OpenBSD: add FFS volume formatting support

Expose FFS as the native OpenBSD filesystem option for volume creation and accept FFS/UFS on the command line, mapping mounts to the OpenBSD ffs filesystem type.

Run newfs through the elevated core service on vnd raw devices, then temporarily mount the new filesystem to transfer root directory ownership back to the invoking user.

Keep the non-interactive creation default as FAT on OpenBSD so existing unattended scripts do not start requiring elevation.

src/Core/Unix/CoreService.cpp

@@ -914,6 +914,168 @@ namespace VeraCrypt
 	}
 #endif
 
+#ifdef TC_OPENBSD
+	static bool ParseOpenBSDVndDevicePath (const string &path, bool rawDevice, string &deviceNumber)
+	{
+		const string prefix = rawDevice ? "/dev/rvnd" : "/dev/vnd";
+		if (path.find (prefix) != 0)
+			return false;
+
+		size_t numberStart = prefix.size();
+		size_t numberEnd = numberStart;
+		while (numberEnd < path.size() && path[numberEnd] >= '0' && path[numberEnd] <= '9')
+			++numberEnd;
+
+		if (numberEnd == numberStart)
+			return false;
+
+		if (numberEnd + 1 != path.size() || path[numberEnd] != 'c')
+			return false;
+
+		deviceNumber = path.substr (numberStart, numberEnd - numberStart);
+		return true;
+	}
+
+	static string GetOpenBSDVndBlockDevicePath (const DevicePath &rawDevice)
+	{
+		string deviceNumber;
+		if (!ParseOpenBSDVndDevicePath (string (rawDevice), true, deviceNumber))
+			throw ParameterIncorrect (SRC_POS);
+
+		return string ("/dev/vnd") + deviceNumber + "c";
+	}
+
+	static void ValidateOpenBSDVndDeviceNode (const string &path, bool rawDevice)
+	{
+		string deviceNumber;
+		if (!ParseOpenBSDVndDevicePath (path, rawDevice, deviceNumber))
+			throw ParameterIncorrect (SRC_POS);
+
+		struct stat sb;
+		if (lstat (path.c_str(), &sb) != 0)
+			throw ParameterIncorrect (SRC_POS);
+
+		if (rawDevice)
+		{
+			if (!S_ISCHR (sb.st_mode))
+				throw ParameterIncorrect (SRC_POS);
+		}
+		else if (!S_ISBLK (sb.st_mode))
+			throw ParameterIncorrect (SRC_POS);
+	}
+
+	static void ValidateOpenBSDFFSFormatterRequest (const ExecuteOpenBSDFFSFormatterRequest &request)
+	{
+		ValidateOpenBSDVndDeviceNode (string (request.Device), true);
+		ValidateOpenBSDVndDeviceNode (GetOpenBSDVndBlockDevicePath (request.Device), false);
+
+		if (request.OwnerUserId > static_cast <uint64> ((uid_t) -1)
+			|| request.OwnerGroupId > static_cast <uint64> ((gid_t) -1))
+		{
+			throw ParameterIncorrect (SRC_POS);
+		}
+	}
+
+	static list <string> BuildOpenBSDFFSFormatterArguments (const ExecuteOpenBSDFFSFormatterRequest &request)
+	{
+		ValidateOpenBSDFFSFormatterRequest (request);
+
+		list <string> arguments;
