56 lines
1.8 KiB
Markdown
56 lines
1.8 KiB
Markdown
QR Code Encoder
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===============
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Reference used was ISO/IEC 18004, 1st Edition (2000)
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This implementation is informed by my specific needs, i.e. to provide
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two-factor authentication for mobile phones running Google Authenticator.
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+ "Byte" mode only (don't need e.g. numeric mode or kanji mode).
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+ Encode only (no detection/decode).
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+ Basic supporting library functions provided (HOTP, PNG image functions) to allow full-cyle demo.
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Demo
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====
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1. Download repo and compile with `erl -make`
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2. Install Google Authenticator App on your mobile:
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+ iPhone: http://itunes.apple.com/us/app/google-authenticator/id388497605?mt=8
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+ Android: https://market.android.com/details?id=com.google.android.apps.authenticator
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3. Run demo: `qrcode_demo:run().`
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4. Open the generated `qrcode.png` file
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5. Scan the qrcode into the phone.
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6. Ensure server clock is correct.
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7. The value of `qrcode_demo:totp()` should show the same passcode as the phone.
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8. Handle PINs/logins for the second part of the "two factor" according to your application design.
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NOTE: This documentation is rather basic as this was open-sourced by specific request!
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How to use QR Code Encoder with Elixir
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======================================
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Add :qrcode to `mix.deps`
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::
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defp deps do
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[{:qrcode, git: “git@gitlab.com:Pacodastre/qrcode.git”}]
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end
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Then run:
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::
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mix deps.get
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mix deps.compile
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Then, whenever you have this compiled, you should have access to the functions available in elixir.
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iex(1)> qrcode = :qrcode.encode(“bla”)
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{:qrcode, 1, :M, 29,
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<<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 254, 211, 248, 4, 16, 208, 64, 46, 152, ...>>}
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iex(2)> png = :qrcode_demo.simple_png_encode(qrcode)
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<<137, 80, 78, 71, 13, 10, 26, 10, 0, 0, 0, 13, 73, 72, 68, 82, 0, 0, 0, 232, 0, 0, 0, ...>>
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iex(3)> :file.write_file(“example.png”, png)
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:ok
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