From 83ec2af13a970695390b5a582692910d71ebf0b5 Mon Sep 17 00:00:00 2001
From: Michael Bestas <mkbestas@lineageos.org>
Date: Wed, 20 Dec 2017 19:12:59 +0200
Subject: cryptfs_hw: Add compatibility for pre-O hw crypto

* Restore compatibility for pre-O way of hw crypto
  interaction with qsee as the new way is not
  compatible with old blobs.
* Old blobs and current OSS keymaster still use the
  old property to check if qseecomd is loaded.
* This conditionally reverts:
  cryptfs_hw: Add new APIs for key management
  84ac4882d6feeceb24e983a4eaba1d148c2ba3e6
  cryptfs_hw: Use HW keymaster for FDE keys
  a5d3a02eb13362490222ac2a7eefde6543546e31
  cryptfs_hw: Update listener status flag
  eec7d0b6d8e690ebe268965e89593812d607b3a8

Change-Id: I9a5db406c16c3610237a1b85fbfab5c0d63e4960
---
 Android.bp   |   8 ++++
 cryptfs_hw.c | 124 ++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 118 insertions(+), 14 deletions(-)

diff --git a/Android.bp b/Android.bp
index 8aea8b6..12e2aa6 100644
--- a/Android.bp
+++ b/Android.bp
@@ -16,6 +16,14 @@ cc_library_shared {
     srcs: sourceFiles,
     shared_libs: commonSharedLibraries,
 
+    product_variables: {
+        lineage: {
+            supports_legacy_hw_fde: {
+                cflags: ["-DLEGACY_HW_DISK_ENCRYPTION"],
+            },
+        },
+    },
+
     owner: "qti",
 }
 
diff --git a/cryptfs_hw.c b/cryptfs_hw.c
index a5d76ef..36d5d48 100644
--- a/cryptfs_hw.c
+++ b/cryptfs_hw.c
@@ -45,6 +45,10 @@
 #include "cutils/android_reboot.h"
 #include "cryptfs_hw.h"
 
+#ifdef LEGACY_HW_DISK_ENCRYPTION
+#define QSEECOM_LIBRARY_NAME "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
@@ -59,6 +63,13 @@
 #define SET_HW_DISK_ENC_KEY				1
 #define UPDATE_HW_DISK_ENC_KEY				2
 
+#ifdef LEGACY_HW_DISK_ENCRYPTION
+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);
+#endif
+
 #define CRYPTFS_HW_KMS_CLEAR_KEY			0
 #define CRYPTFS_HW_KMS_WIPE_KEY				1
 #define CRYPTFS_HW_UP_CHECK_COUNT			10
@@ -85,6 +96,89 @@ static inline void* secure_memset(void* v, int c , size_t n)
 	return v;
 }
 
+#ifdef LEGACY_HW_DISK_ENCRYPTION
+static int is_qseecom_up()
+{
+    int i = 0;
+    char value[PROPERTY_VALUE_MAX] = {0};
+
+    for (; i<CRYPTFS_HW_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_NAME, 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;
+}
+
+static int cryptfs_hw_create_key(enum cryptfs_hw_key_management_usage_type usage,
+					unsigned char *hash32)
+{
+	if (load_qseecom_library())
+		return qseecom_create_key(usage, hash32);
+
+	return CRYPTFS_HW_CREATE_KEY_FAILED;
+}
+
+static int cryptfs_hw_wipe_key(enum cryptfs_hw_key_management_usage_type usage)
+{
+	if (load_qseecom_library())
+		return qseecom_wipe_key(usage);
+
+	return CRYPTFS_HW_WIPE_KEY_FAILED;
+}
+
+static int cryptfs_hw_update_key(enum cryptfs_hw_key_management_usage_type usage,
+			unsigned char *current_hash32, unsigned char *new_hash32)
+{
+	if (load_qseecom_library())
+		return qseecom_update_key(usage, current_hash32, new_hash32);
+
+	return CRYPTFS_HW_UPDATE_KEY_FAILED;
+}
+#else
 static size_t memscpy(void *dst, size_t dst_size, const void *src, size_t src_size)
 {
 	size_t min_size = (dst_size < src_size) ? dst_size : src_size;
@@ -258,6 +352,7 @@ static int cryptfs_hw_update_key(enum cryptfs_hw_key_management_usage_type usage
 	close(qseecom_fd);
 	return ret;
 }
+#endif
 
 static int map_usage(int usage)
 {
@@ -292,20 +387,6 @@ static unsigned char* get_tmp_passwd(const char* passwd)
     return tmp_passwd;
 }
 
-static int is_qseecom_up()
-{
-    int i = 0;
-    char value[PROPERTY_VALUE_MAX] = {0};
-
-    for (; i<CRYPTFS_HW_UP_CHECK_COUNT; i++) {
-        property_get("vendor.sys.keymaster.loaded", value, "");
-        if (!strncmp(value, "true", PROPERTY_VALUE_MAX))
-            return 1;
-        usleep(100000);
-    }
-    return 0;
-}
-
 /*
  * For NON-ICE targets, it would return 0 on success. On ICE based targets,
  * it would return key index in the ICE Key LUT
@@ -383,6 +464,7 @@ int clear_hw_device_encryption_key()
 	return cryptfs_hw_wipe_key(map_usage(CRYPTFS_HW_KM_USAGE_DISK_ENCRYPTION));
 }
 
+#ifdef LEGACY_HW_DISK_ENCRYPTION
 static int get_keymaster_version()
 {
     int rc = -1;
@@ -395,11 +477,25 @@ static int get_keymaster_version()
 
     return mod->module_api_version;
 }
+#endif
 
 int should_use_keymaster()
 {
+#ifdef LEGACY_HW_DISK_ENCRYPTION
+    /*
+     * HW FDE key should be tied to keymaster only if
+     * new Keymaster is available
+     */
+    int rc = 0;
+    if (get_keymaster_version() != KEYMASTER_MODULE_API_VERSION_1_0) {
+        SLOGI("Keymaster version is not 1.0");
+        return rc;
+    }
+#else
     /*
      * HW FDE key should be tied to keymaster
      */
+#endif
+
     return 1;
 }
-- 
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