public void Update_ThrowsAfterGetHashCalled()
{
using (var hashFunc = new Sha512HashFunction())
{
hashFunc.Update(_input, 0, count: 1);
hashFunc.GetHash();
Assert.Throws <InvalidOperationException>(() => hashFunc.Update(_input, 1, count: 1));
}
}
public void Update_SupportsIncrementalUpdates()
{
using (var hashFunc = new Sha512HashFunction())
{
for (var i = 0; i < _input.Length; ++i)
{
hashFunc.Update(_input, i, count: 1);
}
var actualResult = hashFunc.GetHash();
Assert.Equal(_expectedResult, actualResult);
}
}
/// <summary>
/// Hashes given byte array with a specified HashAlgorithm wrapper which works cross platform.
/// </summary>
/// <param name="hashFunc">HashAlgorithm wrapper used to hash contents cross platform</param>
/// <param name="bytes">Content to hash</param>
internal static void HashBytes(Sha512HashFunction hashFunc, byte[] bytes)
{
if (hashFunc == null)
{
throw new ArgumentNullException(nameof(hashFunc));
}
if (bytes == null || bytes.Length == 0)
{
throw new ArgumentException(Strings.ArgumentCannotBeNullOrEmpty, nameof(bytes));
}
hashFunc.Update(bytes, 0, bytes.Length);
}
/// <summary>
/// Hashes given byte array with a specified HashAlgorithm wrapper which works cross platform.
/// </summary>
/// <param name="hashFunc">HashAlgorithm wrapper used to hash contents cross platform</param>
/// <param name="bytes">Content to hash</param>
/// <param name="count">The number of bytes in the input byte array to use as data.</param>
internal static void HashBytes(Sha512HashFunction hashFunc, byte[] bytes, int count)
{
if (hashFunc == null)
{
throw new ArgumentNullException(nameof(hashFunc));
}
if (bytes == null || bytes.Length == 0)
{
throw new ArgumentException(Strings.ArgumentCannotBeNullOrEmpty, nameof(bytes));
}
if (count <= 0 || bytes.Length < count)
{
throw new ArgumentOutOfRangeException(nameof(count));
}
hashFunc.Update(bytes, offset: 0, count);
}
internal static string GetPackageContentHash(BinaryReader reader)
{
using (var hashFunc = new Sha512HashFunction())
{
// skip validating signature entry since we're just trying to get the content hash here instead of
// verifying signature entry.
var metadata = SignedPackageArchiveIOUtility.ReadSignedArchiveMetadata(reader, validateSignatureEntry: false);
var signatureCentralDirectoryHeader = metadata.GetPackageSignatureFileCentralDirectoryHeaderMetadata();
var centralDirectoryRecordsWithoutSignature = RemoveSignatureAndOrderByOffset(metadata);
// Read and hash from the start of the archive to the start of the file headers
reader.BaseStream.Seek(offset: 0, origin: SeekOrigin.Begin);
SignedPackageArchiveIOUtility.ReadAndHashUntilPosition(reader, hashFunc, metadata.StartOfLocalFileHeaders);
// Read and hash file headers
foreach (var record in centralDirectoryRecordsWithoutSignature)
{
reader.BaseStream.Seek(offset: record.OffsetToLocalFileHeader, origin: SeekOrigin.Begin);
SignedPackageArchiveIOUtility.ReadAndHashUntilPosition(reader, hashFunc, record.OffsetToLocalFileHeader + record.FileEntryTotalSize);
}
// Order central directory records by their position
centralDirectoryRecordsWithoutSignature.Sort((x, y) => x.Position.CompareTo(y.Position));
// Update offset of any central directory record that has a file entry after signature
foreach (var record in centralDirectoryRecordsWithoutSignature)
{
reader.BaseStream.Seek(offset: record.Position, origin: SeekOrigin.Begin);
// Hash from the start of the central directory record until the relative offset of local file header (42 from the start of central directory record, including signature length)
SignedPackageArchiveIOUtility.ReadAndHashUntilPosition(reader, hashFunc, reader.BaseStream.Position + 42);
var relativeOffsetOfLocalFileHeader = (uint)(reader.ReadUInt32() + record.ChangeInOffset);
HashUInt32(hashFunc, relativeOffsetOfLocalFileHeader);
// Continue hashing file name, extra field, and file comment fields.
SignedPackageArchiveIOUtility.ReadAndHashUntilPosition(reader, hashFunc, reader.BaseStream.Position + record.HeaderSize - CentralDirectoryHeader.SizeInBytesOfFixedLengthFields);
}
reader.BaseStream.Seek(offset: metadata.EndOfCentralDirectory, origin: SeekOrigin.Begin);
// Hash until total entries in end of central directory record (8 bytes from the start of EOCDR)
SignedPackageArchiveIOUtility.ReadAndHashUntilPosition(reader, hashFunc, metadata.EndOfCentralDirectory + 8);
var eocdrTotalEntries = (ushort)(reader.ReadUInt16() - 1);
var eocdrTotalEntriesOnDisk = (ushort)(reader.ReadUInt16() - 1);
HashUInt16(hashFunc, eocdrTotalEntries);
HashUInt16(hashFunc, eocdrTotalEntriesOnDisk);
// update the central directory size by substracting the size of the package signature file's central directory header
var eocdrSizeOfCentralDirectory = (uint)(reader.ReadUInt32() - signatureCentralDirectoryHeader.HeaderSize);
HashUInt32(hashFunc, eocdrSizeOfCentralDirectory);
var eocdrOffsetOfCentralDirectory = reader.ReadUInt32() - (uint)signatureCentralDirectoryHeader.FileEntryTotalSize;
HashUInt32(hashFunc, eocdrOffsetOfCentralDirectory);
// Hash until the end of the reader
SignedPackageArchiveIOUtility.ReadAndHashUntilPosition(reader, hashFunc, reader.BaseStream.Length);
hashFunc.Update(new byte[0], offset: 0, count: 0);
return(hashFunc.GetHash());
}
}