All CBC ciphers in TLS are broken and insecure. TLS 1.2 introduced
AEAD-based ciphers which avoid their many problems. It also introduced
new CBC ciphers based on HMAC-SHA256 and HMAC-SHA384 that share the same
flaws as the original HMAC-SHA1 ones. These serve no purpose. Old
clients don't support them, they have the highest overhead of all TLS
ciphers, and new clients can use AEADs anyway.
Remove them from libssl. This is the smaller, more easily reverted
portion of the removal. If it survives a week or so, we can unwind a lot
more code elsewhere in libcrypto. This removal will allow us to clear
some indirect calls from crypto/cipher_extra/tls_cbc.c, aligning with
the recommendations here:
https://github.com/HACS-workshop/spectre-mitigations/blob/master/crypto_guidelines.md#2-avoid-indirect-branches-in-constant-time-code
Update-Note: The following cipher suites are removed:
- TLS_RSA_WITH_AES_128_CBC_SHA256
- TLS_RSA_WITH_AES_256_CBC_SHA256
- TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
- TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384
- TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
- TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
Change-Id: I7ade0fc1fa2464626560d156659893899aab6f77
Reviewed-on: https://boringssl-review.googlesource.com/27944
Reviewed-by: Adam Langley <agl@google.com>
Chrome needs to support renegotiation at TLS 1.2 + HTTP/1.1, but we're
free to shed the handshake configuration at TLS 1.3 or HTTP/2.
Rather than making config shedding implicitly disable renegotiation,
make the actual shedding dependent on a combination of the two settings.
If config shedding is enabled, but so is renegotiation (including
whether we are a client, etc.), leave the config around. If the
renegotiation setting gets disabled again after the handshake,
re-evaluate and shed the config then.
Bug: 123
Change-Id: Ie833f413b3f15b8f0ede617991e3fef239d4a323
Reviewed-on: https://boringssl-review.googlesource.com/27904
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Matt Braithwaite <mab@google.com>
|SSL_CONFIG| is a container for bits of configuration that are
unneeded after the handshake completes. By default it is retained for
the life of the |SSL|, but it may be shed at the caller's option by
calling SSL_set_shed_handshake_config(). This is incompatible with
renegotiation, and with SSL_clear().
|SSL_CONFIG| is reachable by |ssl->config| and by |hs->config|. The
latter is always non-NULL. To avoid null checks, I've changed the
signature of a number of functions from |SSL*| arguments to
|SSL_HANDSHAKE*| arguments.
When configuration has been shed, setters that touch |SSL_CONFIG|
return an error value if that is possible. Setters that return |void|
do nothing.
Getters that request |SSL_CONFIG| values will fail with an |assert| if
the configuration has been shed. When asserts are compiled out, they
will return an error value.
The aim of this commit is to simplify analysis of split-handshakes by
making it obvious that some bits of state have no effects beyond the
handshake. It also cuts down on memory usage.
Of note: |SSL_CTX| is still reachable after the configuration has been
shed, and a couple things need to be retained only for the sake of
post-handshake hooks. Perhaps these can be fixed in time.
Change-Id: Idf09642e0518945b81a1e9fcd7331cc9cf7cc2d6
Bug: 123
Reviewed-on: https://boringssl-review.googlesource.com/27644
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
Chromium has some code which reaches into this field for memory
accounting.
This fixes a bug in doc.go where this line-wrapping confuses it. doc.go
needs a bit of a rewrite, but this is a bit better.
Change-Id: Ic9cc2c2fe9329d7bc366ccf91e0c9a92eae08ed2
Reviewed-on: https://boringssl-review.googlesource.com/27764
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Rather than expose a (potentially) assembly function directly, wrap it
in a C function to make visibility control easier.
