Commit graph

8829 commits

Author SHA1 Message Date
Hanno Becker a1ab9be367 Adapt server-side signature verification to use raw public key
We must dispatch between the peer's public key stored as part of
the peer's CRT in the current session structure (situation until
now, and future behaviour if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is
enabled), and the sole public key stored in the handshake structure
(new, if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is disabled).
2019-02-26 14:38:09 +00:00
Hanno Becker a6899bb89d Adapt client-side signature verification to use raw public key
We must dispatch between the peer's public key stored as part of
the peer's CRT in the current session structure (situation until
now, and future behaviour if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is
enabled), and the sole public key stored in the handshake structure
(new, if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is disabled).
2019-02-26 14:38:09 +00:00
Hanno Becker be7f50866d Adapt ssl_get_ecdh_params_from_cert() to use raw public key
We must dispatch between the peer's public key stored as part of
the peer's CRT in the current session structure (situation until
now, and future behaviour if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is
enabled), and the sole public key stored in the handshake structure
(new, if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is disabled).
2019-02-26 14:38:09 +00:00
Hanno Becker c7d7e29b46 Adapt ssl_write_encrypted_pms() to use raw public key
We must dispatch between the peer's public key stored as part of
the peer's CRT in the current session structure (situation until
now, and future behaviour if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is
enabled), and the sole public key stored in the handshake structure
(new, if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE is disabled).
2019-02-26 14:38:09 +00:00
Hanno Becker a27475335a Make a copy of peer's raw public key after verifying its CRT chain
This commit modifies `mbedtls_ssl_parse_certificate()` to store a
copy of the peer's public key after parsing and verifying the peer's
CRT chain.

So far, this leads to heavy memory duplication: We have the CRT chain
in the I/O buffer, then parse (and, thereby, copy) it to a
`mbedtls_x509_crt` structure, and then make another copy of the
peer's public key, plus the overhead from the MPI and ECP structures.

This inefficiency will soon go away to a significant extend, because:
- Another PR adds functionality to parse CRTs without taking
  ownership of the input buffers. Applying this here will allow
  parsing and verifying the peer's chain without making an additional
  raw copy. The overhead reduces to the size of `mbedtls_x509_crt`,
  the public key, and the DN structures referenced in the CRT.
- Once copyless parsing is in place and the removal of the peer CRT
  is fully implemented, we can extract the public key bounds from
  the parsed certificate and then free the entire chain before
  parsing the public key again. This means that we never store
  the parsed public key twice at the same time.
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 494dd7a6b4 Add raw public key buffer bounds to mbedtls_x509_crt struct
This commit adds an ASN.1 buffer field `pk_raw` to `mbedtls_x509_crt`
which stores the bounds of the raw public key data within an X.509 CRT.

This will be useful in subsequent commits to extract the peer's public
key from its certificate chain.
2019-02-26 14:38:09 +00:00
Hanno Becker a887d1a5b6 Remove peer CRT from cache if !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE 2019-02-26 14:38:09 +00:00
Hanno Becker c966bd16be Remove peer CRT from tickets if !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE 2019-02-26 14:38:09 +00:00
Hanno Becker c5fcbb33c0 Add peer CRT digest to session tickets
This commit changes the format of session tickets to include
the digest of the peer's CRT if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE
is disabled.

This commit does not yet remove the peer CRT itself.
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 177475a3aa Mitigate triple handshake attack by comparing digests only
This paves the way for the removal of the peer CRT chain from
`mbedtls_ssl_session`.
2019-02-26 14:38:09 +00:00
Hanno Becker 6bbd94c4eb Compute digest of peer's end-CRT in mbedtls_ssl_parse_certificate() 2019-02-26 14:38:09 +00:00
Hanno Becker 9198ad1101 Extend mbedtls_ssl_session by buffer holding peer CRT digest 2019-02-26 14:38:09 +00:00
Hanno Becker 8d84fd83ff Update version_features.c 2019-02-26 14:38:09 +00:00
Hanno Becker bb278f52ca Add configuration option to remove peer CRT after handshake 2019-02-26 14:38:09 +00:00
Hanno Becker 4a82c1ccb4 Improve documentation of mbedtls_ssl_get_peer_cert() 2019-02-26 14:38:09 +00:00
Hanno Becker 8273df8383 Re-classify errors on missing peer CRT
mbedtls_ssl_parse_certificate() will fail if a ciphersuite requires
a certificate, but none is provided. While it is sensible to double-
check this, failure should be reported as an internal error and not
as an unexpected message.
2019-02-26 14:38:09 +00:00
Hanno Becker 0329f75a93 Increase robustness and documentation of ticket implementation 2019-02-26 14:38:09 +00:00
Hanno Becker aee8717877 Simplify session cache implementation via mbedtls_ssl_session_copy() 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 c7bd780e02 Allow passing any X.509 CRT chain to ssl_parse_certificate_chain()
This commit modifies the helper `ssl_parse_certificate_chain()` to
accep any target X.509 CRT chain instead of hardcoding it to
`session_negotiate->peer_cert`. This increases modularity and paves
the way towards removing `mbedtls_ssl_session::peer_cert`.
2019-02-26 14:38:09 +00:00
Hanno Becker 6863619a2f Introduce helper function for peer CRT chain verification 2019-02-26 14:38:09 +00:00
Hanno Becker fcd9e71cdf Don't progress TLS state machine on peer CRT chain parsing error 2019-02-26 14:38:09 +00:00
Hanno Becker 77adddc9e9 Make use of macro and helper detecting whether CertRequest allowed
This commit simplifies the client-side code for outgoing CertificateVerify
messages, and server-side code for outgoing CertificateRequest messages and
incoming CertificateVerify messages, through the use of the macro

