openssl genpkey -algorithm RSA -out avb_key.pem -pkeyopt rsa_keygen_bits:4096 openssl rsa -in avb_key.pem -pubout -out avb_pubkey.bin
| Option | Purpose | |--------|---------| | --algorithm | Signing algorithm (e.g., SHA256_RSA2048 , SHA512_RSA4096 ) | | --key | Path to PEM-encoded RSA private key | | --rollback_index | 64-bit value; must increase with each update | | --include_descriptors_from_image | Extracts footer from another image and includes it | | --append_vbmeta_image | Appends vbmeta metadata directly to a partition | | --prop | Sets a custom com.android.build.* property | | --padding_size | Adds padding for future updates without resizing | avbtool 1.1.0
Example usage from the era:
While the latest versions of AVB (2.0, 3.0) often dominate discussions, version represents a critical maturation point. It is the bridge between experimental security and the robust, production-ready boot verification used in billions of devices today. openssl genpkey -algorithm RSA -out avb_key
This creates a 4096-bit RSA private key. This file must be kept secret and secure. If this key is leaked, an attacker could sign malicious This file must be kept secret and secure
: The full logic of version 1.1.0 is contained in the avbtool.py script.