1513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch// Copyright (c) 2010 The Chromium Authors. All rights reserved. 2513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch// Use of this source code is governed by a BSD-style license that can be 3513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch// found in the LICENSE file. 4513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch 54a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch#ifndef BASE_OPENSSL_UTIL_H_ 64a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch#define BASE_OPENSSL_UTIL_H_ 7513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch#pragma once 8513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch 9513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch#include "base/basictypes.h" 10fc1e79c2b539be25f76e40f653d1fcfdf4f6e522Brian Carlstrom#include "base/compiler_specific.h" 114a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch#include "base/tracked.h" 12513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch 13513209b27ff55e2841eac0e4120199c23acce758Ben Murdochnamespace base { 14513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch 154a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch// A helper class that takes care of destroying OpenSSL objects when it goes out 164a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch// of scope. 174a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdochtemplate <typename T, void (*destructor)(T*)> 184a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdochclass ScopedOpenSSL { 194a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch public: 20201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch ScopedOpenSSL() : ptr_(NULL) { } 21201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch explicit ScopedOpenSSL(T* ptr) : ptr_(ptr) { } 2221d179b334e59e9a3bfcaed4c4430bef1bc5759dKristian Monsen ~ScopedOpenSSL() { 2321d179b334e59e9a3bfcaed4c4430bef1bc5759dKristian Monsen reset(NULL); 2421d179b334e59e9a3bfcaed4c4430bef1bc5759dKristian Monsen } 254a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch 264a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch T* get() const { return ptr_; } 27201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch void reset(T* ptr) { 28201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch if (ptr != ptr_) { 29201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch if (ptr_) (*destructor)(ptr_); 30201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch ptr_ = ptr; 31201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch } 32201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch } 33fc1e79c2b539be25f76e40f653d1fcfdf4f6e522Brian Carlstrom T* release() WARN_UNUSED_RESULT { 34fc1e79c2b539be25f76e40f653d1fcfdf4f6e522Brian Carlstrom T* result = ptr_; 35fc1e79c2b539be25f76e40f653d1fcfdf4f6e522Brian Carlstrom ptr_ = NULL; 36fc1e79c2b539be25f76e40f653d1fcfdf4f6e522Brian Carlstrom return result; 37fc1e79c2b539be25f76e40f653d1fcfdf4f6e522Brian Carlstrom } 384a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch 394a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch private: 404a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch T* ptr_; 41201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch 42201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch DISALLOW_COPY_AND_ASSIGN(ScopedOpenSSL); 434a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch}; 444a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch 45513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch// Provides a buffer of at least MIN_SIZE bytes, for use when calling OpenSSL's 46513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch// SHA256, HMAC, etc functions, adapting the buffer sizing rules to meet those 47513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch// of the our base wrapper APIs. 48513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch// This allows the library to write directly to the caller's buffer if it is of 49513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch// sufficient size, but if not it will write to temporary |min_sized_buffer_| 50513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch// of required size and then its content is automatically copied out on 51513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch// destruction, with truncation as appropriate. 52513209b27ff55e2841eac0e4120199c23acce758Ben Murdochtemplate<int MIN_SIZE> 53513209b27ff55e2841eac0e4120199c23acce758Ben Murdochclass ScopedOpenSSLSafeSizeBuffer { 54513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch public: 55513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch ScopedOpenSSLSafeSizeBuffer(unsigned char* output, size_t output_len) 56513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch : output_(output), 57513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch output_len_(output_len) { 58513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch } 59513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch 60513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch ~ScopedOpenSSLSafeSizeBuffer() { 61513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch if (output_len_ < MIN_SIZE) { 62513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch // Copy the temporary buffer out, truncating as needed. 63513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch memcpy(output_, min_sized_buffer_, output_len_); 64513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch } 65513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch // else... any writing already happened directly into |output_|. 66513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch } 67513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch 68513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch unsigned char* safe_buffer() { 69513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch return output_len_ < MIN_SIZE ? min_sized_buffer_ : output_; 70513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch } 71513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch 72513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch private: 73513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch // Pointer to the caller's data area and it's associated size, where data 74513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch // written via safe_buffer() will [eventually] end up. 75513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch unsigned char* output_; 76513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch size_t output_len_; 77513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch 78513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch // Temporary buffer writen into in the case where the caller's 79513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch // buffer is not of sufficient size. 80513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch unsigned char min_sized_buffer_[MIN_SIZE]; 814a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch 824a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch DISALLOW_COPY_AND_ASSIGN(ScopedOpenSSLSafeSizeBuffer); 83513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch}; 84513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch 854a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch// Initialize OpenSSL if it isn't already initialized. This must be called 864a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch// before any other OpenSSL functions. 874a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch// This function is thread-safe, and OpenSSL will only ever be initialized once. 884a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch// OpenSSL will be properly shut down on program exit. 894a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdochvoid EnsureOpenSSLInit(); 904a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch 914a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch// Drains the OpenSSL ERR_get_error stack. On a debug build the error codes 92201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch// are send to VLOG(1), on a release build they are disregarded. In most 93201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch// cases you should pass FROM_HERE as the |location|. 94201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdochvoid ClearOpenSSLERRStack(const tracked_objects::Location& location); 95201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch 96201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch// Place an instance of this class on the call stack to automatically clear 97201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch// the OpenSSL error stack on function exit. 98201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdochclass OpenSSLErrStackTracer { 99201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch public: 100201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch // Pass FROM_HERE as |location|, to help track the source of OpenSSL error 101201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch // messages. Note any diagnostic emitted will be tagged with the location of 102201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch // the constructor call as it's not possible to trace a destructor's callsite. 103201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch explicit OpenSSLErrStackTracer(const tracked_objects::Location& location) 104201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch : location_(location) { 105201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch EnsureOpenSSLInit(); 106201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch } 107201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch ~OpenSSLErrStackTracer() { 108201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch ClearOpenSSLERRStack(location_); 109201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch } 110201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch 111201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch private: 112201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch const tracked_objects::Location location_; 113201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch 114201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch DISALLOW_IMPLICIT_CONSTRUCTORS(OpenSSLErrStackTracer); 115201ade2fbba22bfb27ae029f4d23fca6ded109a0Ben Murdoch}; 1164a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch 117513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch} // namespace base 118513209b27ff55e2841eac0e4120199c23acce758Ben Murdoch 1194a5e2dc747d50c653511c68ccb2cfbfb740bd5a7Ben Murdoch#endif // BASE_OPENSSL_UTIL_H_ 120