Initialer Commit

CPP/7zip/Crypto/WzAes.cpp

@@ -0,0 +1,235 @@
+// Crypto/WzAes.cpp
+/*
+This code implements Brian Gladman's scheme
+specified in "A Password Based File Encryption Utility".
+
+Note: you must include MyAes.cpp to project to initialize AES tables
+*/
+
+#include "StdAfx.h"
+
+#include "../../../C/CpuArch.h"
+
+#include "../Common/StreamUtils.h"
+
+#include "Pbkdf2HmacSha1.h"
+#include "RandGen.h"
+#include "WzAes.h"
+
+// define it if you don't want to use speed-optimized version of NSha1::Pbkdf2Hmac
+// #define _NO_WZAES_OPTIMIZATIONS
+
+namespace NCrypto {
+namespace NWzAes {
+
+const unsigned kAesKeySizeMax = 32;
+
+static const UInt32 kNumKeyGenIterations = 1000;
+
+STDMETHODIMP CBaseCoder::CryptoSetPassword(const Byte *data, UInt32 size)
+{
+  if (size > kPasswordSizeMax)
+    return E_INVALIDARG;
+  _key.Password.CopyFrom(data, (size_t)size);
+  return S_OK;
+}
+
+void CBaseCoder::Init2()
+{
+  const unsigned dkSizeMax32 = (2 * kAesKeySizeMax + kPwdVerifSize + 3) / 4;
+  Byte dk[dkSizeMax32 * 4];
+
+  const unsigned keySize = _key.GetKeySize();
+  const unsigned dkSize = 2 * keySize + kPwdVerifSize;
+  
+  // for (unsigned ii = 0; ii < 1000; ii++)
+  {
+    #ifdef _NO_WZAES_OPTIMIZATIONS
+
+    NSha1::Pbkdf2Hmac(
+        _key.Password, _key.Password.Size(),
+        _key.Salt, _key.GetSaltSize(),
+        kNumKeyGenIterations,
+        dk, dkSize);
+
+    #else
+
+    UInt32 dk32[dkSizeMax32];
+    const unsigned dkSize32 = (dkSize + 3) / 4;
+    UInt32 salt[kSaltSizeMax / 4];
+    unsigned numSaltWords = _key.GetNumSaltWords();
+    
+    for (unsigned i = 0; i < numSaltWords; i++)
+    {
+      const Byte *src = _key.Salt + i * 4;
+      salt[i] = GetBe32(src);
+    }
+
+    NSha1::Pbkdf2Hmac32(
+        _key.Password, _key.Password.Size(),
+        salt, numSaltWords,
+        kNumKeyGenIterations,
+        dk32, dkSize32);
+    
+    /*
+    for (unsigned j = 0; j < dkSize; j++)
+      dk[j] = (Byte)(dk32[j / 4] >> (24 - 8 * (j & 3)));
+    */
+    for (unsigned j = 0; j < dkSize32; j++)
+      SetBe32(dk + j * 4, dk32[j]);
+    
+    #endif
+  }
+
+  _hmac.SetKey(dk + keySize, keySize);
+  memcpy(_key.PwdVerifComputed, dk + 2 * keySize, kPwdVerifSize);
+
+  Aes_SetKey_Enc(_aes.aes + _aes.offset + 8, dk, keySize);
+  AesCtr2_Init(&_aes);
+}
+
+STDMETHODIMP CBaseCoder::Init()
+{
+  return S_OK;
+}
+
+HRESULT CEncoder::WriteHeader(ISequentialOutStream *outStream)
+{
+  unsigned saltSize = _key.GetSaltSize();
+  g_RandomGenerator.Generate(_key.Salt, saltSize);
+  Init2();
+  RINOK(WriteStream(outStream, _key.Salt, saltSize));
+  return WriteStream(outStream, _key.PwdVerifComputed, kPwdVerifSize);
+}
+
+HRESULT CEncoder::WriteFooter(ISequentialOutStream *outStream)
+{
+  Byte mac[kMacSize];
+  _hmac.Final(mac, kMacSize);
+  return WriteStream(outStream, mac, kMacSize);
