Commit graph

97 commits

Author SHA1 Message Date
Hanno Becker
3fd3f5ebe4 Fix indentation of Doxygen comment in ssl_internal.h 2019-02-26 14:38:09 +00:00
Hanno Becker
1aed7779ec Remove misleading and redundant guard around restartable ECC field
`MBEDTLS_SSL__ECP_RESTARTABLE` is only defined if
`MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED` is set, which
requires `MBEDTLS_X509_PARSE_C` to be set (this is checked
in `check_config.`). The additional `MBEDTLS_X509_PARSE_C`
guard around the `ecrs_peer_cert` field is therefore not
necessary; moreover, it's misleading, because it hasn't
been used consistently throughout the code.
2019-02-26 14:38:09 +00:00
Hanno Becker
75173121fe Add field for peer's raw public key to TLS handshake param structure
When removing the (session-local) copy of the peer's CRT chain, we must
keep a handshake-local copy of the peer's public key, as (naturally) every
key exchange will make use of that public key at some point to verify that
the peer actually owns the corresponding private key (e.g., verify signatures
from ServerKeyExchange or CertificateVerify, or encrypt a PMS in a RSA-based
exchange, or extract static (EC)DH parameters).

This commit adds a PK context field `peer_pubkey` to the handshake parameter
structure `mbedtls_handshake_params_init()` and adapts the init and free
functions accordingly. It does not yet make actual use of the new field.
2019-02-26 14:38:09 +00:00
Hanno Becker
3dad311ef0 Parse and verify peer CRT chain in local variable
`mbedtls_ssl_parse_certificate()` parses the peer's certificate chain
directly into the `peer_cert` field of the `mbedtls_ssl_session`
structure being established. To allow to optionally remove this field
from the session structure, this commit changes this to parse the peer's
chain into a local variable instead first, which can then either be freed
after CRT verification - in case the chain should not be stored - or
mapped to the `peer_cert` if it should be kept. For now, only the latter
is implemented.
2019-02-26 14:38:09 +00:00
Hanno Becker
52055ae91f Give ssl_session_copy() external linkage
A subsequent commit will need this function in the session ticket
and session cache implementations. As the latter are server-side,
this commit also removes the MBEDTLS_SSL_CLI_C guard.

For now, the function is declared in ssl_internal.h and hence not
part of the public API.
2019-02-26 14:38:09 +00:00
Hanno Becker
df51dbe17f Add fields for PSA-based ECDHE to handshake structure
This is the first in a series of commits adding client-side
support for PSA-based ECDHE.

Previously, the state of an ECDHE key agreement was maintained
in the field mbedtls_ssl_handshake_params::ecdh_ctx, of type
::mbedtls_ecdh_context and manipulated through the ECDH API.

The ECDH API will be superseeded by the PSA Crypto API for key
agreement, which needs the following data:
(a) A raw buffer holding the public part of the key agreement
    received from our peer.
(b) A key slot holding the private part of the key agreement.
(c) The algorithm to use.
The commit adds fields to ::mbedtls_ssl_handshake_params
representing these three inputs to PSA-based key agreement.

Specifically, it adds a field for the key slot holding the
ECDH private key, a field for the EC curve identifier, and
a buffer holding the peer's public key.

