Commit Graph

3227 Commits

Author SHA1 Message Date
Andrzej Kurek
8fba6e99ce
Merge pull request #3532 from AndrzejKurek/fi-hmac-drbg-fixes
Fi-related hmac_drbg fixes
2020-08-10 19:02:25 +02:00
Andrzej Kurek
0305753d7a
Merge pull request #3477 from AndrzejKurek/aes-fake-key
Use a fake random key in AES calculations
2020-08-10 13:05:46 +02:00
Piotr Nowicki
e3c4ee51b2 Rename mbedtls_platform_memcmp() to mbedtls_platform_memequal()
Signed-off-by: Piotr Nowicki <piotr.nowicki@arm.com>
2020-08-10 12:41:00 +02:00
Andrzej Kurek
fba5921186
aes: validate keys using crc before encryption/decryption
CRC is calculated when the key is set. This commit also adds new tests
for ecb encryption and decryption, simulating a fault injection after the key is set.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-08-08 19:06:44 -04:00
Andrzej Kurek
9df2b416b9
Add a CRC module to mbedtls and baremetal config
Add a new CRC module along with some tests for it.
The table and the CRC function body is generated using pycrc v0.9.2. 
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-08-08 02:10:52 -04:00
Shelly Liberman
c6319a70ab
Merge pull request #3514 from shelib01/fi_write_user_data
Fi write user data
2020-08-06 07:41:15 +03:00
Shelly Liberman
c6a7e6b0c4 Enhancement fixes
Co-authored-by: Andrzej Kurek <andrzej.kurek@arm.com>
Signed-off-by: Shelly Liberman <shelly.liberman@arm.com>
2020-08-05 15:40:15 +03:00
shelib01
4062d6ca68 Add user pointer and data size duplication to ssl context.
Signed-off-by: Shelly Liberman <shelly.liberman@arm.com>
2020-08-05 15:01:05 +03:00
Andrzej Kurek
7400fae7ee
Merge pull request #3510 from AndrzejKurek/fi-pk-fixes
pk.c FI-related fixes
2020-08-03 12:14:06 +02:00
Andrzej Kurek
898d330148
Merge pull request #3500 from AndrzejKurek/fi-sha256-fixes
Introduce sha256 security review fixes
2020-08-03 12:13:40 +02:00
Andrzej Kurek
4353b698ed
hmac_drbg: make no reseeding behaviour explicit
Add a flag to the hmac_drbg context that will signal that reseeding is not required.
Change tests and one ecdsa call to not use reseeding, as was the previous case.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-07-19 09:00:18 -04:00
Andrzej Kurek
fac2f9b4ce
aes: move the fake key operations to AES_SCA_COUNTERMEASURES define
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-07-19 05:01:44 -04:00
Andrzej Kurek
6bc37fa4e2
hmac_drbg: set_entropy_len can now return an error
Make mbedtls_hmac_drbg_set_entropy_len return an error
in case of a too long entropy length setting.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-07-18 06:05:03 -04:00
Andrzej Kurek
e78775eed2
Use a fake random key in AES calculations
Create an additional field in the AES context to store a randomized fake key.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-07-18 05:21:32 -04:00
Andrzej Kurek
8917326d7b
Introduce sha256 security review fixes
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-07-18 00:42:39 -04:00
Andrzej Kurek
189ee74a82
Add a platform function to return a random uint32_t
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-07-17 03:28:32 -04:00
Andrzej Kurek
c3b69edd2f
Increase hamming distance by changing UECC_SUCCESS from 0 to FFAAAA
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-07-16 11:33:34 -04:00
Andrzej Kurek
e5425a0944
Merge pull request #3408 from AndrzejKurek/hamming-distance-improvements
Hamming distance improvements
2020-06-22 08:28:55 +01:00
Andrzej Kurek
3a0df03364
Increase the Hamming distance of uECC_generate_random_int returns
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-06-12 06:32:13 -04:00
Piotr Nowicki
ce0aab4474 Add new error code PLATFORM_ALLOC_FAILED for mbedtls_platform_memmove()
Signed-off-by: Piotr Nowicki <piotr.nowicki@arm.com>
2020-06-10 13:51:32 +02:00
Piotr Nowicki
5d5841f450 Add mbedtls_platform_memmove() as a secured memcmp()
Signed-off-by: Piotr Nowicki <piotr.nowicki@arm.com>
2020-06-09 14:31:55 +02:00
Andrzej Kurek
090365fe60
Improve the usage of uECC_RNG_Function
Since the mbed TLS implementation of rng wrapper returns the size of random
data generated upon success - check for it explicitly.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-06-08 11:00:51 -04:00
Andrzej Kurek
220e61478f
Add a x509 prerequisite in x509_internal.h
Lack of this requirement caused warning when compiling the 
x509 test suites with config-thread.h from example configs,
resulting in an error when running from test-ref-configs.pl.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-05-21 10:13:38 -04:00
Andrzej Kurek
825ebd483f
Merge mbedtls 2.16.6 into baremetal
Conflicts:
mbedtls.doxyfile - PROJECT_NAME - mbed TLS v2.16.6 chosen.
doc_mainpage.h - mbed TLS v2.16.6 version chosen.
hmac_drbg.h - line 260, extended description chosen.
            - line 313, extended description chosen.
            - line 338, extended description chosen.
version.h - 2.16.6 chosen.
CMakeLists.txt - 2.16.6 chosen.
test_suite_version.data - 2.16.6 chosen.
Makefile - 141 - manual correction - baremetal version of C_SOURCE_FILES
                 with variables for directories plus 2.16.6 CTAGS addition.
pkparse.c - lines 846 onwards - the asn1_get_nonzero_mpi implementation chosen.
ssl_tls.c - line 5269 - edited manually, left the ret=0, because baremetal has
            a different behaviour since commit 87b5626, but added a debug
            message that's new in 2.16.6.    
all.sh:
- component_build_deprecated - chosen the refactored version from 2.16.6,
                               but with extra flags from baremetal.
- rest of the _no_xxx tests - merged make options to have PTHREAD=1 and
                              other changes from 2.16.6 (like -O1 instead of -O0).
- component_build_arm_none_eabi_gcc_no_64bit_multiplication - added 
                              TINYCRYPT_BUILD=0 to the 2.16.6 version of make.

