Commit graph

242 commits

Author SHA1 Message Date
Jaeden Amero a331e0f0af Merge remote-tracking branch 'upstream-restricted/pr/421' into development-proposed 2018-05-04 14:39:24 +01:00
Andres Amaya Garcia 1f6301b3c8 Rename mbedtls_zeroize to mbedtls_platform_zeroize 2018-04-17 10:00:21 -05:00
Andres Amaya Garcia e32df087fb Remove individual copies of mbedtls_zeroize()
This commit removes all the static occurrencies of the function
mbedtls_zeroize() in each of the individual .c modules. Instead the
function has been moved to utils.h that is included in each of the
modules.
2018-04-17 09:19:05 -05:00
Jethro Beekman c645bfe176 Generate RSA keys according to FIPS 186-4
The specification requires that P and Q are not too close. The specification
also requires that you generate a P and stick with it, generating new Qs until
you have found a pair that works. In practice, it turns out that sometimes a
particular P results in it being very unlikely a Q can be found matching all
the constraints. So we keep the original behavior where a new P and Q are
generated every round.
2018-04-11 08:38:37 -07:00
Jethro Beekman 97f95c9ef3 Avoid small private exponents during RSA key generation
Attacks against RSA exist for small D. [Wiener] established this for
D < N^0.25. [Boneh] suggests the bound should be N^0.5.

Multiple possible values of D might exist for the same set of E, P, Q. The
attack works when there exists any possible D that is small. To make sure that
the generated key is not susceptible to attack, we need to make sure we have
found the smallest possible D, and then check that D is big enough. The
Carmichael function λ of p*q is lcm(p-1, q-1), so we can apply Carmichael's
theorem to show that D = d mod λ(n) is the smallest.

[Wiener] Michael J. Wiener, "Cryptanalysis of Short RSA Secret Exponents"
[Boneh] Dan Boneh and Glenn Durfee, "Cryptanalysis of RSA with Private Key d Less than N^0.292"
2018-04-11 08:38:37 -07:00
Gilles Peskine 15ad579895 Merge tag 'mbedtls-2.8.0' into iotssl-1381-x509-verify-refactor-restricted
Conflict resolution:

* ChangeLog
* tests/data_files/Makefile: concurrent additions, order irrelevant
* tests/data_files/test-ca.opensslconf: concurrent additions, order irrelevant
* tests/scripts/all.sh: one comment change conflicted with a code
  addition. In addition some of the additions in the
  iotssl-1381-x509-verify-refactor-restricted branch need support for
  keep-going mode, this will be added in a subsequent commit.
2018-03-23 02:16:22 +01:00
Manuel Pégourié-Gonnard 1ba8a3fc55 Yet another dependency issue (PKCS1_V15)
Found by running:

CC=clang cmake -D CMAKE_BUILD_TYPE="Check"
tests/scripts/depend-pkalgs.pl

(Also tested with same command but CC=gcc)

Another PR will address improving all.sh and/or the depend-xxx.pl scripts
themselves to catch this kind of thing.
2018-03-13 13:42:38 +01:00
Hanno Becker a3389ebb09 Merge branch 'development-restricted' into iotssl-1306-rsa-is-vulnerable-to-bellcore-glitch-attack 2018-03-06 11:55:21 +00:00
Jaeden Amero 66954e1c1f Merge branch 'development' into development-restricted 2018-01-25 17:28:31 +00:00
Gilles Peskine 9e4f77c606 New MD API: rename functions from _ext to _ret
The _ext suffix suggests "new arguments", but the new functions have
the same arguments. Use _ret instead, to convey that the difference is
that the new functions return a value.
2018-01-22 11:54:42 +01:00
Gilles Peskine d91f2a26cb Merge branch 'development' into iotssl-1251-2.7
Conflict resolution:

* ChangeLog: put the new entries in their rightful place.
* library/x509write_crt.c: the change in development was whitespace
  only, so use the one from the iotssl-1251 feature branch.
2018-01-19 11:25:10 +01:00
Gilles Peskine d40c22ba20 Merge branch 'development' into development-restricted 2018-01-17 08:03:33 +01:00
Hanno Becker 87ae197f3e Add explicit uint truncation casts
This commit adds some explicit downcasts from `size_t` to `uint8_t` in
the RSASSA signature encoding function `rsa_rsassa_pkcs1_v15_encode`.
The truncation is safe as it has been checked beforehand that the
respective values are in the range of a `uint8_t`.
2018-01-15 15:27:56 +00:00
Hanno Becker 71b0060af7 Merge branch 'development' into iotssl-247 2018-01-15 11:31:34 +00:00
Jaeden Amero 31f3f0b87b Merge branch 'development' into development-restricted 2018-01-10 13:17:02 +00:00
Hanno Becker d4d60579e4 Address issues found by coverity
1) `mbedtls_rsa_import_raw` used an uninitialized return
   value when it was called without any input parameters.
   While not sensible, this is allowed and should be a
   succeeding no-op.

