Commit Graph

94 Commits

Author SHA1 Message Date
Gabor Mezei
c0ae1cf45a
Rename internal header constant_time.h to constant_time_internal.h
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 11:33:19 +01:00
Gabor Mezei
18a44949d0
Rename constant-time functions to have mbedtls_ct prefix
Rename functions to better suite with the module name.

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 11:32:01 +01:00
Gabor Mezei
e24dea8225
Move mbedtls_cf_memcmp to a new public header
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 11:04:54 +01:00
gabor-mezei-arm
378e7eb5cc
Unify memcmp functions
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 11:04:51 +01:00
gabor-mezei-arm
6e4ace6b40
Delete ssl_invasive.h due to duplicated function declarations
All function declaration provided by ssl_invasive.h is needed only for
testing purposes and all of them are provided by constant_time.h as well.

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 10:59:05 +01:00
gabor-mezei-arm
cb4317b723
Move mbedtls_cf_hmac function to the constant-time module
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 10:59:04 +01:00
gabor-mezei-arm
0f7b9e43e9
Move mbedtls_cf_memcpy_offset function to the constant-time module
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 10:59:04 +01:00
gabor-mezei-arm
ee06febbb4
Move mbedtls_cf_memcpy_if_eq function to the constant-time module
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 10:59:04 +01:00
gabor-mezei-arm
96584ddd4b
Move mbedtls_cf_size_bool_eq function to the constant-time module
There were multiple functions called mbedtls_cf_size_bool_eq. They had exactly
the same behavior, so move the one in bignum.c and remove the other.

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 10:03:55 +01:00
gabor-mezei-arm
a2bcabceb2
Move mbedtls_cf_size_mask_ge function to the constant-time module
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 10:00:17 +01:00
gabor-mezei-arm
4d6b14624e
Move mbedtls_cf_size_mask_lt function to the constant-time module
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 10:00:17 +01:00
gabor-mezei-arm
d361ccd663
Move mbedtls_cf_size_mask function to the constant-time module
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 10:00:17 +01:00
gabor-mezei-arm
944c107744
Move contatnt-time memcmp functions to the contant-time module
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 10:00:12 +01:00
gabor-mezei-arm
e41e3e8a8b Rename function to have suitable name
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
2021-11-11 09:57:28 +01:00
Joe Subbiani
11b7131c2e Fix macro use in ssl_msg.c
After implementing MBEDTLS_PUT_UINT16_BE, I did not remove the
assignment to a variable

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
2021-08-23 12:49:14 +01:00
Joe Subbiani
a651e6f762 Tidy up grouped MBEDTLS_BYTE_x macros
exchange groups of the byte reading macros with MBEDTLS_PUT_UINTxyz
and then shift the pointer afterwards. Easier to read as you can
see how big the data is that you are putting in, and in the case of
UINT32 AND UINT64 it saves some vertical space.

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
2021-08-23 11:35:25 +01:00
Joe Subbiani
ca8a7cf82d Implement byte reading macros to remaining files
The previous commits cherry picked from the changes made with relation
to the development branch. This commit makes the appropriate chnages to
the files not present in the development branch.

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
2021-08-03 16:42:42 +01:00
Joe Subbiani
c54e908656 Replace instances of byte reading macros with PUT
Instances of a group of byte reading macros which are equivilant to
MBEDTLS_PUT_UINTx_yz

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
2021-08-03 14:09:05 +01:00
Joe Subbiani
ad1115a3fd Use byte reading macros in places not using a byte mask
byte shifting opertations throughout library/ were only replaced with
the byte reading macros when an 0xff mask was being used.
The byte reading macros are now more widley used, however they have not
been used in all cases of a byte shift operation, as it detracted from
the immediate readability or otherwise did not seem appropriate.

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
2021-08-03 14:08:33 +01:00
Joe Subbiani
c045dc14b0 Replace MBEDTLS_CHAR_x with MBEDTLS_BYTE_x
The CHAR macros casted to an unsigned char which in this project
is garunteed to be 8 bits - the same as uint8_t (which BYTE casts
to) therefore, instances of CHAR have been swapped with BYTE and
the number of macros have been cut down

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
2021-08-03 14:08:06 +01:00
Joe Subbiani
6b897c930c Add Character byte reading macros
These cast to an unsigned char rather than a uint8_t
like with MBEDTLS_BYTE_x
These save alot of space and will improve maintence by
replacing the appropriate code with MBEDTLS_CHAR_x

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
2021-08-03 14:01:51 +01:00
Joe Subbiani
2bbafda1f8 Prefixed macros with MBEDTLS
As per tests/scripts/check-names.sh, macros in
library/ header files should be prefixed with
MBEDTLS_
The macro functions in common.h where also indented
to comply with the same test

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
2021-08-03 13:38:53 +01:00
Joe Subbiani
61f7d73336 Remove trailing whitespace
Trailing white spaces causing check_files.py to fail

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
2021-08-03 13:19:38 +01:00
Joe Subbiani
ba486b0084 Implement byte reading macros into library/
To improve readability by saving horizontal and vertical space.
Removed unecessary & 0xFF.
Byte reading macros implemented in library/common.h, All files
containing "& 0xff" were modified.
Comments/Documentation not yet added to the macro definitions.

