Pprzlink - Revision history

Ghattenb: /* How to use it */

2021-01-16T11:24:58Z

How to use it

← Older revision		Revision as of 05:24, 16 January 2021
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	</module>		</module>
	</source>		</source>

			The HACL-C library requires at least 2 kBytes of memory for all the stacks sending messages. If you don't use an RTOS (e.g. ChibiOS), You don't have anything to do. If yes, you need to increase the stack size of the FBW thread by adding to the firmware section (only '''fixedwing''' firmware):

			<source lang="xml">
			<define name="FBW_THREAD_STACK_SIZE" value="1024*4"/>
			</source>

			You should have enough space already with the threads AP (fixedwing) and MAIN (rotorcraft).

	Build and upload your code. Secure link works for [[NPS\|NP]] targets, as well as for regular AP targets. Currently STM32-F4 autopilots are supported (you need a random number generator on chip), in bare metal version (ChibiOS will come later).		Build and upload your code. Secure link works for [[NPS\|NP]] targets, as well as for regular AP targets. Currently STM32-F4 autopilots are supported (you need a random number generator on chip), in bare metal version (ChibiOS will come later).

Podhrmic: /* Secure Ppprzlink */

2018-03-27T18:22:44Z

Secure Ppprzlink

← Older revision		Revision as of 12:22, 27 March 2018
Line 265:		Line 265:

	[[File:V2 crypto.png\|500px\|frame\|center\|Pprzlink 2.0 encrypted message]]		[[File:V2 crypto.png\|500px\|frame\|center\|Pprzlink 2.0 encrypted message]]

			== Whitelisting messages ==
			TODO

	= Pprzlink proxy =		= Pprzlink proxy =

Podhrmic: /* Performance */

2018-03-27T18:15:33Z

Performance

← Older revision		Revision as of 12:15, 27 March 2018
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	For typical configuration the increase in transmitted data is from '''1.6''' to '''1.9''', so depending on the channel bandwith the frequency of some messages might have to be adjusted. In the extreme case (such as sending a short ''SONAR'' message at high frequency), secure link can increase the amount of transferred data more than 2.5 times.		For typical configuration the increase in transmitted data is from '''1.6''' to '''1.9''', so depending on the channel bandwith the frequency of some messages might have to be adjusted. In the extreme case (such as sending a short ''SONAR'' message at high frequency), secure link can increase the amount of transferred data more than 2.5 times.

			Chacha20 is a cipher that is fast in software, and is faster than software implementation of AES, but slower than a hardware implementation of AES. Nonetheless, the additional CPU from secure link is negligible (tested on [[Lisa/M v20\|Lisa MX]]).

	== Message Format ==		== Message Format ==

Podhrmic: /* Secure Ppprzlink */

2018-03-18T02:17:39Z

Secure Ppprzlink

Show changes

Podhrmic: /* Secure Ppprzlink */

2018-03-18T01:24:48Z

Secure Ppprzlink

@@ Line 90: / Line 90: @@
 == Installation ==
 Secure link requires [https://www.rust-lang.org/en-US/ Rust]. The recommended way to install Rust on your computer is via [https://www.rustup.rs/ rustup.rs]. The rest is handled by the paparazzi build system.
 = Pprzlink proxy =

Podhrmic: /* Secure Ppprzlink */

2018-03-18T00:50:11Z

Secure Ppprzlink

← Older revision		Revision as of 18:50, 17 March 2018
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	'''s-pprzlink''' uses a formally verified cryptographic library [https://github.com/mitls/hacl-star HACL*] developed by the [http://prosecco.inria.fr/ Prosecco] team at [https://www.inria.fr/en/centre/paris INRIA Paris] in collaboration with Microsoft Research, as part of [https://github.com/project-everest Project Everest].		'''s-pprzlink''' uses a formally verified cryptographic library [https://github.com/mitls/hacl-star HACL*] developed by the [http://prosecco.inria.fr/ Prosecco] team at [https://www.inria.fr/en/centre/paris INRIA Paris] in collaboration with Microsoft Research, as part of [https://github.com/project-everest Project Everest].

	Because certain data have to be ~~send~~ in plaintext (such as the message counter), '''s-pprzlink''' uses ''Authenticated Encryption with Associated Data'' (AEAD) algorithm to authenticate such data before use. Authentication means that any unauthorized change in data is detected upon decryption. Authentication is important because if we decide to send SENDER_ID or DESTINATION_ID in plaintext - so the receiver can decide whether to decrypt the message - we don't want it to be tampered with. '''s-pprzlink''' uses a modified [https://github.com/GaloisInc/gec Galois Embedded Crypto] algorithm for the symmetric key exchange.		Because certain data have to be sent in plaintext (such as the message counter), '''s-pprzlink''' uses ''Authenticated Encryption with Associated Data'' (AEAD) algorithm to authenticate such data before use. Authentication means that any unauthorized change in data is detected upon decryption. Authentication is important because if we decide to send SENDER_ID or DESTINATION_ID in plaintext - so the receiver can decide whether to decrypt the message - we don't want it to be tampered with. '''s-pprzlink''' uses a modified [https://github.com/GaloisInc/gec Galois Embedded Crypto] algorithm for the symmetric key exchange.