x509/req_app.c - left baremetal log but with mbedtls_exit( 0 ) call.
x509/crl_app.c - left baremetal log but with mbedtls_exit( 0 ) call.
x509/cert_app.c - left baremetal log but with mbedtls_exit( 0 ) call.
ssl/ssl_mail_client.c - left baremetal log but with mbedtls_exit( 0 ) call.
ssl/ssl_pthread_server.c - left baremetal log but with mbedtls_exit( 0 ) call.
ssl/ssl_fork_server.c - left baremetal log but with mbedtls_exit( 0 ) call.
ssl_client1.c - line 54 - left baremetal log but with mbedtls_exit( 0 ) call.
ssl_client2.c - line 54 - left baremetal log but with mbedtls_exit( 0 ) call.
              - line 132 - new options of both branches added.
              - skip close notify handled as in 2.16.6, but with `ssl` instead of `&ssl`.
              - Merged the 2.16.6 usage split with additional baremetal usages.
              - Merged options from baremetal and 2.16.6.
ssl_server.c - left baremetal log but with mbedtls_exit( 0 ) call.
ssl_server2.c - Merged the 2.16.6 usage split with additional baremetal usages.
config.pl - fixed missing defines from the documentation, removed duplicates,
            and reorganised so that the documentation and excluded list
            are ordered in the same way.
test_suite_x509parse.data - only added the two new pathlen tests.
x509_crt.c - change the return code by removing
             MBEDTLS_ERR_X509_INVALID_EXTENSIONS, since it's added by
             x509_crt_frame_parse_ext not by an "or", but by "+=".
Changelog - Assigned all entries to appropriate sections.
ssl-opt.sh - line 8263 - merged options.
           - removed lines 1165 - 1176 - there was a duplicate test, probably
             an artifact of previous merges.
check-files.py - sticked to old formatting.

Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
2020-05-18 11:47:25 -04:00
Janos Follath
e7b49d3cd1 Bump version to Mbed TLS 2.16.4 2020-03-13 15:36:05 +00:00
Janos Follath
f8dbfd4f05 Bignum: Document assumptions about the sign field 2020-03-13 15:25:40 +00:00
Janos Follath
8faf1d627b Change mbedtls_mpi_cmp_mpi_ct to check less than
The signature of mbedtls_mpi_cmp_mpi_ct() meant to support using it in
place of mbedtls_mpi_cmp_mpi(). This meant full comparison functionality
and a signed result.

To make the function more universal and friendly to constant time
coding, we change the result type to unsigned. Theoretically, we could
encode the comparison result in an unsigned value, but it would be less
intuitive.

Therefore we won't be able to represent the result as unsigned anymore
and the functionality will be constrained to checking if the first
operand is less than the second. This is sufficient to support the
current use case and to check any relationship between MPIs.

The only drawback is that we need to call the function twice when
checking for equality, but this can be optimised later if an when it is
needed.
2020-03-13 15:25:40 +00:00
Janos Follath
c514ce474a Add new, constant time mpi comparison 2020-03-13 15:25:39 +00:00
Gilles Peskine
a5e2d86c3f Note that mbedtls_ctr_drbg_seed() must not be called twice
You can't reuse a CTR_DRBG context without free()ing it and
re-init()ing it. This generally happened to work, but was never
guaranteed. It could have failed with alternative implementations of
the AES module because mbedtls_ctr_drbg_seed() calls
mbedtls_aes_init() on a context which is already initialized if
mbedtls_ctr_drbg_seed() hasn't been called before, plausibly causing a
memory leak.

Calling free() and seed() with no intervening init fails when
MBEDTLS_THREADING_C is enabled and all-bits-zero is not a valid mutex
representation.
2020-03-13 15:25:39 +00:00
Gilles Peskine
20dbfb9938 CTR_DRBG: support set_entropy_len() before seed()
mbedtls_ctr_drbg_seed() always set the entropy length to the default,
so a call to mbedtls_ctr_drbg_set_entropy_len() before seed() had no
effect. Change this to the more intuitive behavior that
set_entropy_len() sets the entropy length and seed() respects that and
only uses the default entropy length if there was no call to
set_entropy_len().

The former test-only function mbedtls_ctr_drbg_seed_entropy_len() is
no longer used, but keep it for strict ABI compatibility.
2020-03-13 15:25:39 +00:00
Gilles Peskine
1d2a9e88c3 HMAC_DRBG: support set_entropy_len() before seed()
mbedtls_hmac_drbg_seed() always set the entropy length to the default,
so a call to mbedtls_hmac_drbg_set_entropy_len() before seed() had no
effect. Change this to the more intuitive behavior that
set_entropy_len() sets the entropy length and seed() respects that and
only uses the default entropy length if there was no call to
set_entropy_len().
2020-03-13 15:24:20 +00:00
Gilles Peskine
d41a95e223 mbedtls_hmac_drbg_set_entropy_len() only matters when reseeding
The documentation of HMAC_DRBG erroneously claimed that
mbedtls_hmac_drbg_set_entropy_len() had an impact on the initial
seeding. This is in fact not the case: mbedtls_hmac_drbg_seed() forces
the entropy length to its chosen value. Fix the documentation.
2020-03-13 15:22:14 +00:00
Gilles Peskine
5fc111fe69 mbedtls_ctr_drbg_set_entropy_len() only matters when reseeding
The documentation of CTR_DRBG erroneously claimed that
mbedtls_ctr_drbg_set_entropy_len() had an impact on the initial
seeding. This is in fact not the case: mbedtls_ctr_drbg_seed() forces
the initial seeding to grab MBEDTLS_CTR_DRBG_ENTROPY_LEN bytes of
entropy. Fix the documentation and rewrite the discussion of the
entropy length and the security strength accordingly.
2020-03-13 15:22:14 +00:00
Gilles Peskine
4c57b20247 mbedtls_ctr_drbg_seed: correct maximum for len 2020-03-13 15:22:14 +00:00
Gilles Peskine
5953660a6a Add a note about CTR_DRBG security strength to config.h 2020-03-13 15:22:14 +00:00
Gilles Peskine
e1dc2de900 Move MBEDTLS_CTR_DRBG_USE_128_BIT_KEY to the correct section
It's an on/off feature, so it should be listed in version_features.
2020-03-13 15:22:14 +00:00
Gilles Peskine
6e36d0b33c CTR_DRBG: more consistent formatting and wording
In particular, don't use #MBEDTLS_xxx on macros that are undefined in
some configurations, since this would be typeset with a literal '#'.
2020-03-13 15:22:14 +00:00
Gilles Peskine
9640403fa0 CTR_DRBG documentation: further wording improvements 2020-03-13 15:22:14 +00:00
Gilles Peskine
7b674eac64 CTR_DRBG: Improve the explanation of security strength
Separate the cases that achieve a 128-bit strength and the cases that
achieve a 256-bit strength.
2020-03-13 15:22:14 +00:00
Gilles Peskine
7df4b7b3b6 CTR_DRBG: make it easier to understand the security strength
Explain how MBEDTLS_CTR_DRBG_ENTROPY_LEN is set next to the security
strength statement, rather than giving a partial explanation (current
setting only) in the documentation of MBEDTLS_CTR_DRBG_ENTROPY_LEN.
2020-03-13 15:22:14 +00:00
Gilles Peskine
56f628ca26 HMAC_DRBG: note that the initial seeding grabs entropy for the nonce 2020-03-13 15:22:14 +00:00
Gilles Peskine
beddfdcd7f Use standard terminology to describe the personalization string
NIST and many other sources call it a "personalization string", and
certainly not "device-specific identifiers" which is actually somewhat
misleading since this is just one of many things that might go into a
personalization string.
2020-03-13 15:22:13 +00:00
Gilles Peskine
57553fa2f0 Do note that xxx_drbg_random functions reseed with PR enabled 2020-03-13 15:22:13 +00:00
Gilles Peskine
20a3846725 Consistently use \c NULL and \c 0 2020-03-13 15:22:13 +00:00
Gilles Peskine
ccb38381e8 HMAC_DRBG: improve the documentation of the entropy length 2020-03-13 15:21:09 +00:00
Gilles Peskine
4bfe4540f3 HMAC_DRBG documentation improvements clarifications
Improve the formatting and writing of the documentation based on what
had been done for CTR_DRBG.