Change-Id: I4a2dfeb8999ff021b2e10fbc54850eeadabbefff
Reviewed-on: https://boringssl-review.googlesource.com/27724
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
This does not appear to actually pull its weight. The purpose of this
logic is to switch some adds to the faster add_mixed in the wNAF code,
at the cost of a rather expensive inversion. This optimization kicks in
for generic curves, so P-384 and P-521:
With:
Did 32130 ECDSA P-384 signing operations in 30077563us (1068.2 ops/sec)
Did 27456 ECDSA P-384 verify operations in 30073086us (913.0 ops/sec)
Did 14122 ECDSA P-521 signing operations in 30077407us (469.5 ops/sec)
Did 11973 ECDSA P-521 verify operations in 30037330us (398.6 ops/sec)
Without:
Did 32445 ECDSA P-384 signing operations in 30069721us (1079.0 ops/sec)
Did 27056 ECDSA P-384 verify operations in 30032303us (900.9 ops/sec)
Did 13905 ECDSA P-521 signing operations in 30000430us (463.5 ops/sec)
Did 11433 ECDSA P-521 verify operations in 30021876us (380.8 ops/sec)
For single-point multiplication, the optimization is not useful. This
makes sense as we only have one table's worth of additions to convert
but still pay for the inversion. For double-point multiplication, it is
slightly useful for P-384 and very useful for P-521. However, the next
change to stack-allocate EC_FELEMs will more than compensate for
removing it. (The immediate goal here is to simplify the EC_FELEM
story.)
Additionally, that this optimization was not useful for single-point
multiplication implies that, should we wish to recover this, a modest
8-entry pre-computed (affine) base point table should have the same
effect or better.
Update-Note: I do not believe anything was calling either of these
functions. (If necessary, we can always add no-op stubs as whether a
point is affine is not visible to external code. It previously kicked in
some optimizations, but those were removed for constant-time needs
anyway.)
Bug: 239
Change-Id: Ic9c51b001c45595cfe592274c7d5d652f4234839
Reviewed-on: https://boringssl-review.googlesource.com/27667
Reviewed-by: Adam Langley <agl@google.com>
If the caller asked for the base to be treated as secret, we should
provide that. Allowing unbounded inputs is not compatible with being
constant-time.
Additionally, this aligns with the guidance here:
https://github.com/HACS-workshop/spectre-mitigations/blob/master/crypto_guidelines.md#1-do-not-conditionally-choose-between-constant-and-non-constant-time
Update-Note: BN_mod_exp_mont_consttime and BN_mod_exp_mont now require
inputs be fully reduced. I believe current callers tolerate this.
Additionally, due to a quirk of how certain operations were ordered,
using (publicly) zero exponent tolerated a NULL BN_CTX while other
exponents required non-NULL BN_CTX. Non-NULL BN_CTX is now required
uniformly. This is unlikely to cause problems. Any call site where the
exponent is always zero should just be replaced with BN_value_one().
Change-Id: I7c941953ea05f36dc2754facb9f4cf83a6789c61
Reviewed-on: https://boringssl-review.googlesource.com/27665
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@google.com>
This is so the *_small functions can assume somewhat more uniform
widths, to simplify their error-handling.
Change-Id: I0420cb237084b253e918c64b0c170a5dfd99ab40
Reviewed-on: https://boringssl-review.googlesource.com/27584
Reviewed-by: Adam Langley <alangley@gmail.com>
The FIPS 186-4 algorithm we use includes a limit which hits a 2^-20
failure probability, assuming my math is right. We've observed roughly
2^-23. This is a little large at scale. (See b/77854769.)
To avoid modifying the FIPS algorithm, retry the whole thing four times
to bring the failure rate down to 2^-80. Along the way, now that I have
the derivation on hand, adjust
https://boringssl-review.googlesource.com/22584 to target the same
failure probability.
Along the way, fix an issue with RSA_generate_key where, if callers
don't check for failure, there may be half a key in there.
Change-Id: I0e1da98413ebd4ffa65fb74c67a58a0e0cd570ff
Reviewed-on: https://boringssl-review.googlesource.com/27288
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
https://boringssl-review.googlesource.com/10520 and then later
https://boringssl-review.googlesource.com/25285 made BN_MONT_CTX_set
constant-time, which is necessary for RSA's mont_p and mont_q. However,
due to a typo in the benchmark, they did not correctly measure.
Split BN_MONT_CTX creation into a constant-time and variable-time one.
The constant-time one uses our current algorithm and the latter restores
the original BN_mod codepath.
Should we wish to avoid BN_mod, I have an alternate version lying
around:
First, BN_set_bit + bn_mod_lshift1_consttime as now to count up to 2*R.
Next, observe that 2*R = BN_to_montgomery(2) and R*R =
BN_to_montgomery(R) = BN_to_montgomery(2^r_bits) Also observe that
BN_mod_mul_montgomery only needs n0, not RR. Split the core of
BN_mod_exp_mont into its own function so the caller handles conversion.