+		arguments.push_back (string (request.Device));
+		return arguments;
+	}
+
+	static DirectoryPath CreateOpenBSDFFSTemporaryMountPoint ()
+	{
+		string mountPointTemplate = "/tmp/veracrypt-ffs.XXXXXXXXXX";
+		vector <char> mountPoint (mountPointTemplate.begin(), mountPointTemplate.end());
+		mountPoint.push_back ('\0');
+
+		char *createdPath = mkdtemp (&mountPoint.front());
+		throw_sys_sub_if (!createdPath, mountPointTemplate);
+
+		return DirectoryPath (createdPath);
+	}
+
+	static void RemoveOpenBSDFFSTemporaryMountPoint (const DirectoryPath &mountPoint)
+	{
+		if (!mountPoint.IsEmpty())
+			rmdir (string (mountPoint).c_str());
+	}
+
+	static void MountOpenBSDFFSTemporaryFilesystem (const DevicePath &devicePath, const DirectoryPath &mountPoint)
+	{
+		list <string> args;
+		args.push_back ("-t");
+		args.push_back ("ffs");
+		args.push_back ("-o");
+		args.push_back ("nodev,nosuid,noexec");
+		args.push_back ("--");
+		args.push_back (devicePath);
+		args.push_back (mountPoint);
+
+		Process::Execute ("mount", args);
+	}
+
+	static void DismountOpenBSDFFSTemporaryFilesystem (const DirectoryPath &mountPoint)
+	{
+		list <string> args;
+		args.push_back ("--");
+		args.push_back (mountPoint);
+
+		for (int attempt = 0; true; ++attempt)
+		{
+			try
+			{
+				Process::Execute ("umount", args);
+				return;
+			}
+			catch (ExecutedProcessFailed&)
+			{
+				if (attempt >= 5)
+					throw;
+				Thread::Sleep (200);
+			}
+		}
+	}
+
+	static void SetOpenBSDFFSRootOwner (const ExecuteOpenBSDFFSFormatterRequest &request)
+	{
+		ValidateOpenBSDFFSFormatterRequest (request);
+
+		DirectoryPath mountPoint = CreateOpenBSDFFSTemporaryMountPoint();
+		bool mounted = false;
+
+		try
+		{
+			MountOpenBSDFFSTemporaryFilesystem (DevicePath (GetOpenBSDVndBlockDevicePath (request.Device)), mountPoint);
+			mounted = true;
+
+			string mountPointStr = mountPoint;
+			throw_sys_sub_if (chown (mountPointStr.c_str(), static_cast <uid_t> (request.OwnerUserId), static_cast <gid_t> (request.OwnerGroupId)) == -1, mountPointStr);
+
+			DismountOpenBSDFFSTemporaryFilesystem (mountPoint);
+			mounted = false;
+
+			throw_sys_sub_if (rmdir (mountPointStr.c_str()) == -1, mountPointStr);
+		}
+		catch (...)
+		{
+			if (mounted)
+			{
+				try
+				{
+					DismountOpenBSDFFSTemporaryFilesystem (mountPoint);
+				}
+				catch (...) { }
+			}
+
+			RemoveOpenBSDFFSTemporaryMountPoint (mountPoint);
+			throw;
+		}
+	}
+#endif
+
 	unique_ptr <Serializable> CoreService::GetResponseObject ()
 	{
 		unique_ptr <Serializable> deserializedObject (Serializable::DeserializeNew (ServiceOutputStream));
@@ -1131,6 +1293,18 @@ namespace VeraCrypt
 					}
 #endif
 