Document the maximum size and nullability of some buffer parameters.
2020-03-13 15:21:08 +00:00
Gilles Peskine
f17079d960 More CTR_DRBG documentation improvements and clarifications 2020-03-13 12:03:12 +00:00
Gilles Peskine
c32f74cf8e Fix wording 2020-03-13 12:03:12 +00:00
Gilles Peskine
03642fa026 Remove warning that the previous expanded discussion has obsoleted 2020-03-13 12:03:12 +00:00
Gilles Peskine
2d83fe1383 CTR_DRBG: improve the discussion of entropy length vs strength 2020-03-13 12:03:12 +00:00
Gilles Peskine
bb2b8da7d7 CTR_DRBG: Finish an unfinished paragraph 2020-03-13 12:03:12 +00:00
Gilles Peskine
e3dc5942c5 CTR_DRBG: Document the security strength and SP 800-90A compliance
Document that a derivation function is used.

Document the security strength of the DRBG depending on the
compile-time configuration and how it is set up. In particular,
document how the nonce specified in SP 800-90A is set.

Mention how to link the ctr_drbg module with the entropy module.
2020-03-13 12:01:28 +00:00
Gilles Peskine
c1c9292d2f CTR_DRBG: Document the maximum size of some parameters 2020-03-13 12:01:28 +00:00
Gilles Peskine
da5ccce88e CTR_DRBG documentation clarifications
* State explicit whether several numbers are in bits or bytes.
* Clarify whether buffer pointer parameters can be NULL.
* Explain the value of constants that are dependent on the configuration.
2020-03-13 12:01:28 +00:00
Arto Kinnunen
17540ab74c Fix usage of randomized number in AES
-Fix usage of randomized bits (do not reuse the bits)
-Update comments
2020-01-21 12:01:42 +02:00
Arto Kinnunen
311ab594d7 Flag SCA_CM encrypt/decrypt functions
There is a 50% performance drop in the SCA_CM enabled encrypt and
decrypt functions. Therefore use the older version of encrypt/decypt
functions when SCA_CM is disabled.
2020-01-21 12:01:42 +02:00
Arto Kinnunen
10a2ffde5d Merge remote-tracking branch 'upstream/pr/2945' into baremetal
* upstream/pr/2945:
  Rename macro MBEDTLS_MAX_RAND_DELAY
  Update signature of mbedtls_platform_random_delay
  Replace mbedtls_platform_enforce_volatile_reads 2
  Replace mbedtls_platform_enforce_volatile_reads
  Add more variation to random delay countermeasure
  Add random  delay to enforce_volatile_reads
  Update comments of mbedtls_platform_random_delay
  Follow Mbed TLS coding style
  Add random delay function to platform_utils
2020-01-17 11:21:16 +02:00
Arto Kinnunen
ac6d226939 Update signature of mbedtls_platform_random_delay
Skip parameter and return value from mbedtls_platform_random_delay
to make it more resistant for FI attacks.
2020-01-09 10:19:07 +02:00
Simon Butcher
2d9c0eb215 Merge remote-tracking branch 'public/pr/2948' into baremetal 2020-01-08 18:08:28 +00:00
Simon Butcher
4b3b8c208e Merge remote-tracking branch 'public/pr/2886' into baremetal 2020-01-08 17:53:43 +00:00
Arto Kinnunen
e91f0dc905 Replace mbedtls_platform_enforce_volatile_reads
Replace function mbedtls_platform_enforce_volatile_reads() with
mbedtls_platform_random_delay().
2020-01-07 10:47:58 +02:00
Arto Kinnunen
0490485be5 Add random delay to enforce_volatile_reads
Add a random delay to mbedtls_platform_enforce_volatile_reads() as a
countermeasure to fault injection attacks.
2020-01-07 10:47:58 +02:00
Arto Kinnunen
9a506e7424 Update comments of mbedtls_platform_random_delay 2020-01-07 10:47:58 +02:00
Arto Kinnunen
4c63b98e94 Add random delay function to platform_utils
