@@ -76,6 +76,10 @@ if cc.has_header_symbol('stdlib.h', 'secure_getenv', prefix : '#define _GNU_SOUR
config_h.set('HAVE_SECURE_GETENV', 1)
endif
+if get_option('allow_unsigned_ipas_in_process')
+ config_h.set('ALLOW_UNSIGNED_IPAS_IN_PROCESS', 1)
+endif
+
common_arguments = [
'-Wshadow',
'-include', meson.current_build_dir() / 'config.h',
@@ -64,3 +64,8 @@ option('pycamera',
type : 'feature',
value : 'disabled',
description : 'Enable libcamera Python bindings (experimental)')
+
+option('allow_unsigned_ipas_in_process',
+ type : 'boolean',
+ value : false,
+ description : 'Allow unsigned IPAs to run in libcamera\'s address space')
@@ -114,6 +114,14 @@ IPAManager::IPAManager()
LOG(IPAManager, Warning) << "Public key not valid";
#endif
+#if ALLOW_UNSIGNED_IPAS_IN_PROCESS
+ LOG(IPAManager, Warning)
+ << "All IPAs running in-process without signature verification."
+ << " This is recommended only for tightly-managed installs"
+ << " in contexts where both signature verification and out-of-process"
+ << " execution are infeasible, such as Android HALs.";
+#endif
+
unsigned int ipaCount = 0;
/* User-specified paths take precedence. */
@@ -281,6 +289,9 @@ IPAModule *IPAManager::module(PipelineHandler *pipe, uint32_t minVersion,
bool IPAManager::isSignatureValid([[maybe_unused]] IPAModule *ipa) const
{
+#if ALLOW_UNSIGNED_IPAS_IN_PROCESS
+ return true;
+#endif
#if HAVE_IPA_PUBKEY
char *force = utils::secure_getenv("LIBCAMERA_IPA_FORCE_ISOLATION");
if (force && force[0] != '\0') {
Currently, libcamera isolates any IPAs whose signatures cannot be verified. Shared objects are created at build-time, and then signed. The public signing key is embedded in a .cpp file, and libcamera verifies IPA signatures at runtime. When libcamera cannot authenticate an IPA, it runs it out-of-process. This is problematic on three levels: * IPA signing fundamentally does not work on Android for vendor modules like HALs (discussed below) * Executables built to run out-of-process are not ABI-compatible with Android, making isolation infeasible [1] * Linux phone hardware tends to be low-end because of the FOSS requirement, so the performance hit from out-of-process IPA isolation is significant IPA signing fundamentally does not work for Android vendor modules: After we "meson install" built .so files to a known location, Android explicitly access them in PREBUILT_SHARED_LIBRARY or BUILD_PREBUILIT to transform the .so files by stripping symbols among other things [2]. By modifying prebuilt libraries after we have already signed them, the build system renders our signatures useless on Android. Android distribution maintainers can use this flag to disable signature verification, which will allow them to use libcamera. [1] https://github.com/waydroid/waydroid/issues/519 [2] https://cs.android.com/android/platform/superproject/+/master:build/make/core/cc_prebuilt_internal.mk?q=cc_prebuilt_internal Signed-off-by: Nicholas Roth <nicholas@rothemail.net> --- meson.build | 4 ++++ meson_options.txt | 5 +++++ src/libcamera/ipa_manager.cpp | 11 +++++++++++ 3 files changed, 20 insertions(+)