   `MBEDTLS_KEY_EXCHANGE__CERT_REQ_ALLOWED__ENABLED`

indicating whether a ciphersuite allowing CertificateRequest messages
is enabled in the configuration, as well as the helper function

   `mbedtls_ssl_ciphersuite_cert_req_allowed()`

indicating whether a particular ciphersuite allows CertificateRequest
messages.

These were already used in the client-side code to simplify the
parsing functions for CertificateRequest messages.
2019-02-26 14:38:09 +00:00
Hanno Becker 28f2fcd08d Add helper function to check whether a CRT msg is expected
This commit adds a helper function `ssl_parse_certificate_coordinate()`
which checks whether a `Certificate` message is expected from the peer.

The logic is the following:
- For ciphersuites which don't use server-side CRTs, no Certificate
  message is expected (neither for the server, nor the client).
- On the server, no client certificate is expected in the following cases:
  * The server server didn't request a Certificate, which is controlled
    by the `authmode` setting.
  * A RSA-PSK suite is used; this is the only suite using server CRTs
    but not allowing client-side authentication.
2019-02-26 14:38:09 +00:00
Hanno Becker 7177a88a36 Introduce helper function to determine whether suite uses server CRT
This commit introduces a static helper function

   `mbedtls_ssl_ciphersuite_uses_srv_cert()`

which determines whether a ciphersuite may make use of server-side CRTs.

This function is in turn uses in `mbedtls_ssl_parse_certificate()` to
skip certificate parsing for ciphersuites which don't involve CRTs.

Note: Ciphersuites not using server-side CRTs don't allow client-side CRTs
either, so it is safe to guard `mbedtls_ssl_{parse/write}_certificate()`
this way.

Note: Previously, the code uses a positive check over the suites

- MBEDTLS_KEY_EXCHANGE_PSK
- MBEDTLS_KEY_EXCHANGE_DHE_PSK
- MBEDTLS_KEY_EXCHANGE_ECDHE_PSK
- MBEDTLS_KEY_EXCHANGE_ECJPAKE,

while now, it uses a negative check over `mbedtls_ssl_ciphersuite_uses_srv_cert()`,
which checks for the suites

- MBEDTLS_KEY_EXCHANGE_RSA
- MBEDTLS_KEY_EXCHANGE_RSA_PSK
- MBEDTLS_KEY_EXCHANGE_DHE_RSA
- MBEDTLS_KEY_EXCHANGE_ECDH_RSA
- MBEDTLS_KEY_EXCHANGE_ECDHE_RSA
- MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA
- MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA

This is equivalent since, together, those are all ciphersuites.
Quoting ssl_ciphersuites.h:

```
typedef enum {
    MBEDTLS_KEY_EXCHANGE_NONE = 0,
    MBEDTLS_KEY_EXCHANGE_RSA,
    MBEDTLS_KEY_EXCHANGE_DHE_RSA,
    MBEDTLS_KEY_EXCHANGE_ECDHE_RSA,
    MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA,
    MBEDTLS_KEY_EXCHANGE_PSK,
    MBEDTLS_KEY_EXCHANGE_DHE_PSK,
    MBEDTLS_KEY_EXCHANGE_RSA_PSK,
    MBEDTLS_KEY_EXCHANGE_ECDHE_PSK,
    MBEDTLS_KEY_EXCHANGE_ECDH_RSA,
    MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA,
    MBEDTLS_KEY_EXCHANGE_ECJPAKE,
} mbedtls_key_exchange_type_t;
```
2019-02-26 14:38:09 +00:00
Hanno Becker 2148993900 Use helper macro to detect whether some ciphersuite uses CRTs 2019-02-26 14:38:09 +00:00
Hanno Becker 6bdfab2ccc Unify state machine update in mbedtls_ssl_parse_certificate()
The handler `mbedtls_ssl_parse_certificate()` for incoming `Certificate`
messages contains many branches updating the handshake state. For easier
reasoning about state evolution, this commit introduces a single code-path
updating the state machine at the end of `mbedtls_ssl_parse_certificate()`.
2019-02-26 14:38:09 +00:00
Hanno Becker 7a955a043e Clear peer's CRT chain outside before parsing new one
If an attempt for session resumption fails, the `session_negotiate` structure
might be partially filled, and in particular already contain a peer certificate
structure. This certificate structure needs to be freed before parsing the
certificate sent in the `Certificate` message.

