public static void ResignExecutable(MachObjectFile file, string bundleIdentifier, List <X509Certificate> certificateChain, AsymmetricKeyEntry privateKey, byte[] infoFileBytes, byte[] codeResourcesBytes, EntitlementsFile entitlements)
{
X509Certificate signingCertificate = certificateChain[certificateChain.Count - 1];
string certificateCN = CertificateHelper.GetCertificateCommonName(signingCertificate);
string teamID = CertificateHelper.GetCertificateOrganizationalUnit(signingCertificate);
SegmentCommand linkEditSegment = SegmentCommandHelper.FindLinkEditSegment(file.LoadCommands);
if (linkEditSegment == null)
{
throw new InvalidDataException("LinkEdit segment was not found");
}
if (file.LoadCommands[file.LoadCommands.Count - 1].CommandType != LoadCommandType.CodeSignature)
{
throw new NotImplementedException("The last LoadCommand entry is not CodeSignature");
}
CodeSignatureCommand command = (CodeSignatureCommand)file.LoadCommands[file.LoadCommands.Count - 1];
int codeLength = (int)command.DataOffset;
CodeDirectoryBlob codeDirectory = CreateCodeDirectoryBlob(codeLength, bundleIdentifier, teamID, HashType.SHA1);
AttributeTable signedAttributesTable = null;
#if ALT_CODE_DIRECTORY_SHA256
CodeDirectoryBlob alternativeCodeDirectory1 = CreateCodeDirectoryBlob(codeLength, bundleIdentifier, teamID, HashType.SHA256);
signedAttributesTable = GenerateSignedAttributesTable(codeDirectory.GetBytes(), alternativeCodeDirectory1.GetBytes());
#endif
CodeRequirementsBlob codeRequirements = CreateCodeRequirementsBlob(bundleIdentifier, certificateCN);
EntitlementsBlob entitlementsBlob = CreateEntitlementsBlob(entitlements);
CmsSignatureBlob cmsSignature = new CmsSignatureBlob();
// We create a dummy signature to determine the length required
cmsSignature.Data = CMSHelper.GenerateSignature(certificateChain, privateKey, codeDirectory.GetBytes(), signedAttributesTable);
CodeSignatureSuperBlob codeSignature = new CodeSignatureSuperBlob();
codeSignature.Entries.Add(CodeSignatureEntryType.CodeDirectory, codeDirectory);
codeSignature.Entries.Add(CodeSignatureEntryType.Requirements, codeRequirements);
codeSignature.Entries.Add(CodeSignatureEntryType.Entitlements, entitlementsBlob);
#if ALT_CODE_DIRECTORY_SHA256
codeSignature.Entries.Add(CodeSignatureEntryType.AlternateCodeDirectory1, alternativeCodeDirectory1);
#endif
codeSignature.Entries.Add(CodeSignatureEntryType.CmsSignature, cmsSignature);
command.DataSize = (uint)codeSignature.Length;
uint finalFileSize = command.DataOffset + command.DataSize;
SegmentCommandHelper.SetEndOffset(linkEditSegment, finalFileSize);
byte[] codeToHash = ByteReader.ReadBytes(file.GetBytes(), 0, codeLength);
UpdateSpecialHashes(codeDirectory, codeToHash, infoFileBytes, codeRequirements, codeResourcesBytes, entitlementsBlob);
#if ALT_CODE_DIRECTORY_SHA256
UpdateSpecialHashes(alternativeCodeDirectory1, codeToHash, infoFileBytes, codeRequirements, codeResourcesBytes, entitlementsBlob);
signedAttributesTable = GenerateSignedAttributesTable(codeDirectory.GetBytes(), alternativeCodeDirectory1.GetBytes());
#endif
cmsSignature.Data = CMSHelper.GenerateSignature(certificateChain, privateKey, codeDirectory.GetBytes(), signedAttributesTable);
// Store updated code signature:
byte[] codeSignatureBytes = codeSignature.GetBytes();
Array.Resize <byte>(ref file.Data, (codeLength - file.DataOffset) + (int)command.DataSize);
ByteWriter.WriteBytes(file.Data, (int)command.DataOffset - file.DataOffset, codeSignatureBytes);
}
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 CodeRequirementsBlob CreateCodeRequirementsBlob(string ident, string certificateCN)
{
CodeRequirementsBlob codeRequirements = new CodeRequirementsBlob();
CodeRequirementBlob codeRequirement = new CodeRequirementBlob();
codeRequirements.Entries.Add(SecurityRequirementType.DesignatedRequirementType, codeRequirement);
IdentValue identValue = new IdentValue(ident);
AppleGenericAnchor appleGenericAnchor = new AppleGenericAnchor();
CertificateField certificateField = new CertificateField();
certificateField.CertificateIndex = 0;
certificateField.FieldName = "subject.CN";
certificateField.Match = new MatchSuffix(MatchOperationName.Equal, certificateCN);
CertificateGeneric certificateGeneric = new CertificateGeneric();
certificateGeneric.CertificateIndex = 1;
certificateGeneric.OID = APPLE_IOS_OID;
certificateGeneric.Match = new MatchSuffix(MatchOperationName.Exists);
codeRequirement.Expression = new AndExpression(identValue, new AndExpression(appleGenericAnchor, new AndExpression(certificateField, certificateGeneric)));
return(codeRequirements);
}
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())));
}
}
}