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Describe the missing parts of the signer protocol

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Jan Dittberner 6 years ago
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source/signer.rst
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@ -11,7 +11,7 @@ defined here.
Signer request data format specification
========================================
Protocol data is encoded with the following format:
Protocol request data is encoded in the following format:
.. table:: signer request message format
@ -31,11 +31,12 @@ Protocol data is encoded with the following format:
Due to the length encoding in 3 bytes the messages can have a maximum length
of 8\ :sup:`3` = 2\ :sup:`24` Bytes which is around 16 MiB.
General header format
---------------------
General request header format
-----------------------------
Every protocol header (bytes 3-12 of protocol message) follows the same 8 byte
structure. The content of bits 3-8 are protocol action specific.
Every protocol request header (bytes 3-12 of protocol request message) follows
the same 9 byte structure. The content of bytes 3-8 are protocol action
specific.
.. table:: general request header format
@ -54,7 +55,7 @@ structure. The content of bits 3-8 are protocol action specific.
.. _signer-nul-request-format:
Format of NUL Requests
Format of NUL requests
----------------------
NUL requests are sent at the end of each iteration in
@ -81,6 +82,14 @@ NUL requests are sent at the end of each iteration in
- ""
- ""
.. note::
The timestamp sent with the NUL request is used to create a
script to synchronize the time on the signer using :program:`date` and
:program:`hwclock`.
.. _signer-x509-request-format:
Format of X.509 signing request messages
----------------------------------------
@ -186,10 +195,12 @@ table which is one of
10 SHA-512
== ==========
Format of OpenPGP key signing requests
--------------------------------------
.. _signer-openpgp-request-format:
Format of OpenPGP key signing request messages
----------------------------------------------
OpenPGP key signing requests are sent in
OpenPGP key signing request messages are sent in
:ref:`client.pl <commmodule-client-pl>`'s main loop for each requested
OpenPGP key.
@ -217,10 +228,14 @@ OpenPGP key.
.. [#unused-server] the field is unused in
:ref:`server.pl <commmodule-server-pl>`
Format of X.509 certificate revocation requests
-----------------------------------------------
.. _signer-csr-request-format:
.. Request($ver, 2, 1, $row{'rootcert'} - 1, 0, 0, 365, 0, $content, "", $revokehash);
Format of X.509 certificate revocation request messages
-------------------------------------------------------
X.509 certificate revocation request messages are sent in
:ref:`client.pl <commmodule-client-pl>`'s main loop for each requested
X.509 certificate revocation.
==== ===========================
Byte Value
@ -247,7 +262,148 @@ Format of X.509 certificate revocation requests
Signer response data format specification
=========================================
.. todo:: describe signer response
Protocol response data is encoded in the following format:
.. table:: signer response message format:
======= =======================================================
Byte Data
======= =======================================================
0-2 length of header + data in network byte order
3-5 length of header network byte order [#diff-to-request]_
6-9 header data
10-12 length of payload data 1 in network byte order
13-N payload data 1
N+1-N+3 length of payload data 2 network byte order
N+4-M payload data 2
M+1-M+3 length of payload data 3 network byte order
M+4-End payload data 3
======= =======================================================
.. [#diff-to-request] this is a difference to the
:ref:`signer-request-data-format` that does not add the
length of the header
General response header format
------------------------------
Every protocol response header (bytes 6-9 of protocol response message)
follows the same 4 byte structure. The content of bytes 3 and 4 are not used
yet.
.. table:: general response header format
==== ==================
Byte Value
==== ==================
0 Version (``0x01``)
1 Action
3 ``0x00`` unused
4 ``0x00`` unused
==== ==================
.. _signer-nul-response-format:
Format of NUL Responses
-----------------------
NUL responses are sent in response to
:ref:`NUL requests <signer-nul-request-format>`.
