trampoline: Add new pre/post encrypt hooks, fake system properties library

These are needed on Snapdragon 810 where an extra daemon (qseecomd) must
be started prior to decryption, and where the decryption library polls
a system property to make sure that daemon is running

Also fix missing fonts log spam in trampoline_encmnt by symlinking the one available font

hooks.h

@@ -41,6 +41,11 @@ void mrom_hook_fixup_bootimg_cmdline(char *bootimg_cmdline, size_t bootimg_cmdli
 int mrom_hook_has_kexec(void);
 #endif
 
+#if MR_DEVICE_HOOKS >= 6
+void tramp_hook_encryption_setup(void);
+void tramp_hook_encryption_cleanup(void);
+#endif
+
 #endif /* MR_DEVICE_HOOKS */
 
 #endif /* MR_DEVICE_HOOKS_H */

install_zip/Android.mk

@@ -14,7 +14,7 @@ endif
 
 multirom_extra_dep :=
 ifeq ($(MR_ENCRYPTION),true)
-	multirom_extra_dep += trampoline_encmnt linker
+	multirom_extra_dep += trampoline_encmnt linker libmultirom_fake_properties
 else
 	MR_ENCRYPTION := false
 endif
@@ -59,6 +59,7 @@ $(MULTIROM_ZIP_TARGET): multirom trampoline signapk bbootimg mrom_kexec_static m
 		cp -a $(TARGET_OUT_SHARED_LIBRARIES)/libm.so $(MULTIROM_INST_DIR)/multirom/enc/; \
 		cp -a $(TARGET_OUT_SHARED_LIBRARIES)/libstdc++.so $(MULTIROM_INST_DIR)/multirom/enc/; \
 		cp -a $(TARGET_OUT_SHARED_LIBRARIES)/libc++.so $(MULTIROM_INST_DIR)/multirom/enc/; \
+		cp -a $(TARGET_OUT_SHARED_LIBRARIES)/libmultirom_fake_properties.so $(MULTIROM_INST_DIR)/multirom/enc/; \
 		if [ -n "$(MR_ENCRYPTION_SETUP_SCRIPT)" ]; then sh "$(ANDROID_BUILD_TOP)/$(MR_ENCRYPTION_SETUP_SCRIPT)" "$(ANDROID_BUILD_TOP)" "$(MULTIROM_INST_DIR)/multirom/enc"; fi; \
 	fi
 

trampoline/Android.mk

@@ -40,4 +40,8 @@ ifeq ($(MR_ENCRYPTION),true)
     LOCAL_SRC_FILES += encryption.c
 endif
 
+ifeq ($(MR_ENCRYPTION_FAKE_PROPERTIES),true)
+    LOCAL_CFLAGS += -DMR_ENCRYPTION_FAKE_PROPERTIES
+endif
+
 include $(BUILD_EXECUTABLE)

trampoline/encryption.c

@@ -30,12 +30,23 @@
 #include "../lib/log.h"
 #include "encryption.h"
 #include "../trampoline_encmnt/encmnt_defines.h"
+#include "../hooks.h"
 
 static char encmnt_cmd_arg[64] = { 0 };
 static char *const encmnt_cmd[] = { "/mrom_enc/trampoline_encmnt", encmnt_cmd_arg, NULL };
+#ifdef MR_ENCRYPTION_FAKE_PROPERTIES
+static char *const encmnt_envp[] = { "LD_LIBRARY_PATH=/mrom_enc/", "LD_PRELOAD=/mrom_enc/libmultirom_fake_properties.so", NULL };
+#else
 static char *const encmnt_envp[] = { "LD_LIBRARY_PATH=/mrom_enc/", NULL };
+#endif
 static int g_decrypted = 0;
 
+#ifdef __LP64__
+#define LINKER_PATH "/system/bin/linker64"
+#else
+#define LINKER_PATH "/system/bin/linker"
+#endif
+
 int encryption_before_mount(struct fstab *fstab)
 {
     int exit_code = -1;
@@ -43,10 +54,13 @@ int encryption_before_mount(struct fstab *fstab)
     int res = ENC_RES_ERR;
 
     mkdir_recursive("/system/bin", 0755);
-    remove("/system/bin/linker");
-    symlink("/mrom_enc/linker", "/system/bin/linker");
+    remove(LINKER_PATH);
+    symlink("/mrom_enc/linker", LINKER_PATH);
     chmod("/mrom_enc/linker", 0775);
     chmod("/mrom_enc/trampoline_encmnt", 0775);
+    // some fonts not in ramdisk to save space, so use regular instead
+    symlink("/mrom_enc/res/Roboto-Regular.ttf", "/mrom_enc/res/Roboto-Italic.ttf");
+    symlink("/mrom_enc/res/Roboto-Regular.ttf", "/mrom_enc/res/Roboto-Medium.ttf");
 
     remove("/vendor");
     symlink("/mrom_enc/vendor", "/vendor");
@@ -59,6 +73,10 @@ int encryption_before_mount(struct fstab *fstab)
             ERROR("Mounting /firmware for encryption failed with %s\n", strerror(errno));
     }
 
+#if MR_DEVICE_HOOKS >= 6
+    tramp_hook_encryption_setup();
+#endif
+
     INFO("Running trampoline_encmnt\n");
 
     strcpy(encmnt_cmd_arg, "decrypt");
@@ -122,12 +140,15 @@ void encryption_destroy(void)
     }
 
     // Make sure we're removing our symlink and not ROM's linker
-    if(lstat("/system/bin/linker", &info) >= 0 && S_ISLNK(info.st_mode))
-        remove("/system/bin/linker");
+    if(lstat(LINKER_PATH, &info) >= 0 && S_ISLNK(info.st_mode))
+        remove(LINKER_PATH);
 }
 
 int encryption_cleanup(void)
 {
+#if MR_DEVICE_HOOKS >= 6
+    tramp_hook_encryption_cleanup();
+#endif
     remove("/vendor");
 
     if(access("/firmware", R_OK) >= 0 && umount("/firmware") < 0)

trampoline_encmnt/Android.mk

@@ -27,3 +27,14 @@ LOCAL_SRC_FILES := \
 include $(multirom_local_path)/device_defines.mk
 
 include $(BUILD_EXECUTABLE)
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := libmultirom_fake_properties
+LOCAL_MODULE_TAGS := eng
+LOCAL_C_INCLUDES += $(multirom_local_path)
+
+LOCAL_SRC_FILES := fake_properties.c
+
+include $(multirom_local_path)/device_defines.mk
+include $(BUILD_SHARED_LIBRARY)

trampoline_encmnt/fake_properties.c

@@ -0,0 +1,33 @@
+/*
+ * This file is part of MultiROM.
+ *
+ * MultiROM is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * MultiROM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MultiROM.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stdlib.h>
+#include <string.h>
+#include <sys/system_properties.h>
+
+/* MultiROM doesn't initialize the property service,
+ * but decryption on Nexus 6P waits for one property to become true
+ * so we hardcode it here
+ */
+
+int property_get(const char *key, char *value, const char *default_value)
+{
+    if (!strcmp(key, "sys.listeners.registered"))
+        default_value = "true";
+    if (default_value)
+        strncpy(value, default_value, PROP_VALUE_MAX);
+    return strlen(value);
+}