Description
-----------

Upon `EC_GROUP_new_from_ecparameters()` check if the parameters match any
of the built-in curves. If that is the case, return a new
`EC_GROUP_new_by_curve_name()` object instead of the explicit parameters
`EC_GROUP`.

This affects all users of `EC_GROUP_new_from_ecparameters()`:
- direct calls to `EC_GROUP_new_from_ecparameters()`
- direct calls to `EC_GROUP_new_from_ecpkparameters()` with an explicit
  parameters argument
- ASN.1 parsing of explicit parameters keys (as it eventually
  ends up calling `EC_GROUP_new_from_ecpkparameters()`)

A parsed explicit parameter key will still be marked with the
`OPENSSL_EC_EXPLICIT_CURVE` ASN.1 flag on load, so, unless
programmatically forced otherwise, if the key is eventually serialized
the output will still be encoded with explicit parameters, even if
internally it is treated as a named curve `EC_GROUP`.

Before this change, creating any `EC_GROUP` object using
`EC_GROUP_new_from_ecparameters()`, yielded an object associated with
the default generic `EC_METHOD`, but this was never guaranteed in the
documentation.
After this commit, users of the library that intentionally want to
create an `EC_GROUP` object using a specific `EC_METHOD` can still
explicitly call `EC_GROUP_new(foo_method)` and then manually set the
curve parameters using `EC_GROUP_set_*()`.

Motivation
----------

This has obvious performance benefits for the built-in curves with
specialized `EC_METHOD`s and subtle but important security benefits:
- the specialized methods have better security hardening than the
  generic implementations
- optional fields in the parameter encoding, like the `cofactor`, cannot
  be leveraged by an attacker to force execution of the less secure
  code-paths for single point scalar multiplication
- in general, this leads to reducing the attack surface

Check the manuscript at https://arxiv.org/abs/1909.01785 for an in depth
analysis of the issues related to this commit.

It should be noted that `libssl` does not allow to negotiate explicit
parameters (as per RFC 8422), so it is not directly affected by the
consequences of using explicit parameters that this commit fixes.
On the other hand, we detected external applications and users in the
wild that use explicit parameters by default (and sometimes using 0 as
the cofactor value, which is technically not a valid value per the
specification, but is tolerated by parsers for wider compatibility given
that the field is optional).
These external users of `libcrypto` are exposed to these vulnerabilities
and their security will benefit from this commit.

Related commits
---------------

While this commit is beneficial for users using built-in curves and
explicit parameters encoding for serialized keys, commit
b783beeadf6b80bc431e6f3230b5d5585c87ef87 (and its equivalents for the
1.0.2, 1.1.0 and 1.1.1 stable branches) fixes the consequences of the
invalid cofactor values more in general also for other curves
(CVE-2019-1547).

The following list covers commits in `master` that are related to the
vulnerabilities presented in the manuscript motivating this commit:

- d2baf88c43 [crypto/rsa] Set the constant-time flag in multi-prime RSA too
- 311e903d84 [crypto/asn1] Fix multiple SCA vulnerabilities during RSA key validation.
- b783beeadf [crypto/ec] for ECC parameters with NULL or zero cofactor, compute it
- 724339ff44 Fix SCA vulnerability when using PVK and MSBLOB key formats

Note that the PRs that contributed the listed commits also include other
commits providing related testing and documentation, in addition to
links to PRs and commits backporting the fixes to the 1.0.2, 1.1.0 and
1.1.1 branches.

This commit includes a partial backport of
https://github.com/openssl/openssl/pull/8555
(commit 8402cd5f75f8c2f60d8bd39775b24b03dd8b3b38)
for which the main author is Shane Lontis.

Responsible Disclosure
----------------------

This and the other issues presented in https://arxiv.org/abs/1909.01785
were reported by Cesar Pereida García, Sohaib ul Hassan, Nicola Tuveri,
Iaroslav Gridin, Alejandro Cabrera Aldaya and Billy Bob Brumley from the
NISEC group at Tampere University, FINLAND.

