Source code of Windows XP (NT5)
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// AuxHash.cpp -- Auxillary Hash class implementation
// (c) Copyright Schlumberger Technology Corp., unpublished work, created
// 1999. This computer program includes Confidential, Proprietary
// Information and is a Trade Secret of Schlumberger Technology Corp. All
// use, disclosure, and/or reproduction is prohibited unless authorized
// in writing. All Rights Reserved.
#include "NoWarning.h"
#include "ForceLib.h"
#include <malloc.h> // for _alloca
#include <windows.h>
#include <wincrypt.h>
#include <scuOsExc.h>
#include "AuxHash.h"
/////////////////////////// HELPER /////////////////////////////////
/////////////////////////// LOCAL VAR /////////////////////////////////
/////////////////////////// PUBLIC /////////////////////////////////
// Types
// C'tors/D'tors
AuxHash::AuxHash(AuxContext &rauxcontext,
ALG_ID ai,
HCRYPTKEY hKey)
: m_hHash(0)
{
if (!CryptCreateHash(rauxcontext(), ai, hKey, 0, &m_hHash))
throw scu::OsException(GetLastError());
}
AuxHash::~AuxHash()
{
if (m_hHash)
CryptDestroyHash(m_hHash);
}
// Operators
// Operations
// Import a hash value into the hash object.
void
AuxHash::Import(Blob const &rblbHashValue)
{
if (!CryptSetHashParam(m_hHash, HP_HASHVAL,
const_cast<BYTE *>(rblbHashValue.data()), 0))
throw scu::OsException(GetLastError());
}
// Update the hash value with the data blob.
void
AuxHash::Update(Blob const &rblob)
{
if (!CryptHashData(m_hHash, rblob.data(), rblob.length(), 0))
throw scu::OsException(GetLastError());
}
// Access
ALG_ID
AuxHash::AlgId() const
{
ALG_ID ai;
DWORD c = sizeof ai;
if (!CryptGetHashParam(m_hHash, HP_ALGID,
reinterpret_cast<BYTE *>(&ai), &c, 0))
throw scu::OsException(GetLastError());
return ai;
}
DWORD
AuxHash::Size() const
{
DWORD dwSize;
DWORD cSize = sizeof dwSize;
if (!CryptGetHashParam(m_hHash, HP_ALGID,
reinterpret_cast<BYTE *>(&dwSize), &cSize, 0))
throw scu::OsException(GetLastError());
return dwSize;
}
// Completes the hash returning the hash value. No more hashing can
// occur with this object.
Blob
AuxHash::Value() const
{
DWORD dwSize = Size();
BYTE *bp = reinterpret_cast<BYTE *>(_alloca(dwSize));
if (!CryptGetHashParam(m_hHash, HP_HASHVAL, bp, &dwSize, 0))
throw scu::OsException(GetLastError());
return Blob(bp, dwSize);
}
// Returns the hash of the data blob passed. No more hashing can
// occur with this object.
Blob
AuxHash::Value(Blob const &rblob)
{
Update(rblob);
return Value();
}
// Predicates
// Static Variables
/////////////////////////// PROTECTED /////////////////////////////////
// C'tors/D'tors
// Operators
// Operations
// Access
// Predicates
// Static Variables
/////////////////////////// PRIVATE /////////////////////////////////
// C'tors/D'tors
// Operators
// Operations
// Access
// Predicates
// Static Variables