Fixes #4274

Signed-off-by: Joe Subbiani <joe.subbiani@arm.com>
2021-08-03 13:17:40 +01:00
Manuel Pégourié-Gonnard
21bfbdd703 Fix misuse of MD API in SSL constant-flow HMAC
The sequence of calls starts-update-starts-update-finish is not a
guaranteed valid way to abort an operation and start a new one. Our
software implementation just happens to support it, but alt
implementations may very well not support it.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2021-05-19 10:40:02 +02:00
Paul Elliott
d48d5c6615 Fix size_t and longlong specifiers for MinGW
MinGW and older windows compilers cannot cope with %zu or %lld (there is
a workaround for MinGW, but it involves linking more code, there is no
workaround for Windows compilers prior to 2013). Attempt to work around
this by defining printf specifiers for size_t per platform for the
compilers that cannot use the C99 specifiers.

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
2021-03-10 17:00:32 +00:00
Paul Elliott
3891caf1ce Misc review requested fixes
Style fixes and cast certain defines to size_t

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
2021-03-10 17:00:32 +00:00
Paul Elliott
9f35211774 Fixes for invalid printf format specifiers
Fixes for printf format specifiers, where they have been flagged as
invalid sizes by coverity, and new build flags to enable catching these
errors when building using CMake. Note that this patch uses %zu, which
requires C99 or later.

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
2021-03-10 17:00:32 +00:00
Janos Follath
3aae5d4ed7
Merge pull request #781 from mpg/cipher-auth-crypt-restricted
Fix buffer overflow with NIST-KW in cipher layer
2020-12-07 12:58:36 +00:00
Manuel Pégourié-Gonnard
f5cf71e14a Stop using deprecated functions in the library
all.sh -k '*deprecated*' now passes again

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-12-03 12:25:10 +01:00
Christian von Arnim
883d304785
Fix: Add missing arguments to debug message.
Signed-off-by: Christian von Arnim <christian.von-arnim@isw.uni-stuttgart.de>
2020-12-02 10:13:02 +01:00
Hanno Becker
a817ea449a Check presence of DTLS timers only once
Mbed TLS requires users of DTLS to configure timer callbacks
needed to implement the wait-and-retransmit logic of DTLS.

Previously, the presence of these timer callbacks was checked
at every invocation of `mbedtls_ssl_fetch_input()`, so lowest
layer of the messaging stack interfacing with the underlying
transport.

This commit removes this recurring check and instead checks the
presence of timers once at the beginning of the handshake.

The main rationale for this change is that it is a step towards
separating the various layers of the messaging stack more cleanly:
datagram layer, record layer, message layer, retransmission layer.

Signed-off-by: Hanno Becker <hanno.becker@arm.com>
2020-10-20 15:29:14 +01:00
Manuel Pégourié-Gonnard
6d6f8a4b97 Clarify descriptions of constant-flow helpers
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-09-28 09:51:41 +02:00
Manuel Pégourié-Gonnard
822b3729e7 Remove last use of non-bit operations
According to https://www.bearssl.org/ctmul.html even single-precision
multiplication is not constant-time on some older platforms.

An added benefit of the new code is that it removes the somewhat mysterious
constant 0x1ff - which was selected because at that point the maximum value of
padlen was 256. The new code is perhaps a bit more readable for that reason.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-09-18 12:11:22 +02:00
Manuel Pégourié-Gonnard
2a59fb45b5 Add explicit cast when truncating values
MSVC complains about it otherwise.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-09-18 12:11:22 +02:00
Manuel Pégourié-Gonnard
6e2a9a7faa Factor repeated code in ssl_cf functions
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-09-18 12:11:21 +02:00
Manuel Pégourié-Gonnard
2ddec4306f Use bit operations for constant-flow padding check
The previous code used comparison operators >= and == that are quite likely to
be compiled to branches by some compilers on some architectures (with some
optimisation levels).

For example, take the following function:

void old_update( size_t data_len, size_t *padlen )
{
    *padlen  *= ( data_len >= *padlen + 1 );
}

With Clang 3.8, let's compile it for the Arm v6-M architecture:

% clang --target=arm-none-eabi -march=armv6-m -Os foo.c -S -o - |
    sed -n '/^old_update:$/,/\.size/p'

old_update:
        .fnstart
@ BB#0:
        .save   {r4, lr}
        push    {r4, lr}
        ldr     r2, [r1]
        adds    r4, r2, #1
        movs    r3, #0
        cmp     r4, r0
        bls     .LBB0_2
@ BB#1:
        mov     r2, r3
.LBB0_2:
        str     r2, [r1]
        pop     {r4, pc}
.Lfunc_end0:
        .size   old_update, .Lfunc_end0-old_update

We can see an unbalanced secret-dependant branch, resulting in a total
execution time depends on the value of the secret (here padlen) in a
straightforward way.

