retroplasma/flyover-reverse-engineering

Reversing Apple’s 3D satellite mode

This is an attempt to reverse-engineer Flyover (= 3D satellite mode) from Apple Maps. Main goal is to document the results and to provide code that emerges.

Status

We can authenticate URLs and retrieve textured 3D models from given coordinates (latitude, longitude). Limitation: Slow lookup for regions with tall models such as skyscrapers, which is because not all metadata has been reverse-engineered yet; see status board for details.

General

Data is stored in map tiles. These five tile styles are used for Flyover:

• 🅐: URL prefix from resource manifest
• ⓿: Version from resource manifest or altitude manifest using region
• ❶: Region ID from altitude manifest
• ❷❸❹: Map tile numbers (tiled web map scheme)
• ❺: Height/altitude index. Probably from C3MM
• ❻: Incremental part number
• ❼❽: Size/scale. Not sure where its values come from

Resource hierarchy

ResourceManifest
└─ AltitudeManifest
   ├─ C3MM
   │  └─ C3M
   └─ DTM?

Focusing on C3M(M) for now. DTMs are just images with a footer; they’re probably used for the grid that is displayed when Maps is loading.

Code

This repository is structured as follows:

Install

Install Go and run go get github.com/retroplasma/flyover-reverse-engineering. Then edit config.json in $GOPATH/src/github.com/retroplasma/flyover-reverse-engineering:

• automatically on macOS:
  • ./scripts/get_config_macos.sh > config.json
• or manually:
  • resourceManifestURL: from com.apple.GEO.plist or GeoServices binary
  • tokenP1: from GeoServices binary (function: GEOURLAuthenticationGenerateURL)

Command line programs

Here are some independent command line programs that use code from pkg:

Export OBJ (proof of concept, slow)

Usage:

go run cmd/poc-export-obj/main.go [lat] [lon] [zoom] [tryXY] [tryH]

Parameter   Description       Example
--------------------------------------
lat         Latitude          34.007603
lon         Longitude         -118.499741
zoom        Zoom (~ 13-20)    20
tryXY       Horizontal scan   3
tryH        Vertical scan     2

This exports Santa Monica Pier to ./downloaded_files/obj/...:

go run cmd/poc-export-obj/main.go 34.007603 -118.499741 20 3 2

Optional: Center-scale OBJ using node.js script:

node scripts/center_scale_obj.js

In Blender (compatible tutorial here):

Authenticate URLs

This authenticates a URL using parameters from config.json:

go run cmd/auth/main.go [url]

Parse C3M file

This parses a C3M v3 file, decompresses meshes, reads JPEG textures and produces a struct that contains a textured 3d model:

go run cmd/parse-c3m/main.go [file]

Parse C3MM file (work in progress)

go run cmd/parse-c3mm/main.go [file]

Files on macOS

• ~/Library/Preferences/com.apple.GEO.plist
  • last resource manifest url
• ~/Library/Caches/GeoServices/Resources/altitude-*.xml
  • defines regions for c3m urls
  • altitude-*.xml url in resource manifest
• ~/Library/Containers/com.apple.geod/Data/Library/Caches/com.apple.geod/MapTiles/MapTiles.sqlitedb
  • local map tile cache
• /System/Library/PrivateFrameworks/GeoServices.framework/GeoServices
  • resource manifest base url, networking, caching, authentication
• /System/Library/PrivateFrameworks/VectorKit.framework/VectorKit
  • parsers, decoders
• /System/Library/PrivateFrameworks/GeoServices.framework/XPCServices/com.apple.geod.xpc
  • loads GeoServices
• /Applications/Maps.app/Contents/MacOS/Maps
  • loads VectorKit

Important

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.