62 lines
2.2 KiB
Markdown
62 lines
2.2 KiB
Markdown
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# Notes on Hello Perso sample app.
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Hello Perso is a sample app from the LedgerHQ repository
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[blue-sample-apps](https://github.com/LedgerHQ/blue-sample-apps). It's
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stated purpose is to be a "a simple application showing the UI and master
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seed derivation."
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# Compiling:
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Compiles fine inside Docker image, as in the process described in the
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[Getting Started](http://ledger.readthedocs.io/en/latest/nanos/setup.html)
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tutorial (which takes you through the Hello World tutorial).
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In extracting the hex-encoded compiled app from the docker container to my
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local machine, I changed the app name as follows:
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``` bash
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sudo docker cp [container_id]:/home/blue-sample-apps/blue-app-helloperso/bin/app.hex perso-app.hex
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```
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I then loaded the app onto the Nano S using the following, and then
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discovered a problem:
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``` bash
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python -m ledgerblue.loadApp --targetId 0x31100002 --apdu --fileName perso-app.hex --appName HelloPerso --appFlags 0x00 --icon ""
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```
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The problem: Hello Perso app requires the `APPLICATION_FLAG_GLOBAL_PIN`
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permission flag. I had just copied and pasted my loadApp command line for
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HelloWorld and changed the app name and image name. But the `--appFlags`
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argument needed to be changed to `--appFlags 0x40`.
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Symptoms: With the wrong permissions set, even though the app was
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successfuly loaded onto the device, it would freeze the Nano every
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time I started the app, requiring a power-cycle to get back to the
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dashboard.
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The correct load command was:
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``` bash
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python -m ledgerblue.loadApp --targetId 0x31100002 --apdu --fileName perso-app.hex --appName HelloPerso --appFlags 0x40 --icon ""
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```
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### How to remove apps:
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Problem Two: Repeating the loadApp() command with the correct flags failed
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because the app already existed on the device. It apparently won't
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overwrite. Thus I had to find a delete command, which fortunately is
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referenced in the Makefile. To manually delete the app, this is the
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command:
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``` bash
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python -m ledgerblue.deleteApp --targetId 0x31100002 --appName HelloPerso
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```
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### Permission flags defined:
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The `0x40` permission flag that was needed is defined by macro constant
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`APPLICATION_FLAG_GLOBAL_PIN` in
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[nanos-secure-sdk/include/os.h](https://github.com/LedgerHQ/nanos-secure-sdk/blob/master/include/os.h),
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along with many other application flags.
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