commit e041be8dc8b5b9e3012e752c2636fcf1cd8b0b1d
author Richard Knoll <knollr@chromium.org> Fri Apr 23 08:56:16 2021
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Apr 23 08:56:16 2021
tree 8e1f4a269be1d37dabc719c4df6a0bcf07fd1188
parent cc22cf0882acd6bbfbdb6fddb4462c85c085d6bd

Prevent USSD codes via Click to Call

Click to Call allows users to send a phone number from their Chrome
desktop instance to their Android phone. This number either comes from a
user's selection and sent via the context menu, or by clicking on a link
with a "tel:" href.
Sending from the context menu is gated by a regular expression and will
not allow any special characters like '#' or '*' to be contained in the
phone number.
Sending link hrefs does not go through that check as we assume the link
is a valid phone number. We do call GURL::GetContent() to get the number
which should discard anything after a (and including the) '#' character.
However, we also URL-decoded the resulting string before then sending it
over to Android, where we URL-decoded it again when constructing the
Dialer intent. This allows sending double-URL-encoded USSD tel links
which will be sent straight to the Dialer on certain Android versions
and device states.

The fix here is on both desktop and Android side:
Desktop:
 - URL-decode the number and ignore if it contains '#', '*' or '%'.
 - Send the raw number (URL-encoded) to Android
Android:
 - Verify that URL-decoding the received raw number is valid as above
 - Show the decoded number in the notification
 - Parse the raw number in Java into a Uri object for the Dialer

Together this makes sure that we only URL-decode tel: links once and
verify it on both sender and receiver side before passing it on to the
Android Dialer.

Bug: 1180510
Test: updated unit_tests and browser_tests to check for conversion
Change-Id: Idf380b629cdf00155ecab054398af69f37ec2ef9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2825704
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: David Jacobo <djacobo@chromium.org>
Reviewed-by: Gayane Petrosyan <gayane@chromium.org>
Reviewed-by: Istiaque Ahmed <lazyboy@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Commit-Queue: Richard Knoll <knollr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#875572}