Raise 2*R to the r_bits power to get 2^r_bits*R = R*R.
The advantage of that algorithm is that it is still constant-time, so we
only need one BN_MONT_CTX_new. Additionally, it avoids BN_mod which is
otherwise (almost, but the remaining links should be easy to cut) out of
the critical path for correctness. One less operation to worry about.
The disadvantage is that it is gives a 25% (RSA-2048) or 32% (RSA-4096)
slower RSA verification speed. I went with the BN_mod one for the time
being.
Before:
Did 9204 RSA 2048 signing operations in 10052053us (915.6 ops/sec)
Did 326000 RSA 2048 verify (same key) operations in 10028823us (32506.3 ops/sec)
Did 50830 RSA 2048 verify (fresh key) operations in 10033794us (5065.9 ops/sec)
Did 1269 RSA 4096 signing operations in 10019204us (126.7 ops/sec)
Did 88435 RSA 4096 verify (same key) operations in 10031129us (8816.1 ops/sec)
Did 14552 RSA 4096 verify (fresh key) operations in 10053411us (1447.5 ops/sec)
After:
Did 9150 RSA 2048 signing operations in 10022831us (912.9 ops/sec)
Did 322000 RSA 2048 verify (same key) operations in 10028604us (32108.2 ops/sec)
Did 289000 RSA 2048 verify (fresh key) operations in 10017205us (28850.4 ops/sec)
Did 1270 RSA 4096 signing operations in 10072950us (126.1 ops/sec)
Did 87480 RSA 4096 verify (same key) operations in 10036328us (8716.3 ops/sec)
Did 80730 RSA 4096 verify (fresh key) operations in 10073614us (8014.0 ops/sec)
Change-Id: Ie8916d1634ccf8513ceda458fa302f09f3e93c07
Reviewed-on: https://boringssl-review.googlesource.com/27287
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
Chrome uses the platform certificate verifier and thus cannot reliably
expect PSS signatures to work in all configurations. Add an API for the
consumer to inform BoringSSL of this ability. We will then adjust our
advertisements accordingly.
Note that, because TLS 1.2 does not have the signature_algorithms_cert
extension, turning off TLS 1.3 and using this API will stop advertising
RSA-PSS. I believe this is the correct behavior given the semantics of
that code point.
The tests check the various combinations here, as well as checking that
the peer never sends signature_algorithms_cert identical to
signature_algorithms.
Bug: 229
Change-Id: I8c33a93efdc9252097e3899425b49548fc42a93a
Reviewed-on: https://boringssl-review.googlesource.com/27488
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@google.com>
This reflects the change to add the key type into the constant. The old
constants are left around for now as legacy aliases and will be removed
later.
Change-Id: I67f1b50c01fbe0ebf4a2e9e89d3e7d5ed5f5a9d7
Reviewed-on: https://boringssl-review.googlesource.com/27486
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Update-Note: I believe everything relying on this overload has since
been updated.
Change-Id: I7facf59cde56098e5e3c79470293b67abb715f4c
Reviewed-on: https://boringssl-review.googlesource.com/27485
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Conscrypt need this function right now. They ought to be fixed up to not
need this but, in the meantime, this API is also provided by OpenSSL and
will clear one most consumer reaching into SSL_SESSION.
Bumping the API since Conscrypt often involves multi-sided stuff.
Change-Id: I665ca6b6a17ef479133c29c23fc639f278128c69
Reviewed-on: https://boringssl-review.googlesource.com/27405
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
OpenSSL 1.1.0 renamed that. Also clang-format wanted to smush it all
onto one line.
Change-Id: Icdaa0eefc503c4aab1b309ccb34625f5e811c537
Reviewed-on: https://boringssl-review.googlesource.com/27404
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Change-Id: I7298c878bd2c8187dbd25903e397e8f0c2575aa4
Reviewed-on: https://boringssl-review.googlesource.com/26846
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
This changes the contract for split handshakes such that on the
receiving side, the connection is to be driven until it returns
|SSL_ERROR_HANDBACK|, rather than until SSL_do_handshake() returns
success.