+#ifdef TC_OPENBSD
+					// ExecuteOpenBSDFFSFormatterRequest
+					ExecuteOpenBSDFFSFormatterRequest *executeFFSFormatterRequest = dynamic_cast <ExecuteOpenBSDFFSFormatterRequest*> (request.get());
+					if (executeFFSFormatterRequest)
+					{
+						Process::Execute (CoreService::GetOpenBSDFFSFormatterPath(), BuildOpenBSDFFSFormatterArguments (*executeFFSFormatterRequest));
+						SetOpenBSDFFSRootOwner (*executeFFSFormatterRequest);
+						ExecuteOpenBSDFFSFormatterResponse().Serialize (outputStream);
+						continue;
+					}
+#endif
+
 					// MountVolumeRequest
 					MountVolumeRequest *mountRequest = dynamic_cast <MountVolumeRequest*> (request.get());
 					if (mountRequest)
@@ -1237,6 +1411,19 @@ namespace VeraCrypt
 	}
 #endif
 
+#ifdef TC_OPENBSD
+	const char *CoreService::GetOpenBSDFFSFormatterPath ()
+	{
+		return "/sbin/newfs";
+	}
+
+	void CoreService::RequestExecuteOpenBSDFFSFormatter (const DevicePath &devicePath, uint64 userId, uint64 groupId)
+	{
+		ExecuteOpenBSDFFSFormatterRequest request (devicePath, userId, groupId);
+		SendRequest <ExecuteOpenBSDFFSFormatterResponse> (request);
+	}
+#endif
+
 	shared_ptr <VolumeInfo> CoreService::RequestMountVolume (MountOptions &options)
 	{
 		MountVolumeRequest request (&options);

src/Core/Unix/CoreService.h

@@ -38,6 +38,10 @@ namespace VeraCrypt
 #ifdef TC_MACOSX
 		static const char *GetMacOSXAPFSFormatterPath ();
 		static void RequestExecuteMacOSXAPFSFormatter (const DevicePath &devicePath, uint64 userId, uint64 groupId);
+#endif
+#ifdef TC_OPENBSD
+		static const char *GetOpenBSDFFSFormatterPath ();
+		static void RequestExecuteOpenBSDFFSFormatter (const DevicePath &devicePath, uint64 userId, uint64 groupId);
 #endif
 		static shared_ptr <VolumeInfo> RequestMountVolume (MountOptions &options);
 		static void RequestSetFileOwner (const FilesystemPath &path, const UserId &owner);

src/Core/Unix/CoreServiceRequest.cpp

@@ -245,6 +245,32 @@ namespace VeraCrypt
 	}
 #endif
 
+#ifdef TC_OPENBSD
+	// ExecuteOpenBSDFFSFormatterRequest
+	void ExecuteOpenBSDFFSFormatterRequest::Deserialize (shared_ptr <Stream> stream)
+	{
+		CoreServiceRequest::Deserialize (stream);
+		Serializer sr (stream);
+		Device = sr.DeserializeWString ("Device");
+		sr.Deserialize ("OwnerGroupId", OwnerGroupId);
+		sr.Deserialize ("OwnerUserId", OwnerUserId);
+	}
+
+	bool ExecuteOpenBSDFFSFormatterRequest::RequiresElevation () const
+	{
+		return !Core->HasAdminPrivileges();
+	}
+
+	void ExecuteOpenBSDFFSFormatterRequest::Serialize (shared_ptr <Stream> stream) const
+	{
+		CoreServiceRequest::Serialize (stream);
+		Serializer sr (stream);
+		sr.Serialize ("Device", wstring (Device));
+		sr.Serialize ("OwnerGroupId", OwnerGroupId);
+		sr.Serialize ("OwnerUserId", OwnerUserId);
+	}
+#endif
+
 	// MountVolumeRequest
 	void MountVolumeRequest::Deserialize (shared_ptr <Stream> stream)
 	{
@@ -322,6 +348,9 @@ namespace VeraCrypt
 	TC_SERIALIZER_FACTORY_ADD_CLASS (ExitRequest);
 #ifdef TC_MACOSX
 	TC_SERIALIZER_FACTORY_ADD_CLASS (ExecuteMacOSXAPFSFormatterRequest);
+#endif
+#ifdef TC_OPENBSD
+	TC_SERIALIZER_FACTORY_ADD_CLASS (ExecuteOpenBSDFFSFormatterRequest);
 #endif
 	TC_SERIALIZER_FACTORY_ADD_CLASS (GetDeviceSectorSizeRequest);
 	TC_SERIALIZER_FACTORY_ADD_CLASS (GetDeviceSizeRequest);

src/Core/Unix/CoreServiceRequest.h

@@ -142,6 +142,22 @@ namespace VeraCrypt
 	};
 #endif
 
+#ifdef TC_OPENBSD
+	struct ExecuteOpenBSDFFSFormatterRequest : CoreServiceRequest
+	{
+		ExecuteOpenBSDFFSFormatterRequest () { }
+		ExecuteOpenBSDFFSFormatterRequest (const DevicePath &devicePath, uint64 userId, uint64 groupId)
+			: Device (devicePath), OwnerGroupId (groupId), OwnerUserId (userId) { }
+		TC_SERIALIZABLE (ExecuteOpenBSDFFSFormatterRequest);
+
+		virtual bool RequiresElevation () const;
+
+		DevicePath Device;
+		uint64 OwnerGroupId;
+		uint64 OwnerUserId;
+	};
+#endif
+
 	struct MountVolumeRequest : CoreServiceRequest
 	{
 		MountVolumeRequest () { }