.. table:: NUL response header format
==== ==================
Byte Value
==== ==================
0 Version (``0x01``)
1 Action (``0x00``)
3 ``0x00`` unused
4 ``0x00`` unused
==== ==================
**NUL Response Payload:**
- ""
- ""
- ""
Format of X.509 certificate response messages
---------------------------------------------
X.509 certificate response messages are sent in response to
:ref:`X.509 certificate signing request messages <signer-x509-request-format>`.
.. table:: X.509 certificate response header format
==== ==================
Byte Value
==== ==================
0 Version (``0x01``)
1 Action (``0x01``)
3 ``0x00`` unused
4 ``0x00`` unused
==== ==================
**X.509 certificate response payload:**
- PEM encoded X.509 certificate
- ""
- ""
.. _signer-openpgp-response-format:
Format of OpenPGP key signature response messages
-------------------------------------------------
OpenPGP key signature response messages are sent in response to
:ref:`OpenPGP key signing request messages <signer-openpgp-request-format>`.
.. table:: OpenPGP key signature response header format
==== ==================
Byte Value
==== ==================
0 Version (``0x01``)
1 Action (``0x02``)
3 ``0x00`` unused
4 ``0x00`` unused
==== ==================
**OpenPGP key signature response payload:**
- ASCII armored PGP public key block
- ""
- ""
Format of X.509 certificate revocation response messages
--------------------------------------------------------
X.509 certificate revocation response messages are sent in response to
:ref:`X.509 certificate revocation request messages
<signer-csr-request-format>`.
.. table:: X.509 certificate revocation response header format
==== =====================================
Byte Value
==== =====================================
0 Version (``0x01``)
1 Action (``0x02``) [#overlap-openpgp]_
3 ``0x00`` unused
4 ``0x00`` unused
==== =====================================
.. [#overlap-openpgp] this response type uses the same action byte as the
:ref:`OpenPGP key signature response message <signer-openpgp-response-format>`
**X.509 certificate revocation response payload:**
- CRL diff in :program:`xdelta` format or "" if the original CRL specified
by the SHA-1 hash in the third payload field of the request is not
available
- ""
- ""
Protocol messages
=================
@ -271,6 +427,8 @@ Handshake
If anything different is received there was a protocol error and no further
messages should be sent over the serial connection.
.. _signer-message-senddata:
Send data
---------
@ -286,9 +444,10 @@ Send data
.. seqdiag::
seqdiag with_retry {
seqdiag request_with_retry {
client -> client [label = "xor $data"];
client -> server [label = "$data . $xor . \"rie4Ech7\""];
server -> server [label = "detect corruption"];
client <-- server [label = "0x11"];
client -> server [label = "$data . $xor . \"rie4Ech7\""];
client <-- server [label = "0x10"];
@ -296,3 +455,35 @@ Send data
If anything different is received there was a protocol error and no further
messages should be sent over the serial connection.
Receive data
------------
:Preconditions:
client :ref:`sent data <signer-message-senddata>`
#. client waits for a response (with a 120 second timeout)
#. server builds byte wise xor of all data bytes in 1 byte $xor
#. server sends ``0x02`` to start transmission
#. client sends ``0x10`` to confirm receipt (server timeout 1 second)
#. server sends concatenated $data string + xor-Byte + "rie4Ech7"
#. client reads data in 100 byte segments (5 second timeout)
#. client sends ``0x11`` in case of corrupted data and retries reading
#. client sends ``0x10`` if successful
#. server waits for response for 5 seconds
#. server sends concatenated $data string + xor-Byte + "rie4Ech7" if client
response is ``0x11``
.. seqdiag::
seqdiag response_with_retry {
client -> server [label = "wait"];
server -> server [label = "xor $data"];
client <- server [label = "0x02"];
client --> server [label = "0x10"];
client <- server [label = "$data . $xor . \"rie4Ech7\""];
client -> client [label = "detect corruption"];
client --> server [label = "0x11"];
client <- server [label = "$data . $xor . \"rie4Ech7\""];
client --> server [label = "0x10"];
}

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