The OpenSSL Security Team evaluated the security risk for this
vulnerability as low, and encouraged to propose fixes using public Pull
Requests.

_______________________________________________________________________________
Co-authored-by: NShane Lontis <shane.lontis@oracle.com>

(Backport from https://github.com/openssl/openssl/pull/9808)
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9809)

Fixes #6646
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6815)

Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6290)

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6314)

Per SEC 1, the curve coefficients must be padded up to size. See C.2's
definition of Curve, C.1's definition of FieldElement, and 2.3.5's definition
of how to encode the field elements in http://www.secg.org/sec1-v2.pdf.

This comes up for P-521, where b needs a leading zero.
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6314)

Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/5110)

Similar to commit 17b60280(
"Remove extra `the` in SSL_SESSION_set1_id.pod"), this commit removes
typos where additional 'the' have been added.
Reviewed-by: NAndy Polyakov <appro@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4999)

Since return is inconsistent, I removed unnecessary parentheses and
unified them.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4541)

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: NAndy Polyakov <appro@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4188)

Fixes #3191
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3199)

Replace all remaining uses of LONG and ZLONG with INT32 / ZINT32.
Reviewed-by: NMatt Caswell <matt@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3126)

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2689)

Prevent that memory beyond the last element is accessed if every element
of group->poly[] is non-zero
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2689)

The variable 'buffer', allocated by EC_POINT_point2buf(), isn't
free'd on the success path.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

Deprecate the function ASN1_STRING_data() and replace with a new function
ASN1_STRING_get0_data() which returns a constant pointer. Update library
to use new function.
Reviewed-by: NRich Salz <rsalz@openssl.org>

To avoid having to immediately free up r/s when setting them
don't allocate them automatically in DSA_SIG_new() and ECDSA_SIG_new().

RT#4590
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reorder arguments to follow convention.

Also allow r/s to be NULL in DSA_SIG_get0, similarly to ECDSA_SIG_get0.

This complements GH1193 which adds non-const setters.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NEmilia Käsper <emilia@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1193)

per review comments.
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NEmilia Käsper <emilia@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1193)

SSH2 implementations which use DSA_do_verify() and ECDSA_do_verify() are given
the R and S values, and the data to be signed, by the client.  Thus in order
to validate these signatures, SSH2 implementations will digest and sign
the data -- and then pass in properly provisioned DSA_SIG and ECDSA_SIG objects.

Unfortunately, the existing OpenSSL-1.1.0 APIs do not allow for directly setting
those R and S values in these objects, which makes using OpenSSL for such
SSH2 implementations much more difficult.
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NEmilia Käsper <emilia@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1193)

Reviewed-by: NRichard Levitte <levitte@openssl.org>

PR#4436
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NDr. Stephen Henson <steve@openssl.org>

Instead of overriding a default operation move default operation to a
separate function which is then explicitly included in any EC_METHOD
that uses it.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Extract compression form in EC_KEY_oct2key() instead of manually in the
ASN.1 code. For custom curves do not assume the initial octet is the
compression form: it isn't for X25519 et al.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NEmilia Käsper <emilia@openssl.org>

Add support for optional overrides of various private key operations
in EC_METHOD.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NEmilia Käsper <emilia@openssl.org>

Signed-off-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>

Add new function EC_KEY_priv2buf() to allocated and encode private
key octet in one call. Update and simplify ASN.1 and print routines.
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

Update EC ASN.1 and print routines to use EC_KEY_oct2priv and
EC_KEY_priv2oct.
Reviewed-by: NViktor Dukhovni <viktor@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: NRich 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: NViktor Dukhovni <viktor@openssl.org>

New functions EC_POINT_point2buf and EC_KEY_key2buf which encode
a point and allocate a buffer in one call.

New function EC_KEY_oct2key() which sets public key in an EC_KEY
structure from an encoded point.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Continuing from previous commit ensure our style is consistent for malloc
return checks.
Reviewed-by: NKurt Roeckx <kurt@openssl.org>