Change-Id: Idd1ebfbd943d88474d7c934f4c0ae757ff3c0f37
Reviewed-on: https://boringssl-review.googlesource.com/26864
Commit-Queue: Matt Braithwaite <mab@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
The relevant result (Damgård, Landrock, and Pomerance, Average Case
Error Estimates for the Strong Probably Prime Test) is only applicable
for randomly selected candidates. It relies on there being very few odd
composites with many false witnesses.
(If testing an adversarially-selected composite, false witnesses are
bounded by ϕ(n)/4 for n != 9, so one needs about 40 iterations for a
2^-80 false positive rate.)
Change-Id: I2a063dac5f9042dcb9e6affee8d2ae575f2238a9
Reviewed-on: https://boringssl-review.googlesource.com/26972
Reviewed-by: Adam Langley <agl@google.com>
AUTHORITY_INFO_ACCESS is a STACK_OF(ACCESS_DESCRIPTION), so we want to
add a deleter for ACCESS_DESCRIPTION, at which point
AUTHORITY_INFO_ACCESS's deleter will show up for free.
Change-Id: Id9efb74093868c39a893de67dd26f1fc15379252
Reviewed-on: https://boringssl-review.googlesource.com/26973
Reviewed-by: Ryan Sleevi <rsleevi@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
We don't check it is fully reduced because different implementations use
Carmichael vs Euler totients, but if d exceeds n, something is wrong.
Note the fixed-width BIGNUM changes already fail operations with
oversized d.
Update-Note: Some blatantly invalid RSA private keys will be rejected at
RSA_check_key time. Note that most of those keys already are not
usable with BoringSSL anyway. This CL moves the failure from
sign/decrypt to RSA_check_key.
Change-Id: I468dbba74a148aa58c5994cc27f549e7ae1486a2
Reviewed-on: https://boringssl-review.googlesource.com/26374
Reviewed-by: Adam Langley <alangley@gmail.com>
The extra details in Enhanced Rabin-Miller are only used in
RSA_check_key_fips, on the public RSA modulus, which the static linker
will drop in most of our consumers anyway. Implement normal Rabin-Miller
for RSA keygen and use Montgomery reduction so it runs in constant-time.
Note that we only need to avoid leaking information about the input if
it's a large prime. If the number ends up composite, or we find it in
our table of small primes, we can return immediately.
The leaks not addressed by this CL are:
- The difficulty of selecting |b| leaks information about |w|.
- The distribution of whether step 4.4 runs leaks information about w.
- We leak |a| (the largest power of two which divides w) everywhere.
- BN_mod_word in the trial division is not constant-time.
These will be resolved in follow-up changes.
Median of 29 RSA keygens: 0m0.521 -> 0m0.621s
(Accuracy beyond 0.1s is questionable.)
Bug: 238
Change-Id: I0cf0ff22079732a0a3ababfe352bb4327e95b879
Reviewed-on: https://boringssl-review.googlesource.com/25886
Reviewed-by: Adam Langley <agl@google.com>
Constructed types with a recursive definition could eventually exceed
the stack given malicious input with excessive recursion. Therefore we
limit the stack depth.
CVE-2018-0739
Credit to OSSFuzz for finding this issue.
(Imported from upstream's 9310d45087ae546e27e61ddf8f6367f29848220d.)
BoringSSL does not contain any such structures, but import this anyway
with a test.
Change-Id: I0e84578ea795134f25dae2ac8b565f3c26ef3204
Reviewed-on: https://boringssl-review.googlesource.com/26844
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Change-Id: Ia4fdd1eb848abacf43e18f6741ffa4ff79e40fd8
Reviewed-on: https://boringssl-review.googlesource.com/26664
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Folks should use curve25519 or P-256 if in doubt.
Change-Id: Ie35381ef739744788a80345286f7b21e2bb67c88
Reviewed-on: https://boringssl-review.googlesource.com/26646
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
On the other hand, the type-specific
|CBS_get_optional_asn1_octet_string| must have a valid pointer and we
should check this in the “present” case or there could be a lucking
crash in some user waiting for an expected value to be missing.
Change-Id: Ida40e069ac7f0e50967e3f6c6b3fc01e49bd8894
Reviewed-on: https://boringssl-review.googlesource.com/26564
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
It has now been folded into ServerHello. Additionally, TLS 1.2 and TLS
1.3 ServerHellos are now more uniform, so we can avoid the extra
ServerHello parser.
