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Deleo Python CLI tool for downgrading iOS devices

Promotion image of Deleo article.

One of the leading solutions for downgrading iOS to an unsigned firmware version using blobs is futurerestore. However, the landscape has recently witnessed a surge in the availability of iOS downgrade tools, with Deleo emerging as a notable addition to the arsenal. Deleo, a command-line utility coded in Python, stands out for its capability to facilitate the downgrade of iOS and iPadOS devices leveraging SHSH blobs.

What is Deleo?

Deleo, a fresh venture in the realm of iOS and iPadOS downgrading, is a Python-based project designed to supersede futurerestore. It mandates Python version 3.8 or later and necessitates valid SHSH blobs to initiate the downgrade procedure. Typically, the restoration process is constrained to utilizing IPSW versions signed up to iOS 15 or earlier.

SHSH blobs, often referred to as SHSH blobs, are digital signatures generated by Apple for iOS or iPadOS devices during specific firmware signing. These blobs are unique to each device and firmware combination. They serve as a means of authentication, allowing users to install or downgrade to older iOS firmware versions, even after Apple stops signing them.

When Apple releases a new iOS firmware version, it stops signing the previous versions after a short period. Without SHSH blobs, it becomes impossible to install or downgrade to these older firmware versions. However, with valid SHSH blobs saved for a specific device and firmware version, users can install the desired firmware using tools like futurerestore or Deleo.

Screenshot of Deleo Python CLI tool for downgrading iOS devices.

When utilizing Deleo, it's essential to verify that the version you're restoring to is compatible with the Secure Enclave Processor (SEP) version in the latest IPSW. You can refer to a spreadsheet that outlines the compatibility between iOS versions and the latest SEP version.

In iOS 16, Apple unveiled a addition to its firmware called Cryptex1. Functioning as a "virtual" co-processor, Cryptex1 represents a pivotal advancement in iOS architecture. Its primary objective is to facilitate the swift deployment of Rapid Security Responses (RSRs), distinct from conventional iOS updates, thereby streamlining the security enhancement process.

Similar to other firmware components, Cryptex1 incorporates a signing ticket tethered to a cryptographic nonce, commonly known as SHSH blobs within the Apple ecosystem. This means that installation of the firmware necessitates both a valid signing ticket and a corresponding nonce, ensuring robust security measures are upheld.

Therefore, this implies that downgrading on non-checkm8 devices is highly improbable, except within the confines of patch versions (e.g., from 16.3 to 16.3.1). In other words A12 and later, downgrading is impossible, dead in the water, a no-go.

Deleo requires that users download IPSW images of iOS firmware for the downgrade process. To streamline this task, we offer a convenient web-based IPSW Download Tool, facilitating easy access to and downloading of all IPSW images tailored to your iDevice. Select your device name and generate all URLs to IPWS images on Apple servers compatible with your device.

Alternatively, you can turn to Semaphorin, a tethered downgrade tool for A7, A8, A8X, and A9 iDevices running iOS 12.5.7, iOS 11, or iOS 10. Semaphorin enables users to regress to earlier iOS versions such as iOS 8 or iOS 7. Released under the MPL-2.0 license, Semaphorin is compatible with macOS, although it does not support Windows and Linux PCs. It doesn't require blobs.

How to install Deleo

pip is a package management system used to install and manage software packages written in Python. It simplifies the process of installing Python libraries and dependencies from the Python Package Index (PyPI) as well as other sources. Deleo can be installed from PyPI.

python3 -m pip install deleo



  A Python CLI tool for downgrading i(Pad)OS devices.

  --ecid INTEGER
  -v, --verbose
  --version                    Show the version and exit.
  -t, --shsh-blob FILENAME     SHSH blob for target restore.  [required]
  -u, --update                 Keep user data during restore (not recommended if downgrading).
  -o, --ota-manifest FILENAME  OTA build manifest for latest IPSW.
  --help                       Show this message and exit.
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Kuba has over 20 years of experience in journalism, focusing on jailbreak since 2012. He has interviewed professionals from various companies. Besides journalism, Kuba specializes in video editing and drone flying. He studied IT at university before his writing career.

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