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 <nic.tuv@gmail.com>
Co-authored-by: Billy Brumley <bbrumley@gmail.com>
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6501)
We check that the curve name associated with the point is the same as that
for the curve.
Fixes#6302
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6323)
* EC_POINT_mul is now responsible for constant time point multiplication
(for single fixed or variable point multiplication, when the scalar is
in the range [0,group_order), so we need to strip the nonce padding
from ECDSA.
* Entry added to CHANGES
* Updated EC_POINT_mul documentation
- Integrate existing EC_POINT_mul and EC_POINTs_mul entries in the
manpage to reflect the shift in constant-time expectations when
performing a single fixed or variable point multiplication;
- Add documentation to ec_method_st to reflect the updated "contract"
between callers and implementations of ec_method_st.mul.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6070)
Co-authored-by: Nicola Tuveri <nic.tuv@gmail.com>
Co-authored-by: Cesar Pereida Garcia <cesar.pereidagarcia@tut.fi>
Co-authored-by: Sohaib ul Hassan <soh.19.hassan@gmail.com>
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6009)
Removed e_os.h from all bar three headers (apps/apps.h crypto/bio/bio_lcl.h and
ssl/ssl_locl.h).
Added e_os.h into the files that need it now.
Directly reference internal/nelem.h when required.
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4188)
The ec_wNAF_mul() function allocates some temporary storage that it
doesn't always free on an error condition.
Reviewed-by: Richard Levitte <levitte@openssl.org>
New functions to return internal pointer for order and cofactor. This
avoids the need to allocate a new BIGNUM which to copy the value to.
Simplify code to use new functions.
Reviewed-by: Rich Salz <rsalz@openssl.org>
This was done by the following
find . -name '*.[ch]' | /tmp/pl
where /tmp/pl is the following three-line script:
print unless $. == 1 && m@/\* .*\.[ch] \*/@;
close ARGV if eof; # Close file to reset $.
And then some hand-editing of other files.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Add CRYPTO_EX_DATA add EndC_KEY_[gs]et_method, From Roumen Petrov.
Had to add various exdata calls to init/copy/free the exdata.
Had to remove const from some EC functions because exdata isn't
const-correct. :(
Also remove EC_EXTRA_DATA and use a union to hold the possible
pre-computed values and an enum to tell which value is in the
union. (Rich Salz)
Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
For a local variable:
TYPE *p;
Allocations like this are "risky":
p = OPENSSL_malloc(sizeof(TYPE));
if the type of p changes, and the malloc call isn't updated, you
could get memory corruption. Instead do this:
p = OPENSSL_malloc(sizeof(*p));
Also fixed a few memset() calls that I noticed while doing this.
Reviewed-by: Richard Levitte <levitte@openssl.org>
After the finale, the "real" final part. :) Do a recursive grep with
"-B1 -w [a-zA-Z0-9_]*_free" to see if any of the preceeding lines are
an "if NULL" check that can be removed.
Reviewed-by: Tim Hudson <tjh@openssl.org>
This gets BN_.*free:
BN_BLINDING_free BN_CTX_free BN_FLG_FREE BN_GENCB_free
BN_MONT_CTX_free BN_RECP_CTX_free BN_clear_free BN_free BUF_MEM_free
Also fix a call to DSA_SIG_free to ccgost engine and remove some #ifdef'd
dead code in engines/e_ubsec.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Add OPENSSL_clear_free which merges cleanse and free.
(Names was picked to be similar to BN_clear_free, etc.)
Removed OPENSSL_freeFunc macro.
Fixed the small simple ones that are left:
CRYPTO_free CRYPTO_free_locked OPENSSL_free_locked
Reviewed-by: Richard Levitte <levitte@openssl.org>
Move compression, point2oct and oct2point functions into separate files.
Add a flags field to EC_METHOD.
Add a flag EC_FLAGS_DEFAULT_OCT to use the default compession and oct
functions (all existing methods do this). This removes dependencies from
EC_METHOD while keeping original functionality.
