Move nitrocli source code into repository root

Now that all vendored dependencies have been removed, this change moves
the program's source code from the nitrocli/ directory into the root of
the repository.

1 files changed, 166 insertions, 0 deletions

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+[![pipeline](https://gitlab.com/d-e-s-o/nitrocli/badges/master/pipeline.svg)](https://gitlab.com/d-e-s-o/nitrocli/commits/master)
+[![crates.io](https://img.shields.io/crates/v/nitrocli.svg)](https://crates.io/crates/nitrocli)
+[![rustc](https://img.shields.io/badge/rustc-1.35+-blue.svg)](https://blog.rust-lang.org/2019/05/23/Rust-1.35.0.html)
+
+nitrocli
+========
+
+- [Changelog](CHANGELOG.md)
+
+**nitrocli** is a program that provides a command line interface for
+interaction with [Nitrokey Pro][nitrokey-pro] and [Nitrokey
+Storage][nitrokey-storage] devices.
+
+
+The following commands are currently supported:
+- status: Report status information about the Nitrokey.
+- lock: Lock the Nitrokey.
+- config: Access the Nitrokey's configuration
+  - get: Read the current configuration.
+  - set: Change the configuration.
+- encrypted: Work with the Nitrokey Storage's encrypted volume.
+  - open: Open the encrypted volume. The user PIN needs to be entered.
+  - close: Close the encrypted volume.
+- hidden: Work with the Nitrokey Storage's hidden volume.
+  - create: Create a hidden volume.
+  - open: Open a hidden volume with a password.
+  - close: Close a hidden volume.
+- otp: Access one-time passwords (OTP).
+  - get: Generate a one-time password.
+  - set: Set an OTP slot.
+  - status: List all OTP slots.
+  - clear: Delete an OTP slot.
+- pin: Manage the Nitrokey's PINs.
+  - clear: Remove the user and admin PIN from gpg-agent's cache.
+  - set: Change the admin or the user PIN.
+  - unblock: Unblock and reset the user PIN.
+- pws: Access the password safe (PWS).
+  - get: Query the data on a PWS slot.
+  - set: Set the data on a PWS slot.
+  - status: List all PWS slots.
+  - clear: Delete a PWS slot.
+- unencrypted: Work with the Nitrokey Storage's unencrypted volume.
+  - set: Change the read-write mode of the unencrypted volume.
+
+
+Usage
+-----
+
+Usage is as simple as providing the name of the respective command as a
+parameter (note that some commands are organized through subcommands,
+which are required as well), e.g.:
+```bash
+# Open the nitrokey's encrypted volume.
+$ nitrocli storage open
+
+$ nitrocli status
+Status:
+  model:             Storage
+  serial number:     0x00053141
+  firmware version:  0.47
+  user retry count:  3
+  admin retry count: 3
+  Storage:
+    SD card ID:        0x05dcad1d
+    firmware:          unlocked
+    storage keys:      created
+    volumes:
+      unencrypted:     active
+      encrypted:       active
+      hidden:          inactive
+
+# Close it again.
+$ nitrocli storage close
+```
+
+More examples, a more detailed explanation of the purpose, the potential
+subcommands, as well as the parameters of each command are provided in
+the [`man` page](doc/nitrocli.1.pdf).
+
+
+Installation
+------------
+
+In addition to Rust itself and Cargo, its package management tool, the
+following dependencies are required:
+- **hidapi**: In order to provide USB access this library is used.
+- **GnuPG**: The `gpg-connect-agent` program allows the user to enter
+             PINs.
+
+#### Via Packages
+Packages are available for:
+- Arch Linux: [`nitrocli`][nitrocli-arch] in the Arch User Repository
+- Debian: [`nitrocli`][nitrocli-debian] (since Debian Buster)
+- Gentoo Linux: [`app-crypt/nitrocli`][nitrocli-gentoo] ebuild
+- Ubuntu: [`nitrocli`][nitrocli-ubuntu] (since Ubuntu 19.04)
+
+#### From Crates.io
+**nitrocli** is [published][nitrocli-cratesio] on crates.io and can
+directly be installed from there:
+```bash
+$ cargo install nitrocli --root=$PWD/nitrocli
+```
+
+#### From Source
+After cloning the repository the build is as simple as running:
+```bash
+$ cargo build --release
+```
+
+It is recommended that the resulting executable be installed in a
+directory accessible via the `PATH` environment variable.
+
+
+Known Problems
+--------------
+
+- Due to a problem with the default `hidapi` version on macOS, users are
+  advised to build and install [`libnitrokey`][] from source and then
+  set the `USE_SYSTEM_LIBNITROKEY` environment variable when building
+  `nitrocli` using one of the methods described above.
+- `nitrocli` cannot connect to a Nitrokey device that is currently being
+  accessed by `nitrokey-app` ([upstream issue][libnitrokey#32]). To
+  prevent this problem, quit `nitrokey-app` before using `nitrocli`.
+- Applications using the Nitrokey device (such as `nitrocli` or
+  `nitrokey-app`) cannot easily share access with an instance of GnuPG
+  running shortly afterwards ([upstream issue][libnitrokey#137]).
+
+
+Contributing
+------------
+
+Contributions are generally welcome. Please follow the guidelines
+outlined in [CONTRIBUTING.md](doc/CONTRIBUTING.md).
+
+
+Acknowledgments
+---------------
+
+Robin Krahl ([@robinkrahl](https://github.com/robinkrahl)) has been
+a crucial help for the development of **nitrocli**.
+
+The [Nitrokey UG][nitrokey-ug] has generously provided the necessary
+hardware for developing and testing the program.
+
+
+License
+-------
+**nitrocli** is made available under the terms of the
+[GPLv3][gplv3-tldr].
+
+See the [LICENSE](LICENSE) file that accompanies this distribution for
+the full text of the license.
+
+
+[`libnitrokey`]: https://github.com/nitrokey/libnitrokey
+[nitrokey-ug]: https://www.nitrokey.com
+[nitrokey-pro]: https://shop.nitrokey.com/shop/product/nitrokey-pro-2-3
+[nitrokey-storage]: https://shop.nitrokey.com/shop/product/nitrokey-storage-2-16gb-23
+[nitrocli-arch]: https://aur.archlinux.org/packages/nitrocli
+[nitrocli-cratesio]: https://crates.io/crates/nitrocli
+[nitrocli-debian]: https://packages.debian.org/stable/nitrocli
+[nitrocli-gentoo]: https://packages.gentoo.org/packages/app-crypt/nitrocli
+[nitrocli-ubuntu]: https://packages.ubuntu.com/search?keywords=nitrocli
+[gplv3-tldr]: https://tldrlegal.com/license/gnu-general-public-license-v3-(gpl-3)
+[libnitrokey#32]: https://github.com/Nitrokey/libnitrokey/issues/32
+[libnitrokey#137]: https://github.com/Nitrokey/libnitrokey/issues/137