The padding check functions will need to tweak their calling conventions
and the constant-time helpers, so leaving those alone for now. These
were the easy ones.
BUG=22
Change-Id: Ia00e41e26a134de17d56be3def5820cb042794e1
Reviewed-on: https://boringssl-review.googlesource.com/14265
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>
Require the public exponent to be available unless
|RSA_FLAG_NO_BLINDING| is set on the key. Also, document this.
If the public exponent |e| is not available, then we could compute it
from |p|, |q|, and |d|. However, there's no reasonable situation in
which we'd have |p| or |q| but not |e|; either we have all the CRT
parameters, or we have (e, d, n), or we have only (d, n). The
calculation to compute |e| exposes the private key to risk of side
channel attacks.
Also, it was particularly wasteful to compute |e| for each
|BN_BLINDING| created, instead of just once before the first
|BN_BLINDING| was created.
|BN_BLINDING| now no longer needs to contain a duplicate copy of |e|,
so it is now more space-efficient.
Note that the condition |b->e != NULL| in |bn_blinding_update| was
always true since commit cbf56a5683.
Change-Id: Ic2fd6980e0d359dcd53772a7c31bdd0267e316b4
Reviewed-on: https://boringssl-review.googlesource.com/7594
Reviewed-by: David Benjamin <davidben@google.com>
We do not need to support engine-provided verification methods.
Change-Id: Iaad8369d403082b728c831167cc386fdcabfb067
Reviewed-on: https://boringssl-review.googlesource.com/7311
Reviewed-by: David Benjamin <davidben@google.com>
|BN_mod_mul_montgomery| has better constant-time behavior (usually)
than |BN_mod_mul| and |BN_mod_sqr| and on platforms where we have
assembly language optimizations (when |OPENSSL_BN_ASM_MONT| is set in
crypto/bn/montgomery.c) it is faster. While doing so, reorder and
rename the |BN_MONT_CTX| parameters of the blinding functions to match
the order normally used in Montgomery math functions.
As a bonus, remove a redundant copy of the RSA public modulus from the
|BN_BLINDING| structure, which reduces memory usage.
Change-Id: I70597e40246429c7964947a1dc46d0d81c7530ef
Reviewed-on: https://boringssl-review.googlesource.com/7524
Reviewed-by: David Benjamin <davidben@google.com>
In |bn_blinding_update| the condition |b->e != NULL| would never be
true (probably), but the test made reasoning about the correctness of
the code confusing. That confusion was amplified by the circuitous and
unusual way in which |BN_BLINDING|s are constructed. Clarify all this
by simplifying the construction of |BN_BLINDING|s, making it more like
the construction of other structures.
Also, make counter unsigned as it is no longer ever negative.
Change-Id: I6161dcfeae19a80c780ccc6762314079fca1088b
Reviewed-on: https://boringssl-review.googlesource.com/7530
Reviewed-by: David Benjamin <davidben@google.com>
This removes a hard dependency on |BN_mod_exp|, which will allow the
linker to drop it in programs that don't use other features that
require it.
Also, remove the |mont| member of |bn_blinding_st| in favor of having
callers pass it when necssaary. The |mont| member was a weak reference,
and weak references tend to be error-prone.
Finally, reduce the scope of some parts of the blinding code to
|static|.
Change-Id: I16d8ccc2d6d950c1bb40377988daf1a377a21fe6
Reviewed-on: https://boringssl-review.googlesource.com/7111
Reviewed-by: David Benjamin <davidben@google.com>
The |_ex| versions of these functions are unnecessary because when they
are used, they are always passed |NULL| for |r|, which is what the
non-|_ex| versions do. Just use the non-|_ex| versions instead and
remove the |_ex| versions.
Also, drop the unused flags mechanism.
Change-Id: Ida4cb5a2d4c89d9cd318e06f71867aea98408d0d
Reviewed-on: https://boringssl-review.googlesource.com/7110
Reviewed-by: David Benjamin <davidben@google.com>
Most functions can take this in as const. Note this changes an
RSA_METHOD hook, though one I would not expect anyone to override.