+}
+
+/*
+STDMETHODIMP CDecoder::SetDecoderProperties2(const Byte *data, UInt32 size)
+{
+  if (size != 1)
+    return E_INVALIDARG;
+  _key.Init();
+  return SetKeyMode(data[0]) ? S_OK : E_INVALIDARG;
+}
+*/
+
+HRESULT CDecoder::ReadHeader(ISequentialInStream *inStream)
+{
+  unsigned saltSize = _key.GetSaltSize();
+  unsigned extraSize = saltSize + kPwdVerifSize;
+  Byte temp[kSaltSizeMax + kPwdVerifSize];
+  RINOK(ReadStream_FAIL(inStream, temp, extraSize));
+  unsigned i;
+  for (i = 0; i < saltSize; i++)
+    _key.Salt[i] = temp[i];
+  for (i = 0; i < kPwdVerifSize; i++)
+    _pwdVerifFromArchive[i] = temp[saltSize + i];
+  return S_OK;
+}
+
+static inline bool CompareArrays(const Byte *p1, const Byte *p2, unsigned size)
+{
+  for (unsigned i = 0; i < size; i++)
+    if (p1[i] != p2[i])
+      return false;
+  return true;
+}
+
+bool CDecoder::Init_and_CheckPassword()
+{
+  Init2();
+  return CompareArrays(_key.PwdVerifComputed, _pwdVerifFromArchive, kPwdVerifSize);
+}
+
+HRESULT CDecoder::CheckMac(ISequentialInStream *inStream, bool &isOK)
+{
+  isOK = false;
+  Byte mac1[kMacSize];
+  RINOK(ReadStream_FAIL(inStream, mac1, kMacSize));
+  Byte mac2[kMacSize];
+  _hmac.Final(mac2, kMacSize);
+  isOK = CompareArrays(mac1, mac2, kMacSize);
+  return S_OK;
+}
+
+CAesCtr2::CAesCtr2()
+{
+  offset = ((0 - (unsigned)(ptrdiff_t)aes) & 0xF) / sizeof(UInt32);
+}
+
+void AesCtr2_Init(CAesCtr2 *p)
+{
+  UInt32 *ctr = p->aes + p->offset + 4;
+  unsigned i;
+  for (i = 0; i < 4; i++)
+    ctr[i] = 0;
+  p->pos = AES_BLOCK_SIZE;
+}
+
+/* (size != 16 * N) is allowed only for last call */
+
+void AesCtr2_Code(CAesCtr2 *p, Byte *data, SizeT size)
+{
+  unsigned pos = p->pos;
+  UInt32 *buf32 = p->aes + p->offset;
+  if (size == 0)
+    return;
+  
+  if (pos != AES_BLOCK_SIZE)
+  {
+    const Byte *buf = (const Byte *)buf32;
+    do
+      *data++ ^= buf[pos++];
+    while (--size != 0 && pos != AES_BLOCK_SIZE);
+  }
+  
+  if (size >= 16)
+  {
+    SizeT size2 = size >> 4;
+    g_AesCtr_Code(buf32 + 4, data, size2);
+    size2 <<= 4;
+    data += size2;
+    size -= size2;
+    pos = AES_BLOCK_SIZE;
+  }
+  
+  if (size != 0)
+  {
+    unsigned j;
+    const Byte *buf;
+    for (j = 0; j < 4; j++)
+      buf32[j] = 0;
+    g_AesCtr_Code(buf32 + 4, (Byte *)buf32, 1);
+    buf = (const Byte *)buf32;
+    pos = 0;
+    do
+      *data++ ^= buf[pos++];
+    while (--size != 0);
+  }
+  
+  p->pos = pos;
+}
+
+/* (size != 16 * N) is allowed only for last Filter() call */
+
+STDMETHODIMP_(UInt32) CEncoder::Filter(Byte *data, UInt32 size)
+{
+  AesCtr2_Code(&_aes, data, size);
+  _hmac.Update(data, size);
+  return size;
+}
+
+STDMETHODIMP_(UInt32) CDecoder::Filter(Byte *data, UInt32 size)
+{
+  _hmac.Update(data, size);
+  AesCtr2_Code(&_aes, data, size);
+  return size;
+}
+
+}}