2) The MPI test for prime generation missed a return value
   check for a call to `mbedtls_mpi_shift_r`. This is neither
   critical nor new but should be fixed.

3) Both the RSA keygeneration example program and the
   RSA test suites contained code initializing an RSA context
   after a potentially failing call to CTR DRBG initialization,
   leaving the corresponding RSA context free call in the
   cleanup section of the respective function orphaned.
   While this defect existed before, Coverity picked up on
   it again because of newly introduced MPI's that were
   also wrongly initialized only after the call to CTR DRBG
   init. The commit fixes both the old and the new issue
   by moving the initializtion of both the RSA context and
   all MPI's prior to the first potentially failing call.
2018-01-10 07:30:47 +00:00
Jaeden Amero f342cb791b Merge branch 'development' into development-restricted 2018-01-09 13:16:37 +00:00
Hanno Becker 3a760a1857 Add size check for RSA modulus to mbedtls_rsa_complete
The function `mbedtls_rsa_complete` is supposed to guarantee that
RSA operations will complete without failure. In contrast, it does
not ensure consistency of parameters, which is the task of the
checking functions `rsa_check_pubkey` and `rsa_check_privkey`.

Previously, the maximum allowed size of the RSA modulus was checked
in `mbedtls_rsa_check_pubkey`. However, exceeding this size would lead
to failure of some RSA operations, hence this check belongs to
`mbedtls_rsa_complete` rather than `mbedtls_rsa_check_pubkey`.
This commit moves it accordingly.
2018-01-05 08:14:49 +00:00
Hanno Becker 63073aa3d3 Don't require P,Q in rsa_private in case of non-blinded non-CRT
For non-CRT, P and Q are only used for the purpose of blinding the exponent.
2017-11-27 15:33:18 +00:00
Gilles Peskine 91048a3aac RSA PSS: remove redundant check; changelog
Remove a check introduced in the previous buffer overflow fix with keys of
size 8N+1 which the subsequent fix for buffer start calculations made
redundant.

Added a changelog entry for the buffer start calculation fix.
2017-10-19 17:46:14 +02:00
Gilles Peskine b00b0da452 RSA PSS: fix first byte check for keys of size 8N+1
For a key of size 8N+1, check that the first byte after applying the
public key operation is 0 (it could have been 1 instead). The code was
incorrectly doing a no-op check instead, which led to invalid
signatures being accepted. Not a security flaw, since you would need the
private key to craft such an invalid signature, but a bug nonetheless.
2017-10-19 15:23:49 +02:00
Gilles Peskine 139108af94 RSA PSS: fix minimum length check for keys of size 8N+1
The check introduced by the previous security fix was off by one. It
fixed the buffer overflow but was not compliant with the definition of
PSS which technically led to accepting some invalid signatures (but
not signatures made without the private key).
2017-10-18 19:03:42 +02:00
Gilles Peskine 6a54b0240d RSA: Fix another buffer overflow in PSS signature verification
Fix buffer overflow in RSA-PSS signature verification when the masking
operation results in an all-zero buffer. This could happen at any key size.
2017-10-17 19:12:36 +02:00
Gilles Peskine 28a0c72795 RSA: Fix buffer overflow in PSS signature verification
Fix buffer overflow in RSA-PSS signature verification when the hash is
too large for the key size. Found by Seth Terashima, Qualcomm.

Added a non-regression test and a positive test with the smallest
permitted key size for a SHA-512 hash.
2017-10-17 19:01:38 +02:00
Hanno Becker f8c028a2fb Minor corrections 2017-10-17 09:20:57 +01:00
Hanno Becker c36aab69b5 Swap D,E parameters in mbedtls_rsa_deduce_primes 2017-10-17 09:15:06 +01:00
Hanno Becker ebd2c024dc Don't require P,Q in rsa_private if neither CRT nor blinding used 2017-10-12 10:57:39 +01:00
Hanno Becker b82a5b554c Fix typos and mixup related to RSA_NO_CRT 2017-10-11 19:12:00 +01:00
Hanno Becker a565f54c4c Introduce new files rsa_internal.[ch] for RSA helper functions
This commit splits off the RSA helper functions into separate headers and
compilation units to have a clearer separation of the public RSA interface,
intended to be used by end-users, and the helper functions which are publicly
provided only for the benefit of designers of alternative RSA implementations.
2017-10-11 11:00:19 +01:00
Hanno Becker 705fc68d72 Unify sanity checks for RSA private and public keys 2017-10-10 18:01:25 +01:00
Hanno Becker e867489ff6 Remove outdated comments from mbedtls_rsa_complete 2017-10-10 17:56:14 +01:00
Hanno Becker 7f25f850ac Adapt uses of mbedtls_rsa_complete to removed PRNG argument 2017-10-10 16:56:22 +01:00
Hanno Becker f9e184b9df Remove PRNG argument from mbedtls_rsa_complete 2017-10-10 16:55:41 +01:00
Hanno Becker 68b4d58bd8 Remove PRNG argument from mbedtls_rsa_deduce_moduli
It is not necessary to pass a CSPRNG to `mbedtls_rsa_deduce_moduli`, as there
exist well-working static strategies, and even if a PRNG is preferred, a
non-secure one would be sufficient.

