Skill

---
name: ipsw
description: Apple firmware and binary reverse engineering with the ipsw CLI tool. Use when analyzing iOS/macOS binaries, disassembling functions in dyld_shared_cache, dumping Objective-C headers from private frameworks, downloading IPSWs or kernelcaches, extracting entitlements, analyzing Mach-O files, or researching Apple security. Triggers on requests involving Apple RE, iOS internals, kernel analysis, KEXT extraction, or vulnerability research on Apple platforms.
---

# IPSW - Apple Reverse Engineering Toolkit

**Install:** `brew install blacktop/tap/ipsw`

## Choose Your Workflow

| Goal | Start Here |
|------|------------|
| Download/extract firmware | [Firmware Acquisition](#firmware-acquisition) |
| Reverse engineer userspace | [Userspace RE](#userspace-re-dyld_shared_cache) |
| Analyze kernel/KEXTs | [Kernel Analysis](#kernel-analysis) |
| Research entitlements | [Entitlements](#entitlements) |
| Dump private API headers | [Class Dump](#class-dump) |
| Analyze standalone binary | [Mach-O Analysis](#mach-o-analysis) |

---

## Firmware Acquisition

```bash
# Download latest IPSW for device
ipsw download ipsw --device iPhone16,1 --latest

# Download with automatic kernel/DSC extraction
ipsw download ipsw --device iPhone16,1 --latest --kernel --dyld

# Extract components from local IPSW
ipsw extract --kernel iPhone16,1_18.0_Restore.ipsw
ipsw extract --dyld --dyld-arch arm64e iPhone16,1_18.0_Restore.ipsw

# Remote extraction (no full download)
ipsw extract --kernel --remote <IPSW_URL>
```

See [references/download.md](references/download.md) for device identifiers and advanced options.

---

## Userspace RE (dyld_shared_cache)

**macOS DSC:** `/System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_arm64e`

### Essential Commands

| Command | Purpose |
|---------|---------|
| `dyld a2s <DSC> <ADDR>` | Address → symbol (triage crash LR/PC) |
| `dyld symaddr <DSC> <SYM> --image <DYLIB>` | Symbol → address |
| `dyld disass <DSC> --vaddr <ADDR>` | Disassemble at address |
| `dyld disass <DSC> --symbol <SYM> --image <DYLIB>` | Disassemble by symbol |
| `dyld xref <DSC> <ADDR> --all` | Find all references to address |
| `dyld dump <DSC> <ADDR> --size 256` | Dump raw bytes at address |
| `dyld str <DSC> "pattern" --image <DYLIB>` | Search strings |
| `dyld objc --class <DSC> --image <DYLIB>` | List ObjC classes |
| `dyld extract <DSC> <DYLIB> -o ./out/` | Extract dylib for external tools |

### Common Workflow

```bash
# 1. Resolve address from crash/trace
ipsw dyld a2s $DSC 0x1bc39e1e0
# → -[SomeClass someMethod:] + 0x40

# 2. Disassemble around that address
ipsw dyld disass $DSC --vaddr 0x1bc39e1e0

# 3. Find who calls this function
ipsw dyld xref $DSC 0x1bc39e1a0 --all

# 4. Extract string/data referenced in disassembly
ipsw dyld dump $DSC 0x1bc39e200 --size 64
```

**Tip:** Always use `--image <DYLIB>` - it's 10x+ faster.

See [references/dyld.md](references/dyld.md) for complete DSC commands.

---

## Kernel Analysis

```bash
# List all KEXTs
ipsw kernel kexts kernelcache.release.iPhone16,1

# Extract specific KEXT
ipsw kernel extract kernelcache sandbox --output ./kexts/

# Dump syscalls
ipsw kernel syscall kernelcache

# Diff KEXTs between versions
ipsw kernel kexts --diff kernelcache_17.0 kernelcache_18.0
```

See [references/kernel.md](references/kernel.md) for KEXT extraction and kernel analysis.

---

## Entitlements

```bash
# Single binary entitlements
ipsw macho info --ent /path/to/binary

# Build searchable database from IPSW
ipsw ent --sqlite ent.db --ipsw iOS18.ipsw

# Query database
ipsw ent --sqlite ent.db --key "com.apple.private.security.no-sandbox"
ipsw ent --sqlite ent.db --key "platform-application"
ipsw ent --sqlite ent.db --key "com.apple.private.tcc.manager"
```

See [references/entitlements.md](references/entitlements.md) for common entitlements and query patterns.

---

## Class Dump

Dump Objective-C headers from binaries or dyld_shared_cache:

```bash
# Dump all headers from framework in DSC
ipsw class-dump $DSC SpringBoardServices --headers -o ./headers/

# Dump specific class
ipsw class-dump $DSC Security --class SecKey

# Filter by pattern
ipsw class-dump $DSC UIKit --class 'UIApplication.*' --headers -o ./headers/

# Include runtime addresses (for hooking)
ipsw class-dump $DSC Security --re
```

See [references/class-dump.md](references/class-dump.md) for filtering and output options.

---

## Mach-O Analysis

```bash
# Full binary info
ipsw macho info /path/to/binary

# Disassemble function
ipsw macho disass /path/to/binary --symbol _main

# Get entitlements and signature
ipsw macho info --ent /path/to/binary
ipsw macho info --sig /path/to/binary
```

See [references/macho.md](references/macho.md) for complete Mach-O commands.

---

## Reference Files

- [references/download.md](references/download.md) - Firmware download, device IDs, extraction
- [references/dyld.md](references/dyld.md) - Complete DSC commands (a2s, xref, dump, str, extract)
- [references/kernel.md](references/kernel.md) - Kernel and KEXT analysis
- [references/entitlements.md](references/entitlements.md) - Entitlements database and queries
- [references/class-dump.md](references/class-dump.md) - ObjC header dumping
- [references/macho.md](references/macho.md) - Mach-O binary analysis

## Tips

1. **Symbol caching:** First `a2s`/`symaddr` creates `.a2s` cache - subsequent lookups are instant
2. **Use --image flag:** Specifying dylib is 10x+ faster for DSC operations
3. **JSON output:** Most commands support `--json` for scripting
4. **Device IDs:** Use `ipsw device-list` to find device identifiers