Note: Storing the peer's public key buffer is slightly
inefficient, as one could perform the ECDH computation
as soon as the peer sends its public key, either working
with in-place or using a stack-buffer to reformat the
public key before passing it to PSA. This optimization
is left for a later commit.
2019-02-18 16:41:55 +00:00
Andrzej Kurek
8a2e97c2df Merge development-psa commit 80b5662 into development-psa-merged branch
Adjust crypto submodule version to use new, forked crypto version accordingly.
2019-02-05 06:02:51 -05:00
Jaeden Amero
80b566267f Merge remote-tracking branch 'origin/pr/2386' into development-psa 2019-02-04 16:42:23 +00:00
Andrzej Kurek
c470b6b021 Merge development commit 8e76332 into development-psa
Additional changes to temporarily enable running tests:
ssl_srv.c and test_suite_ecdh use mbedtls_ecp_group_load instead of
mbedtls_ecdh_setup
test_suite_ctr_drbg uses mbedtls_ctr_drbg_update instead of 
mbedtls_ctr_drbg_update_ret
2019-01-31 08:20:20 -05:00
Andrzej Kurek
972fba51ed ssl_tls: rename sha_512_psa to sha_384_psa 2019-01-30 03:29:12 -05:00
Andrzej Kurek
eb342241a5 ssl_tls: use PSA to compute running handshake hash for TLS 1.2 2019-01-29 09:14:33 -05:00
Andrzej Kurek
814feffd15 Whitespace, logging and documentation fixes
Introduce a psa_status_t status to handle return values.
Add a debug message with API usage description.
2019-01-28 07:04:19 -05:00
Andrzej Kurek
d6db9be598 Adapt mbedtls_ssl_get_key_exchange_md_tls1_2 to PSA hashing 2019-01-28 07:04:19 -05:00
Andrzej Kurek
2349c4db88 Adapt to the new key allocation mechanism 2019-01-08 09:36:01 -05:00
Hanno Becker
d9f7d43b5f Add opaque PSK identifier to mbedtls_ssl_handshake_params
This commit adds a field `psk_opaque` to the handshake parameter
struct `mbedtls_ssl_handshake_params` which indicates if the user
has configured the use of an opaque PSK.
2018-11-21 21:12:58 +00:00
Manuel Pégourié-Gonnard
c37423fa76 Fix misleading sub-state name and comments
The enum constant had 'ske' in its name while this was a sub-state of the
"write client key exchange" state; corresponding issue in the comment.
2018-10-16 10:28:17 +02:00
Manuel Pégourié-Gonnard
125af948c3 Merge branch 'development-restricted' into iotssl-1260-non-blocking-ecc-restricted
* development-restricted: (578 commits)
  Update library version number to 2.13.1
  Don't define _POSIX_C_SOURCE in header file
  Don't declare and define gmtime()-mutex on Windows platforms
  Correct preprocessor guards determining use of gmtime()
  Correct documentation of mbedtls_platform_gmtime_r()
  Correct typo in documentation of mbedtls_platform_gmtime_r()
  Correct POSIX version check to determine presence of gmtime_r()
  Improve documentation of mbedtls_platform_gmtime_r()
  platform_utils.{c/h} -> platform_util.{c/h}
  Don't include platform_time.h if !MBEDTLS_HAVE_TIME
  Improve wording of documentation of MBEDTLS_PLATFORM_GMTIME_R_ALT
  Fix typo in documentation of MBEDTLS_PLATFORM_GMTIME_R_ALT
  Replace 'thread safe' by 'thread-safe' in the documentation
  Improve documentation of MBEDTLS_HAVE_TIME_DATE
  ChangeLog: Add missing renamings gmtime -> gmtime_r
  Improve documentation of MBEDTLS_HAVE_TIME_DATE
  Minor documentation improvements
  Style: Add missing period in documentation in threading.h
  Rename mbedtls_platform_gmtime() to mbedtls_platform_gmtime_r()
  Guard decl and use of gmtime mutex by HAVE_TIME_DATE and !GMTIME_ALT
  ...
2018-09-11 12:39:14 +02:00
Hanno Becker
98081a09e6 Don't use uint8_t for bitfields
Fixing a build failure using armcc.
2018-08-22 13:32:50 +01:00
Hanno Becker
3546201dbc Merge branch 'datagram_packing' into message_reordering 2018-08-22 10:25:40 +01:00
Hanno Becker
a67dee256d Merge branch 'iotssl-2402-basic-pmtu-adaptation' into datagram_packing 2018-08-22 10:06:38 +01:00
Manuel Pégourié-Gonnard
f47a4afea3 Fix a typo in comments 2018-08-22 10:50:30 +02:00
Manuel Pégourié-Gonnard
b8eec192f6 Implement PMTU auto-reduction in handshake 2018-08-22 10:50:30 +02:00
Hanno Becker
e0b150f96b Allow limiting the total amount of heap allocations for buffering
This commit introduces a compile time constant MBEDTLS_SSL_DTLS_MAX_BUFFERING
to mbedtls/config.h which allows the user to control the cumulative size of
all heap buffer allocated for the purpose of reassembling and buffering
handshake messages.

