diff options
author | lloyd <[email protected]> | 2009-07-16 15:07:59 +0000 |
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committer | lloyd <[email protected]> | 2009-07-16 15:07:59 +0000 |
commit | bd58db8eb1384fe26222d021325382f57f178cc7 (patch) | |
tree | b54713202d613e88407279e5319a97126e894d2a /src/alloc/secmem.h | |
parent | 1172c616fa849af893c1935b8b1dee085f8aaac8 (diff) |
Move some files around to break up dependencies between directories
Diffstat (limited to 'src/alloc/secmem.h')
-rw-r--r-- | src/alloc/secmem.h | 438 |
1 files changed, 438 insertions, 0 deletions
diff --git a/src/alloc/secmem.h b/src/alloc/secmem.h new file mode 100644 index 000000000..d64a376ca --- /dev/null +++ b/src/alloc/secmem.h @@ -0,0 +1,438 @@ +/* +* Secure Memory Buffers +* (C) 1999-2007 Jack Lloyd +* +* Distributed under the terms of the Botan license +*/ + +#ifndef BOTAN_SECURE_MEMORY_BUFFERS_H__ +#define BOTAN_SECURE_MEMORY_BUFFERS_H__ + +#include <botan/allocate.h> +#include <botan/mem_ops.h> +#include <algorithm> + +namespace Botan { + +/** +* This class represents variable length memory buffers. +*/ +template<typename T> +class MemoryRegion + { + public: + /** + * Find out the size of the buffer, i.e. how many objects of type T it + * contains. + * @return the size of the buffer + */ + u32bit size() const { return used; } + + /** + * Find out whether this buffer is empty. + * @return true if the buffer is empty, false otherwise + */ + bool is_empty() const { return (used == 0); } + + /** + * Find out whether this buffer is non-empty + * @return true if the buffer is non-empty, false otherwise + */ + bool has_items() const { return (used != 0); } + + /** + * Get a pointer to the first element in the buffer. + * @return a pointer to the first element in the buffer + */ + operator T* () { return buf; } + + /** + * Get a constant pointer to the first element in the buffer. + * @return a constant pointer to the first element in the buffer + */ + operator const T* () const { return buf; } + + /** + * Get a pointer to the first element in the buffer. + * @return a pointer to the first element in the buffer + */ + T* begin() { return buf; } + + /** + * Get a constant pointer to the first element in the buffer. + * @return a constant pointer to the first element in the buffer + */ + const T* begin() const { return buf; } + + /** + * Get a pointer to the last element in the buffer. + * @return a pointer to the last element in the buffer + */ + T* end() { return (buf + size()); } + + /** + * Get a constant pointer to the last element in the buffer. + * @return a constant pointer to the last element in the buffer + */ + const T* end() const { return (buf + size()); } + + /** + * Check two buffers for equality. + * @return true iff the content of both buffers is byte-wise equal + */ + bool operator==(const MemoryRegion<T>& other) const + { + return (size() == other.size() && + same_mem(buf, other.buf, size())); + } + + /** + * Compare two buffers lexicographically. + * @return true if this buffer is lexicographically smaller than other. + */ + bool operator<(const MemoryRegion<T>& other) const; + + /** + * Check two buffers for inequality. + * @return false if the content of both buffers is byte-wise equal, true + * otherwise. + */ + bool operator!=(const MemoryRegion<T>& in) const + { return (!(*this == in)); } + + /** + * Copy the contents of another buffer into this buffer. + * The former contents of *this are discarded. + * @param in the buffer to copy the contents from. + * @return a reference to *this + */ + MemoryRegion<T>& operator=(const MemoryRegion<T>& in) + { if(this != &in) set(in); return (*this); } + + /** + * The use of this function is discouraged because of the risk of memory + * errors. Use MemoryRegion<T>::set() + * instead. + * Copy the contents of an array of objects of type T into this buffer. + * The former contents of *this are discarded. + * The length of *this must be at least n, otherwise memory errors occur. + * @param in the array to copy the contents from + * @param n the length of in + */ + void copy(const T in[], u32bit n) + { copy(0, in, n); } + + /** + * The use of this function is discouraged because of the risk of memory + * errors. Use