Commit Graph

6566 Commits

Author SHA1 Message Date
Gilles Peskine
6331d78675 Don't use the printf format %zd
We target C89 libc, so don't use %zd or %zu. Just use %u, and make
slot numbers `unsigned` for simplicity.
2018-06-14 13:26:51 +02:00
Gilles Peskine
03af7f6ae7 Change boolean bitfield to unsigned
Reminder to self: 1 is not a valid value in a 1-bit bitfield. It's
undefined behavior and gcc -ansi -pedantic helpfully complains about it.
2018-06-14 13:26:51 +02:00
Gilles Peskine
ac5e8a3286 Document that callbacks must not return arbitrary SSL errors 2018-04-26 11:50:07 +02:00
Gilles Peskine
8f97af7ea3 Don't pass the async config data to async callbacks
The config data is in the SSL config, so callbacks can retrieve it
from there, with the new function mbedtls_ssl_conf_get_async_config_data.
2018-04-26 11:46:10 +02:00
Gilles Peskine
e141638868 Finish writing an unfinished comment 2018-04-26 10:23:34 +02:00
Gilles Peskine
a36ac4fe68 New wrapper mbedtls_status_is_ssl_in_progress(ret)
Wrapper function to check whether a return status indicates that an
SSL operation is in progress.
2018-04-26 10:00:40 +02:00
Gilles Peskine
0fd90dd713 ssl_prepare_server_key_exchange: clarify where the signature is written 2018-04-26 10:00:40 +02:00
Gilles Peskine
2481a712ed Doxygen formatting improvements 2018-04-26 10:00:40 +02:00
Gilles Peskine
c912572a7f ssl_server2: merge redundant async_private_error=resume/pk
Testing the case where the resume callback returns an error at the
beginning and the case where it returns an error at the end is
redundant. Keep the test after the output has been produced, to
validate that the product does not use even a valid output if the
return value is an error code.
2018-04-26 10:00:40 +02:00
Gilles Peskine
d3268834f3 Document what the SSL async sign callback needs to do with RSA
Document how the SSL async sign callback must treat its md_alg and
hash parameters when doing an RSA signature: sign-the-hash if md_alg
is nonzero (TLS 1.2), and sign-the-digestinfo if md_alg is zero
(TLS <= 1.1).

In ssl_server2, don't use md_alg=MBEDTLS_MD_NONE to indicate that
ssl_async_resume must perform an encryption, because md_alg is also
MBEDTLS_MD_NONE in TLS <= 1.1. Add a test case to exercise this
case (signature with MBEDTLS_MD_NONE).
2018-04-26 10:00:40 +02:00
Gilles Peskine
ceb541b7de ssl_server2: rename delay in ssl_async_operation_context_t
Rename to remaining_delay to convey that it is decremented over time.
2018-04-26 10:00:40 +02:00
Gilles Peskine
22e695fc5a Be more precise about when a variable is unused 2018-04-26 10:00:40 +02:00
Gilles Peskine
ad28bf0e58 Documentation improvements 2018-04-26 10:00:40 +02:00
Gilles Peskine
168dae8567 Comment formatting and whitespace fixes 2018-04-26 10:00:40 +02:00
Gilles Peskine
df13d5c7a6 Pass the SSL context to async callbacks
When a handshake step starts an asynchronous operation, the
application needs to know which SSL connection the operation is for,
so that when the operation completes, the application can wake that
connection up. Therefore the async start callbacks need to take the
SSL context as an argument. It isn't enough to let them set a cookie
in the SSL connection, the application needs to be able to find the
right SSL connection later.

Also pass the SSL context to the other callbacks for consistency. Add
a new field to the handshake that the application can use to store a
per-connection context. This new field replaces the former
context (operation_ctx) that was created by the start function and
passed to the resume function.