It is put to use by introducing a new field `total_bytes_buffered` to
the buffering substructure of `mbedtls_ssl_handshake_params` that keeps
track of the total size of heap allocated buffers for the purpose of
reassembly and buffering at any time. It is increased whenever a handshake
message is buffered or prepared for reassembly, and decreased when a
buffered or fully reassembled message is copied into the input buffer
and passed to the handshake logic layer.

This commit does not yet include future epoch record buffering into
account; this will be done in a subsequent commit.

Also, it is now conceivable that the reassembly of the next expected
handshake message fails because too much buffering space has already
been used up for future messages. This case currently leads to an
error, but instead, the stack should get rid of buffered messages
to be able to buffer the next one. This will need to be implemented
in one of the next commits.
2018-08-21 16:11:04 +01:00
Hanno Becker
3a0aad1c9d Rename update_digest to update_hs_digest 2018-08-20 09:44:02 +01:00
Hanno Becker
d488b9e490 Increase maximum number of buffered handshake messages 2018-08-17 16:52:08 +01:00
Hanno Becker
5f066e7aac Implement future record buffering
This commit implements the buffering of a record from the next epoch.

- The buffering substructure of mbedtls_ssl_handshake_params
  gets another field to hold a raw record (incl. header) from
  a future epoch.
- If ssl_parse_record_header() sees a record from the next epoch,
  it signals that it might be suitable for buffering by returning
  MBEDTLS_ERR_SSL_EARLY_MESSAGE.
- If ssl_get_next_record() finds this error code, it passes control
  to ssl_buffer_future_record() which may or may not decide to buffer
  the record; it does so if
  - a handshake is in progress,
  - the record is a handshake record
  - no record has already been buffered.
  If these conditions are met, the record is backed up in the
  aforementioned buffering substructure.
- If the current datagram is fully processed, ssl_load_buffered_record()
  is called to check if a record has been buffered, and if yes,
  if by now the its epoch is the current one; if yes, it copies
  the record into the (empty! otherwise, ssl_load_buffered_record()
  wouldn't have been called) input buffer.
2018-08-17 16:52:08 +01:00
Hanno Becker
6d97ef5a03 Use uniform treatment for future messages and proper HS fragments
This commit returns the error code MBEDTLS_ERR_SSL_EARLY_MESSAGE
for proper handshake fragments, forwarding their treatment to
the buffering function ssl_buffer_message(); currently, though,
this function does not yet buffer or reassembly HS messages, so:

! This commit temporarily disables support for handshake reassembly !
2018-08-17 16:52:08 +01:00
Hanno Becker
0271f967d6 Introduce buffering structure for handshake messages
This commit introduces, but does not yet put to use, a sub-structure
of mbedtls_ssl_handshake_params::buffering that will be used for the
buffering and/or reassembly of handshake messages with handshake
sequence numbers that are greater or equal to the next expected
sequence number.
2018-08-17 16:52:08 +01:00
Hanno Becker
d7f8ae2508 Introduce sub-structure of ssl_handshake_params for buffering
This commit introduces a sub-structure `buffering` within
mbedtls_ssl_handshake_params that shall contain all data
related to the reassembly and/or buffering of handshake
messages.