Add delay function to platform_utils. The function will delay
program execution by incrementing local variable randomised number of
times.
2020-01-07 10:47:58 +02:00
Jarno Lamsa
5aa4c07b85 Minor review fixes 2019-12-20 13:09:27 +02:00
Jarno Lamsa
616fbe177c Increase hamming distance for authmode
Prevent glitching mode by single bit flipping.
2019-12-19 17:07:35 +02:00
Jarno Lamsa
afff4d0679 Remove unused flag 2019-12-19 14:41:56 +02:00
Jarno Lamsa
e1621d4700 Check that the peer_authenticated flag
Check that the peer has been authenticated in the end
of the handshake.
2019-12-19 14:29:24 +02:00
Jarno Lamsa
b57d7fd568 Add flags for protecting TLS state machine
Flags are there to prevent skipping vital parts of the TLS
handshake.
2019-12-19 09:01:54 +02:00
Jarno Lamsa
9e8e820993 Increase hamming distance for some error codes
The MBEDTLS_ERR_SSL_WANT_READ and MBEDTLS_ERR_SSL_WANT_WRITE are
errors that can be ignored, so increase the hamming distance between
them and the non-ignorable errors and keep still some distance from
a success case. This mitigates an attack where single bit-flipping could
change a non-ignorable error to being an ignorable one.
2019-12-19 07:56:10 +02:00
Jarno Lamsa
4708d66af5 Change the mbedtls_ssl_states values
The changed values have now the minimum hamming distance
of 16 from each other. This is to prevent changing the state
by just flipping one bit.
2019-12-19 07:56:10 +02:00
Jarno Lamsa
70abd7aadc Add enumeration for invalid state
The invalid state can be used when state-mismatch is noticed.
The invalid state should report a FI-alert upwards.
2019-12-19 07:56:10 +02:00
Simon Butcher
e76c638d6f Merge remote-tracking branch 'public/pr/2925' into baremetal 2019-12-13 14:51:29 +00:00
Arto Kinnunen
6ce4988768 AES FI resistance
Add FI countermeasures to AES.
2019-12-10 15:00:37 +02:00
Arto Kinnunen
34139ba9fc Updates to AES countermeasures
-Update comments regarding flag MBEDTLS_AES_SCA_COUNTERMEASURES
-Remove MBEDTLS_AES_SCA_COUNTERMEASURES dependency check
-More comments and coding style changes
2019-12-10 14:54:43 +02:00
Arto Kinnunen
430ac13112 Add config and test for AES SCA countermeasures
- Add configuration for AES_SCA_COUNTERMEASURES to config.h. By
  default the feature is disabled.
- Add AES_SCA_COUNTERMEASURES configuration check to check_config.h
- Add AES_SCA_COUNTERMEASURES test to all.sh
2019-12-10 14:54:43 +02:00
Simon Butcher
501c466d01 Merge remote-tracking branch 'public/pr/2934' into baremetal 2019-12-05 14:32:44 +00:00
Simon Butcher
5b45c6e1b3 Merge remote-tracking branch 'public/pr/2932' into baremetal 2019-12-05 14:32:31 +00:00
Simon Butcher
7c5de360da Merge remote-tracking branch 'public/pr/2922' into baremetal 2019-12-05 14:31:03 +00:00
Manuel Pégourié-Gonnard
766c9e9781 Improve description of ERR_PLATFORM_FAULT_DETECTED 2019-11-29 09:40:08 +01:00
Manuel Pégourié-Gonnard
65be6b48de Add compile guard in platform.h
We may want to include it just for the errors it defines without having all of
the other defines that only make sense when PLATFORM_C is enabled.
2019-11-28 12:51:45 +01:00
Manuel Pégourié-Gonnard
9d6a535ba1 Return and propagate UECC_FAULT_DETECTED
This commit first changes the return convention of EccPoint_mult_safer() so
that it properly reports when faults are detected. Then all functions that
call it need to be changed to (1) follow the same return convention and (2)
properly propagate UECC_FAULT_DETECTED when it occurs.

Here's the reverse call graph from EccPoint_mult_safer() to the rest of the
library (where return values are translated to the MBEDTLS_ERR_ space) and test
functions (where expected return values are asserted explicitly).

EccPoint_mult_safer()
    EccPoint_compute_public_key()
        uECC_compute_public_key()
            pkparse.c
            tests/suites/test_suite_pkparse.function
        uECC_make_key_with_d()
        uECC_make_key()
            ssl_cli.c
            ssl_srv.c
            tests/suites/test_suite_pk.function
            tests/suites/test_suite_tinycrypt.function
    uECC_shared_secret()
        ssl_tls.c
        tests/suites/test_suite_tinycrypt.function
    uECC_sign_with_k()
        uECC_sign()
            pk.c
            tests/suites/test_suite_tinycrypt.function

Note: in uECC_sign_with_k() a test for uECC_vli_isZero(p) is suppressed
because it is redundant with a more thorough test (point validity) done at the
end of EccPoint_mult_safer(). This redundancy was introduced in a previous
commit but not noticed earlier.
2019-11-26 12:54:06 +01:00
Manuel Pégourié-Gonnard
4d6186beb0 Rename ATTACK_DETECTED to FAULT_DETECTED
We don't know for sure it's an attack, it could be the hardware failing
randomly as well.
2019-11-26 12:54:06 +01:00
Manuel Pégourié-Gonnard
2b90961b8d Add integrity check for curve parameters
We don't really need a secure hash for that, something like CRC32 would
probably be enough - but we have SHA-256 handy, not CRC32, so use that for the
sake of simplicity.
2019-11-26 12:54:06 +01:00
Manuel Pégourié-Gonnard
1a5337179f Remove curve parameter from public functions 2019-11-26 12:54:06 +01:00
Manuel Pégourié-Gonnard
be5f833c9c Remove curve parameter from (semi-)internal functions
By semi-internal I mean functions that are only public because they're used in
more than once compilation unit in the library (for example in ecc.c and
ecc_dsa.c) but should not really be part of the public-facing API.
2019-11-26 12:54:06 +01:00
Manuel Pégourié-Gonnard
bc3f49011a Remove struct curve entirely 2019-11-26 12:54:06 +01:00
Manuel Pégourié-Gonnard
ffd13996fd Move b from curve structure to its own constant
Same motivation as for the other parameters. This is the last one, making the
curve structure empty, so it's left with a dummy parameter for legal reasons.
2019-11-26 12:54:04 +01:00
Manuel Pégourié-Gonnard
a6115087a0 Move G from struct curve to its own constant 2019-11-26 12:53:13 +01:00
Manuel Pégourié-Gonnard
356d8594d7 Move n from struct curve to its own constant 2019-11-26 12:52:57 +01:00
Manuel Pégourié-Gonnard
4d8777cbb6 Move p from curve structure to its own constant
This removes an indirection, which both makes the code smaller and decreases
the number of glitching opportunities for an attacker.
2019-11-26 12:51:58 +01:00
Arto Kinnunen
5b36693774 Harden hmac_drbg and md against fault injection
-Add flow monitor, loop integrity check and variable doubling to
 harden mbedtls_hmac_drbg_update_ret.

