SIZE> |
+class ScopedOpenSSLSafeSizeBuffer { |
+ public: |
+ ScopedOpenSSLSafeSizeBuffer(unsigned char* output, size_t output_len) |
+ : output_(output), |
+ output_len_(output_len) { |
+ } |
+ |
+ ~ScopedOpenSSLSafeSizeBuffer() { |
+ if (output_len_ < MIN_SIZE) { |
+ // Copy the temporary buffer out, truncating as needed. |
+ memcpy(output_, min_sized_buffer_, output_len_); |
+ } |
+ // else... any writing already happened directly into |output_|. |
+ } |
+ |
+ unsigned char* safe_buffer() { |
+ return output_len_ < MIN_SIZE ? min_sized_buffer_ : output_; |
+ } |
+ |
+ private: |
+ // Pointer to the caller's data area and it's associated size, where data |
+ // written via safe_buffer() will [eventually] end up. |
+ unsigned char* output_; |
+ size_t output_len_; |
+ |
+ // Temporary buffer writen into in the case where the caller's |
+ // buffer is not of sufficient size. |
+ unsigned char min_sized_buffer_[MIN_SIZE]; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(ScopedOpenSSLSafeSizeBuffer); |
+}; |
+ |
+// Initialize OpenSSL if it isn't already initialized. This must be called |
+// before any other OpenSSL functions. |
+// This function is thread-safe, and OpenSSL will only ever be initialized once. |
+// OpenSSL will be properly shut down on program exit. |
+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. 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. |
+class OpenSSLErrStackTracer { |
+ public: |
+ // Pass FROM_HERE as |location|, to help track the source of OpenSSL error |
+ // messages. Note any diagnostic emitted will be tagged with the location of |
+ // the constructor call as it's not possible to trace a destructor's callsite. |
+ explicit OpenSSLErrStackTracer(const tracked_objects::Location& location) |
+ : location_(location) { |
+ EnsureOpenSSLInit(); |
+ } |
+ ~OpenSSLErrStackTracer() { |
+ ClearOpenSSLERRStack(location_); |
+ } |
+ |
+ private: |
+ const tracked_objects::Location location_; |
+ |
+ DISALLOW_IMPLICIT_CONSTRUCTORS(OpenSSLErrStackTracer); |
+}; |
+ |
+} // namespace crypto |
+ |
+#endif // CRYPTO_OPENSSL_UTIL_H_ |
Property changes on: crypto\openssl_util.h |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |