From 78cb5f1282764996a653be1251a904581f3cf01a Mon Sep 17 00:00:00 2001
From: Simon Sickle <simon@simonsickle.com>
Date: Sat, 25 Nov 2017 01:22:08 -0600
Subject: [PATCH] Add cryptfs_hw

Signed-off-by: Simon Sickle <simon@simonsickle.com>
---
 BoardConfig.mk          |   8 +-
 cryptfs_hw/Android.mk   |  34 +++++
 cryptfs_hw/cryptfs_hw.c | 284 ++++++++++++++++++++++++++++++++++++++++
 cryptfs_hw/cryptfs_hw.h |  47 +++++++
 4 files changed, 369 insertions(+), 4 deletions(-)
 create mode 100644 cryptfs_hw/Android.mk
 create mode 100644 cryptfs_hw/cryptfs_hw.c
 create mode 100644 cryptfs_hw/cryptfs_hw.h

diff --git a/BoardConfig.mk b/BoardConfig.mk
index c622d7b..053cc0b 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -44,9 +44,6 @@ TARGET_BOOTLOADER_BOARD_NAME := msm8998
 TARGET_NO_BOOTLOADER := true
 TARGET_USES_UEFI := true
 
-# Crypto
-TARGET_HW_DISK_ENCRYPTION := true
-
 # Kernel
 BOARD_KERNEL_BASE := 0x00000000
 BOARD_KERNEL_CMDLINE := androidboot.hardware=qcom user_debug=31 msm_rtb.filter=0x237 ehci-hcd.park=3 lpm_levels.sleep_disabled=1 sched_enable_hmp=1 sched_enable_power_aware=1 service_locator.enable=1 swiotlb=2048 androidboot.usbcontroller=a800000.dwc3  androidboot.selinux=permissive
@@ -71,6 +68,10 @@ BOARD_FLASH_BLOCK_SIZE := 131072 # (BOARD_KERNEL_PAGESIZE * 64)
 BOARD_VENDORIMAGE_FILE_SYSTEM_TYPE := ext4
 TARGET_COPY_OUT_VENDOR := vendor
 
+# Crypto
+TARGET_HW_DISK_ENCRYPTION := true
+TARGET_CRYPTFS_HW_PATH := $(BOARD_PATH)/cryptfs_hw
+
 # Recovery
 BOARD_HAS_LARGE_FILESYSTEM := true
 BOARD_HAS_NO_SELECT_BUTTON := true
@@ -94,5 +95,4 @@ TW_SCREEN_BLANK_ON_BOOT := true
 
