OSX v10.5 Hash

What is OSX v10.5?

The **OS X v10.5 (Leopard) password hash format** is a proprietary cryptographic scheme introduced by Apple in 2007 as part of its transition from the older Unix-style crypt(3) hashing to a more secure, hardware-accelerated solution. Structurally, it combines a **SHA-1-based key derivation function (KDF)** with a **salted iteration count** (typically 10,000 iterations) to resist brute-force attacks. The format stores the salt as a 16-byte random value prepended to the plaintext password before hashing, followed by the SHA-1 hash of the salted input. Unlike traditional Unix hashes, OS X v10.5 leverages the **Secure Enclave** in Apple’s T2 chip (later models) and software-based optimizations (e.g., **Apple’s "AppleCrypto" library**) to accelerate key stretching, though the core algorithm remains vulnerable to offline attacks. This format was primarily designed for local authentication on macOS, replacing the legacy MD5-based hashes of earlier versions, though it lacks modern best practices like adaptive iteration counts or memory-hard functions.

The **OS X v10.5 hash format is susceptible to cracking due to several architectural flaws**. Its reliance on **SHA-1** renders it vulnerable to collision attacks and preimage resistance weaknesses, particularly given SHA-1’s known vulnerabilities to length-extension and birthday paradox exploits. The fixed iteration count (10,000) is insufficient for modern hardware, allowing GPU/ASIC-based attacks (e.g., via **Hashcat’s "apple-leopard" mode**) to brute-force hashes at rates exceeding 10,000 hashes per second. Additionally, the **lack of a salt in the final hash output** (only used during derivation) enables rainbow table attacks if salts are leaked, and the absence of **peppering** or **adaptive work factors** makes it trivial to downgrade to weaker algorithms. Optimizations like **Apple’s hardware-accelerated SHA-1** further exacerbate the problem by enabling attackers to process millions of hashes per second, rendering the scheme impractical for modern security standards.

Identifying OSX v10.5 Hashes

Identifying a hash blindly is often difficult because multiple algorithms can output strings of the exact same length. For example, a standard 32-character hexadecimal string could be MD5, NTLM, MD4, or LM. To definitively identify OSX v10.5, security researchers analyze the hash against a strict regular expression (regex) signature (shown above) to find structural matches.

How to Crack OSX v10.5

If you need to recover the plaintext password for a OSX v10.5 hash during a penetration test or forensics investigation, you must supply the correct module ID to your cracking software. Use the exact commands provided at the top of this page to target the hash successfully.