Messages Format - Revision history

Podhrmic at 01:25, 18 March 2018

2018-03-18T01:25:45Z

@@ Line 38: / Line 38: @@
       D PPRZ_CHECKSUM_A (sum[B->C])
       E PPRZ_CHECKSUM_B (sum[ck_a])
 ==XBee API format==

Podhrmic: /* Types */

2017-12-29T03:53:54Z

Types

@@ Line 48: / Line 48: @@
 The cryptographic overhead during regular communication is 20 bytes (4 bytes of the counter, 16 bytes of the authentication tag), plus the necessary key exchange at the beginning of communication.
 ===S-Pprzlink v2.0===
 In this case both source and destination ID are not encrypted (but are authenticated).
 {|border="1"  cellspacing="0" style="text-align:center" cellpadding="2%" width="70%"
@@ Line 102: / Line 81: @@
 |1||length N (PPRZ_STX->checksum B)||style="background:orange; color:black"|Header
 |-
-|2|| source ID ||style="background:green; color:white"|Authenticated data
+|2||counter LSB 1 ||style="background:green; color:white"|Authenticated data
 |-
-|3|| destination ID ||style="background:green; color:white"|Authenticated data
+|3||counter LSB 2 ||style="background:green; color:white"|Authenticated data
 |-
-|4||counter LSB 1 ||style="background:green; color:white"|Authenticated data
+|4||counter LSB 3 ||style="background:green; color:white"|Authenticated data
 |-
-|5||counter LSB 2 ||style="background:green; color:white"|Authenticated data
+|5||counter LSB 4 ||style="background:green; color:white"|Authenticated data
 |-
-|6||counter LSB 3 ||style="background:green; color:white"|Authenticated data
+|6|| source ID ||style="background:green; color:white"|Authenticated data
 |-
-|7||counter LSB 4 ||style="background:green; color:white"|Authenticated data
+|7|| destination ID ||style="background:green; color:white"|Authenticated data
 |-
 |8|| class component ||style="background:yellow; color:black"|Encrypted payload

Podhrmic: /* Paparazzi "PPRZ" standard message for direct serial connection */

2017-12-29T03:48:00Z

Paparazzi "PPRZ" standard message for direct serial connection

← Older revision		Revision as of 21:48, 28 December 2017
Line 12:		Line 12:

	PPRZ-message: ABCxxxxxxxDE		PPRZ-message: ABCxxxxxxxDE
	~~byte: \| value:~~		A PPRZ_STX (0x99)
	0 PPRZ_STX (0x99)		B LENGTH (PPRZ_STX->PPRZ_CHECKSUM_B)
	1 LENGTH (PPRZ_STX->PPRZ_CHECKSUM_B)		C PPRZ_DATA
	2 SENDER_ID		0 SENDER_ID
	3 MSG_ID		1 MSG_ID
	~~4..(N-~~2) MSG_PAYLOAD (messages.xml)		2 MSG_PAYLOAD
	~~N-1~~ PPRZ_CHECKSUM_A (sum[B->C])		. DATA (messages.xml)
	N PPRZ_CHECKSUM_B (sum[ck_a])		D PPRZ_CHECKSUM_A (sum[B->C])
			E PPRZ_CHECKSUM_B (sum[ck_a])

	===Pprzlink v2.0===		===Pprzlink v2.0===

Podhrmic: /* Secure Paparazzi (S-PPRZ) for serial and transparent modem communication */

2017-11-04T21:09:37Z

Secure Paparazzi (S-PPRZ) for serial and transparent modem communication

← Older revision		Revision as of 15:09, 4 November 2017
Line 91:		Line 91:

	===S-Pprzlink v2.0===		===S-Pprzlink v2.0===
	In this case ~~we decrypt only packets with matching DESTINATION~~ (~~or broadcast~~)~~, to avoid decrypting unwanted data~~.		In this case both source and destination ID are not encrypted (but are authenticated).
	~~PPRZ~~-~~message~~: ~~ABCxxxxxxxDE~~
	A PPRZ_STX (0x99)		{\|border="1" cellspacing="0" style="text-align:center" cellpadding="2%" width="70%"
	~~B LENGTH~~ (A->E)		\|+'''S-Pprzlink v2.0'''
	~~C PPRZ_DATA~~		!width="7%"\|''byte''!!width="10%"\|''Value''!!width="10%"\|''Type''
	~~0 SOURCE (~sender_ID)~~		\|-
	~~1 DESTINATION (can be a broadcast~~ ID)		\|0\|\|PPRZ_STX (0x99)\|\|style="background:orange; color:black"\|Header
	2-~~5 COUNTER (~~4 ~~bytes)~~		\|-
	~~// ciphertext start~~		\|1\|\|length N (PPRZ_STX->checksum B)\|\|style="background:orange; color:black"\|Header
	~~6 CLASS/COMPONENT~~		\|-
	~~bits 0~~-3: ~~16 class ID available~~		\|2\|\| source ID \|\|style="background:green; color:white"\|Authenticated data
	~~bits 4~~-7: 16 component ID ~~available~~		\|-
	~~7 MSG_ID~~		\|3\|\| destination ID \|\|style="background:green; color:white"\|Authenticated data
	~~8 MSG_PAYLOAD~~		\|-
	. ~~DATA~~ (~~messages.xml~~)		\|4\|\|counter LSB 1 \|\|style="background:green; color:white"\|Authenticated data
	~~// ciphertext end~~		\|-
	8-~~19 TAG~~ (12 bytes)		\|5\|\|counter LSB 2 \|\|style="background:green; color:white"\|Authenticated data
	~~D PPRZ_CHECKSUM_A (sum[~~B~~->C])~~		\|-
	~~E PPRZ_CHECKSUM_B (sum[ck_a])~~		\|6\|\|counter LSB 3 \|\|style="background:green; color:white"\|Authenticated data
			\|-
			\|7\|\|counter LSB 4 \|\|style="background:green; color:white"\|Authenticated data
			\|-
			\|8\|\| class component \|\|style="background:yellow; color:black"\|Encrypted payload
			\|-
			\|9\|\| message ID \|\|style="background:yellow; color:black"\|Encrypted payload
			\|-
			\|10..(N-16)\|\| (optional) message payload (0-234 bytes) \|\|style="background:yellow; color:black"\|Encrypted payload
			\|-
			\|(N-15)..(N-2)\|\| tag (16 bytes) \|\|style="background:blue; color:white"\|Authentication tag
			\|-
			\|N-1\|\|checksum A\|\|style="background:orange; color:black"\|Header
			\|-
			\|N\|\|checksum B\|\|style="background:orange; color:black"\|Header
			\|}

	==XBee API format==		==XBee API format==

Podhrmic: /* S-Pprzlink v1.0 */

2017-11-04T21:05:59Z

S-Pprzlink v1.0

← Older revision		Revision as of 15:05, 4 November 2017
Line 69:		Line 69:
	\|1\|\|length N (PPRZ_STX->checksum B)\|\|style="background:orange; color:black"\|Header		\|1\|\|length N (PPRZ_STX->checksum B)\|\|style="background:orange; color:black"\|Header
	\|-		\|-
	\|2\|\|~~counter LSB 1~~ \|\|style="background:green; color:white"\|Authenticated data		\|2\|\| sender ID \|\|style="background:green; color:white"\|Authenticated data
	\|-		\|-
	\|3\|\|counter LSB 2 \|\|style="background:green; color:white"\|Authenticated data		\|3\|\|counter LSB 1 \|\|style="background:green; color:white"\|Authenticated data
	\|-		\|-
	\|4\|\|counter LSB 3 \|\|style="background:green; color:white"\|Authenticated data		\|4\|\|counter LSB 2 \|\|style="background:green; color:white"\|Authenticated data
	\|-		\|-
	\|5\|\|counter LSB 4 \|\|style="background:green; color:white"\|Authenticated data		\|5\|\|counter LSB 3 \|\|style="background:green; color:white"\|Authenticated data
	\|-		\|-
	\|6\|\| ~~sender ID~~ \|\|style="background:~~yellow~~; color:~~black~~"\|~~Encrypted payload~~		\|6\|\|counter LSB 4 \|\|style="background:green; color:white"\|Authenticated data
	\|-		\|-
	\|7\|\| message ID \|\|style="background:yellow; color:black"\|Encrypted payload		\|7\|\| message ID \|\|style="background:yellow; color:black"\|Encrypted payload

Podhrmic: /* Secure Paparazzi (S-PPRZ) for serial and transparent modem communication */

2017-11-04T02:41:58Z

Secure Paparazzi (S-PPRZ) for serial and transparent modem communication

← Older revision		Revision as of 20:41, 3 November 2017
Line 38:		Line 38:
	E PPRZ_CHECKSUM_B (sum[ck_a])		E PPRZ_CHECKSUM_B (sum[ck_a])

	==Secure Paparazzi (S-PPRZ) for serial and transparent modem communication==		==Secure Paparazzi (S-PPRZ) for serial and transparent modem communication==
	The overhead is 16 bytes (4 bytes of counter, 16 bytes of tag), plus the necessary key exchange at the beginning of communication.		Secure Paparazzi link ([https://github.com/paparazzi/pprzlink/tree/hacl-c pprzlink]) 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, refer there for more details about the algorithm itself.