Currently, only buffering of CCS messages is implemented,
so the only member of this struct is the previously introduced
`seen_ccs` field.
2018-08-17 16:52:08 +01:00
Hanno Becker
2ed6bcc793 Implement support for remembering CCS messages
This commit implements support for remembering out-of-order
CCS messages. Specifically, a flag is set whenever a CCS message
is read which remains until the end of a flight, and when a
CCS message is expected and a CCS message has been seen in the
current flight, a synthesized CCS record is created.
2018-08-17 16:52:08 +01:00
Hanno Becker
4162b11eb4 Make mbedtls_ssl_read_record_layer() static
This function was previously global because it was
used directly within ssl_parse_certificate_verify()
in library/ssl_srv.c. The previous commit removed
this dependency, replacing the call by a call to
the global parent function mbedtls_ssl_read_record().
This renders mbedtls_ssl_read_record_layer() internal
and therefore allows to make it static, and accordingly
rename it as ssl_read_record_layer().
2018-08-17 16:52:08 +01:00
Hanno Becker
327c93b182 Add parameter to ssl_read_record() controlling checksum update
Previously, mbedtls_ssl_read_record() always updated the handshake
checksum in case a handshake record was received. While desirable
most of the time, for the CertificateVerify message the checksum
update must only happen after the message has been fully processed,
because the validation requires the handshake digest up to but
excluding the CertificateVerify itself. As a remedy, the bulk
of mbedtls_ssl_read_record() was previously duplicated within
ssl_parse_certificate_verify(), hardening maintenance in case
mbedtls_ssl_read_record() is subject to changes.

This commit adds a boolean parameter to mbedtls_ssl_read_record()
indicating whether the checksum should be updated in case of a
handshake message or not. This allows using it also for
ssl_parse_certificate_verify(), manually updating the checksum
after the message has been processed.
2018-08-17 16:52:08 +01:00
Hanno Becker
67bc7c3a38 Don't immediately flush datagram after preparing a record
This commit finally enables datagram packing by modifying the
record preparation function ssl_write_record() to not always
calling mbedtls_ssl_flush_output().
2018-08-17 15:44:09 +01:00
Manuel Pégourié-Gonnard
28f4beab1c Start implementing fragmentation 2018-08-16 10:01:10 +02:00
Manuel Pégourié-Gonnard
87a346f64e Always save flight first, (re)send later
This will allow fragmentation to always happen in the same place, always from
a buffer distinct from ssl->out_msg, and with the same way of resuming after
returning WANT_WRITE
2018-08-16 10:01:10 +02:00
Manuel Pégourié-Gonnard
31c1586893 Start separating handshake from record writing 2018-08-16 10:00:27 +02:00
Manuel Pégourié-Gonnard
79d9b50421 Merge branch 'development' into iotssl-1260-non-blocking-ecc-restricted
* development: (180 commits)
  Change the library version to 2.11.0
  Fix version in ChangeLog for fix for #552
  Add ChangeLog entry for clang version fix. Issue #1072
  Compilation warning fixes on 32b platfrom with IAR
  Revert "Turn on MBEDTLS_SSL_ASYNC_PRIVATE by default"
  Fix for missing len var when XTS config'd and CTR not
  ssl_server2: handle mbedtls_x509_dn_gets failure
  Fix harmless use of uninitialized memory in ssl_parse_encrypted_pms
  SSL async tests: add a few test cases for error in decrypt
  Fix memory leak in ssl_server2 with SNI + async callback
  SNI + SSL async callback: make all keys async
  ssl_async_resume: free the operation context on error
  ssl_server2: get op_name from context in ssl_async_resume as well
  Clarify "as directed here" in SSL async callback documentation
  SSL async callbacks documentation: clarify resource cleanup
  Async callback: use mbedtls_pk_check_pair to compare keys
  Rename mbedtls_ssl_async_{get,set}_data for clarity
  Fix copypasta in the async callback documentation
  SSL async callback: cert is not always from mbedtls_ssl_conf_own_cert
  ssl_async_set_key: detect if ctx->slots overflows
  ...
2018-06-20 09:46:17 +02:00
Angus Gratton
d8213d00db Let MBEDTLS_SSL_MAX_CONTENT_LEN to be split into outward & inward sizes
For the situation where the mbedTLS device has limited RAM, but the
other end of the connection doesn't support the max_fragment_length
extension. To be spec-compliant, mbedTLS has to keep a 16384 byte
incoming buffer. However the outgoing buffer can be made smaller without
breaking spec compliance, and we save some RAM.

