Merge local changes from v2.7 -> v2.9 for wpa_supplicant and hostapd

This adds an explicit check for 0 < x,y < prime based on RFC 5931,
2.8.5.2.2 requirement. The earlier checks might have covered this
implicitly, but it is safer to avoid any dependency on implicit checks
and specific crypto library behavior. (CVE-2019-9498 and CVE-2019-9499)

Furthermore, this moves the EAP-pwd element and scalar parsing and
validation steps into shared helper functions so that there is no need
to maintain two separate copies of this common functionality between the
server and peer implementations.

When processing an EAP-pwd Commit frame, the server's scalar and element
(elliptic curve point) were not validated. This allowed an adversary to
bypass authentication, and act as a rogue Access Point (AP) if the
crypto implementation did not verify the validity of the EC point.

Fix this vulnerability by assuring the received scalar lies within the
valid range, and by checking that the received element is not the point
at infinity and lies on the elliptic curve being used. (CVE-2019-9499)

The vulnerability is only exploitable if OpenSSL version 1.0.2 or lower
is used, or if LibreSSL or wolfssl is used. Newer versions of OpenSSL
(and also BoringSSL) implicitly validate the elliptic curve point in
EC_POINT_set_affine_coordinates_GFp(), preventing the attack.

merge conflicts.

branches: 1.5.10; 1.5.12; 1.5.14; 1.5.18; 1.5.20;
Merge conflicts.

branches: 1.4.2;
The L (Length) and M (More) flags needs to be cleared before deciding
whether the locally generated response requires fragmentation. This
fixes an issue where these flags from the server could have been invalid
for the following message. In some cases, this could have resulted in
triggering the wpabuf security check that would terminate the process
due to invalid buffer allocation.

XXX: pullup-7

The remaining number of bytes in the message could be smaller than the
Total-Length field size, so the length needs to be explicitly checked
prior to reading the field and decrementing the len variable. This could
have resulted in the remaining length becoming negative and interpreted
as a huge positive integer.

In addition, check that there is no already started fragment in progress
before allocating a new buffer for reassembling fragments. This avoid a
potential memory leak when processing invalid message.

XXX: pullup-7

The length of the received Commit and Confirm message payloads was not
checked before reading them. This could result in a buffer read
overflow when processing an invalid message.

Fix this by verifying that the payload is of expected length before
processing it. In addition, enforce correct state transition sequence to
make sure there is no unexpected behavior if receiving a Commit/Confirm
message before the previous exchanges have been completed.

Thanks to Kostya Kortchinsky of Google security team for discovering and
reporting this issue.

XXX: pullup-7

branches: 1.1.1;
Initial revision

This adds an explicit check for 0 < x,y < prime based on RFC 5931,
2.8.5.2.2 requirement. The earlier checks might have covered this
implicitly, but it is safer to avoid any dependency on implicit checks
and specific crypto library behavior. (CVE-2019-9498 and CVE-2019-9499)

Furthermore, this moves the EAP-pwd element and scalar parsing and
validation steps into shared helper functions so that there is no need
to maintain two separate copies of this common functionality between the
server and peer implementations.

When processing an EAP-pwd Commit frame, the server's scalar and element
(elliptic curve point) were not validated. This allowed an adversary to
bypass authentication, and act as a rogue Access Point (AP) if the
crypto implementation did not verify the validity of the EC point.

Fix this vulnerability by assuring the received scalar lies within the
valid range, and by checking that the received element is not the point
at infinity and lies on the elliptic curve being used. (CVE-2019-9499)

The vulnerability is only exploitable if OpenSSL version 1.0.2 or lower
is used, or if LibreSSL or wolfssl is used. Newer versions of OpenSSL
(and also BoringSSL) implicitly validate the elliptic curve point in
EC_POINT_set_affine_coordinates_GFp(), preventing the attack.

merge conflicts.

branches: 1.5.10; 1.5.12; 1.5.14; 1.5.18;
Merge conflicts.

branches: 1.4.2;
The L (Length) and M (More) flags needs to be cleared before deciding
whether the locally generated response requires fragmentation. This
fixes an issue where these flags from the server could have been invalid
for the following message. In some cases, this could have resulted in
triggering the wpabuf security check that would terminate the process
due to invalid buffer allocation.

XXX: pullup-7

The remaining number of bytes in the message could be smaller than the
Total-Length field size, so the length needs to be explicitly checked
prior to reading the field and decrementing the len variable. This could
have resulted in the remaining length becoming negative and interpreted
as a huge positive integer.

In addition, check that there is no already started fragment in progress
before allocating a new buffer for reassembling fragments. This avoid a
potential memory leak when processing invalid message.

XXX: pullup-7

The length of the received Commit and Confirm message payloads was not
checked before reading them. This could result in a buffer read
overflow when processing an invalid message.

Fix this by verifying that the payload is of expected length before
processing it. In addition, enforce correct state transition sequence to
make sure there is no unexpected behavior if receiving a Commit/Confirm
message before the previous exchanges have been completed.

Thanks to Kostya Kortchinsky of Google security team for discovering and
reporting this issue.

XXX: pullup-7

branches: 1.1.1;
Initial revision

Merge conflicts.

The L (Length) and M (More) flags needs to be cleared before deciding
whether the locally generated response requires fragmentation. This
fixes an issue where these flags from the server could have been invalid
for the following message. In some cases, this could have resulted in
triggering the wpabuf security check that would terminate the process
due to invalid buffer allocation.

XXX: pullup-7

The remaining number of bytes in the message could be smaller than the
Total-Length field size, so the length needs to be explicitly checked
prior to reading the field and decrementing the len variable. This could
have resulted in the remaining length becoming negative and interpreted
as a huge positive integer.

In addition, check that there is no already started fragment in progress
before allocating a new buffer for reassembling fragments. This avoid a
potential memory leak when processing invalid message.

XXX: pullup-7

The length of the received Commit and Confirm message payloads was not
checked before reading them. This could result in a buffer read
overflow when processing an invalid message.

Fix this by verifying that the payload is of expected length before
processing it. In addition, enforce correct state transition sequence to
make sure there is no unexpected behavior if receiving a Commit/Confirm
message before the previous exchanges have been completed.

Thanks to Kostya Kortchinsky of Google security team for discovering and
reporting this issue.

XXX: pullup-7

branches: 1.1.1;
Initial revision