public static CodeDirectoryBlob CreateCodeDirectoryBlob(int codeLength, string ident, string teamID)
{
HashType hashType = HashType.SHA1;
int pageSize = 4096;
CodeDirectoryBlob codeDirectory = new CodeDirectoryBlob();
codeDirectory.CodeLimit = (uint)codeLength;
codeDirectory.HashType = hashType;
codeDirectory.HashSize = (byte)HashAlgorithmHelper.GetHashLength(hashType);
codeDirectory.PageSize = pageSize;
codeDirectory.Ident = ident;
codeDirectory.TeamID = teamID;
// We put empty hashes as placeholder to ensure that the blob length will not change later.
for (int index = 0; index < SpecialHashCount; index++)
{
codeDirectory.SpecialHashes.Add(new byte[codeDirectory.HashSize]);
}
int codeHashEntries = (int)Math.Ceiling((double)codeLength / pageSize);
for (int index = 0; index < codeHashEntries; index++)
{
codeDirectory.CodeHashes.Add(new byte[codeDirectory.HashSize]);
}
return(codeDirectory);
}
private static byte[] GenerateHashesPList(byte[] codeDirectoryBytes, byte[] alternativeCodeDirectory1Bytes)
{
PListFile plist = new PListFile();
DictionaryNode rootNode = new DictionaryNode();
ArrayNode hashesNode = new ArrayNode();
hashesNode.Add(new DataNode(HashAlgorithmHelper.ComputeHash(HashType.SHA1, codeDirectoryBytes)));
hashesNode.Add(new DataNode(HashAlgorithmHelper.ComputeHash(HashType.SHA256Truncated, alternativeCodeDirectory1Bytes)));
rootNode.Add("cdhashes", hashesNode);
plist.RootNode = rootNode;
return(plist.GetBytes(PListFormat.Xml));
}
public static void UpdateHashes(CodeDirectoryBlob codeDirectory, byte[] codeToHash, byte[] infoFileBytes, CodeRequirementsBlob codeRequirements, byte[] codeResourcesBytes, EntitlementsBlob entitlements)
{
codeDirectory.CodeHashes = HashAlgorithmHelper.ComputeHashes(codeDirectory.HashType, codeDirectory.PageSize, codeToHash);
codeDirectory.SpecialHashes = new List <byte[]>();
codeDirectory.SpecialHashes.Insert(0, (HashAlgorithmHelper.ComputeHash(codeDirectory.HashType, infoFileBytes)));
codeDirectory.SpecialHashes.Insert(0, (HashAlgorithmHelper.ComputeHash(codeDirectory.HashType, codeRequirements.GetBytes())));
codeDirectory.SpecialHashes.Insert(0, (HashAlgorithmHelper.ComputeHash(codeDirectory.HashType, codeResourcesBytes)));
if (SpecialHashCount >= CodeDirectoryBlob.ApplicationSpecificHashOffset)
{
codeDirectory.SpecialHashes.Insert(0, new byte[HashAlgorithmHelper.GetHashLength(codeDirectory.HashType)]);
if (SpecialHashCount >= CodeDirectoryBlob.EntitlementsHashOffset)
{
codeDirectory.SpecialHashes.Insert(0, (HashAlgorithmHelper.ComputeHash(codeDirectory.HashType, entitlements.GetBytes())));
}
}
}
public static bool ValidateSpecialHashes(MachObjectFile file, byte[] infoFileBytes, byte[] codeResourcesBytes)
{
byte[] codeSignatureBytes = file.GetCodeSignatureBytes();
if (CodeSignatureSuperBlob.IsCodeSignatureSuperBlob(codeSignatureBytes, 0))
{
CodeSignatureSuperBlob codeSignature = new CodeSignatureSuperBlob(codeSignatureBytes, 0);
CodeDirectoryBlob codeDirectory = codeSignature.GetEntry(CodeSignatureEntryType.CodeDirectory) as CodeDirectoryBlob;
byte[] infoFileHash = HashAlgorithmHelper.ComputeHash(codeDirectory.HashType, infoFileBytes);
if (!ByteUtils.AreByteArraysEqual(infoFileHash, codeDirectory.SpecialHashes[codeDirectory.SpecialHashes.Count - CodeDirectoryBlob.InfoFileHashOffset]))
{
return(false);
}
byte[] codeResourcesHash = HashAlgorithmHelper.ComputeHash(codeDirectory.HashType, codeResourcesBytes);
if (!ByteUtils.AreByteArraysEqual(codeResourcesHash, codeDirectory.SpecialHashes[codeDirectory.SpecialHashes.Count - CodeDirectoryBlob.CodeResourcesFileHashOffset]))
{
return(false);
}
CodeRequirementsBlob codeRequirements = codeSignature.GetEntry(CodeSignatureEntryType.Requirements) as CodeRequirementsBlob;
byte[] codeRequirementsBytes = codeRequirements.GetBytes();
byte[] codeRequirementsHash = HashAlgorithmHelper.ComputeHash(codeDirectory.HashType, codeRequirementsBytes);
if (!ByteUtils.AreByteArraysEqual(codeRequirementsHash, codeDirectory.SpecialHashes[codeDirectory.SpecialHashes.Count - CodeDirectoryBlob.RequirementsHashOffset]))
{
return(false);
}
if (codeDirectory.SpecialHashes.Count >= CodeDirectoryBlob.EntitlementsHashOffset)
{
CodeSignatureGenericBlob entitlements = codeSignature.GetEntry(CodeSignatureEntryType.Entitlements) as CodeSignatureGenericBlob;
byte[] entitlementsBytes = entitlements.GetBytes();
byte[] entitlementsHash = HashAlgorithmHelper.ComputeHash(codeDirectory.HashType, entitlementsBytes);
if (!ByteUtils.AreByteArraysEqual(entitlementsHash, codeDirectory.SpecialHashes[codeDirectory.SpecialHashes.Count - CodeDirectoryBlob.EntitlementsHashOffset]))
{
return(false);
}
}
return(true);
}
return(false);
}
public static bool ValidateExecutableHash(MachObjectFile file)
{
byte[] codeSignatureBytes = file.GetCodeSignatureBytes();
if (CodeSignatureSuperBlob.IsCodeSignatureSuperBlob(codeSignatureBytes, 0))
{
CodeSignatureSuperBlob codeSignature = new CodeSignatureSuperBlob(codeSignatureBytes, 0);
CodeDirectoryBlob codeDirectory = codeSignature.GetEntry(CodeSignatureEntryType.CodeDirectory) as CodeDirectoryBlob;
byte[] signedFileData = ByteReader.ReadBytes(file.GetBytes(), 0, (int)codeDirectory.CodeLimit);
List <byte[]> hashes = HashAlgorithmHelper.ComputeHashes(codeDirectory.HashType, codeDirectory.PageSize, signedFileData);
if (hashes.Count != codeDirectory.CodeHashes.Count)
{
return(false);
}
for (int index = 0; index < hashes.Count; index++)
{
if (!ByteUtils.AreByteArraysEqual(hashes[index], codeDirectory.CodeHashes[index]))
{
return(false);
}
}
return(true);
}
return(false);
}