See comments in include/mbedtls/config.h for some more details.

(The lower limit of outgoing buffer size is the buffer size used during
handshake/cert negotiation. As the handshake is half-duplex it might
even be possible to store this data in the "incoming" buffer during the
handshake, which would save even more RAM - but it would also be a lot
hackier and error-prone. I didn't really explore this possibility, but
thought I'd mention it here in case someone sees this later on a mission
to jam mbedTLS into an even tinier RAM footprint.)
2018-06-18 20:51:51 +10:00
Simon Butcher
5f57f1e3cc Merge remote-tracking branch 'public/pr/1270' into development 2018-06-15 14:17:31 +01:00
Manuel Pégourié-Gonnard
da19f4c79f Merge branch 'development' into iotssl-1260-non-blocking-ecc-restricted
Summary of merge conflicts:

include/mbedtls/ecdh.h -> documentation style
include/mbedtls/ecdsa.h -> documentation style
include/mbedtls/ecp.h -> alt style, new error codes, documentation style
include/mbedtls/error.h -> new error codes
library/error.c -> new error codes (generated anyway)
library/ecp.c:
    - code of an extracted function was changed
library/ssl_cli.c:
    - code addition on one side near code change on the other side
      (ciphersuite validation)
library/x509_crt.c -> various things
    - top fo file: helper structure added near old zeroize removed
    - documentation of find_parent_in()'s signature: improved on one side,
      added arguments on the other side
    - documentation of find_parent()'s signature: same as above
    - verify_chain(): variables initialised later to give compiler an
      opportunity to warn us if not initialised on a code path
    - find_parent(): funcion structure completely changed, for some reason git
      tried to insert a paragraph of the old structure...
    - merge_flags_with_cb(): data structure changed, one line was fixed with a
      cast to keep MSVC happy, this cast is already in the new version
    - in verify_restratable(): adjacent independent changes (function
      signature on one line, variable type on the next)
programs/ssl/ssl_client2.c:
    - testing for IN_PROGRESS return code near idle() (event-driven):
      don't wait for data in the the socket if ECP_IN_PROGRESS
tests/data_files/Makefile: adjacent independent additions
tests/suites/test_suite_ecdsa.data: adjacent independent additions
tests/suites/test_suite_x509parse.data: adjacent independent additions

* development: (1059 commits)
  Change symlink to hardlink to avoid permission issues
  Fix out-of-tree testing symlinks on Windows
  Updated version number to 2.10.0 for release
  Add a disabled CMAC define in the no-entropy configuration
  Adapt the ARIA test cases for new ECB function
  Fix file permissions for ssl.h
  Add ChangeLog entry for PR#1651
  Fix MicroBlaze register typo.
  Fix typo in doc and copy missing warning
  Fix edit mistake in cipher_wrap.c
  Update CTR doc for the 64-bit block cipher
  Update CTR doc for other 128-bit block ciphers
  Slightly tune ARIA CTR documentation
  Remove double declaration of mbedtls_ssl_list_ciphersuites
  Update CTR documentation
  Use zeroize function from new platform_util
  Move to new header style for ALT implementations
  Add ifdef for selftest in header file
  Fix typo in comments
  Use more appropriate type for local variable
  ...
2018-06-13 09:52:54 +02:00
Azim Khan
45b79cf12b Treat warnings as errors for IAR
Fix IAR compiler warnings

Two warnings have been fixed:
1. code 'if( len <= 0xFFFFFFFF )' gave warning 'pointless integer comparison'.
   This was fixed by wraping the condition in '#if SIZE_MAX > 0xFFFFFFFF'.
2. code 'diff |= A[i] ^ B[i];' gave warning 'the order of volatile accesses is undefined in'.
   This was fixed by read the volatile data in temporary variables before the computation.

Explain IAR warning on volatile access

Consistent use of CMAKE_C_COMPILER_ID
2018-05-25 14:54:14 +01:00
Gilles Peskine
783007375f 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.
2018-04-26 13:03:29 +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
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
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
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
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
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