Add a boolean flag to the handshake structure to track whether an
asynchronous operation is in progress. This is more robust than
relying on the application to set a non-null application context.
2018-04-26 10:00:40 +02:00
Gilles Peskine
9b562d5c36 mbedtls_ssl_handshake_free: take the SSL context as argument
Change the signature of mbedtls_ssl_handshake_free again. Now take the
whole SSL context as argument and not just the configuration and the
handshake substructure.

This is in preparation for changing the asynchronous cancel callback
to take the SSL context as an argument.
2018-04-26 10:00:40 +02:00
Gilles Peskine
2e33337570 Fix invalid data being accepted in RSA-decryption-based ciphersuites
In the refactoring of ssl_parse_encrypted_pms, I advertently broke the
case when decryption signalled an error, with the variable ret getting
overwritten before calculating diff. Move the calculation of diff
immediately after getting the return code to make the connection more
obvious. Also move the calculation of mask immediately after the
calculation of diff, which doesn't change the behavior, because I find
the code clearer that way.
2018-04-26 10:00:39 +02:00
Gilles Peskine
b74a1c73b1 Rename MBEDTLS_SSL_ASYNC_PRIVATE_C to MBEDTLS_SSL_ASYNC_PRIVATE
This is an optional feature, not a module of its own, so don't call it
MBEDTLS_xxx_C and put it in the appropriate section of config.h.
2018-04-26 10:00:39 +02:00
Gilles Peskine
f112725487 Style and grammar fixes 2018-04-26 10:00:39 +02:00
Gilles Peskine
12ab5d4cfb Don't shadow the variable p 2018-04-26 10:00:39 +02:00
Gilles Peskine
b44692f126 Merge branch 'mbedtls_ssl_get_key_exchange_md_ssl_tls-return_hashlen' into tls_async_server-2.9
Conflict resolution:
* ChangeLog: put the new entry from my branch in the proper place.
* include/mbedtls/error.h: counted high-level module error codes again.
* include/mbedtls/ssl.h: picked different numeric codes for the
  concurrently added errors; made the new error a full sentence per
  current standards.
* library/error.c: ran scripts/generate_errors.pl.
* library/ssl_srv.c:
    * ssl_prepare_server_key_exchange "DHE key exchanges": the conflict
      was due to style corrections in development
      (4cb1f4d49c) which I merged with
      my refactoring.
    * ssl_prepare_server_key_exchange "For key exchanges involving the
      server signing", first case, variable declarations: merged line
      by line:
        * dig_signed_len: added in async
        * signature_len: removed in async
        * hashlen: type changed to size_t in development
        * hash: size changed to MBEDTLS_MD_MAX_SIZE in async
        * ret: added in async
    * ssl_prepare_server_key_exchange "For key exchanges involving the
      server signing", first cae comment: the conflict was due to style
      corrections in development (4cb1f4d49c)
      which I merged with my comment changes made as part of refactoring
      the function.
    * ssl_prepare_server_key_exchange "Compute the hash to be signed" if
      `md_alg != MBEDTLS_MD_NONE`: conflict between
      ebd652fe2d
      "ssl_write_server_key_exchange: calculate hashlen explicitly" and
      46f5a3e9b4 "Check return codes from
      MD in ssl code". I took the code from commit
      ca1d742904 made on top of development
      which makes mbedtls_ssl_get_key_exchange_md_ssl_tls return the
      hash length.
* programs/ssl/ssl_server2.c: multiple conflicts between the introduction
  of MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS and new auxiliary functions and
  definitions for async support, and the introduction of idle().
    * definitions before main: concurrent additions, kept both.
    * main, just after `handshake:`: in the loop around
      mbedtls_ssl_handshake(), merge the addition of support for
      MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS and SSL_ASYNC_INJECT_ERROR_CANCEL
      with the addition of the idle() call.
    * main, if `opt.transport == MBEDTLS_SSL_TRANSPORT_STREAM`: take the
      code from development and add a check for
      MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS.
    * main, loop around mbedtls_ssl_read() in the datagram case:
      take the code from development and add a check for
      MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS; revert to a do...while loop.
    * main, loop around mbedtls_ssl_write() in the datagram case:
      take the code from development and add a check for
      MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS; revert to a do...while loop.
2018-04-26 10:00:27 +02:00
Gilles Peskine
ca1d742904 mbedtls_ssl_get_key_exchange_md_tls1_2: return hashlen
In mbedtls_ssl_get_key_exchange_md_tls1_2, add an output parameter for
the hash length. The code that calls this function can currently do
without it, but it will need the hash length in the future, when
adding support for a third-party callback to calculate the signature
of the hash.
2018-04-24 11:53:22 +02:00
Gilles Peskine
0329d72ad4 SSL asynchronous decryption (server side): update ChangeLog 2018-04-24 09:36:37 +02:00
Gilles Peskine
fcca9d8cef SSL asynchronous decryption (server side): tests
Test SSL asynchronous private operation for the case of a
decryption operation on a server.
2018-04-24 09:36:37 +02:00
Gilles Peskine
2c6078ed3b SSL asynchronous decryption (server side)
Support SSL asynchronous private operation for the case of a
decryption operation on a server.
2018-04-24 09:36:36 +02:00
Gilles Peskine
bcd98a5306 ssl_parse_encrypted_pms refactor: prepare, decrypt, return
Reorganize ssl_parse_encrypted_pms so that it first prepares the
ciphertext to decrypt, then decrypts it, then returns either the
decrypted premaster secret or random data in an appropriate manner.