The new version, based on bit operations, doesn't have this issue:

new_update:
        .fnstart
@ BB#0:
        ldr     r2, [r1]
        subs    r0, r0, #1
        subs    r0, r0, r2
        asrs    r0, r0, #31
        bics    r2, r0
        str     r2, [r1]
        bx      lr
.Lfunc_end1:
        .size   new_update, .Lfunc_end1-new_update

(As a bonus, it's smaller and uses less stack.)

While there's no formal guarantee that the version based on bit operations in
C won't be translated using branches by the compiler, experiments tend to show
that's the case [1], and it is commonly accepted knowledge in the practical
crypto community that if we want to sick to C, bit operations are the safest
bet [2].

[1] https://github.com/mpg/ct/blob/master/results
[2] https://github.com/veorq/cryptocoding

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-09-18 12:10:33 +02:00
Janos Follath
d2ce916b58 Merge branch 'development-restricted' 2020-08-26 14:15:34 +01:00
Janos Follath
d4ac4e037b
Merge pull request #736 from mpg/cf-varpos-copy-dev-restricted
Constant-flow copy of HMAC from variable position
2020-08-25 14:35:55 +01:00
Gilles Peskine
ed19762a22
Merge pull request #3574 from makise-homura/e2k_support
Support building on e2k (Elbrus) architecture
2020-08-25 09:46:36 +02:00
makise-homura
af9513bb48 A different approach of signed-to-unsigned comparison
Suggsted by @hanno-arm

Signed-off-by: makise-homura <akemi_homura@kurisa.ch>
2020-08-24 23:42:49 +03:00
Manuel Pégourié-Gonnard
ba6fc9796a Fix a typo in a comment
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-08-24 12:59:55 +02:00
Dan Handley
abccfc1684 Merge development into development-restricted
* development:
  Update copyright notices to use Linux Foundation guidance
  Undef ASSERT before defining it to ensure that no previous definition has sneaked in through included files.
  Add ChangeLog entry for X.509 CN-type vulnerability
  Improve documentation of cn in x509_crt_verify()
  Fix comparison between different name types
  Add test: DNS names should not match IP addresses
  Remove obsolete buildbot reference in compat.sh
  Fix misuse of printf in shell script
  Fix added proxy command when IPv6 is used
  Simplify test syntax
  Fix logic error in setting client port
  ssl-opt.sh: include test name in log files
  ssl-opt.sh: remove old buildbot-specific condition
  ssl-opt.sh: add proxy to all DTLS tests

Signed-off-by: Dan Handley <dan.handley@arm.com>
2020-08-20 11:07:12 +01:00
Manuel Pégourié-Gonnard
de1cf2c5e1 Make mbedtls_ssl_cf_memcpy_offset() constant-flow
all.sh component test_valgrind_constant_flow is now passing.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-08-20 10:22:41 +02:00
Manuel Pégourié-Gonnard
7fe2c5f086 Add mbedtls_ssl_cf_memcpy_offset() with tests
The tests are supposed to be failing now (in all.sh component
test_memsan_constant_flow), but they don't as apparently MemSan doesn't
complain when the src argument of memcpy() is uninitialized, see
https://github.com/google/sanitizers/issues/1296

The next commit will add an option to test constant flow with valgrind, which
will hopefully correctly flag the current non-constant-flow implementation.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-08-19 11:56:02 +02:00
Manuel Pégourié-Gonnard
3c31afaca6 Use temporary buffer to hold the peer's HMAC
This paves the way for a constant-flow implementation of HMAC checking, by
making sure that the comparison happens at a constant address. The missing
step is obviously to copy the HMAC from the secret offset to this temporary
buffer with constant flow, which will be done in the next few commits.

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-08-19 11:56:01 +02:00
Bence Szépkúti
1e14827beb Update copyright notices to use Linux Foundation guidance
As a result, the copyright of contributors other than Arm is now
acknowledged, and the years of publishing are no longer tracked in the
source files.

Also remove the now-redundant lines declaring that the files are part of
MbedTLS.

This commit was generated using the following script:

# ========================
#!/bin/sh

# Find files
find '(' -path './.git' -o -path './3rdparty' ')' -prune -o -type f -print | xargs sed -bi '

# Replace copyright attribution line
s/Copyright.*Arm.*/Copyright The Mbed TLS Contributors/I

# Remove redundant declaration and the preceding line
$!N
/This file is part of Mbed TLS/Id
P
D
'
# ========================

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
2020-08-19 10:35:41 +02:00
makise-homura
0be6aa9957 Get back -Wsign-compare and fix sources according to it
Signed-off-by: makise-homura <akemi_homura@kurisa.ch>
2020-08-18 23:52:53 +03:00
Gilles Peskine
e900b59703
Merge pull request #719 from gabor-mezei-arm/689_zeroising_of_plaintext_buffers
Zeroising of plaintext buffers in mbedtls_ssl_read()
2020-08-12 18:51:42 +02:00
Manuel Pégourié-Gonnard
f009542747 Add missing const for consistency
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
2020-07-27 09:34:10 +02:00