MemoryRegion<T>::set() + * instead. + * Copy the contents of an array of objects of type T into this buffer. + * The former contents of *this are discarded. + * The length of *this must be at least n, otherwise memory errors occur. + * @param off the offset position inside this buffer to start inserting + * the copied bytes + * @param in the array to copy the contents from + * @param n the length of in + */ + void copy(u32bit off, const T in[], u32bit n) + { copy_mem(buf + off, in, (n > size() - off) ? (size() - off) : n); } + + /** + * Set the contents of this according to the argument. The size of + * *this is increased if necessary. + * @param in the array of objects of type T to copy the contents from + * @param n the size of array in + */ + void set(const T in[], u32bit n) { create(n); copy(in, n); } + + /** + * Set the contents of this according to the argument. The size of + * *this is increased if necessary. + * @param in the buffer to copy the contents from + */ + void set(const MemoryRegion<T>& in) { set(in.begin(), in.size()); } + + /** + * Append data to the end of this buffer. + * @param data the array containing the data to append + * @param n the size of the array data + */ + void append(const T data[], u32bit n) + { grow_to(size()+n); copy(size() - n, data, n); } + + /** + * Append a single element. + * @param x the element to append + */ + void append(T x) { append(&x, 1); } + + /** + * Append data to the end of this buffer. + * @param data the buffer containing the data to append + */ + void append(const MemoryRegion<T>& x) { append(x.begin(), x.size()); } + + /** + * Zeroise the bytes of this buffer. The length remains unchanged. + */ + void clear() { clear_mem(buf, allocated); } + + /** + * Reset this buffer to an empty buffer with size zero. + */ + void destroy() { create(0); } + + /** + * Reset this buffer to a buffer of specified length. The content will be + * initialized to zero bytes. + * @param n the new length of the buffer + */ + void create(u32bit n); + + /** + * Preallocate memory, so that this buffer can grow up to size n without + * having to perform any actual memory allocations. (This is + * the same principle as for std::vector::reserve().) + */ + void grow_to(u32bit N); + + /** + * Swap this buffer with another object. + */ + void swap(MemoryRegion<T>& other); + + ~MemoryRegion() { deallocate(buf, allocated); } + protected: + MemoryRegion() { buf = 0; alloc = 0; used = allocated = 0; } + MemoryRegion(const MemoryRegion<T>& other) + { + buf = 0; + used = allocated = 0; + alloc = other.alloc; + set(other.buf, other.used); + } + + void init(bool locking, u32bit length = 0) + { alloc = Allocator::get(locking); create(length); } + private: + T* allocate(u32bit n) + { + return static_cast<T*>(alloc->allocate(sizeof(T)*n)); + } + + void deallocate(T* p, u32bit n) + { alloc->deallocate(p, sizeof(T)*n); } + + T* buf; + u32bit used; + u32bit allocated; + Allocator* alloc; + }; + +/* +* Create a new buffer +*/ +template<typename T> +void MemoryRegion<T>::create(u32bit n) + { + if(n <= allocated) { clear(); used = n; return; } + deallocate(buf, allocated); + buf = allocate(n); + allocated = used = n; + } + +/* +* Increase the size of the buffer +*/ +template<typename T> +void MemoryRegion<T>::grow_to(u32bit n) + { + if(n > used && n <= allocated) + { + clear_mem(buf + used, n - used); + used = n; + return; + } + else if(n > allocated) + { + T* new_buf = allocate(n); + copy_mem(new_buf, buf, used); + deallocate(buf, allocated); + buf = new_buf; + allocated = used = n; + } + } + +/* +* Compare this buffer with another one +*/ +template<typename T> +bool MemoryRegion<T>::operator<(const MemoryRegion<T>& in) const + { + if(size() < in.size()) return true; + if(size() > in.size()) return false; + + for(u32bit j = 0; j != size(); j++) + { + if(buf[j] < in[j]) return true; + if(buf[j] > in[j]) return false; + } + + return false; + } + +/* +* Swap this buffer with another one +*/ +template<typename T> +void MemoryRegion<T>::swap(MemoryRegion<T>& x) + { + std::swap(buf, x.buf); + std::swap(used, x.used); + std::swap(allocated, x.allocated); + std::swap(alloc, x.alloc); + } + +/** +* This class represents variable length buffers that do not +* make use of memory locking. +*/ +template<typename T> +class MemoryVector : public MemoryRegion<T> + { + public: + /** + * Copy the contents of another buffer into this buffer. + * @param in the buffer to copy the contents from + * @return a reference to *this + */ + MemoryVector<T>& operator=(const MemoryRegion<T>& in) + { if(this != &in) set(in); return (*this); } + + /** + * Create a buffer of the specified length. + * @param n the length of the buffer to create. + + */ + MemoryVector(u32bit n = 0) { MemoryRegion<T>::init(false, n); } + + /** + * Create a buffer with the specified contents. + * @param in the array containing the data to be initially copied + * into the newly created buffer + * @param n the size of the arry in + */ + MemoryVector(const T in[], u32bit n) + { MemoryRegion<T>::init(false); set(in, n); } + + /** + * Copy constructor. + */ + MemoryVector(const MemoryRegion<T>& in) + { MemoryRegion<T>::init(false); set(in); } + + /** + * Create a buffer whose content is the concatenation of two other + * buffers. + * @param in1 the first part of the new contents + * @param in2 the contents to be appended to in1 + */ + MemoryVector(const MemoryRegion<T>& in1, const MemoryRegion<T>& in2) + { MemoryRegion<T>::init(false); set(in1); append(in2); } + }; + +/** +* This class represents variable length buffers using the operating +* systems capability to lock memory, i.e. keeping it from being +* swapped out to disk. In this way, a security hole allowing attackers +* to find swapped out secret keys is closed. Please refer to +* Botan::InitializerOptions::secure_memory() for restrictions and +* further details. +*/ +template<typename T> +class SecureVector : public MemoryRegion<T> + { + public: + /** + * Copy the contents of another buffer into this buffer. + * @param in the buffer to copy the contents from + * @return a reference to *this + */ + SecureVector<T>& operator=(const MemoryRegion<T>& in) + { if(this != &in) set(in); return (*this); } + + /** + * Create a buffer of the specified length. + * @param n the length of the buffer to create. + + */ + SecureVector(u32bit n = 0) { MemoryRegion<T>::init(true, n); } + + /** + * Create a buffer with the specified contents. + * @param in the array containing the data to be initially copied + * into the newly created buffer + * @param n the size of the array in + */ + SecureVector(const T in[], u32bit n) + { MemoryRegion<T>::init(true); set(in, n); } + + /** + * Create a buffer with contents specified contents. + * @param in the buffer holding the contents that will be + * copied into the newly created buffer. + */ + SecureVector(const MemoryRegion<T>& in) + { MemoryRegion<T>::init(true); set(in); } + + /** + * Create a buffer whose content is the concatenation of two other + * buffers. + * @param in1 the first part of the new contents + * @param in2 the contents to be appended to in1 + */ + SecureVector(const MemoryRegion<T>& in1, const MemoryRegion<T>& in2) + { MemoryRegion<T>::init(true); set(in1); append(in2); } + }; + +/** +* This class represents fixed length buffers using the operating +* systems capability to lock memory, i.e. keeping it from being +* swapped out to disk. In this way, a security hole allowing attackers +* to find swapped out secret keys is closed. Please refer to +* Botan::InitializerOptions::secure_memory() for restrictions and +* further details. +*/ +template<typename T, u32bit L> +class SecureBuffer : public MemoryRegion<T> + { + public: + /** + * Copy the contents of another buffer into this buffer. + * @param in the buffer to copy the contents from + * @return a reference to *this + */ + SecureBuffer<T,L>& operator=(const SecureBuffer<T,L>& in) + { if(this != &in) set(in); return (*this); } + + /** + * Create a buffer of the length L. + */ + SecureBuffer() { MemoryRegion<T>::init(true, L); } + + /** + * Create a buffer of size L with the specified contents. + * @param in the array containing the data to be initially copied + * into the newly created buffer + * @param n the size of the array in + */ + SecureBuffer(const T in[], u32bit n) + { MemoryRegion<T>::init(true, L); copy(in, n); } + private: + SecureBuffer<T, L>& operator=(const MemoryRegion<T>& in) + { if(this != &in) set(in); return (*this); } + }; + +} + +#endif |