/// <summary>
/// Create an AES helper based on a previously saved keyfile and a password to decrypt it
/// </summary>
/// <param name="file"></param>
/// <param name="password"></param>
/// <returns></returns>
public static AesHelper CreateFromKeyFile(byte[] file, string password)
{
Dictionary <string, byte[]> savedobjects = BinaryEncoding.dict_decode(file);
var phasher = new Rfc2898DeriveBytes(password, savedobjects["passwordsalt-v1"]);
var datakeykey = phasher.GetBytes(16);
var phashhasher = new Rfc2898DeriveBytes(datakeykey, savedobjects["datakeykeyhashsalt-v1"], 8192);
var phashhash = phashhasher.GetBytes(IVSize);
if (phashhash.SequenceEqual(savedobjects["datakeykeyhash-v1"]))
{
return(new AesHelper(datakeykey, savedobjects["passwordsalt-v1"], savedobjects["datakeykeyhash-v1"],
savedobjects["datakeykeyhashsalt-v1"],
DecryptAesDataKey(savedobjects["encrypteddatakey-v1"], datakeykey, savedobjects["datakeyiv-v1"]),
savedobjects["datakeyiv-v1"]));
}
else
{
throw new PasswordIncorrectException("The password used to decrypt the keyfile " +
"does not match the file used to creat it.");
}
}
/// <summary>
/// Store this node and its descendents in a blobstore
/// Breaks with circular references, but these should only occur
/// with hard- (and soft-?) -links TODO: handle links
/// </summary>
/// <param name="blobs"></param>
/// <param name="storeGetHash">Function called to store node data, returns hash</param>
/// <returns>The hash of the stored tree and a tree of its child hashes.</returns>
public (byte[] nodehash, HashTreeNode node) Store(Func <byte[], byte[]> storeGetHash)
{
List <(byte[] nodehash, HashTreeNode node)> children = new List <(byte[] nodehash, HashTreeNode node)>();
List <byte[]> dirhashes = new List <byte[]>();
foreach (MetadataNode dir in Directories.Values)
{
var(newhash, newnode) = dir.Store(storeGetHash);
dirhashes.Add(newhash);
children.Add((newhash, newnode));
}
foreach (var fm in Files.Values.AsEnumerable())
{
children.Add((fm.FileHash, null));
}
Dictionary <string, byte[]> mtdata = new Dictionary <string, byte[]>();
// -"-v1"
// DirMetadata = FileMetadata DirMetadata.serialize()
// Directories = enum_encode([Directories.Values MetadataNode.serialize(),... ])
// Files = enum_encode([Files.Values FileMetadata.serialize(),... ])
// -"-v2"
// Directories = enum_encode([dirrefs,...])
// "-v3"
// DirectoriesMultiblock = enum_encode([BitConverter.GetBytes(multiblock),...])
// -v4
// removed DirectoriesMultiblock
mtdata.Add("DirMetadata-v1", DirMetadata.serialize());
mtdata.Add("Files-v1", BinaryEncoding.enum_encode(Files.Values.AsEnumerable()
.Select(fm => fm.serialize())));
mtdata.Add("Directories-v2", BinaryEncoding.enum_encode(dirhashes));
byte[] nodehash = storeGetHash(BinaryEncoding.dict_encode(mtdata));
HashTreeNode node = new HashTreeNode(children);
return(nodehash, node);
}
public static BlobLocation deserialize(byte[] data)
{
Dictionary <string, byte[]> savedobjects = BinaryEncoding.dict_decode(data);
byte[]? encryptedHash = savedobjects["EncryptedHash-v9"].Length == 0 ? null : savedobjects["EncryptedHash-v9"];
string relfilepath = Encoding.UTF8.GetString(savedobjects["RelativeFilePath-v1"]);
int bytelength = BitConverter.ToInt32(savedobjects["ByteLength-v1"], 0);
var encodedBackupSets = BinaryEncoding.enum_decode(savedobjects["BSetReferenceCounts.BackupSets-v5"]);
if (encodedBackupSets == null)
{
throw new Exception("Backup sets are required");
}
List <BackupSetKey> backupsets = new List <BackupSetKey>();
foreach (var bin in encodedBackupSets)
{
if (bin == null)
{
throw new Exception("Backup sets cannot be null");
}
backupsets.Add(BackupSetKey.decode(bin));
}
List <byte[]?>?encodedRefCounts = BinaryEncoding.enum_decode(savedobjects["BSetReferenceCounts.ReferenceCounts-v5"]);
if (encodedRefCounts == null)
{
throw new Exception("Reference counts are required");
}
List <int> referencecounts = new List <int>();
foreach (var bin in encodedRefCounts)
{
if (bin == null)
{
throw new Exception("Reference counts cannot be null");
}
referencecounts.Add(BitConverter.ToInt32(bin, 0));
}
Dictionary <BackupSetKey, int> bsrc = new Dictionary <BackupSetKey, int>();
for (int i = 0; i < backupsets.Count; i++)
{
bsrc[backupsets[i]] = referencecounts[i];
}
var multiblock = BitConverter.ToBoolean(savedobjects["IsMultiBlockReference-v7"], 0);
List <byte[]>?childhashes = null;
if (multiblock)
{
childhashes = new List <byte[]>();
var binchildhashes = BinaryEncoding.enum_decode(savedobjects["BlockHashes-v8"]);
if (binchildhashes == null)
{
throw new Exception("Multiblock blobs must have child hashes");
}
foreach (var bin in binchildhashes)
{
if (bin == null)
{
throw new Exception("Child hashes cannot be null");
}
childhashes.Add(bin);
}
}
return(new BlobLocation(encryptedHash, relfilepath, bytelength, childhashes, bsrc));
}
