init

.gitignore

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+/libs
+/obj

LICENSE

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+MIT License
+
+Copyright (c) 2022 LibXZR
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# vbmeta-disable-verification
+
+Patch Android vbmeta image and disable verification flags inside.
+
+## Usage
+
+Get prebuilts from [releases](https://github.com/libxzr/vbmeta-disable-verification/releases).
+
+```
+$ ./vbmeta-disable-verification vbmeta.img 
+Successfully disabled verification on the provided vbmeta image.
+```
+
+Give it a vbmeta image and then verification will be disabled on it.
+
+This should be equal to `fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img`. The only difference is that it directly patch the image file. Fastboot doesn't provide the ability to generate an image with verification disabled, but sometimes I need it :) .
+
+## Building
+
+It's easy to build it with [Android NDK](https://developer.android.com/ndk).
+
+```
+$ export PATH="/path/to/your/ndk:${PATH}"
+$ git clone https://github.com/libxzr/vbmeta-disable-verification
+......
+$ cd vbmeta-disable-verification
+$ ndk-build
+......
+$ tree libs          
+libs
+├── arm64-v8a
+│   └── vbmeta-disable-verification
+├── armeabi-v7a
+│   └── vbmeta-disable-verification
+├── x86
+│   └── vbmeta-disable-verification
+└── x86_64
+    └── vbmeta-disable-verification
+```
+
+## References
+
+- [libavb](https://android.googlesource.com/platform/external/avb/+/refs/tags/android-13.0.0_r15/libavb/avb_vbmeta_image.h)
+- [fastboot](https://android.googlesource.com/platform/system/core/+/refs/tags/android-13.0.0_r15/fastboot/fastboot.cpp)
+
+## License
+
+[MIT](LICENSE)

jni/Android.mk

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+LOCAL_PATH := $(call my-dir)
+include $(CLEAR_VARS)
+LOCAL_MODULE := vbmeta-disable-verification
+LOCAL_SRC_FILES := main.c
+LOCAL_LDFLAGS := -static
+include $(BUILD_EXECUTABLE)

jni/Application.mk

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+APP_ABI := all
+APP_PLATFORM := android-33

jni/main.c

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+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+/* Magic for the vbmeta image header. */
+#define AVB_MAGIC "AVB0"
+#define AVB_MAGIC_LEN 4
+
+/* Information about the verification flags */
+#define FLAGS_OFFSET 123
+#define FLAG_DISABLE_VERITY 0x01
+#define FLAG_DISABLE_VERIFICATION 0x02
+
+static void help()
+{
+    printf("vbmeta-disable-verify by LibXZR <i@xzr.moe>\n");
+    printf("Usage:\n vbmeta-disable-verify <vbmeta-image>\n");
+}
+
+int main(int argc, char *argv[])
+{
+    int fd;
+    char magic[AVB_MAGIC_LEN] = {0};
+    char buf;
+
+    argc--;
+    argv++;
+
+    if (argc != 1) {
+        help();
+        return 0;
+    }
+
+    fd = open(*argv, O_RDWR);
+    if (fd < 0) {
+        printf("Error: Unable to access the provided vbmeta image.\n");
+        return 1;
+    }
+
+    read(fd, magic, AVB_MAGIC_LEN);
+    if (strncmp(magic, AVB_MAGIC, AVB_MAGIC_LEN)) {
+        printf("Error: The provided image is not a valid vbmeta image.\n");
+        goto error_cleanup;
+    }
+
+    if (lseek(fd, FLAGS_OFFSET, SEEK_SET) != FLAGS_OFFSET)
+        goto error_patching;
+    if (read(fd, &buf, 1) != 1)
+        goto error_patching;
+    buf |= FLAG_DISABLE_VERITY | FLAG_DISABLE_VERIFICATION;
+    if (lseek(fd, FLAGS_OFFSET, SEEK_SET) != FLAGS_OFFSET)
+        goto error_patching;
+    if (write(fd, &buf, 1) != 1)
+        goto error_patching;
+
+    printf("Successfully disabled verification on the provided vbmeta image.\n");
+    close(fd);
+    return 0;
+
+error_patching:
+    printf("Error: Failed when patching the vbmeta image\n");
+error_cleanup:
+    close(fd);
+    return 1;
+}