This is in preparation for allowing the private key operation to be
offloaded to an external cryptographic module which can operate
asynchronously. The refactored code no longer calculates state before
the decryption that needs to be saved until after the decryption,
which allows the decryption to be started and later resumed.
2018-04-24 09:36:36 +02:00
Gilles Peskine
422ccabe29 ssl_parse_encrypted_pms refactor: prepare for remote private key
Use the public key to extract metadata rather than the public key.
Don't abort early if there is no private key.

This is in preparation for allowing the private key operation to be
offloaded to an external cryptographic module.
2018-04-24 09:36:36 +02:00
Gilles Peskine
d9bfcabcb9 SSL asynchronous signature: fix renegotiation tests
Fixed typo in "SSL async private: renegotiation" tests that caused the
renegotiation not to actually take place.
2018-04-24 09:36:36 +02:00
Gilles Peskine
e630aed5ae SSL asynchronous signature: ChangeLog entry 2018-04-24 09:36:36 +02:00
Gilles Peskine
dbb14e09f2 all.sh: run ssl-opt.sh on ECJPAKE, SSL async
Run ssl-opt.sh in the "full" configuration on things that are not in
the default configuration: SSL async private, ECJPAKE.
2018-04-24 09:36:36 +02:00
Gilles Peskine
9d12b4c849 SSL asynchronous signature: turn off by default 2018-04-24 09:36:36 +02:00
Gilles Peskine
60ee4cadce SSL asynchronous signature: basic test of recovery after error
Add test cases where the server goes through an async operation which
fails, then the server makes a successful connection.
2018-04-24 09:36:36 +02:00
Gilles Peskine
f9f15ae5a1 ssl_write_server_key_exchange refactor: don't use p at all
Use ssl->out_msglen as the cursor in ssl->out_msg throughout, rather
than switching a between pointer and an offset.
2018-04-24 09:36:36 +02:00
Gilles Peskine
d3eb0619a6 ssl_write_server_key_exchange refactor: minor cleanup
Clean up some debug messages and improve some comments.
2018-04-24 09:36:36 +02:00
Gilles Peskine
ebd30ae205 ssl_write_server_key_exchange refactor: ssl_resume_server_key_exchange
Continue clarifying the control flow. This gets rid of the last goto
introduced by the initial code for asynchronous signature support.
2018-04-24 09:36:36 +02:00
Gilles Peskine
d04d292b64 Get rid of useless handshake field out_async_start
The location where the signature goes is now tracked via
ssl->out_msglen, which makes ssl->handshake->out_async_start redundant.
2018-04-24 09:36:36 +02:00
Gilles Peskine
ab50f83a93 Improve documentation of async operation start callbacks 2018-04-24 09:36:36 +02:00
Gilles Peskine
7ab013a08a ssl_write_server_key_exchange refactor: move signature_len out
Move the writing of signature_len out of
ssl_prepare_server_key_exchange. This simplifies the control flow (one
less goto).
2018-04-24 09:36:36 +02:00
Gilles Peskine
1004c19ed0 ssl_write_server_key_exchange refactor: don't use p in the signing phase
This is in preparation of further splitting ssl_write_server_key_exchange
into several functions.
2018-04-24 09:36:36 +02:00
Gilles Peskine
184a3faa8a ssl_write_server_key_exchange refactor: create ssl_prepare_server_key_exchange
This is in the process of splitting ssl_write_server_key_exchange
into several functions.
2018-04-24 09:36:36 +02:00
Gilles Peskine
3ce9b900d2 ssl_write_server_key_exchange refactor: remove dig_signed_len
Simplify the redundant varaible dig_signed_len away.