 # Encryption support
 TW_INCLUDE_CRYPTO := true
-TARGET_HW_DISK_ENCRYPTION := true
 TARGET_KEYMASTER_WAIT_FOR_QSEE := true
diff --git a/cryptfs_hw/Android.mk b/cryptfs_hw/Android.mk
new file mode 100644
index 0000000..605c944
--- /dev/null
+++ b/cryptfs_hw/Android.mk
@@ -0,0 +1,34 @@
+ifeq ($(TARGET_HW_DISK_ENCRYPTION),true)
+LOCAL_PATH:= $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_PROPRIETARY_MODULE := true
+
+sourceFiles := \
+               cryptfs_hw.c
+
+commonSharedLibraries := \
+                        libcutils \
+                        libutils \
+                        libdl \
+                        libhardware
+commonIncludes := \
+                  hardware/libhardware/include/hardware/
+
+LOCAL_C_INCLUDES := $(commonIncludes)
+LOCAL_SRC_FILES := $(sourceFiles)
+
+LOCAL_MODULE_TAGS       := optional
+LOCAL_MODULE:= libcryptfs_hw
+LOCAL_SHARED_LIBRARIES := $(commonSharedLibraries)
+
+LOCAL_MODULE_OWNER := qcom
+
+# USE_ICE_FOR_STORAGE_ENCRYPTION would be true in future if
+# TARGET_USE_EMMC_USE_ICE is set
+ifeq ($(TARGET_USE_UFS_ICE),true)
+LOCAL_CFLAGS += -DUSE_ICE_FOR_STORAGE_ENCRYPTION
+endif
+
+include $(BUILD_SHARED_LIBRARY)
+endif
diff --git a/cryptfs_hw/cryptfs_hw.c b/cryptfs_hw/cryptfs_hw.c
new file mode 100644
index 0000000..c633e57
--- /dev/null
+++ b/cryptfs_hw/cryptfs_hw.c
@@ -0,0 +1,284 @@
+/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *   * Neither the name of The Linux Foundation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <cryptfs_hw.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <dlfcn.h>
+#include "cutils/log.h"
+#include "cutils/properties.h"
+#include "cutils/android_reboot.h"
+#include "keymaster_common.h"
+#include "hardware.h"
+
+#if defined(__LP64__)
+#define QSEECOM_LIBRARY_PATH "/vendor/lib64/libQSEEComAPI.so"
+#else
+#define QSEECOM_LIBRARY_PATH "/vendor/lib/libQSEEComAPI.so"
+#endif
+
+
+// When device comes up or when user tries to change the password, user can
+// try wrong password upto a certain number of times. If user enters wrong
+// password further, HW would wipe all disk encryption related crypto data
+// and would return an error ERR_MAX_PASSWORD_ATTEMPTS to VOLD. VOLD would
+// wipe userdata partition once this error is received.
+#define ERR_MAX_PASSWORD_ATTEMPTS -10
+#define QSEECOM_DISK_ENCRYPTION 1
+#define QSEECOM_UFS_ICE_DISK_ENCRYPTION 3
+#define QSEECOM_SDCC_ICE_DISK_ENCRYPTION 4
+#define MAX_PASSWORD_LEN 32
+#define QCOM_ICE_STORAGE_UFS 1
+#define QCOM_ICE_STORAGE_SDCC 2
+
+/* Operations that be performed on HW based device encryption key */
+#define SET_HW_DISK_ENC_KEY 1
+#define UPDATE_HW_DISK_ENC_KEY 2
+
+#define QSEECOM_UP_CHECK_COUNT 10
+
+static int loaded_library = 0;
+static int (*qseecom_create_key)(int, void*);
+static int (*qseecom_update_key)(int, void*, void*);
+static int (*qseecom_wipe_key)(int);
+
+inline void* secure_memset(void* v, int c , size_t n) {
+    volatile unsigned char* p = (volatile unsigned char* )v;
+    while (n--) *p++ = c;
+    return v;
+}
+
+
+static int map_usage(int usage)
+{
+    int storage_type = is_ice_enabled();
+    if (usage == QSEECOM_DISK_ENCRYPTION) {
+        if (storage_type == QCOM_ICE_STORAGE_UFS) {
+            return QSEECOM_UFS_ICE_DISK_ENCRYPTION;
+        }
+        else if (storage_type == QCOM_ICE_STORAGE_SDCC) {
+            return QSEECOM_SDCC_ICE_DISK_ENCRYPTION ;
+        }
+    }
+    return usage;
+}
+
+static unsigned char* get_tmp_passwd(const char* passwd)
+{
+    int passwd_len = 0;
+    unsigned char * tmp_passwd = NULL;
+    if(passwd) {
+        tmp_passwd = (unsigned char*)malloc(MAX_PASSWORD_LEN);
+        if(tmp_passwd) {
+            memset(tmp_passwd, 0, MAX_PASSWORD_LEN);
+            passwd_len = strnlen(passwd, MAX_PASSWORD_LEN);
+            memcpy(tmp_passwd, passwd, passwd_len);
+        } else {
+            SLOGE("%s: Failed to allocate memory for tmp passwd \n", __func__);
+        }
+    } else {
+        SLOGE("%s: Passed argument is NULL \n", __func__);
+    }
+    return tmp_passwd;
+}
+
+static int is_qseecom_up()
+{
+    int i = 0;
+    char value[PROPERTY_VALUE_MAX] = {0};
+
+    for (; i<QSEECOM_UP_CHECK_COUNT; i++) {
+        property_get("sys.keymaster.loaded", value, "");
+        if (!strncmp(value, "true", PROPERTY_VALUE_MAX))
+            return 1;
+        usleep(100000);
+    }
+    return 0;
+}
+
+
+static int load_qseecom_library()
+{
+    const char *error = NULL;
+    if (loaded_library)
+        return loaded_library;
+
+    if (!is_qseecom_up()) {
+        SLOGE("Timed out waiting for QSEECom listeners..aborting FDE key operation");
+        return 0;
+    }
+
+    void * handle = dlopen(QSEECOM_LIBRARY_PATH, RTLD_NOW);
+    if(handle) {
+        dlerror(); /* Clear any existing error */
+        *(void **) (&qseecom_create_key) = dlsym(handle,"QSEECom_create_key");
+
+        if((error = dlerror()) == NULL) {
+            SLOGD("Success loading QSEECom_create_key \n");
+            *(void **) (&qseecom_update_key) = dlsym(handle,"QSEECom_update_key_user_info");
+            if ((error = dlerror()) == NULL) {
+                SLOGD("Success loading QSEECom_update_key_user_info\n");
+                *(void **) (&qseecom_wipe_key) = dlsym(handle,"QSEECom_wipe_key");
+                if ((error = dlerror()) == NULL) {
+                    loaded_library = 1;
+                    SLOGD("Success loading QSEECom_wipe_key \n");
+                }
+                else
+                    SLOGE("Error %s loading symbols for QSEECom APIs \n", error);
+            }
+            else
+                SLOGE("Error %s loading symbols for QSEECom APIs \n", error);
+        }
+    } else {
+        SLOGE("Could not load libQSEEComAPI.so \n");
+    }
+
+    if(error)
+        dlclose(handle);
+
+    return loaded_library;
+}
+
+/*
+ * For NON-ICE targets, it would return 0 on success. On ICE based targets,
+ * it would return key index in the ICE Key LUT
+ */
+static int set_key(const char* currentpasswd, const char* passwd, const char* enc_mode, int operation)
+{
+    int err = -1;
+    if (is_hw_disk_encryption(enc_mode) && load_qseecom_library()) {
+        unsigned char* tmp_passwd = get_tmp_passwd(passwd);
+        unsigned char* tmp_currentpasswd = get_tmp_passwd(currentpasswd);
+        if(tmp_passwd) {
+            if (operation == UPDATE_HW_DISK_ENC_KEY) {
+                if (tmp_currentpasswd) {
+                   err = qseecom_update_key(map_usage(QSEECOM_DISK_ENCRYPTION), tmp_currentpasswd, tmp_passwd);
+                   secure_memset(tmp_currentpasswd, 0, MAX_PASSWORD_LEN);
+                }
+            } else if (operation == SET_HW_DISK_ENC_KEY) {
+                err = qseecom_create_key(map_usage(QSEECOM_DISK_ENCRYPTION), tmp_passwd);
+            }
+            if(err < 0) {
+                if(ERR_MAX_PASSWORD_ATTEMPTS == err)
+                    SLOGI("Maximum wrong password attempts reached, will erase userdata\n");
+            }
+            secure_memset(tmp_passwd, 0, MAX_PASSWORD_LEN);
+            free(tmp_passwd);
+            free(tmp_currentpasswd);
+        }
+    }
+    return err;
+}
+
+int set_hw_device_encryption_key(const char* passwd, const char* enc_mode)
+{
+    return set_key(NULL, passwd, enc_mode, SET_HW_DISK_ENC_KEY);
+}
+
+int update_hw_device_encryption_key(const char* oldpw, const char* newpw, const char* enc_mode)
+{
+    return set_key(oldpw, newpw, enc_mode, UPDATE_HW_DISK_ENC_KEY);
+}
+
+unsigned int is_hw_disk_encryption(const char* encryption_mode)
+{
+    int ret = 0;
+    if(encryption_mode) {
+        if (!strcmp(encryption_mode, "aes-xts")) {
+            SLOGD("HW based disk encryption is enabled \n");
+            ret = 1;
+        }
+    }
+    return ret;
+}
+
+unsigned int is_hw_fde_enabled(void)
+{
+    return 1;
+}
+
+int is_ice_enabled(void)
+{
+  char prop_storage[PATH_MAX];
+  int storage_type = 0;
+  int fd;
+
+  if (property_get("ro.boot.bootdevice", prop_storage, "")) {
+    if (strstr(prop_storage, "ufs")) {
+      /* All UFS based devices has ICE in it. So we dont need
+       * to check if corresponding device exists or not
+       */
+      storage_type = QCOM_ICE_STORAGE_UFS;
+    } else if (strstr(prop_storage, "sdhc")) {
+      if (access("/dev/icesdcc", F_OK) != -1)
+        storage_type = QCOM_ICE_STORAGE_SDCC;
+    }
+  }
+  return storage_type;
+}
+
+int clear_hw_device_encryption_key()
+{
+    if (load_qseecom_library())
+        return qseecom_wipe_key(map_usage(QSEECOM_DISK_ENCRYPTION));
+
+    return 0;
+}
+
+static int get_keymaster_version()
+{
+    int rc = -1;
+    const hw_module_t* mod;
+    rc = hw_get_module_by_class(KEYSTORE_HARDWARE_MODULE_ID, NULL, &mod);
+    if (rc) {
+        SLOGE("could not find any keystore module");
+        return rc;
+    }
+
+    return mod->module_api_version;
+}
+
+int should_use_keymaster()
+{
+    /* HW FDE key would be tied to keymaster only if:
+     * New Keymaster is available
+     * keymaster partition exists on the device
+     */
+    int rc = 0;
+    if (get_keymaster_version() != KEYMASTER_MODULE_API_VERSION_1_0) {
+        SLOGI("Keymaster version is not 1.0");
+        return rc;
+    }
+
+    return 1;
+}
diff --git a/cryptfs_hw/cryptfs_hw.h b/cryptfs_hw/cryptfs_hw.h
new file mode 100644
index 0000000..9862212
--- /dev/null
+++ b/cryptfs_hw/cryptfs_hw.h
@@ -0,0 +1,47 @@
+/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above
+ *     copyright notice, this list of conditions and the following
+ *     disclaimer in the documentation and/or other materials provided
+ *     with the distribution.
+ *   * Neither the name of The Linux Foundation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
+ * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+ * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __CRYPTFS_HW_H_
+#define __CRYPTFS_HW_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int set_hw_device_encryption_key(const char*, const char*);
+int update_hw_device_encryption_key(const char*, const char*, const char*);
+int clear_hw_device_encryption_key();
+unsigned int is_hw_disk_encryption(const char*);
+unsigned int is_hw_fde_enabled(void);
+int is_ice_enabled(void);
+int should_use_keymaster();
+
+#ifdef __cplusplus
+}
+#endif
+#endif
-- 
2.20.1