Change-Id: I46641128c3f65fe37e7effca5bef4a76bf3ba84c
Reviewed-on: https://boringssl-review.googlesource.com/26524
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@google.com>
This clearly was supposed to be a return 1. See
https://github.com/openssl/openssl/issues/5537 for details.
(Additionally, now that our BIGNUMs may be non-minimal, this function
violates the rule that BIGNUM functions should not depend on widths. We
should use w >= bn_minimal_width(a) to retain the original behavior. But
the original behavior is nuts, so let's just fix it.)
Update-Note: BN_mask_bits no longer reports failure in some cases. These
cases were platform-dependent and not useful, and code search confirms
nothing was relying on it.
Change-Id: I31b1c2de6c5de9432c17ec3c714a5626594ee03c
Reviewed-on: https://boringssl-review.googlesource.com/26464
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
EC_KEY_copy left unset fields alone, which meant it was possible to
create an EC_KEY with mismatched private key and group. Nothing was
using EC_KEY_copy anyway, and in keeping of us generally preferring
fresh objects over object reuse, remove it. EC_KEY_dup itself can also
be made simpler by using the very setters available.
Additionally, skip copying the method table. As of
https://boringssl-review.googlesource.com/16344, we no longer copy the
ex_data, so we probably shouldn't copy the method pointers either,
aligning with RSAPrivateKey_dup.
Update-Note: If I missed anything and someone uses EC_KEY_copy, it
should be easy to port them to EC_KEY_dup.
Change-Id: Ibbdcea73345d91fa143fbe70a15bb527972693e8
Reviewed-on: https://boringssl-review.googlesource.com/26404
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Checking |initial_handshake_complete| was a mistake—it's not true for
False Start connections at the time when Chrome wants to measure whether
PQ padding was used or not.
Change-Id: I51757e00f3e02129666ee1ce31c30d63f1bcbe74
Reviewed-on: https://boringssl-review.googlesource.com/26444
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
The probability of stumbling on a non-invertible b->A is negligible;
it's equivalent to accidentally factoring the RSA key. Relatedly,
document the slight caveat in BN_mod_inverse_blinded.
Change-Id: I308d17d12f5d6a12c444dda8c8fcc175ef2f5d45
Reviewed-on: https://boringssl-review.googlesource.com/26344
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
The Bluetooth Mesh spec uses both apparently. Also extract a pile of
test vectors from that document (thanks to Kyle Lund for showing me
which to extract).
Change-Id: I04a04fafb7386ca28adfe1446fa388e841778931
Reviewed-on: https://boringssl-review.googlesource.com/26324
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
On reflection, I think we'll need to note whether dummy PQ padding was
echoed on a given connection. Otherwise measurements in Chrome will be
mixed with cases where people have MITM proxies that ignored the
extension, or possibly Google frontends that haven't been updated.
Therefore this change will be used to filter latency measurements in
Chrome to only include those where the extension was echoed and we'll
measure at levels of 1 byte (for control), 400 bytes, and 1100 bytes.
This also makes it an error if the server didn't echo an extension of
the same length as was sent.
Change-Id: Ib2a0b29cfb8719a75a28f3cf96710c57d88eaa68
Reviewed-on: https://boringssl-review.googlesource.com/26284
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
SSLv3_method, SSLv3_client_method, and SSLv3_server_method produce
SSL_CTXs which fail every handshake. They appear no longer necessary for
compatibility, so remove them.
SSLv3 is still accessible to callers who explicitly re-enable SSLv3 on a
TLS_method, but that will be removed completely later this year.
Meanwhile, clear out a weird hack we had here.
Update-Note: I believe there are no more callers of these functions. Any
that were were already non-functional as these methods haven't been
unable to handshake for a while now.
Change-Id: I622f785b428ab0ceab77b5a9db05b2b0df28145a
Reviewed-on: https://boringssl-review.googlesource.com/26004
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
OpenSSL's RSA API is poorly designed and does not have a single place to
properly initialize the key. See
https://github.com/openssl/openssl/issues/5158.
To workaround this flaw, we must lazily instantiate pre-computed
Montgomery bits with locking. This is a ton of complexity. More
importantly, it makes it very difficult to implement RSA without side
channels. The correct in-memory representation of d, dmp1, and dmq1
depend on n, p, and q, respectively. (Those values have private
magnitudes and must be sized relative to the respective moduli.)