src/Core/Unix/CoreServiceResponse.cpp

@@ -110,6 +110,18 @@ namespace VeraCrypt
 	}
 #endif
 
+#ifdef TC_OPENBSD
+	// ExecuteOpenBSDFFSFormatterResponse
+	void ExecuteOpenBSDFFSFormatterResponse::Deserialize (shared_ptr <Stream> stream)
+	{
+	}
+
+	void ExecuteOpenBSDFFSFormatterResponse::Serialize (shared_ptr <Stream> stream) const
+	{
+		Serializable::Serialize (stream);
+	}
+#endif
+
 	// MountVolumeResponse
 	void MountVolumeResponse::Deserialize (shared_ptr <Stream> stream)
 	{
@@ -143,6 +155,9 @@ namespace VeraCrypt
 	TC_SERIALIZER_FACTORY_ADD_CLASS (GetHostDevicesResponse);
 #ifdef TC_MACOSX
 	TC_SERIALIZER_FACTORY_ADD_CLASS (ExecuteMacOSXAPFSFormatterResponse);
+#endif
+#ifdef TC_OPENBSD
+	TC_SERIALIZER_FACTORY_ADD_CLASS (ExecuteOpenBSDFFSFormatterResponse);
 #endif
 	TC_SERIALIZER_FACTORY_ADD_CLASS (MountVolumeResponse);
 	TC_SERIALIZER_FACTORY_ADD_CLASS (SetFileOwnerResponse);

src/Core/Unix/CoreServiceResponse.h

@@ -83,6 +83,14 @@ namespace VeraCrypt
 	};
 #endif
 
+#ifdef TC_OPENBSD
+	struct ExecuteOpenBSDFFSFormatterResponse : CoreServiceResponse
+	{
+		ExecuteOpenBSDFFSFormatterResponse () { }
+		TC_SERIALIZABLE (ExecuteOpenBSDFFSFormatterResponse);
+	};
+#endif
+
 	struct MountVolumeResponse : CoreServiceResponse
 	{
 		MountVolumeResponse () { }

src/Core/VolumeCreator.h

@@ -55,7 +55,8 @@ namespace VeraCrypt
 				Btrfs,
 				MacOsExt,
 				APFS,
-				UFS
+				UFS,
+				FFS
 			};
 
 			static Enum GetPlatformNative ()
@@ -68,6 +69,8 @@ namespace VeraCrypt
 				return VolumeCreationOptions::FilesystemType::MacOsExt;
 #elif defined (TC_FREEBSD) || defined (TC_SOLARIS)
 				return VolumeCreationOptions::FilesystemType::UFS;
+#elif defined (TC_OPENBSD)
+				return VolumeCreationOptions::FilesystemType::FFS;
 #else
 				return VolumeCreationOptions::FilesystemType::FAT;
 #endif
@@ -90,6 +93,8 @@ namespace VeraCrypt
 				case VolumeCreationOptions::FilesystemType::APFS:		return "newfs_apfs";
 	#elif defined (TC_FREEBSD) || defined (TC_SOLARIS)
 				case VolumeCreationOptions::FilesystemType::UFS:		return "newfs" ;
+	#elif defined (TC_OPENBSD)
+				case VolumeCreationOptions::FilesystemType::FFS:		return "newfs" ;
 	#endif
 				default: return NULL;
 				}

