openbsd/src/lib/libcrypto/ec/ec_lib.c, branch OPENBSD_6_8_BASE

If a NULL or zero cofactor is passed to EC_GROUP_set_generator(),

2019-09-29T10:09:09+00:00

try to compute it using Hasse's bound. This works as long as the cofactor is small enough. Port of Brumley's fix for CVE-2019-1547 in OpenSSL 1.1.1 (old license) tests & ok inoguchi input & ok jsing commit 30c22fa8b1d840036b8e203585738df62a03cec8 Author: Billy Brumley Date: Thu Sep 5 21:25:37 2019 +0300 [crypto/ec] for ECC parameters with NULL or zero cofactor, compute it The cofactor argument to EC_GROUP_set_generator is optional, and SCA mitigations for ECC currently use it. So the library currently falls back to very old SCA-vulnerable code if the cofactor is not present. This PR allows EC_GROUP_set_generator to compute the cofactor for all curves of cryptographic interest. Steering scalar multiplication to more SCA-robust code. This issue affects persisted private keys in explicit parameter form, where the (optional) cofactor field is zero or absent. It also affects curves not built-in to the library, but constructed programatically with explicit parameters, then calling EC_GROUP_set_generator with a nonsensical value (NULL, zero). The very old scalar multiplication code is known to be vulnerable to local uarch attacks, outside of the OpenSSL threat model. New results suggest the code path is also vulnerable to traditional wall clock timing attacks. CVE-2019-1547 Reviewed-by: Matt Caswell Reviewed-by: Tomas Mraz Reviewed-by: Nicola Tuveri (Merged from https://github.com/openssl/openssl/pull/9781)

unrevert the use of bn_rand_interval().

2018-11-06T07:02:33+00:00

ok beck jsing

Implement coordinate blinding for EC_POINT.

2018-11-05T20:18:21+00:00

Based on OpenSSL commit 875ba8b21ecc65ad9a6bdc66971e50 by Billy Brumley, Sohaib ul Hassan and Nicola Tuveri. ok beck jsing commit 875ba8b21ecc65ad9a6bdc66971e50461660fcbb Author: Sohaib ul Hassan Date: Sat Jun 16 17:07:40 2018 +0300 Implement coordinate blinding for EC_POINT This commit implements coordinate blinding, i.e., it randomizes the representative of an elliptic curve point in its equivalence class, for prime curves implemented through EC_GFp_simple_method, EC_GFp_mont_method, and EC_GFp_nist_method. This commit is derived from the patch https://marc.info/?l=openssl-dev&m=131194808413635 by Billy Brumley. Coordinate blinding is a generally useful side-channel countermeasure and is (mostly) free. The function itself takes a few field multiplicationss, but is usually only necessary at the beginning of a scalar multiplication (as implemented in the patch). When used this way, it makes the values that variables take (i.e., field elements in an algorithm state) unpredictable. For instance, this mitigates chosen EC point side-channel attacks for settings such as ECDH and EC private key decryption, for the aforementioned curves. For EC_METHODs using different coordinate representations this commit does nothing, but the corresponding coordinate blinding function can be easily added in the future to extend these changes to such curves. Co-authored-by: Nicola Tuveri Co-authored-by: Billy Brumley Reviewed-by: Tim Hudson Reviewed-by: Nicola Tuveri Reviewed-by: Andy Polyakov (Merged from https://github.com/openssl/openssl/pull/6526)

Recommit Billy Brumley's ECC constant time patch with a fix for sparc64

2018-07-16T17:32:39+00:00

from Nicola Tuveri (who spotted the omission of ecp_nist.c from the PR). discussed with jsing tested by jsg

recommit label indentation part of the backout; clearly unrelated to the

2018-07-15T16:27:39+00:00

breakage.

back out ecc constant time changes

2018-07-15T05:38:48+00:00

after the constant time commits various regress tests started failing on sparc64 ssh t9, libcrypto ec ecdh ecdsa and trying to ssh out resulted in 'invalid elliptic curve value' ok tb@

Indent labels by a space so they don't obliterate function names in diffs.

2018-07-10T22:06:14+00:00

ECC constant time scalar multiplication support. First step in overhauling

2018-07-10T21:55:49+00:00

the EC module. From Billy Brumley and his team, via https://github.com/libressl-portable/openbsd/pull/94 With tweaks from jsing and me. ok jsing

use freezero() instead of memset/explicit_bzero + free. Substantially

2017-05-02T03:59:45+00:00

reduces conditional logic (-218, +82). MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH cache alignment calculation bn/bn_exp.c wasn'tt quite right. Two other tricky bits with ASN1_STRING_FLAG_NDEF and BN_FLG_STATIC_DATA where the condition cannot be collapsed completely. Passes regress. ok beck

Send the function codes from the error functions to the bit bucket,

2017-01-29T17:49:23+00:00

as was done earlier in libssl. Thanks inoguchi@ for noticing libssl had more reacharounds into this. ok jsing@ inoguchi@