This is in preparation for splitting ssl_write_server_key_exchange
into several functions.
2018-04-24 09:36:36 +02:00
Gilles Peskine
3665f1db9d SSL asynchronous signature: test cases
Add test cases for SSL asynchronous signature to ssl-opt.sh:

* Delay=0,1 to test the sequences of calls to f_async_resume
* Test fallback when the async callbacks don't support that key
* Test error injection at each stage
* Test renegotiation
2018-04-24 09:36:36 +02:00
Gilles Peskine
4bf9a28d1d SSL asynchronous signature: first implementation
Implement SSL asynchronous private operation for the case of a
signature operation in a server.

This is a first implementation. It is functional, but the code is not
clean, with heavy reliance on goto.
2018-04-24 09:36:06 +02:00
Gilles Peskine
ebd652fe2d ssl_write_server_key_exchange: calculate hashlen explicitly
The pk layer can infer the hash length from the hash type. Calculate
it explicitly here anyway because it's needed for debugging purposes,
and it's needed for the upcoming feature allowing the signature
operation to be offloaded to an external cryptographic processor, as
the offloading code will need to know what length hash to copy.
2018-04-24 09:34:38 +02:00
Gilles Peskine
e1efdf912f ssl_write_server_key_exchange: don't hard-code max hash size 2018-04-24 09:32:29 +02:00
Gilles Peskine
e198df53a0 ssl_pick_cert: use the public key for can_do
This is in preparation for support of external private key operations,
where there is no private key object.
2018-04-24 09:32:29 +02:00
Gilles Peskine
9eb5e9a16e SSL asynchronous private key operation callbacks: test server
New options in ssl_server2 to use the asynchronous private key
operation feature.

Features: resume delay to call resume more than once; error injection
at each stage; renegotiation support.
2018-04-24 09:32:29 +02:00
Gilles Peskine
8bf79f6dc6 SSL asynchronous private key operation callbacks: interface
New compile-time option MBEDTLS_SSL_ASYNC_PRIVATE_C, enabling
callbacks to replace private key operations. These callbacks allow the
SSL stack to make an asynchronous call to an external cryptographic
module instead of calling the cryptography layer inside the library.
The call is asynchronous in that it may return the new status code
MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS, in which case the SSL stack returns
and can be later called where it left off.

This commit introduces the configuration option. Later commits will
implement the feature proper.
2018-04-24 09:32:28 +02:00
Gilles Peskine
59e83d96db Add conf parameter to mbedtls_ssl_handshake_free
This function is declared in ssl_internal.h, so this is not a public
API change.

This is in preparation for mbedtls_ssl_handshake_free needing to call
methods from the config structure.
2018-04-24 09:32:28 +02:00
Gilles Peskine
fe1c0937d7 ssl_write_server_key_exchange refactor: remove redundant variable n
Remove redundant variable n, which counts in parallel to p. Having
both adds the burden of keeping them in synch for no benefit.
2018-04-24 09:32:28 +02:00