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>
Rather than recompute values the same as in key generation, where
possible, we check differently. In particular, most RSA values are
modular inverses of some value. Check each of them by multiplying and
using our naive constant-time division function.
Median of 29 RSA keygens: 0m0.218s -> 0m0.205s
(Accuracy beyond 0.1s is questionable.)
Bug: 238
Change-Id: Iaca19f12c045457013def844a17bf502ed09136e
Reviewed-on: https://boringssl-review.googlesource.com/26373
Reviewed-by: Adam Langley <alangley@gmail.com>
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>
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>
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>
RSA_METHOD_FLAG_NO_CHECK is the same as our RSA_FLAG_OPAQUE. cURL uses
this to determine if it should call SSL_CTX_check_private_key.
Change-Id: Ie2953632346a31de346a4452f4eaad8435cf76e8
Reviewed-on: https://boringssl-review.googlesource.com/24245
Reviewed-by: Adam Langley <agl@google.com>
wpa_supplicant appear to be using these.
Change-Id: I1f220cae69162901bcd9452e8daf67379c5e276c
Reviewed-on: https://boringssl-review.googlesource.com/23324
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>
Although we are derived from 1.0.2, we mimic 1.1.0 in some ways around
our FOO_up_ref functions and opaque libssl types. This causes some
difficulties when porting third-party code as any OPENSSL_VERSION_NUMBER
checks for 1.1.0 APIs we have will be wrong.
Moreover, adding accessors without changing OPENSSL_VERSION_NUMBER can
break external projects. It is common to implement a compatibility
version of an accessor under #ifdef as a static function. This then
conflicts with our headers if we, unlike OpenSSL 1.0.2, have this
function.
This change switches OPENSSL_VERSION_NUMBER to 1.1.0 and atomically adds
enough accessors for software with 1.1.0 support already. The hope is
this will unblock hiding SSL_CTX and SSL_SESSION, which will be
especially useful with C++-ficiation. The cost is we will hit some
growing pains as more 1.1.0 consumers enter the ecosystem and we
converge on the right set of APIs to import from upstream.
It does not remove any 1.0.2 APIs, so we will not require that all
projects support 1.1.0. The exception is APIs which changed in 1.1.0 but
did not change the function signature. Those are breaking changes.
Specifically:
- SSL_CTX_sess_set_get_cb is now const-correct.
- X509_get0_signature is now const-correct.
For C++ consumers only, this change temporarily includes an overload
hack for SSL_CTX_sess_set_get_cb that keeps the old callback working.
This is a workaround for Node not yet supporting OpenSSL 1.1.0.
The version number is set at (the as yet unreleased) 1.1.0g to denote
that this change includes https://github.com/openssl/openssl/pull/4384.
Bug: 91
Change-Id: I5eeb27448a6db4c25c244afac37f9604d9608a76
Reviewed-on: https://boringssl-review.googlesource.com/10340
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>
crypto/{asn1,x509,x509v3,pem} were skipped as they are still OpenSSL
style.
Change-Id: I3cd9a60e1cb483a981aca325041f3fbce294247c
Reviewed-on: https://boringssl-review.googlesource.com/19504
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
There are still a ton of them, almost exclusively complaints that
function declaration and definitions have different parameter names. I
just fixed a few randomly.
Change-Id: I1072f3dba8f63372cda92425aa94f4aa9e3911fa
Reviewed-on: https://boringssl-review.googlesource.com/18706
Reviewed-by: Steven Valdez <svaldez@google.com>
The only place it is used is EC_KEY_{dup,copy} and no one calls that
function on an EC_KEY with ex_data. This aligns with functions like
RSAPublicKey_dup which do not copy ex_data. The logic is also somewhat
subtle in the face of malloc errors (upstream's PR 3323).
In fact, we'd even changed the function pointer signature from upstream,
so BoringSSL-only code is needed to pass this pointer in anyway. (I
haven't switched it to CRYPTO_EX_unused because there are some callers
which pass in an implementation anyway.)
Note, in upstream, the dup hook is also used for SSL_SESSIONs when those
are duplicated (for TLS 1.2 ticket renewal or TLS 1.3 resumption). Our
interpretation is that callers should treat those SSL_SESSIONs
equivalently to newly-established ones. This avoids every consumer
providing a dup hook and simplifies the interface.
(I've gone ahead and removed the TODO(fork). I don't think we'll be able
to change this API. Maybe introduce a new one, but it may not be worth
it? Then again, this API is atrocious... I've never seen anyone use argl
and argp even.)
BUG=21
Change-Id: I6c9e9d5a02347cb229d4c084c1e85125bd741d2b
Reviewed-on: https://boringssl-review.googlesource.com/16344
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