-Use longer hamming distance for nonce usage in hmac_drbg_reseed_core

-Return actual value instead of success in mbedtls_hmac_drbg_seed and
 mbedtls_hmac_drbg_seed_buf

-Check illegal condition in hmac_drbg_reseed_core.

-Double buf/buf_len variables in mbedtls_hmac_drbg_random_with_add

-Add more hamming distance to MBEDTLS_HMAC_DRBG_PR_ON/OFF
2019-11-25 13:45:44 +02:00
Simon Butcher
35e535a74a Remove TinyCrypt config condition in source files
This commit removes from the TinyCrypt header and source code files, the
configuration condition on MBEDTLS_USE_TINYCRYPT to include the file
contents.

This is to allow use of the library by the Factory Tool without enabling
MBEDTLS_USE_TINYCRYPT, and also removes a modification we've made to make the
code closer to the upstream TinyCrypt making it easier to maintain.
2019-11-21 17:54:16 +00:00
Manuel Pégourié-Gonnard
30833f2a07 Remove num_n_bits member from curve structure 2019-11-21 15:37:22 +01:00
Manuel Pégourié-Gonnard
72c1764c00 Remove num_bytes member from curve structure
Reduces code size and size of the structure.
2019-11-21 15:37:22 +01:00
Manuel Pégourié-Gonnard
1765933ab2 Remove num_words member from curve structure
Saves code size, and makes the curve structure simpler.
2019-11-21 15:37:22 +01:00
Manuel Pégourié-Gonnard
1c6f7eae2d Remove function pointers from curve structure
They're not needed in practice, and removing them decreases the code size
slightly and provides less opportunities for an attacker.
2019-11-21 15:37:22 +01:00
Manuel Pégourié-Gonnard
ea7eab1fde Add redundancy (Hamming distance) to cert flags
Before this commit, if a certificate only had one issue (for example, if the
"untrusted" bit was the only set in flags), an attacker that could flip this
single bit between the moment it's set and the moment flags are checked before
returning from mbedtls_x509_crt_verify() could make the entire verification
routine appear to succeed (return 0 with no bit set in flags).

Avoid that by making sure that flags always has either 0 or at least 9 bits
set during the execution of the function. However, to preserve the API, clear
the 8 extra bits before returning. This doesn't open the door to other
attacks, as fortunately the API already had redundancy: either both flags and
the return value are 0, or flags has bits set and the return value is non-zero
with at least 16 bits set (assuming 32-bit 2-complement ints).
2019-11-21 15:32:45 +01:00
Manuel Pégourié-Gonnard
72a8c9e7dc Force some compilers to respect volatile reads
Inspection of the generated assembly showed that before this commit, armcc 5
was optimizing away the successive reads to the volatile local variable that's
used for double-checks. Inspection also reveals that inserting a call to an
external function is enough to prevent it from doing that.

The tested versions of ARM-GCC, Clang and Armcc 6 (aka armclang) all keep the
double read, with our without a call to an external function in the middle.

The inserted function can also be changed to insert a random delay if
desired in the future, as it is appropriately places between the reads.
2019-11-21 15:14:59 +01:00
Manuel Pégourié-Gonnard
324c6e9cc9 Add error code MBEDTLS_ERR_PLATFORM_FAULT_DETECTED
This can be used by Mbed TLS functions in any module to signal that a fault
attack is likely happening, so this can be appropriately handled by the
application (report, fall back to safer mode or even halt, etc.)
2019-11-21 15:14:59 +01:00