	The overhead for encrypted communication is 21 bytes (1 byte signaling crypto/plaintext message, 4 bytes of the counter, 16 bytes of the authentication tag), for plaintext messages (such as key-exchange and some info messages) is only one byte.		The overhead for encrypted communication is 21 bytes (1 byte signaling crypto/plaintext message, 4 bytes of the counter, 16 bytes of the authentication tag), for plaintext messages (such as key-exchange and some info messages) is only one byte.

Podhrmic: /* Language supports */

2018-03-18T00:48:43Z

Language supports

← Older revision		Revision as of 18:48, 17 March 2018
Line 65:		Line 65:

	The supported languages are:		The supported languages are:
	* C language		* [https://github.com/paparazzi/pprzlink/tree/master/lib/v1.0/C C language]
	** generation of code (header files) for sending and decoding messages		** generation of code (header files) for sending and decoding messages
	** mostly used for the airborne code of Paparazzi		** mostly used for the airborne code of Paparazzi
	* Ocaml		* [https://github.com/paparazzi/pprzlink/tree/master/lib/v1.0/ocaml Ocaml]
	** library based high-level functions for binding, subscribing and parsing messages		** library based high-level functions for binding, subscribing and parsing messages
	** mostly used by the ground station agents: links, GCS, server, ...		** mostly used by the ground station agents: links, GCS, server, ...
	* Python		* [https://github.com/paparazzi/pprzlink/tree/master/lib/v1.0/python Python]
	** Provide similar functionality than the Ocaml implemetation		** Provide similar functionality than the Ocaml implemetation
	** used in a large variety of smaller tools and ground agents		** used in a large variety of smaller tools and ground agents
	* Rust		* [https://github.com/paparazzi/pprzlink-rust Rust]
	** similar to Python implementation, plus added memory safety		** similar to Python implementation, plus added memory safety
	** used mainly for secure pprzlink (see below)		** used mainly for secure pprzlink (see below)

Podhrmic: /* Secure Ppprzink */

2018-03-15T00:41:41Z

Secure Ppprzink

← Older revision		Revision as of 18:41, 14 March 2018
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	** used mainly for secure pprzlink (see below)		** used mainly for secure pprzlink (see below)

	= Secure ~~Ppprzink~~ =		= Secure Ppprzlink =
			Secure Paparazzi link uses [https://en.wikipedia.org/wiki/Symmetric-key_algorithm symmetric key encryption] with [https://en.wikipedia.org/wiki/Salsa20#ChaCha_variant Chacha20] cipher.

			'''s-pprzlink''' uses a formally verified cryptographic library [https://github.com/mitls/hacl-star HACL*] developed by the [http://prosecco.inria.fr/ Prosecco] team at [https://www.inria.fr/en/centre/paris INRIA Paris] in collaboration with Microsoft Research, as part of [https://github.com/project-everest Project Everest].

			Because certain data have to be send in plaintext (such as the message counter), '''s-pprzlink''' uses ''Authenticated Encryption with Associated Data'' (AEAD) algorithm to authenticate such data before use. Authentication means that any unauthorized change in data is detected upon decryption. Authentication is important because if we decide to send SENDER_ID or DESTINATION_ID in plaintext - so the receiver can decide whether to decrypt the message - we don't want it to be tampered with. '''s-pprzlink''' uses a modified [https://github.com/GaloisInc/gec Galois Embedded Crypto] algorithm for the symmetric key exchange.

			The overhead for encrypted communication is 21 bytes (1 byte signaling crypto/plaintext message, 4 bytes of the counter, 16 bytes of the authentication tag), for plaintext messages (such as key-exchange and some info messages) is only one byte.


	== Installation ==		== Installation ==

Podhrmic: /* Secure Ppprzink */

2018-03-15T00:34:36Z

Secure Ppprzink

← Older revision		Revision as of 18:34, 14 March 2018
Line 81:		Line 81:

	== Installation ==		== Installation ==
	Secure link requires [https://www.rust-lang.org/en-US/ Rust]. The recommended way to install Rust on your computer is via [https://www.rustup.rs/ rustup.rs].		Secure link requires [https://www.rust-lang.org/en-US/ Rust]. The recommended way to install Rust on your computer is via [https://www.rustup.rs/ rustup.rs]. The rest is handled by the paparazzi build system.

	~~[https://github.com/mitls/hacl-star HACL] also has to be installed. Paparazzi provides a convenient [https://github.com/~~paparazzi~~/hacl-c snapshot] of the generated C code. To install HACL, go to ''sw/ext/hacl-c'' and type:~~
	~~<nowiki>~~
	~~make~~
	~~sudo cp libhacl.* /usr/local/lib/~~.
	~~</nowiki>~~

	= Pprzlink proxy =		= Pprzlink proxy =

Podhrmic: /* Language supports */

2018-03-15T00:33:47Z

Language supports

← Older revision		Revision as of 18:33, 14 March 2018
Line 76:		Line 76:
	* Rust		* Rust
	** similar to Python implementation, plus added memory safety		** similar to Python implementation, plus added memory safety
	** used mainly for secure ~~link~~		** used mainly for secure pprzlink (see below)

	= Secure Ppprzink =		= Secure Ppprzink =