Code Repack - Hap 5.1 Authorization

HAP 5.1 Authorization Code is a unique, machine-specific key required to activate the Carrier Hourly Analysis Program (HAP)

software. While HAP 5.1 is an older version—superseded by HAP 6.x—it remains in use for projects requiring compatibility with specific legacy HVAC designs or building standards. Understanding the Authorization Process

The authorization code serves as the final step in the licensing sequence to unlock the full functionality of the software: Software ID : When you install HAP 5.1, the program generates a unique Software ID based on your computer's hardware. Requesting the Code

: Users must provide this Software ID, along with their serial number and site information, to Carrier’s licensing department or through their automated portal. Authorization Code : Carrier then issues an Authorization Code

that corresponds specifically to that Software ID. Entering this code "binds" the license to that workstation. Key Features of HAP 5.1 Licensing Version Specificity

: Codes generated for HAP 5.1 are not interchangeable with newer versions like HAP 6.1, which uses a different data management and installation scheme. Transferability hap 5.1 authorization code

: To move the software to a new machine, users must typically "de-authorize" the current installation to receive a credit, allowing a new code to be generated for the new Software ID. Legacy Support

: Many users still maintain 5.1 licenses to "convert HAP 5.1 data" into newer formats for modern energy analysis. Troubleshooting Common Issues Invalid Code

: This usually occurs if the hardware has changed (e.g., a new hard drive or motherboard) after the code was generated, which alters the Software ID. Trial Mode

: Without a valid authorization code, the software operates in a limited "Trial" or "Demo" mode, restricting the number of spaces or systems you can model. Missing License

: If you are an existing user who lost your code, you can typically retrieve it by contacting Carrier Software Support with your original purchase information. The Shift to Modern Versions Current industry standards often prefer Step-by-step :

, which eliminates the "Archive and Retrieve" system found in 5.1 in favor of a portable

file format. If you are using 5.1 for a new project, consider if an upgrade is necessary to meet current ASHRAE 90.1 or LEED requirements. how to convert your 5.1 projects to the newest version of HAP?

Carrier HAP License Activation Info | PDF | Computing | Software

6. Security Properties

| Property | How HAP 5.1 ensures it | |----------|------------------------| | Replay attack | Timestamp + single-use nonce | | Man-in-the-middle | Encrypted with accessory’s public key | | Brute force | Code invalid after 3 failures within 10 sec | | Session isolation | Each auth code links to a specific pairing ID |

4. How It Works (Simplified Flow)

Controller                          Accessory (HAP 5.1)
    |                                      |
    |--- Request new session ------------->|
    |                                      |
    |<--- Challenge (nonce) ---------------|
    |                                      |
    |--- Authorization Code --------------->| 
    |    (encrypted with accessory's public key)
    |                                      |
    |<--- Session keys & success ----------|

Step-by-step:

  1. Controller sends a POST /pairings request with reason=renew or addController.
  2. Accessory replies with a cryptographic challenge.
  3. Controller signs the challenge using its long-term private key and returns the Authorization Code (encrypted payload).
  4. Accessory verifies the code (validity: ~5 minutes, single use).
  5. New session keys are generated and exchanged.

Typical Flows Involving an Authorization Code

  1. Device Setup and Pairing

    • User scans QR or enters setup code.
    • Controller and accessory perform cryptographic handshake.
    • Controller becomes an authorized paired controller (often as owner/admin).

  2. Additional Controller Authorization

    • New controller requests pairing.
    • Accessory may require an authorization code (provided by owner) to grant pairing.
    • Owner provides code (often via Home app) to authorize a new device.

  3. Ownership Transfer / Reset with Authorization

    • If accessory is already owned, an authorization code can be used to transfer ownership without a physical reset.
    • Accessory verifies the code against an owner-issued token or cloud-mediated check.

  4. Role/Capability Granting

    • Authorization codes can be scoped: e.g., temporary guest access, limited control, or full admin.
    • Tokens may include expiry or capability flags.

Part 3: How the HAP 5.1 Authorization Code Works (Technical Deep Dive)

When you attempt to pair a HAP 5.1-compliant smart plug or light bulb, behind the scenes, your iPhone executes the following steps involving the authorization code: the ChaCha20 encryption prevents replay attacks.

  1. Discovery: The HomeKit app discovers the accessory via mDNS (Bonjour).
  2. QR Code Scan: You scan the QR code. That QR data contains:
    • Version: (5.1)
    • Accessory Category ID
    • Setup Payload: This is the obfuscated authorization code.
  3. SRP Start: Your iOS device sends an M1 message containing its ephemeral public key.
  4. Verification: The accessory responds with M2 (its own public key) and a salt. Your iPhone uses the authorization code (decoded from the QR payload) as the password in the SRP protocol.
  5. Proof & Confirmation: If the code matches, both sides generate a shared secret.
  6. Long-Term Pairing: The accessory stores your iPhone’s Long Term Public Key (LTPK). Future connections no longer require the authorization code—they use the established Ed25519 session keys.

Key Insight: Without the correct HAP 5.1 authorization code, an attacker cannot complete step #4. Even if they sniff the Wi-Fi traffic, the ChaCha20 encryption prevents replay attacks.