/// <summary>
/// 解密提取package
/// </summary>
/// <param name="stream">内存流 </param>
/// <param name="encryption">加密对象</param>
/// <returns></returns>
internal MemoryStream DecryptPackage(MemoryStream stream, ExcelEncryption encryption)
{
//创建lockBytes对象。
ILockBytes lb = GetLockbyte(stream);
ExceptionHelper.TrueThrow <Exception>(StgIsStorageILockBytes(lb) != 0, "不是加密文件");
MemoryStream ret = null;
IStorage storage = null;
if (StgOpenStorageOnILockBytes(
lb,
null,
STGM.DIRECT | STGM.READ | STGM.SHARE_EXCLUSIVE,
IntPtr.Zero,
0,
out storage) == 0)
{
ret = GetStreamFromPackage(storage, encryption);
}
Marshal.ReleaseComObject(storage);
Marshal.ReleaseComObject(lb);
return(ret);
}
private MemoryStream GetStreamFromPackage(IStorage storage, ExcelEncryption encryption)
{
MemoryStream ret = null;
comTypes.STATSTG statstg;
storage.Stat(out statstg, (uint)STATFLAG.STATFLAG_DEFAULT);
IEnumSTATSTG pIEnumStatStg = null;
storage.EnumElements(0, IntPtr.Zero, 0, out pIEnumStatStg);
comTypes.STATSTG[] regelt = { statstg };
uint fetched = 0;
uint res = pIEnumStatStg.Next(1, regelt, out fetched);
if (res == 0)
{
byte[] data;
EncryptionInfo encryptionInfo = null;
while (res != 1)
{
switch (statstg.pwcsName)
{
case "EncryptionInfo":
data = GetOleStream(storage, statstg);
encryptionInfo = new EncryptionInfo();
encryptionInfo.ReadBinary(data);
encryption.Algorithm = encryptionInfo.Header.AlgID == AlgorithmID.AES128 ?
EncryptionAlgorithm.AES128 :
encryptionInfo.Header.AlgID == AlgorithmID.AES192 ?
EncryptionAlgorithm.AES192 :
EncryptionAlgorithm.AES256;
break;
case "EncryptedPackage":
data = GetOleStream(storage, statstg);
ret = DecryptDocument(data, encryptionInfo, encryption.Password);
break;
}
if ((res = pIEnumStatStg.Next(1, regelt, out fetched)) != 1)
{
statstg = regelt[0];
}
}
}
Marshal.ReleaseComObject(pIEnumStatStg);
return(ret);
}
/// <summary>
/// 解密提取Package
/// </summary>
/// <param name="fi">文件</param>
/// <param name="encryption"></param>
/// <returns></returns>
internal MemoryStream DecryptPackage(FileInfo fi, ExcelEncryption encryption)
{
ExceptionHelper.TrueThrow(StgIsStorageFile(fi.FullName) != 0, "文件{0}不是一个加密包", fi.FullName);
MemoryStream ret = null;
IStorage storage = null;
if (StgOpenStorage(
fi.FullName,
null,
STGM.DIRECT | STGM.READ | STGM.SHARE_EXCLUSIVE,
IntPtr.Zero,
0,
out storage) == 0)
{
ret = GetStreamFromPackage(storage, encryption);
Marshal.ReleaseComObject(storage);
}
return(ret);
}
/// <summary>
/// 解密提取Package
/// </summary>
/// <param name="fi">文件</param>
/// <param name="encryption"></param>
/// <returns></returns>
internal MemoryStream DecryptPackage(FileInfo fi, ExcelEncryption encryption)
{
ExceptionHelper.TrueThrow(StgIsStorageFile(fi.FullName) != 0, "文件{0}不是一个加密包", fi.FullName);
MemoryStream ret = null;
IStorage storage = null;
if (StgOpenStorage(
fi.FullName,
null,
STGM.DIRECT | STGM.READ | STGM.SHARE_EXCLUSIVE,
IntPtr.Zero,
0,
out storage) == 0)
{
ret = GetStreamFromPackage(storage, encryption);
Marshal.ReleaseComObject(storage);
}
return ret;
}
private MemoryStream GetStreamFromPackage(IStorage storage, ExcelEncryption encryption)
{
MemoryStream ret = null;
comTypes.STATSTG statstg;
storage.Stat(out statstg, (uint)STATFLAG.STATFLAG_DEFAULT);
IEnumSTATSTG pIEnumStatStg = null;
storage.EnumElements(0, IntPtr.Zero, 0, out pIEnumStatStg);
comTypes.STATSTG[] regelt = { statstg };
uint fetched = 0;
uint res = pIEnumStatStg.Next(1, regelt, out fetched);
if (res == 0)
{
byte[] data;
EncryptionInfo encryptionInfo = null;
while (res != 1)
{
switch (statstg.pwcsName)
{
case "EncryptionInfo":
data = GetOleStream(storage, statstg);
encryptionInfo = new EncryptionInfo();
encryptionInfo.ReadBinary(data);
encryption.Algorithm = encryptionInfo.Header.AlgID == AlgorithmID.AES128 ?