			The cryptographic overhead during regular communication is 20 bytes (4 bytes of the counter, 16 bytes of the authentication tag), plus the necessary key exchange at the beginning of communication.

	===S-Pprzlink v1.0===		===S-Pprzlink v1.0===

Podhrmic: /* S-Pprzlink v1.0 */

2017-11-04T02:29:12Z

S-Pprzlink v1.0

@@ Line 54: / Line 54: @@
      N-1           PPRZ_CHECKSUM_A (sum[B->C])
      N             PPRZ_CHECKSUM_B (sum[ck_a])
 ===S-Pprzlink v2.0===

Podhrmic: /* S-Pprzlink v1.0 */

2017-11-04T02:17:59Z

S-Pprzlink v1.0

← Older revision		Revision as of 20:17, 3 November 2017
Line 51:		Line 51:
	7 encrypted MSG_ID		7 encrypted MSG_ID
	8..(N-16) encrypted MSG_PAYLOAD (messages.xml)		8..(N-16) encrypted MSG_PAYLOAD (messages.xml)
	(N-15)..(N-2) TAG (12 bytes)		(N-15)..(N-2) TAG (16 bytes)
	N-1 PPRZ_CHECKSUM_A (sum[B->C])		N-1 PPRZ_CHECKSUM_A (sum[B->C])
	N PPRZ_CHECKSUM_B (sum[ck_a])		N PPRZ_CHECKSUM_B (sum[ck_a])

Podhrmic: /* Secure Paparazzi (S-PPRZ) for serial and transparent modem communication */

2017-11-04T02:17:44Z

Secure Paparazzi (S-PPRZ) for serial and transparent modem communication

← Older revision		Revision as of 20:17, 3 November 2017
Line 39:		Line 39:

	==Secure Paparazzi (S-PPRZ) for serial and transparent modem communication==		==Secure Paparazzi (S-PPRZ) for serial and transparent modem communication==
	The overhead is 16 bytes (4 bytes of counter, 12 bytes of tag), plus the necessary key exchange at the beginning of communication.		The overhead is 16 bytes (4 bytes of counter, 16 bytes of tag), plus the necessary key exchange at the beginning of communication.

	===S-Pprzlink v1.0===		===S-Pprzlink v1.0===
Line 50:		Line 50:
	6 encrypted SENDER_ID		6 encrypted SENDER_ID
	7 encrypted MSG_ID		7 encrypted MSG_ID
	8..(N-12) encrypted MSG_PAYLOAD (messages.xml)		8..(N-16) encrypted MSG_PAYLOAD (messages.xml)
	(N-11)..(N-2) TAG (12 bytes)		(N-15)..(N-2) TAG (12 bytes)
	N-1 PPRZ_CHECKSUM_A (sum[B->C])		N-1 PPRZ_CHECKSUM_A (sum[B->C])
	N PPRZ_CHECKSUM_B (sum[ck_a])		N PPRZ_CHECKSUM_B (sum[ck_a])

Podhrmic: /* S-Pprzlink v1.0 */

2017-10-07T21:40:09Z

S-Pprzlink v1.0

← Older revision		Revision as of 15:40, 7 October 2017
Line 42:		Line 42:

	===S-Pprzlink v1.0===		===S-Pprzlink v1.0===

	PPRZ-message: ABCxxxxxxxDE		PPRZ-message: ABCxxxxxxxDE
	A PPRZ_STX (0x99)		byte: \| value:
	B LENGTH (A->E)		0 PPRZ_STX (0x99)
	~~C PPRZ_DATA~~		1 LENGTH (PPRZ_STX->PPRZ_CHECKSUM_B)
	0-3 COUNTER		2-5 COUNTER (4 bytes)
	~~// ciphertext start~~		6 encrypted SENDER_ID
	4 SENDER_ID		7 encrypted MSG_ID
	5 MSG_ID		8..(N-12) encrypted MSG_PAYLOAD (messages.xml)
	6 MSG_PAYLOAD		(N-11)..(N-2) TAG (12 bytes)
	~~. DATA~~ (messages.xml)		N-1 PPRZ_CHECKSUM_A (sum[B->C])
	~~// ciphertext end~~		N PPRZ_CHECKSUM_B (sum[ck_a])
	7-18 TAG (12 bytes)
	D PPRZ_CHECKSUM_A (sum[B->C])
	E PPRZ_CHECKSUM_B (sum[ck_a])

	===S-Pprzlink v2.0===		===S-Pprzlink v2.0===