src/Main/CommandLineInterface.cpp

@@ -415,6 +415,12 @@ namespace VeraCrypt
 					ArgFilesystem = VolumeCreationOptions::FilesystemType::NTFS;
 				else if (str.IsSameAs (L"exFAT", false))
 					ArgFilesystem = VolumeCreationOptions::FilesystemType::exFAT;
+#elif defined (TC_OPENBSD)
+				else if (str.IsSameAs (L"FFS", false) || str.IsSameAs (L"UFS", false))
+				{
+					ArgMountOptions.FilesystemType = L"ffs";
+					ArgFilesystem = VolumeCreationOptions::FilesystemType::FFS;
+				}
 #endif
 				else
 					throw_err (LangString["UNKNOWN_OPTION"] + L": " + str);

src/Main/Forms/VolumeCreationWizard.cpp

@@ -25,6 +25,9 @@
 #ifdef TC_MACOSX
 #include "Main/MacOSXFormatterDevice.h"
 #endif
+#ifdef TC_OPENBSD
+#include "Main/OpenBSDFormatterDevice.h"
+#endif
 #include "Main/Resources.h"
 #include "VolumeCreationWizard.h"
 #include "EncryptionOptionsWizardPage.h"
@@ -857,9 +860,11 @@ namespace VeraCrypt
 
 					// Temporarily take ownership of the device if the user is not an administrator
 					DevicePath virtualDevice = volume->VirtualDevice;
+					DevicePath formatterDevice = virtualDevice;
 #ifdef TC_MACOSX
 					string virtualDeviceStr = virtualDevice;
 					virtualDevice = GetMacOSXRawDevicePath (virtualDeviceStr);
+					formatterDevice = virtualDevice;
 
 					MacOSXFormatterDeviceOwnerRestoreList changedDeviceOwners;
 					finally_do_arg (MacOSXFormatterDeviceOwnerRestoreList *, &changedDeviceOwners,
@@ -868,25 +873,37 @@ namespace VeraCrypt
 					});
 					bool useElevatedAPFSFormatter = UseElevatedMacOSXAPFSFormatter (fsFormatter);
 					if (!useElevatedAPFSFormatter)
-						PrepareMacOSXFormatterDevice (virtualDevice, changedDeviceOwners);
+						PrepareMacOSXFormatterDevice (formatterDevice, changedDeviceOwners);
 #else
+#ifdef TC_OPENBSD
+					if (SelectedFilesystemType == VolumeCreationOptions::FilesystemType::FFS)
+						formatterDevice = GetOpenBSDRawFormatterDevicePath (virtualDevice);
+#endif
+					bool prepareFormatterDeviceOwnership = true;
+#ifdef TC_OPENBSD
+					if (SelectedFilesystemType == VolumeCreationOptions::FilesystemType::FFS)
+						prepareFormatterDeviceOwnership = false;
+#endif
 					UserId origDeviceOwner ((uid_t) -1);
 
-					try
+					if (prepareFormatterDeviceOwnership)
 					{
-						File file;
-						file.Open (virtualDevice, File::OpenReadWrite);
-					}
-					catch (...)
-					{
-						if (!Core->HasAdminPrivileges())
+						try
 						{
-							origDeviceOwner = virtualDevice.GetOwner();
-							Core->SetFileOwner (virtualDevice, UserId (getuid()));
+							File file;
+							file.Open (formatterDevice, File::OpenReadWrite);
+						}
+						catch (...)
+						{
+							if (!Core->HasAdminPrivileges())
+							{
+								origDeviceOwner = formatterDevice.GetOwner();
+								Core->SetFileOwner (formatterDevice, UserId (getuid()));
+							}
 						}
 					}
 
-					finally_do_arg2 (FilesystemPath, virtualDevice, UserId, origDeviceOwner,
+					finally_do_arg2 (FilesystemPath, formatterDevice, UserId, origDeviceOwner,
 					{
 						if (finally_arg2.SystemId != (uid_t) -1)
 							Core->SetFileOwner (finally_arg, finally_arg2);
@@ -921,11 +938,13 @@ namespace VeraCrypt
 						AddMacOSXAPFSFormatterUserArgs (args);
 #endif
 
-					args.push_back (string (virtualDevice));
+					args.push_back (string (formatterDevice));
 
