1 files changed, 438 insertions, 0 deletions
diff --git a/botan/src/alloc/secmem.h b/botan/src/alloc/secmem.h
new file mode 100644
index 0000000..d64a376
--- /dev/null
+++ b/botan/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