view tests/test-mq-missingfiles.t @ 30766:d7bf7d2bd5ab

hgweb: support Content Security Policy

Content-Security-Policy (CSP) is a web security feature that allows
servers to declare what loaded content is allowed to do. For example,
a policy can prevent loading of images, JavaScript, CSS, etc unless
the source of that content is whitelisted (by hostname, URI scheme,
hashes of content, etc). It's a nifty security feature that provides
extra mitigation against some attacks, notably XSS.

Mitigation against these attacks is important for Mercurial because
hgweb renders repository data, which is commonly untrusted. While we
make attempts to escape things, etc, there's the possibility that
malicious data could be injected into the site content. If this happens
today, the full power of the web browser is available to that
malicious content. A restrictive CSP policy (defined by the server
operator and sent in an HTTP header which is outside the control of
malicious content), could restrict browser capabilities and mitigate
security problems posed by malicious data.

CSP works by emitting an HTTP header declaring the policy that browsers
should apply. Ideally, this header would be emitted by a layer above
Mercurial (likely the HTTP server doing the WSGI "proxying"). This
works for some CSP policies, but not all.

For example, policies to allow inline JavaScript may require setting
a "nonce" attribute on <script>. This attribute value must be unique
and non-guessable. And, the value must be present in the HTTP header
and the HTML body. This means that coordinating the value between
Mercurial and another HTTP server could be difficult: it is much
easier to generate and emit the nonce in a central location.

This commit introduces support for emitting a
Content-Security-Policy header from hgweb. A config option defines
the header value. If present, the header is emitted. A special
"%nonce%" syntax in the value triggers generation of a nonce and
inclusion in <script> elements in templates. The inclusion of a
nonce does not occur unless "%nonce%" is present. This makes this
commit completely backwards compatible and the feature opt-in.

The nonce is a type 4 UUID, which is the flavor that is randomly
generated. It has 122 random bits, which should be plenty to satisfy
the guarantees of a nonce.

Issue835: qpush fails immediately when patching a missing file, but
remaining added files are still created empty which will trick a
future qrefresh.

  $ cat > writelines.py <<EOF
  > import sys
  > path = sys.argv[1]
  > args = sys.argv[2:]
  > assert (len(args) % 2) == 0
  > 
  > f = file(path, 'wb')
  > for i in xrange(len(args)/2):
  >    count, s = args[2*i:2*i+2]
  >    count = int(count)
  >    s = s.decode('string_escape')
  >    f.write(s*count)
  > f.close()
  > EOF

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init normal
  $ cd normal
  $ python ../writelines.py b 10 'a\n'
  $ hg ci -Am addb
  adding b
  $ echo a > a
  $ python ../writelines.py b 2 'b\n' 10 'a\n' 2 'c\n'
  $ echo c > c
  $ hg add a c
  $ hg qnew -f changeb
  $ hg qpop
  popping changeb
  patch queue now empty
  $ hg rm b
  $ hg ci -Am rmb

Push patch with missing target:

  $ hg qpush
  applying changeb
  unable to find 'b' for patching
  (use '--prefix' to apply patch relative to the current directory)
  2 out of 2 hunks FAILED -- saving rejects to file b.rej
  patch failed, unable to continue (try -v)
  patch failed, rejects left in working directory
  errors during apply, please fix and qrefresh changeb
  [2]

Display added files:

  $ cat a
  a
  $ cat c
  c

Display rejections:

  $ cat b.rej
  --- b
  +++ b
  @@ -1,3 +1,5 @@
  +b
  +b
   a
   a
   a
  @@ -8,3 +10,5 @@
   a
   a
   a
  +c
  +c

Test missing renamed file

  $ hg qpop
  popping changeb
  patch queue now empty
  $ hg up -qC 0
  $ echo a > a
  $ hg mv b bb
  $ python ../writelines.py bb 2 'b\n' 10 'a\n' 2 'c\n'
  $ echo c > c
  $ hg add a c
  $ hg qnew changebb
  $ hg qpop
  popping changebb
  patch queue now empty
  $ hg up -qC 1
  $ hg qpush
  applying changebb
  patching file bb
  Hunk #1 FAILED at 0
  Hunk #2 FAILED at 7
  2 out of 2 hunks FAILED -- saving rejects to file bb.rej
  b not tracked!
  patch failed, unable to continue (try -v)
  patch failed, rejects left in working directory
  errors during apply, please fix and qrefresh changebb
  [2]
  $ cat a
  a
  $ cat c
  c
  $ cat bb.rej
  --- bb
  +++ bb
  @@ -1,3 +1,5 @@
  +b
  +b
   a
   a
   a
  @@ -8,3 +10,5 @@
   a
   a
   a
  +c
  +c

  $ cd ..


  $ echo "[diff]" >> $HGRCPATH
  $ echo "git=1" >> $HGRCPATH

  $ hg init git
  $ cd git
  $ python ../writelines.py b 1 '\x00'
  $ hg ci -Am addb
  adding b
  $ echo a > a
  $ python ../writelines.py b 1 '\x01' 1 '\x00'
  $ echo c > c
  $ hg add a c
  $ hg qnew -f changeb
  $ hg qpop
  popping changeb
  patch queue now empty
  $ hg rm b
  $ hg ci -Am rmb

Push git patch with missing target:

  $ hg qpush
  applying changeb
  unable to find 'b' for patching
  (use '--prefix' to apply patch relative to the current directory)
  1 out of 1 hunks FAILED -- saving rejects to file b.rej
  patch failed, unable to continue (try -v)
  patch failed, rejects left in working directory
  errors during apply, please fix and qrefresh changeb
  [2]
  $ hg st
  ? b.rej

Display added files:

  $ cat a
  a
  $ cat c
  c

Display rejections:

  $ cat b.rej
  --- b
  +++ b
  GIT binary patch
  literal 2
  Jc${No0000400IC2
  
  $ cd ..

Test push creating directory during git copy or rename:

  $ hg init missingdir
  $ cd missingdir
  $ echo a > a
  $ hg ci -Am adda
  adding a
  $ mkdir d
  $ hg copy a d/a2
  $ hg mv a d/a
  $ hg qnew -g -f patch
  $ hg qpop
  popping patch
  patch queue now empty
  $ hg qpush
  applying patch
  now at: patch

  $ cd ..