 					SetCreationProgressText (StringFormatter (LangString["FORMAT_STAGE_CREATING_FILESYSTEM"], fsFormatter));
 #ifdef TC_MACOSX
 					ExecuteMacOSXFilesystemFormatter (fsFormatter, args);
+#elif defined (TC_OPENBSD)
+					ExecuteOpenBSDFilesystemFormatter (fsFormatter, args);
 #else
 					Process::Execute (fsFormatter, args);
 #endif

src/Main/Forms/VolumeFormatOptionsWizardPage.cpp

@@ -52,6 +52,8 @@ namespace VeraCrypt
 			FilesystemTypeChoice->Append (L"APFS",			(void *) VolumeCreationOptions::FilesystemType::APFS);
 #elif defined (TC_FREEBSD) || defined (TC_SOLARIS)
 		FilesystemTypeChoice->Append (L"UFS",				(void *) VolumeCreationOptions::FilesystemType::UFS);
+#elif defined (TC_OPENBSD)
+		FilesystemTypeChoice->Append (L"FFS",				(void *) VolumeCreationOptions::FilesystemType::FFS);
 #endif
 
 		if (!disable32bitFilesystems && filesystemSize <= TC_MAX_FAT_SECTOR_COUNT * sectorSize)
@@ -94,6 +96,7 @@ namespace VeraCrypt
 		case VolumeCreationOptions::FilesystemType::MacOsExt:	FilesystemTypeChoice->SetStringSelection (L"Mac OS Extended"); break;
 		case VolumeCreationOptions::FilesystemType::APFS:		FilesystemTypeChoice->SetStringSelection (L"APFS"); break;
 		case VolumeCreationOptions::FilesystemType::UFS:		FilesystemTypeChoice->SetStringSelection (L"UFS"); break;
+		case VolumeCreationOptions::FilesystemType::FFS:		FilesystemTypeChoice->SetStringSelection (L"FFS"); break;
 
 		default:
 			throw ParameterIncorrect (SRC_POS);