EncryptionAlgorithm.AES128 :
encryptionInfo.Header.AlgID == AlgorithmID.AES192 ?
EncryptionAlgorithm.AES192 :
EncryptionAlgorithm.AES256;
break;
case "EncryptedPackage":
data = GetOleStream(storage, statstg);
ret = DecryptDocument(data, encryptionInfo, encryption.Password);
break;
}
if ((res = pIEnumStatStg.Next(1, regelt, out fetched)) != 1)
{
statstg = regelt[0];
}
}
}
Marshal.ReleaseComObject(pIEnumStatStg);
return ret;
}
/// <summary>
/// 加密Package
/// </summary>
/// <param name="package">作为一个字节数组封装</param>
/// <param name="encryption">加密信息</param>
/// <returns></returns>
internal MemoryStream EncryptPackage(byte[] package, ExcelEncryption encryption)
{
byte[] encryptionKey;
//创建加密信息。这也返回了Encryptionkey
var encryptionInfo = CreateEncryptionInfo(encryption.Password,
encryption.Algorithm == EncryptionAlgorithm.AES128 ?
AlgorithmID.AES128 :
encryption.Algorithm == EncryptionAlgorithm.AES192 ?
AlgorithmID.AES192 :
AlgorithmID.AES256, out encryptionKey);
ILockBytes lb;
var iret = CreateILockBytesOnHGlobal(IntPtr.Zero, true, out lb);
IStorage storage = null;
MemoryStream ret = null;
//创建内存中的文件
if (StgCreateDocfileOnILockBytes(lb,
STGM.CREATE | STGM.READWRITE | STGM.SHARE_EXCLUSIVE | STGM.TRANSACTED,
0,
out storage) == 0)
{
//创建数据空间存储
CreateDataSpaces(storage);
//创建加密信息流
comTypes.IStream stream;
storage.CreateStream("EncryptionInfo", (uint)(STGM.CREATE | STGM.WRITE | STGM.DIRECT | STGM.SHARE_EXCLUSIVE), (uint)0, (uint)0, out stream);
byte[] ei = encryptionInfo.WriteBinary();
stream.Write(ei, ei.Length, IntPtr.Zero);
stream = null;
//加密包
byte[] encryptedPackage = EncryptData(encryptionKey, package, false);
storage.CreateStream("EncryptedPackage", (uint)(STGM.CREATE | STGM.WRITE | STGM.DIRECT | STGM.SHARE_EXCLUSIVE), (uint)0, (uint)0, out stream);
//文件大小
MemoryStream ms = new MemoryStream();
BinaryWriter bw = new BinaryWriter(ms);
bw.Write((ulong)package.LongLength);
bw.Flush();
byte[] length = ms.ToArray();
//先写加密的数据长度
stream.Write(length, length.Length, IntPtr.Zero);
//现在加密的数据
stream.Write(encryptedPackage, encryptedPackage.Length, IntPtr.Zero);
stream = null;
storage.Commit(0);
lb.Flush();
//复制非托管的流为字节数组
var statstg = new comTypes.STATSTG();
lb.Stat(out statstg, 0);
int size = (int)statstg.cbSize;
IntPtr buffer = Marshal.AllocHGlobal(size);
UIntPtr readSize;
byte[] pack = new byte[size];
lb.ReadAt(0, buffer, size, out readSize);
Marshal.Copy(buffer, pack, 0, size);
Marshal.FreeHGlobal(buffer);
ret = new MemoryStream();
ret.Write(pack, 0, size);
}
Marshal.ReleaseComObject(storage);
Marshal.ReleaseComObject(lb);
return ret;
}
/// <summary>
/// 解密提取package
/// </summary>
/// <param name="stream">内存流 </param>
/// <param name="encryption">加密对象</param>