08805fe279 attempted to fix up the various
widths under lock, when we set up BN_MONT_CTX. However, this introduces
threading issues because other threads may access those exposed
components (RSA_get0_* also count as exposed for these purposes because
they are get0 functions), while a private key operation is in progress.
Instead, we do the following:
- There is no actual need to minimize n, p, and q, but we have minimized
copies in the BN_MONT_CTXs, so use those.
- Store additional copies of d, dmp1, and dmq1, at the cost of more
memory used. These copies have the correct width and are private,
unlike d, dmp1, and dmq1 which are sadly exposed. Fix private key
operations to use them.
- Move the frozen bit out of rsa->flags, as that too was historically
accessible without locking.
(Serialization still uses the original BIGNUMs, but the RSAPrivateKey
serialization format already inherently leaks the magnitude, so this
doesn't matter.)
Change-Id: Ia3a9b0629f8efef23abb30bfed110d247d1db42f
Reviewed-on: https://boringssl-review.googlesource.com/25824
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
This allows a BIGNUM consumer to avoid messing around with bn->d and
bn->top/width.
Bug: 232
Change-Id: I134cf412fef24eb404ff66c84831b4591d921a17
Reviewed-on: https://boringssl-review.googlesource.com/25484
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
This is a bit easier to read than BN_less_than_consttime when we must do
>= or <=, about as much work to compute, and lots of code calls BN_cmp
on secret data. This also, by extension, makes BN_cmp_word
constant-time.
BN_equal_consttime is probably a little more efficient and is perfectly
readable, so leave that one around.
Change-Id: Id2e07fe312f01cb6fd10a1306dcbf6397990cf13
Reviewed-on: https://boringssl-review.googlesource.com/25444
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
Alas, the existence of RSA keys with q > p is obnoxious, but we can
canonicalize it away. To my knowledge, the remaining leaks in RSA are:
- Key generation. This is kind of hopelessly non-constant-time but
perhaps deserves a more careful ponder. Though hopefully it does not
come in at a measurable point for practical purposes.
- Private key serialization. RSAPrivateKey inherently leaks the
magnitudes of d, dmp1, dmq1, and iqmp. This is unavoidable but
hopefully does not come in at a measurable point for practical
purposes.
- If p and q have different word widths, we currently fall back to the
variable-time BN_mod rather than Montgomery reduction at the start of
CRT. I can think of ways to apply Montgomery reduction, but it's
probably better to deny CRT to such keys, if not reject them outright.
- bn_mul_fixed and bn_sqr_fixed which affect the Montgomery
multiplication bn_mul_mont-less configurations, as well as the final
CRT multiplication. We should fix this.
Bug: 233
Change-Id: I8c2ecf8f8ec104e9f26299b66ac8cbb0cad04616
Reviewed-on: https://boringssl-review.googlesource.com/25263
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
d, dmp1, dmq1, and iqmp have private magnitudes. This is awkward because
the RSAPrivateKey serialization leaks the magnitudes. Do the best we can
and fix them up before any RSA operations.
This moves the piecemeal BN_MONT_CTX_set_locked into a common function
where we can do more complex canonicalization on the keys. Ideally this
would be done on key import, but the exposed struct (and OpenSSL 1.1.0's
bad API design) mean there is no single point in time when key import is
finished.
Also document the constraints on RSA_set0_* functions. (These
constraints aren't new. They just were never documented before.)
Update-Note: If someone tried to use an invalid RSA key where d >= n,
dmp1 >= p, dmq1 >= q, or iqmp >= p, this may break. Such keys would not
have passed RSA_check_key, but it's possible to manually assemble
keys that bypass it.
Bug: 232
Change-Id: I421f883128952f892ac0cde0d224873a625f37c5
Reviewed-on: https://boringssl-review.googlesource.com/25259
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
This has no behavior change, but it has a semantic one. This CL is an
assertion that all BIGNUM functions tolerate non-minimal BIGNUMs now.
Specifically:
- Functions that do not touch top/width are assumed to not care.
- Functions that do touch top/width will be changed by this CL. These
should be checked in review that they tolerate non-minimal BIGNUMs.
Subsequent CLs will start adjusting the widths that BIGNUM functions
output, to fix timing leaks.
Bug: 232
Change-Id: I3a2b41b071f2174452f8d3801bce5c78947bb8f7
Reviewed-on: https://boringssl-review.googlesource.com/25257
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