Change-Id: Ib70ae65e5876b01169bdc594e465e3e3c4319a8b
Reviewed-on: https://boringssl-review.googlesource.com/6419
Reviewed-by: Adam Langley <agl@google.com>
Although those are only created by code owned by RSA_METHOD, custom RSA_METHODs
shouldn't be allowed to squat our internal fields and then change how you free
things.
Remove 'method' from their names now that they're not method-specific.
Change-Id: I9494ef9a7754ad59ac9fba7fd463b3336d826e0b
Reviewed-on: https://boringssl-review.googlesource.com/6423
Reviewed-by: Adam Langley <agl@google.com>
Having a single RSA_METHOD means they all get pulled in. Notably, RSA key
generation pulls in the primality-checking code.
Change-Id: Iece480113754da090ddf87b64d8769f01e05d26c
Reviewed-on: https://boringssl-review.googlesource.com/6389
Reviewed-by: Adam Langley <agl@google.com>
RSA_PADDING_NONE is actually the important one for RSA_decrypt since OAEP isn't
used much and RSA_PKCS1_PADDING is unsafe to use due to timing constraints.
(The SSL stack uses RSA_PADDING_NONE and does the padding check separately.)
Change-Id: I5f9d168e7c34796a41bf01fc1878022742b63501
Reviewed-on: https://boringssl-review.googlesource.com/5641
Reviewed-by: Adam Langley <agl@google.com>
It's never used. (Only used upstream as part of some CMS hooks.)
Change-Id: I7c59badc3e4771d7debbef0c3e0def93dc605e7b
Reviewed-on: https://boringssl-review.googlesource.com/5274
Reviewed-by: Adam Langley <agl@google.com>
Beyond generally eliminating unnecessary includes, eliminate as many
includes of headers that declare/define particularly error-prone
functionality like strlen, malloc, and free. crypto/err/internal.h was
added to remove the dependency on openssl/thread.h from the public
openssl/err.h header. The include of <stdlib.h> in openssl/mem.h was
retained since it defines OPENSSL_malloc and friends as macros around
the stdlib.h functions. The public x509.h, x509v3.h, and ssl.h headers
were not changed in order to minimize breakage of source compatibility
with external code.
Change-Id: I0d264b73ad0a720587774430b2ab8f8275960329
Reviewed-on: https://boringssl-review.googlesource.com/4220
Reviewed-by: Adam Langley <agl@google.com>
Now that ERR is using thread-local storage, there's very little that the
THREADID code is doing and it can be turned into stub functions.
Change-Id: I668613fec39b26c894d029b10a8173c3055f6019
(system/keymaster is using them now.)
Change-Id: I8fba501005b9318b7d3a76bf1715fb772b23c49d
Reviewed-on: https://boringssl-review.googlesource.com/4092
Reviewed-by: Adam Langley <agl@google.com>
This change extracts two, common parts of RSA_decrypt and RSA_sign into
a function called |private_transform|. It also allows this to be
overridden in a method, which is convenient for opaque keys that only
expose the raw RSA transform as it means that the padding code from
BoringSSL can be easily reimplemented.
One significant change here is that short RSA ciphertexts will no longer
be accepted. I think this is correct and OpenSSL has a comment about PGP
mistakenly stripping leading zeros. However, these is the possibility
that it could break something.
Change-Id: I258c5cbbf21314cc9b6e8d2a2b898fd9a440cd40
Reviewed-on: https://boringssl-review.googlesource.com/1554
Reviewed-by: Adam Langley <agl@google.com>
It's unused with SSLv2 gone. Also, being a decryption padding check, it really
should be constant-time and isn't.
Change-Id: I96be02cb50f9bf0229b9174eccd80fa338bf8e3e
Reviewed-on: https://boringssl-review.googlesource.com/1254
Reviewed-by: Adam Langley <agl@google.com>
This change adds a new function, BN_bn2bin_padded, that attempts, as
much as possible, to serialise a BIGNUM in constant time.
This is used to avoid some timing leaks in RSA decryption.
Initial fork from f2d678e6e89b6508147086610e985d4e8416e867 (1.0.2 beta).
(This change contains substantial changes from the original and
effectively starts a new history.)
