[Downloads] Consider Windows PowerShell file types as dangerous.

[Downloads] Consider Windows PowerShell file types as dangerous.

BUG=507795
Committed: https://crrev.com/b17687c98e6999780ead655d4a93932d01db3832
Cr-Commit-Position: refs/heads/master@{#337839}

[asanka, 2015-07-07 20:01:00]

asanka@chromium.org changed reviewers:
+ palmer@chromium.org, rdsmith@chromium.org

[asanka, 2015-07-07 20:04:54]

PTAL

[Randy Smith (Not in Mondays), 2015-07-07 20:35:47]

LGTM in concept and implementation, though I'm not deeply familiar with the MS
file types.  Agreed about eventually unifying the lists in some fashion.

https://codereview.chromium.org/1220333007/diff/1/chrome/browser/download/dow...
File chrome/browser/download/download_extensions.cc (right):

https://codereview.chromium.org/1220333007/diff/1/chrome/browser/download/dow...
chrome/browser/download/download_extensions.cc:315: // can in effect sidestep
origin restrictions etc.
nit, not even a suggestion: I do find myself thinking that "Obey the user's
wishes" should override the BB or small bullet opportunities to shoot oneself in
the foot, and sidestepping origin restriction feels like a small bullet (as
compared to shell/executable access, which feels like an exploding bullet that
could destroy the entire foot).  But you aren't changing the behavior in this
CL, and I don't feel strongly, so just mentioning the thought.

[palmer, 2015-07-07 20:54:42]

lgtm

https://codereview.chromium.org/1220333007/diff/1/chrome/browser/download/dow...
File chrome/browser/download/download_extensions.cc (right):

https://codereview.chromium.org/1220333007/diff/1/chrome/browser/download/dow...
chrome/browser/download/download_extensions.cc:254: {"ocx", DANGEROUS,
ALLOW_AUTO_OPEN},
This seems wrong.

[asanka, 2015-07-07 22:12:10]

asanka@chromium.org changed reviewers:
+ asvitkine@chromium.org

[asanka, 2015-07-07 22:40:53]

Thanks!

+asvitkine: Could you take a look at histograms.xml?

https://codereview.chromium.org/1220333007/diff/1/chrome/browser/download/dow...
File chrome/browser/download/download_extensions.cc (right):

https://codereview.chromium.org/1220333007/diff/1/chrome/browser/download/dow...
chrome/browser/download/download_extensions.cc:254: {"ocx", DANGEROUS,
ALLOW_AUTO_OPEN},
On 2015/07/07 at 20:54:42, palmer wrote:
> This seems wrong.

Changed to DISALLOW_AUTO_OPEN.

https://codereview.chromium.org/1220333007/diff/1/chrome/browser/download/dow...
chrome/browser/download/download_extensions.cc:315: // can in effect sidestep
origin restrictions etc.
On 2015/07/07 at 20:35:47, rdsmith wrote:
> nit, not even a suggestion: I do find myself thinking that "Obey the user's
wishes" should override the BB or small bullet opportunities to shoot oneself in
the foot, and sidestepping origin restriction feels like a small bullet (as
compared to shell/executable access, which feels like an exploding bullet that
could destroy the entire foot).  But you aren't changing the behavior in this
CL, and I don't feel strongly, so just mentioning the thought.

Acknowledged. Note that since SB now handles these file types, the DANGEROUS
flag doesn't apply whenever SB is enabled. The only effective restriction is
DISALLOW_AUTO_OPEN. Side-stepping origin restrictions also mean the possibility
of reaching into the user's file system, so auto opening before the user has an
opportunity to examine the file still involves a moderate amount of risk. The
auto-open restriction was put in place because of potential lack of opportunity
for the user to intervene.

[Alexei Svitkine (slow), 2015-07-08 14:40:19]

lgtm

[asanka, 2015-07-08 15:38:41]

On 2015/07/08 at 14:40:19, asvitkine wrote:
> lgtm

Thanks!

[asanka, 2015-07-08 15:38:44]

The CQ bit was checked by asanka@chromium.org

[asanka, 2015-07-08 15:38:44]

The patchset sent to the CQ was uploaded after l-g-t-m from palmer@chromium.org,
rdsmith@chromium.org
Link to the patchset: https://codereview.chromium.org/1220333007/#ps20001
(title: " ")

[commit-bot: I haz the power, 2015-07-08 15:39:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1220333007/20001

[commit-bot: I haz the power, 2015-07-08 16:44:32]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-07-08 16:45:22]

Patchset 2 (id:??) landed as
https://crrev.com/b17687c98e6999780ead655d4a93932d01db3832
Cr-Commit-Position: refs/heads/master@{#337839}