/// <returns></returns>
internal MemoryStream DecryptPackage(MemoryStream stream, ExcelEncryption encryption)
{
//创建lockBytes对象。
ILockBytes lb = GetLockbyte(stream);
ExceptionHelper.TrueThrow<Exception>(StgIsStorageILockBytes(lb) != 0, "不是加密文件");
MemoryStream ret = null;
IStorage storage = null;
if (StgOpenStorageOnILockBytes(
lb,
null,
STGM.DIRECT | STGM.READ | STGM.SHARE_EXCLUSIVE,
IntPtr.Zero,
0,
out storage) == 0)
{
ret = GetStreamFromPackage(storage, encryption);
}
Marshal.ReleaseComObject(storage);
Marshal.ReleaseComObject(lb);
return ret;
}
/// <summary>
/// 加密Package
/// </summary>
/// <param name="package">作为一个字节数组封装</param>
/// <param name="encryption">加密信息</param>
/// <returns></returns>
internal MemoryStream EncryptPackage(byte[] package, ExcelEncryption encryption)
{
byte[] encryptionKey;
//创建加密信息。这也返回了Encryptionkey
var encryptionInfo = CreateEncryptionInfo(encryption.Password,
encryption.Algorithm == EncryptionAlgorithm.AES128 ?
AlgorithmID.AES128 :
encryption.Algorithm == EncryptionAlgorithm.AES192 ?
AlgorithmID.AES192 :
AlgorithmID.AES256, out encryptionKey);
ILockBytes lb;
var iret = CreateILockBytesOnHGlobal(IntPtr.Zero, true, out lb);
IStorage storage = null;
MemoryStream ret = null;
//创建内存中的文件
if (StgCreateDocfileOnILockBytes(lb,
STGM.CREATE | STGM.READWRITE | STGM.SHARE_EXCLUSIVE | STGM.TRANSACTED,
0,
out storage) == 0)
{
//创建数据空间存储
CreateDataSpaces(storage);
//创建加密信息流
comTypes.IStream stream;
storage.CreateStream("EncryptionInfo", (uint)(STGM.CREATE | STGM.WRITE | STGM.DIRECT | STGM.SHARE_EXCLUSIVE), (uint)0, (uint)0, out stream);
byte[] ei = encryptionInfo.WriteBinary();
stream.Write(ei, ei.Length, IntPtr.Zero);
stream = null;
//加密包
byte[] encryptedPackage = EncryptData(encryptionKey, package, false);
storage.CreateStream("EncryptedPackage", (uint)(STGM.CREATE | STGM.WRITE | STGM.DIRECT | STGM.SHARE_EXCLUSIVE), (uint)0, (uint)0, out stream);
//文件大小
MemoryStream ms = new MemoryStream();
BinaryWriter bw = new BinaryWriter(ms);
bw.Write((ulong)package.LongLength);
bw.Flush();
byte[] length = ms.ToArray();
//先写加密的数据长度
stream.Write(length, length.Length, IntPtr.Zero);
//现在加密的数据
stream.Write(encryptedPackage, encryptedPackage.Length, IntPtr.Zero);
stream = null;
storage.Commit(0);
lb.Flush();
//复制非托管的流为字节数组
var statstg = new comTypes.STATSTG();
lb.Stat(out statstg, 0);
int size = (int)statstg.cbSize;
IntPtr buffer = Marshal.AllocHGlobal(size);
UIntPtr readSize;
byte[] pack = new byte[size];
lb.ReadAt(0, buffer, size, out readSize);
Marshal.Copy(buffer, pack, 0, size);
Marshal.FreeHGlobal(buffer);
ret = new MemoryStream();
ret.Write(pack, 0, size);
}
Marshal.ReleaseComObject(storage);
Marshal.ReleaseComObject(lb);
return(ret);
}