src/Main/OpenBSDFormatterDevice.h

@@ -0,0 +1,123 @@
+/*
+ VeraCrypt source code
+ Copyright (c) 2026 AM Crypto
+
+ This file is part of VeraCrypt and is governed by the Apache License 2.0
+ the full text of which is contained in the file License.txt included in
+ VeraCrypt binary and source code distribution packages.
+*/
+
+#ifndef TC_HEADER_Main_OpenBSDFormatterDevice
+#define TC_HEADER_Main_OpenBSDFormatterDevice
+
+#include "Main/Main.h"
+
+#ifdef TC_OPENBSD
+#include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "Core/Unix/CoreService.h"
+#include "Core/Unix/UnixUser.h"
+#include "Platform/Unix/Process.h"
+
+namespace VeraCrypt
+{
+	inline bool IsOpenBSDVndDevicePath (const string &path, bool rawDevice)
+	{
+		const string prefix = rawDevice ? "/dev/rvnd" : "/dev/vnd";
+		if (path.find (prefix) != 0)
+			return false;
+
+		size_t numberStart = prefix.size();
+		size_t numberEnd = numberStart;
+		while (numberEnd < path.size() && path[numberEnd] >= '0' && path[numberEnd] <= '9')
+			++numberEnd;
+
+		return numberEnd > numberStart
+			&& numberEnd + 1 == path.size()
+			&& path[numberEnd] == 'c';
+	}
+
+	inline DevicePath GetOpenBSDRawFormatterDevicePath (const DevicePath &path)
+	{
+		string pathStr = path;
+
+		if (IsOpenBSDVndDevicePath (pathStr, true))
+			return path;
+
+		if (IsOpenBSDVndDevicePath (pathStr, false))
+			return DevicePath (string ("/dev/r") + pathStr.substr (5));
+
+		return path;
+	}
+
+	inline string GetOpenBSDFormatterName (const string &fsFormatter)
+	{
+		size_t namePos = fsFormatter.find_last_of ('/');
+		return namePos == string::npos ? fsFormatter : fsFormatter.substr (namePos + 1);
+	}
+
+	inline bool IsOpenBSDFFSFormatter (const string &fsFormatter)
+	{
+		return GetOpenBSDFormatterName (fsFormatter) == "newfs";
+	}
+
+	inline bool GetOpenBSDFormatterEnvId (const char *name, uint64 &id)
+	{
+		const char *env = getenv (name);
+		if (!env || !env[0])
+			return false;
+
+		char *endPtr = nullptr;
+		errno = 0;
+		unsigned long long value = strtoull (env, &endPtr, 10);
+		if (errno != 0 || !endPtr || *endPtr != '\0')
+			return false;
+
+		id = static_cast <uint64> (value);
+		return true;
+	}
+
+	inline uint64 GetOpenBSDFormatterOwnerUserId ()
+	{
+		uint64 id;
+		if (GetOpenBSDFormatterEnvId ("SUDO_UID", id))
+			return id;
+
+		uid_t doasUid;
+		if (GetDoasUserIds (&doasUid, nullptr))
+			return static_cast <uint64> (doasUid);
+
+		return static_cast <uint64> (getuid());
+	}
+
+	inline uint64 GetOpenBSDFormatterOwnerGroupId ()
+	{
+		uint64 id;
+		if (GetOpenBSDFormatterEnvId ("SUDO_GID", id))
+			return id;
+
+		gid_t doasGid;
+		if (GetDoasUserIds (nullptr, &doasGid))
+			return static_cast <uint64> (doasGid);
+
+		return static_cast <uint64> (getgid());
+	}
+
+	inline void ExecuteOpenBSDFilesystemFormatter (const string &fsFormatter, const list <string> &args)
+	{
+		if (IsOpenBSDFFSFormatter (fsFormatter))
+		{
+			if (args.empty())
+				throw ParameterIncorrect (SRC_POS);
+
+			CoreService::RequestExecuteOpenBSDFFSFormatter (DevicePath (args.back()), GetOpenBSDFormatterOwnerUserId(), GetOpenBSDFormatterOwnerGroupId());
+			return;
+		}
+
+		Process::Execute (fsFormatter, args);
+	}
+}
+#endif // TC_OPENBSD
+
+#endif // TC_HEADER_Main_OpenBSDFormatterDevice

src/Main/TextUserInterface.cpp

@@ -29,6 +29,9 @@
 #ifdef TC_MACOSX
 #include "Main/MacOSXFormatterDevice.h"
 #endif
+#ifdef TC_OPENBSD
+#include "Main/OpenBSDFormatterDevice.h"
+#endif
 #include "TextUserInterface.h"
 
 namespace VeraCrypt
@@ -933,7 +936,13 @@ namespace VeraCrypt
 		{
 			if (Preferences.NonInteractive)
 			{
+#ifdef TC_OPENBSD
+				// Preserve the historical OpenBSD batch default. Native FFS
+				// formatting requires elevation, so scripts should opt in.
+				options->Filesystem = VolumeCreationOptions::FilesystemType::FAT;
+#else
 				options->Filesystem = VolumeCreationOptions::FilesystemType::GetPlatformNative();
+#endif
 			}
 			else
 			{
@@ -974,6 +983,8 @@ namespace VeraCrypt
 				}
 #elif defined (TC_FREEBSD) || defined (TC_SOLARIS)
 				ShowInfo (wxString::Format (L" %li) %s", filesystems.size() + 1, "UFS")); filesystems.push_back (VolumeCreationOptions::FilesystemType::UFS);
+#elif defined (TC_OPENBSD)
+				ShowInfo (wxString::Format (L" %li) %s", filesystems.size() + 1, "FFS")); filesystems.push_back (VolumeCreationOptions::FilesystemType::FFS);
 #endif
 
 				ssize_t defaultFilesystem = fatAvailable ? 2 : 1;
@@ -1123,9 +1134,11 @@ namespace VeraCrypt
 
