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Diffstat (limited to 'Plugins/jingle/libjingle/talk/base/sec_buffer.h')
-rw-r--r-- | Plugins/jingle/libjingle/talk/base/sec_buffer.h | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/Plugins/jingle/libjingle/talk/base/sec_buffer.h b/Plugins/jingle/libjingle/talk/base/sec_buffer.h new file mode 100644 index 0000000..585e27f --- /dev/null +++ b/Plugins/jingle/libjingle/talk/base/sec_buffer.h @@ -0,0 +1,173 @@ +/* + * libjingle + * Copyright 2004--2005, Google Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO + * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; + * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +// @file Contains utility classes that make it easier to use SecBuffers + +#ifndef TALK_BASE_SEC_BUFFER_H__ +#define TALK_BASE_SEC_BUFFER_H__ + +namespace talk_base { + +// A base class for CSecBuffer<T>. Contains +// all implementation that does not require +// template arguments. +class CSecBufferBase : public SecBuffer { + public: + CSecBufferBase() { + Clear(); + } + + // Uses the SSPI to free a pointer, must be + // used for buffers returned from SSPI APIs. + static void FreeSSPI(void *ptr) { + if ( ptr ) { + SECURITY_STATUS status; + status = ::FreeContextBuffer(ptr); + ASSERT(SEC_E_OK == status); // "Freeing context buffer" + } + } + + // Deletes a buffer with operator delete + static void FreeDelete(void *ptr) { + delete [] reinterpret_cast<char*>(ptr); + } + + // A noop delete, for buffers over other + // people's memory + static void FreeNone(void *ptr) { + } + + protected: + // Clears the buffer to EMPTY & NULL + void Clear() { + this->BufferType = SECBUFFER_EMPTY; + this->cbBuffer = 0; + this->pvBuffer = NULL; + } +}; + +// Wrapper class for SecBuffer to take care +// of initialization and destruction. +template <void (*pfnFreeBuffer)(void *ptr)> +class CSecBuffer: public CSecBufferBase { + public: + // Initializes buffer to empty & NULL + CSecBuffer() { + } + + // Frees any allocated memory + ~CSecBuffer() { + Release(); + } + + // Frees the buffer appropriately, and re-nulls + void Release() { + pfnFreeBuffer(this->pvBuffer); + Clear(); + } + + private: + // A placeholder function for compile-time asserts on the class + void CompileAsserts() { + // never invoked... + assert(false); // _T("Notreached") + + // This class must not extend the size of SecBuffer, since + // we use arrays of CSecBuffer in CSecBufferBundle below + cassert(sizeof(CSecBuffer<SSPIFree> == sizeof(SecBuffer))); + } +}; + +// Contains all generic implementation for the +// SecBufferBundle class +class SecBufferBundleBase { + public: +}; + +// A template class that bundles a SecBufferDesc with +// one or more SecBuffers for convenience. Can take +// care of deallocating buffers appropriately, as indicated +// by pfnFreeBuffer function. +// By default does no deallocation. +template <int num_buffers, + void (*pfnFreeBuffer)(void *ptr) = CSecBufferBase::FreeNone> +class CSecBufferBundle : public SecBufferBundleBase { + public: + // Constructs a security buffer bundle with num_buffers + // buffers, all of which are empty and nulled. + CSecBufferBundle() { + desc_.ulVersion = SECBUFFER_VERSION; + desc_.cBuffers = num_buffers; + desc_.pBuffers = buffers_; + } + + // Frees all currently used buffers. + ~CSecBufferBundle() { + Release(); + } + + // Accessor for the descriptor + PSecBufferDesc desc() { + return &desc_; + } + + // Accessor for the descriptor + const PSecBufferDesc desc() const { + return &desc_; + } + + // returns the i-th security buffer + SecBuffer &operator[] (size_t num) { + ASSERT(num < num_buffers); // "Buffer index out of bounds" + return buffers_[num]; + } + + // returns the i-th security buffer + const SecBuffer &operator[] (size_t num) const { + ASSERT(num < num_buffers); // "Buffer index out of bounds" + return buffers_[num]; + } + + // Frees all non-NULL security buffers, + // using the deallocation function + void Release() { + for ( size_t i = 0; i < num_buffers; ++i ) { + buffers_[i].Release(); + } + } + + private: + // Our descriptor + SecBufferDesc desc_; + // Our bundled buffers, each takes care of its own + // initialization and destruction + CSecBuffer<pfnFreeBuffer> buffers_[num_buffers]; +}; + +} // namespace talk_base + +#endif // TALK_BASE_SEC_BUFFER_H__ |