Further, the implementation is changed to use a static strategy for the choice
of candidates which according to some benchmarks even performs better than the
previous one using random candidate choices.
2017-10-10 16:39:10 +01:00
Hanno Becker 0f65e0ca03 Rename rsa_deduce_moduli to rsa_deduce_primes 2017-10-03 14:40:44 +01:00
Hanno Becker 8ba6ce4f4f Rename rsa_deduce_private to rsa_deduce_private_exponent 2017-10-03 14:40:43 +01:00
Hanno Becker 45a0ef32d9 Correct memory leak in mbedtls_rsa_validate_crt 2017-10-03 14:32:56 +01:00
Hanno Becker e58d38c66f Minor improvements 2017-10-03 07:59:29 +01:00
Hanno Becker 2b2f898cbd Streamline code-path in rsa_rsassa_pkcs1_v15_encode 2017-10-03 07:59:29 +01:00
Hanno Becker 64a8c0acd6 Verify PKCS1 v1.5 signature without parsing
This commit modifies the PKCS1 v1.5 signature verification function `mbedtls_rsa_rsassa_pkcs1_v15_verify` to prepare the
expected PKCS1-v1.5-encoded hash using the function also used by the signing routine `mbedtls_rsa_rsassa_pkcs1_v15_sign`
and comparing it to the provided byte-string afterwards. This comes at the benefits of (1) avoiding any error-prone
parsing, (2) removing the dependency of the RSA module on the ASN.1 parsing module, and (3) reducing code size.
2017-10-03 07:58:00 +01:00
Hanno Becker fdf38030de Outsource code for generating PKCS1 v1.5 encoding
This commit moves the code preparing PKCS1 v1.5 encoded hashes from `mbedtls_rsa_rsassa_pkcs1_v15_sign` to a separate
non-public function `rsa_rsassa_pkcs1_v15_encode`. This code-path will then be re-used by the signature verification function
`mbetls_rsa_rsassa_pkcs1_v15_verify` in a later commit.
2017-10-03 07:58:00 +01:00
Hanno Becker 171a8f1c95 Move constant time memcmp for signature verification
This commit replaces the ad-hoc code for constant-time double-checking the PKCS1 v1.5 RSA signature by an invocation of
`mbedtls_safer_memcmp`.
2017-10-03 07:58:00 +01:00
Hanno Becker 2dec5e8b00 Correct outdated comment 2017-10-03 07:49:52 +01:00
Hanno Becker 4e1be398f6 Remove FORCE_VERIFICATION and FORCE_BLINDING 2017-10-02 16:02:55 +01:00
Hanno Becker b5beaa8995 Check that 1 < D, E < N in mbedtls_rsa_validate_params 2017-10-02 13:20:20 +01:00
Hanno Becker c6fc878eda Remove mbedtls_rsa_check_crt
This is no longer needed after the decision to not exhaustively validate private key material.
2017-10-02 13:20:15 +01:00
Hanno Becker 98838b04af Minor improvements 2017-10-02 13:17:01 +01:00
Hanno Becker 7471631dde Make input arguments to mbedtls_rsa_import_raw constant
Original intention was to be allowed to perform in-place operations like changing the byte-order before importing
parameters into an HSM. Now a copy is needed in this case, but there's no more danger of a user expecting the arguments
to be left untouched.
2017-10-02 13:17:01 +01:00
Hanno Becker bdefff1dde Change signature of mbedtls_rsa_deduce_private
Make input arguments constant and adapt the implementation to use a temporary instead of in-place operations.
2017-10-02 09:59:48 +01:00
Hanno Becker ba5b755f1a Change signature and semantics of mbedtls_rsa_deduce_moduli
Input arguments are marked as constant. Further, no double-checking is performed when a factorization of the modulus has
been found.
2017-10-02 09:55:49 +01:00