 			// Temporarily take ownership of the device if the user is not an administrator
 			DevicePath virtualDevice = volume->VirtualDevice;
+			DevicePath formatterDevice = virtualDevice;
 #ifdef TC_MACOSX
 			string virtualDeviceStr = virtualDevice;
 			virtualDevice = GetMacOSXRawDevicePath (virtualDeviceStr);
+			formatterDevice = virtualDevice;
 
 			MacOSXFormatterDeviceOwnerRestoreList changedDeviceOwners;
 			finally_do_arg (MacOSXFormatterDeviceOwnerRestoreList *, &changedDeviceOwners,
@@ -1134,25 +1147,37 @@ namespace VeraCrypt
 			});
 			bool useElevatedAPFSFormatter = UseElevatedMacOSXAPFSFormatter (fsFormatter);
 			if (!useElevatedAPFSFormatter)
-				PrepareMacOSXFormatterDevice (virtualDevice, changedDeviceOwners);
+				PrepareMacOSXFormatterDevice (formatterDevice, changedDeviceOwners);
 #else
+#ifdef TC_OPENBSD
+			if (options->Filesystem == VolumeCreationOptions::FilesystemType::FFS)
+				formatterDevice = GetOpenBSDRawFormatterDevicePath (virtualDevice);
+#endif
+			bool prepareFormatterDeviceOwnership = true;
+#ifdef TC_OPENBSD
+			if (options->Filesystem == VolumeCreationOptions::FilesystemType::FFS)
+				prepareFormatterDeviceOwnership = false;
+#endif
 			UserId origDeviceOwner ((uid_t) -1);
 
-			try
+			if (prepareFormatterDeviceOwnership)
 			{
-				File file;
-				file.Open (virtualDevice, File::OpenReadWrite);
-			}
-			catch (...)
-			{
-				if (!Core->HasAdminPrivileges())
+				try
 				{
-					origDeviceOwner = virtualDevice.GetOwner();
-					Core->SetFileOwner (virtualDevice, UserId (getuid()));
+					File file;
+					file.Open (formatterDevice, File::OpenReadWrite);
+				}
+				catch (...)
+				{
+					if (!Core->HasAdminPrivileges())
+					{
+						origDeviceOwner = formatterDevice.GetOwner();
+						Core->SetFileOwner (formatterDevice, UserId (getuid()));
+					}
 				}
 			}
 
-			finally_do_arg2 (FilesystemPath, virtualDevice, UserId, origDeviceOwner,
+			finally_do_arg2 (FilesystemPath, formatterDevice, UserId, origDeviceOwner,
 			{
 				if (finally_arg2.SystemId != (uid_t) -1)
 					Core->SetFileOwner (finally_arg, finally_arg2);
@@ -1187,10 +1212,12 @@ namespace VeraCrypt
 				AddMacOSXAPFSFormatterUserArgs (args);
 #endif
 
-			args.push_back (string (virtualDevice));
+			args.push_back (string (formatterDevice));
 
 #ifdef TC_MACOSX
 			ExecuteMacOSXFilesystemFormatter (fsFormatter, args);
+#elif defined (TC_OPENBSD)
+			ExecuteOpenBSDFilesystemFormatter (fsFormatter, args);
 #else
 			Process::Execute (fsFormatter, args);
 #endif

src/Main/UserInterface.cpp

@@ -1373,6 +1373,10 @@ const FileManager fileManagers[] = {
 					" with option -t. Default type is 'auto'. When creating a new volume, this\n"
 					" option specifies the filesystem to be created on the new volume.\n"
 					" Filesystem type 'none' disables mounting or creating a filesystem.\n"
+#ifdef TC_OPENBSD
+					" On OpenBSD, filesystem type 'FFS' creates a native FFS volume and\n"
+					" mounts with filesystem type 'ffs'.\n"
+#endif
 #ifdef TC_LINUX
 					" On Linux, filesystem type 'ntfs3' mounts with the in-kernel ntfs3\n"
 					" driver and bypasses mount helpers. Filesystem type 'kernel-ntfs'\n"