This commit moves the code-path taking care of this from the helper
function `ssl_parse_certificate_chain()`, whose purpose should be parsing
only, to the top-level handler `mbedtls_ssl_parse_certificate()`.

The fact that we don't know the state of `ssl->session_negotiate` after
a failed attempt for session resumption is undesirable, and a separate
issue #2414 has been opened to improve on this.
2019-02-26 14:38:09 +00:00
Hanno Becker 4a55f638e2 Introduce helper to check for no-CRT notification from client
This commit introduces a server-side static helper function
`ssl_srv_check_client_no_crt_notification()`, which checks if
the message we received during the incoming certificate state
notifies the server of the lack of certificate on the client.

For SSLv3, such a notification comes as a specific alert,
while for all other TLS versions, it comes as a `Certificate`
handshake message with an empty CRT list.
2019-02-26 14:38:09 +00:00
Hanno Becker a028c5bbd8 Introduce CRT counter to CRT chain parsing function
So far, we've used the `peer_cert` pointer to detect whether
we're parsing the first CRT, but that will soon be removed
if `MBEDTLS_SSL_KEEP_PEER_CERTIFICATE` is unset.
2019-02-26 14:38:09 +00:00
Hanno Becker 1294a0b260 Introduce helper function to clear peer CRT from session structure
This commit introduces a helper function `ssl_clear_peer_cert()`
which frees all data related to the peer's certificate from an
`mbedtls_ssl_session` structure. Currently, this is the peer's
certificate itself, while eventually, it'll be its digest only.
2019-02-26 14:38:09 +00:00
Hanno Becker f852b1c035 Break overly long line in definition of mbedtls_ssl_get_session() 2019-02-26 14:38:09 +00:00
Hanno Becker 60848e6574 Don't reuse CRT from initial handshake during renegotiation
After mitigating the 'triple handshake attack' by checking that
the peer's end-CRT didn't change during renegotation, the current
code avoids re-parsing the CRT by moving the CRT-pointer from the
old session to the new one. While efficient, this will no longer
work once only the hash of the peer's CRT is stored beyond the
handshake.

This commit removes the code-path moving the old CRT, and instead
frees the entire peer CRT chain from the initial handshake as soon
as the 'triple handshake attack' protection has completed.
2019-02-26 14:38:09 +00:00
Jaeden Amero 86016a03a1 Merge remote-tracking branch 'origin/pr/2338' into development 2019-02-22 12:55:30 +00:00
Jaeden Amero e895342522 Merge remote-tracking branch 'origin/pr/2427' into development 2019-02-22 12:53:13 +00:00
Jaeden Amero d247762a8d Merge remote-tracking branch 'origin/pr/2460' into development 2019-02-22 12:52:51 +00:00
Hanno Becker 85fd913950 Fix typo in check_config.h 2019-02-22 12:50:35 +00:00
Jaeden Amero caca307f42 crypto: Update submodule to Mbed Crypto 1.0.0d6 2019-02-22 10:48:48 +00:00
Jaeden Amero 415620c1f2 Merge remote-tracking branch 'origin/pr/2105' into development
Additional work done as part of merge:
    - Run ./tests/scripts/check-generated-files.sh and check in the
      resulting changes to programs/ssl/query_config.c
2019-02-22 10:33:15 +00:00
Jaeden Amero 461bd3dcca Merge remote-tracking branch 'origin/pr/2454' into development 2019-02-22 10:32:44 +00:00
Jaeden Amero 9f47f82218 Merge remote-tracking branch 'origin/pr/2391' into development 2019-02-22 10:32:44 +00:00
Jaeden Amero 8963b0311c Merge remote-tracking branch 'origin/pr/2411' into development 2019-02-22 10:32:44 +00:00
Jaeden Amero d9516b508a Merge remote-tracking branch 'origin/pr/2407' into development 2019-02-22 10:32:44 +00:00
Jaeden Amero 0ae63f7bc3 Merge remote-tracking branch 'origin/pr/2383' into development 2019-02-22 10:32:43 +00:00
Hanno Becker 241b524964 Disable restartable ECC in full config PSA test in all.sh 2019-02-22 10:26:30 +00:00
Hanno Becker 1ce51e4dc3 Forbid setting MBEDTLS_ECP_RESTARTABLE and MBEDTLS_USE_PSA_CRYPTO_C
Restartable ECC isn't supported in PSA yet.
2019-02-22 10:25:47 +00:00
Jaeden Amero 3497323f79 Initialize PSA Crypto operation contexts
It is now required to initialize PSA Crypto operation contexts before
calling psa_*_setup(). Otherwise, one gets a PSA_ERROR_BAD_STATE error.
2019-02-20 10:58:55 +00:00
Hanno Becker 135baef1bd Define maximum EC public key length depending on enabled curves 2019-02-18 17:04:24 +00:00